WO2026006841A1 - Return electrode - Google Patents

Abstract

Disclosed is a peripheral nerve stimulation system, and devices and components thereof. In an embodiment, the system comprises a pulse generator and one or more leads with multiple electrodes. In an embodiment, the system comprises one or more return electrodes that are large in surface area and positioned distant from the stimulating electrodes and power-receiving component. In an embodiment, this configuration can facilitate selective activation of large peripheral nerve fibers while minimizing discomfort and unwanted responses by optimizing electrode size, placement, and spacing. The disclosed system may further comprise one or more of: non-uniform electrode spacing, coiled or patterned electrodes, and the use of multiple leads or segmented return electrodes to increase surface area, reduce current density, and enhance mechanical flexibility.

Description

PATENT APPLICATION

Inventors: Joseph Boggs

Milite Abraha William Clark Nathan D. Crosby Matthew deBock John Gilbert William Huffman Meredith McGee Robert B. Strother Brandon Swan Amom Wongsampigoon

Docket No.: 37695-00470

TITLE

RETURN ELECTRODE

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The application claims priority to U.S. Provisional Patent Application No.

63/665,518, filed on June 28, 2024, entitled “RETURN ELECTRODE,” U.S. Provisional

Patent Application No. 63/750,359, filed January 28, 2025, entitled “STIMULATION

LEAD.” U.S. Provisional Patent Application No. 63/790,330. filed April 17. 2025, entitled “IMPROVED SYSTEMS AND METHODS FOR ELECTRICAL STIMULATION USING

A MULTI-CONTACT LEAD,” U.S. Provisional Patent Application No. 63/810,832, filed May 23, 2025, entitled “STIMULATION LEAD.” each of which are incorporated herein by reference in their entirety’.

FIELD OF THE INVENTION

[0002] The present disclosure relates generally to peripheral nen e stimulation devices and systems, and more particularly, devices and systems comprising leads with multiple electrodes, including distant and large-surface return electrodes, to selectively activate large nerve fibers while minimizing discomfort and unwanted effects.

BACKGROUND

[0003] Electrical stimulation of peripheral nerves has become an established therapeutic modality for the treatment of various conditions, including chronic pain, nerve repair, movement disorders, and other neurological or functional impairments. Peripheral nerve stimulation (PNS) systems typically consist of a pulse generator that is external or implantable, and one or more leads with electrodes that deliver electrical pulses to targeted nen e fibers. SUMMARY

[0004] The following presents a summary of this disclosure to provide a basic understanding of some aspects. This summary is intended to neither identify key or critical elements nor define any limitations of embodiments or claims. Furthermore, this summary may provide a simplified overview of some aspects that may be described in greater detail in other portions of this disclosure. Any of the described aspects may be isolated or combined with other described aspects without limitation to the same effect as if they had been described separately and in every possible combination explicitly.

[0005] Disclosed is a peripheral nerve stimulation system, and devices and components thereof. In an embodiment, the system comprises a stimulator (e.g., pulse generator) and one or more leads with multiple electrodes. In an example embodiment, the system comprises one or more return electrodes that are large in surface area and positioned distant from the stimulating electrodes and power receiving component. In an embodiment, this configuration can facilitate selective activation of large peripheral nen e fibers while avoiding or minimizing discomfort and/or unwanted responses by optimizing electrode size, placement, and/or spacing. For example, the electrode spacing may be non-uniform, with distal stimulating electrodes (e g., electrodes closer to the end of the lead opposite to the connection point of the lead to the pulse generator, connection cable, adapter, etc.) placed close together to enable or ensure overlapping fields for comprehensive nerve activation (e.g., for target nerve fibers), while the return electrodes are spaced farther away to create a uniquely advantageous field and/or reduce field overlap (e.g., for non-target and/or off-target nen e fibers). The disclosed system may further comprise one or more of: coiled or patterned electrodes, and the use of one or more leads or segmented return electrodes to optimize surface area, current density, and charge distribution while enhancing mechanical flexibility’, durability', and other characteristics.

[0006] The disclosed embodiments in the present invention address limitations of the prior art by, for example, reducing unwanted stimulation of non-target fibers and/or off-target fibers, improving patient comfort, and enabling efficient wireless power transfer without excessive heating, while also increasing efficacy and safety and reducing risk to the patient and the system by reducing the potential for system failure or interruption of treatment, thereby providing a versatile and effective solution for penpheral nerve stimulation in various anatomical locations.

[0007] Disclosed is a peripheral nen e stimulation system. In an embodiment, the system comprises a pulse generator. In an embodiment, the system comprises a lead comprising a distal end, a proximal end, and a plurality of electrodes. In an embodiment, the plurality of electrodes comprise at least one distal stimulating electrode configured to deliver electrical stimulation to a target peripheral nerve and at least one return electrode positioned distant from the distal stimulating electrode. It is noted that the at least one return electrode may be located on this lead or on an additional lead (or both or neither, e.g., on a pad). In an embodiment, the at least one return electrode has a larger surface area than the distal stimulating electrode. In an embodiment, the at least one return electrode is configured to return current to the pulse generator.

[0008] In an embodiment, the at least one return electrode comprises a plurality of return electrodes. In an embodiment, the at least one return electrode is located distant from the pulse generator. In an embodiment, the at least one return electrode is located on the proximal end of the lead. In an embodiment, the system further comprises at least one additional lead comprising at least one electrode configured to serve as a return electrode.

[0009] In an embodiment, the additional lead comprising the return electrode is positionable distant from the lead comprising the stimulating electrode. In an embodiment, the additional lead comprising the return electrode is positionable distant from the pulse generator. In an embodiment, the additional lead is positionable to avoid causing activation of excitable tissue. In an embodiment, the additional lead the additional lead is positionable in non- excitable tissue.

[0010] In an embodiment, the plurality of electrodes, including the at least one distal stimulating and the at least one return electrode, are not all a same size. In an embodiment, the at least one return electrode is larger than the distal at least one stimulating electrode. In an embodiment, spacing between the plurality of electrodes is not uniform. In an embodiment, spacing between the at least one distal stimulating electrode and the at least one return electrode is greater than a spacing between adjacent distal stimulating electrodes.

[0011] In an embodiment, the lead comprises a plurality of return electrodes having a total surface area greater than a surface are of the at least one distal stimulating electrode. In an embodiment, the lead comprises a plurality' of return electrodes having a perimeter greater than a perimeter of the at least one distal stimulating electrode.

[0012] In an embodiment, the at least one return electrode is formed by a coiled conductor or a series of ring electrodes. In an embodiment, the system further comprises a lead connector or adaptor having at least one return electrode electrically coupled to the pulse generator. In an embodiment, the at least one return electrode is recessed within an electrically insulating portion of the lead. In an embodiment, the at least one return electrode extends beyond an electrically insulating portion of the lead. In an embodiment, the at least one return electrode is recessed from an adjacent surface. In an embodiment, the at least one return electrode is extends beyond an adjacent surface.

[0013] In an embodiment, a proportion of current returned through each of multiple return electrodes is programmable or automatically adjustable to minimize patient discomfort. In an embodiment, the lead is fully implantable within a patient’s body. In an embodiment, the lead is percutaneous and exits skin to connect to the pulse generator. In an embodiment, the return electrode is located on or forms a pad. In an embodiment, the return electrode is located on an open-coil lead or a closed-coil lead.

[0014] Disclosed is a peripheral nene stimulation system. In an embodiment, the system comprises a pulse generator. In an embodiment, the system comprises a lead comprising a distal end, a proximal end and a plurality of electrodes. In an embodiment, the plurality of electrodes comprise a distal stimulating electrode configured to deliver electrical stimulation to a target peripheral nen e and a return electrode positioned distant from the distal stimulating electrode. It is noted that the return electrode may be located on this lead or on an additional lead (or both or neither, e.g.. on a pad). In an embodiment, the return electrode is configured to return current to the pulse generator. In an embodiment, the return electrode is positioned such that it is distant from both the stimulating electrode and a power-receiving component of the system.

[0015] In an embodiment, the power-receiving component of the system is the pulse generator. In an embodiment, the return electrode is located on the proximal end of the lead. In an embodiment, the system further comprises at least one additional lead with an electrode configured to serve as a return electrode.

[0016] In an embodiment, the additional lead comprising the return electrode is positionable distant from the lead comprising the stimulating electrode. In an embodiment, the additional lead comprising the return electrode is positionable distant from the pulse generator. In an embodiment, the additional lead is positionable to avoid causing activation of excitable tissue. In an embodiment, the additional lead is positionable in non-excitable tissue.

[0017] In an embodiment, the plurality of electrodes, including the distal stimulating and return electrodes, are not all a same size. In an embodiment, the return electrode is larger than the distal stimulating electrode. In an embodiment, spacing between the plurality of electrodes is not uniform. In an embodiment, spacing between the distal stimulating electrode and the return electrode is greater than spacing between adjacent distal stimulating electrodes.

[0018] In an embodiment, the lead comprises a plurality of return electrodes having a total surface area greater than a surface area of the distal stimulating electrode. In an embodiment, the lead comprises a plurality of return electrodes having a perimeter greater than a perimeter of the distal stimulating electrode.

[0019] In an embodiment, the return electrode is formed by a coiled conductor or a series of ring electrodes. In an embodiment, the system further comprises a lead connector or adaptor having at least one return electrode electrically coupled to the pulse generator. In an embodiment, the return electrode is recessed within an electrically insulating portion of the lead. In an embodiment, the return electrode extends beyond an electrically insulating portion of the lead. In an embodiment, the return electrode is recessed from an adjacent surface. In an embodiment, the return electrode extends beyond an adjacent surface.

[0020] In an embodiment, a proportion of cunent returned through each of multiple return electrodes is programmable or automatically adjustable to minimize patient discomfort. In an embodiment, the lead is fully implantable within a patient’s body. In an embodiment, the lead is percutaneous and exits skin to connect to the pulse generator. In an embodiment, the return electrode is located on or forms a pad. In an embodiment, the lead is an open-coil lead. In an embodiment, the lead is a closed-coil lead.

[0021] Disclosed is a peripheral nerve stimulation system. In an embodiment, the system comprises a pulse generator. In an embodiment, the system comprises a lead comprising a distal end, a proximal end and a plurality of electrodes. In an embodiment, the plurality of electrodes comprise a distal stimulating electrode configured to deliver electrical stimulation to a target peripheral nerve. In an embodiment, the system comprises one or more return electrodes. It is noted that the one or more return electrodes may be located on this lead or on an additional lead (or both or neither, e.g., on a pad). In an embodiment, the one or more return electrodes are configured to return current to the pulse generator. In an embodiment, the one or more return electrodes are positioned distant from the stimulating electrode.

[0022] In an embodiment, the one or more return electrodes are positioned distant from the pulse generator. In an embodiment, the one or more return electrodes are located on the proximal end of the lead. In an embodiment, the system further comprises at least one additional lead with at least one electrode configured to serve as a return electrode.

[0023] In an embodiment, the additional lead comprising the return electrode is positionable distant from the lead comprising the stimulating electrode. In an embodiment, the additional lead comprising the return electrode is positionable distant from the pulse generator. In an embodiment, the additional lead is positionable to avoid causing activation of excitable tissue. In an embodiment, the additional lead is positionable in non-excitable tissue.

[0024] In an embodiment, the plurality of electrodes, including the distal stimulating and return electrodes, are not all the same size. In an embodiment, the one or more return electrodes are larger than the distal stimulating electrodes. In an embodiment, spacing between the plurality of electrodes is not uniform. In an embodiment, spacing between the distal stimulating electrode and the one or more return electrodes is greater than spacing between adjacent distal stimulating electrodes.

[0025] In an embodiment, the lead comprises a plurality' of return electrodes having a total surface area greater than a surface area of the distal stimulating electrode. In an embodiment, the lead comprises a plurality of return electrodes having a perimeter greater than a perimeter of the distal stimulating electrode.

[0026] In an embodiment, the return electrode is formed by a coiled conductor or a series of ring electrodes. In an embodiment, the system further comprises a lead connector or adaptor having at least one return electrode electrically coupled to the pulse generator. In an embodiment, the one or more return electrode is recessed within an electrically insulating portion of the lead. In an embodiment, the one or more return electrodes extends beyond an electrically insulating portion of the lead. In an embodiment, the one or more return electrodes is recessed from an adjacent surface. In an embodiment, the one or more return electrodes extends beyond an adjacent surface.

[0027] In an embodiment, a proportion of current returned through each of multiple return electrodes is programmable or automatically adjustable to minimize patient discomfort. In an embodiment, the lead is fully implantable within a patient’s body. In an embodiment, the lead is percutaneous and exits skin to connect to the pulse generator. In an embodiment, the one or more return electrodes are located on or forms a pad. In an embodiment, the lead is an opencoil lead. In an embodiment, the lead is a closed-coil lead.

[0028] The following description and the draw ings disclose various illustrative aspects. Some improvements and novel aspects may be expressly identified, while others may be apparent from the description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present teachings may be better understood by reference to the following detailed description taken in connection with the following illustrations, in which like reference characters refer to like parts throughout, wherein:

[0030] FIG. 1 shows an embodiment of a nerve stimulation system comprising return electrode in accordance with various disclosed aspects herein;

[0031] FIG. 2 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0032] FIG. 3 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0033] FIG. 4 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0034] FIG. 5 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0035] FIG. 6 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0036] FIG. 7 shows an embodiment of a nerve stimulation system compnsing a return electrode in accordance with various disclosed aspects herein;

[0037] FIG. 8 shows an embodiment of a nerve stimulation system composing a return electrode in accordance with various disclosed aspects herein;

[0038] FIG. 9 shows an embodiment of a nerve stimulation system composing a return electrode in accordance with various disclosed aspects herein;

[0039] FIG. 10 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0040] FIG. 11 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0041] FIG. 12 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0042] FIG. 13 shows an embodiment of a nen e stimulation system comprising return electrode in accordance with various disclosed aspects herein;

[0043] FIG. 14 shows an embodiment of a nerve stimulation system comprising return electrode in accordance with various disclosed aspects herein; [0044] FIG. 15 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0045] FIG. 16 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0046] FIG. 17 shows an embodiment of placement targets for a nen e stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0047] FIG. 18 shows an embodiment of placement targets for a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0048] FIG. 19 shows an embodiment of placement targets for a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0049] FIG. 20 shows embodiments of return electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0050] FIG. 21 shows embodiments of pulse generator cases in accordance with various disclosed aspects herein;

[0051] FIG. 22 shows embodiments of return electrodes and pulse generator cases in accordance with various disclosed aspects herein;

[0052] FIG. 23 shows embodiments of a return electrode and pulse generator case in accordance with various disclosed aspects herein;

[0053] FIG. 24 shows embodiments of a return electrode and pulse generator case in accordance with various disclosed aspects herein;

[0054] FIG. 25 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0055] FIG. 26 shows an embodiment of a nen e stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0056] FIG. 27 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0057] FIG. 28 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0058] FIG. 29 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0059] FIG. 30 shows an embodiment of a nen e stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0060] FIG. 31 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein; [0061] FIG. 32 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0062] FIG. 33 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0063] FIG. 34 shows an embodiment of a nerv e stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0064] FIG. 35 shows an embodiment of a nerve stimulation system comprising a return electrode in accordance with various disclosed aspects herein;

[0065] FIG. 36 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0066] FIG. 37 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0067] FIG. 38 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0068] FIG. 39 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0069] FIG. 40 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance wi th various disclosed aspects herein;

[0070] FIG. 41 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0071] FIG. 42 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0072] FIG. 43 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0073] FIG. 44 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0074] FIG. 45 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0075] FIG. 46 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0076] FIG. 47 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein;

[0077] FIG. 48 shows an embodiment of electrodes that may be used with a nerve stimulation system in accordance with various disclosed aspects herein. [0078] FIG. 49A illustrates lead placement remote of the nerve. It shows conventional PNS leads that are designed to be placed in intimate nerve contact, which often undesirably activates non-targeted pain (red) or motor fibers (blue) in addition to targeted pain-relieving fibers (green).

[0079] FIG 49B illustrates lead placement remote of the nerve. It show s the novel approach validated by Phase I and II studies using a single-contact open-coil lead designed to be placed remote from the nerve and widen the therapeutic window sufficiently to relieve pain while avoiding non-targeted fiber activation.

[0080] FIG. 49C illustrates lead placement remote of the nerve. It show s a Phase IIB project that proposes system development to further widen the therapeutic window to enable placement without assessing patient feedback to test.

[0081] FIG. 50A shows a 3D model target deployment area using a conventional singlecontact lead.

[0082] FIG. 50B shows a target deploy ment area using the disclosed multi-contact lead in a 3D model delivering stimulation in human tissue. Lead insertion was modeled as superficial to sciatic nerve in a lateral to medial direction as typical in clinical practice. Grid points correspond to location of center of contact (i.e., blue "X" on either lead). The target deployment area (green) shows the lead locations where all target fibers (e.g., 22pm diameter) in the nerve trunk were activated at lower thresholds than non-target fibers (e.g., 10pm diameter), and stimulation intensities were at non-damaging levels.

[0083] FIGs. 51A-B show an example placement of conventional neurostimulation leads used off label for the stimulation of occipital nerves for the treatment of chronic headache.

[0084] FIG. 51 A is a lateral view⁷ of the head and neck.

[0085] FIG. 5 IB is a posterolateral view of the head and neck showing skin erosion associated with use of conventional leads not designed for the mobile area of the neck including skin erosion. It is an image from 1 year after lead placement.

[0086] FIGs. 52A-B show⁷ a minimally invasive PNS system including flexible, open-coil PNS leads coupled to an external pulse generator to deliver neurostimulation of the occipital nerves.

[0087] FIG. 52C shows the remote placement from target nerves (e.g., 5-10 mm) to selectively activate pain relieving fibers to produce long-term sustained relief of headache.

[0088] FIG. 53A shows that intimate nerve placement limits conventional PNS by the unintended activation of pain fibers (red). Substantial changes in threshold amplitudes with lead movement (e.g., 1 mm migration from 1 to 2 mm away from nerve) and the lack of overlap of the therapeutic windows at these distances suggests that lead movements may cause loss of pain relief.

[0089] FIG. 53B shows that remote selective targeting enables selective activation of targeted fibers (green) with the proposed system. The substantial overlap of the therapeutic windows for remotely placed leads suggests that comfortable stimulation may still provide relief even after lead movements (e.g., 1 mm migration from 10 to 11mm away from nerve).

[0090] FIG. 53C shows data from computational modeling of electrode-nerve distance and threshold amplitude.

[0091] FIGs. 54A-B are sagittal MRI at A) and ultrasound images at B) showing the greater occipital nerve (“ON"’) at the mid-vertebral C2 level. Review of anatomy at this level confirms there is sufficient tissue depth to place the novel 0.7 mm-diameter lead >1 cm from ON to activate pain relieving fibers using remote selective targeting, while also being 1-2 cm deep to the skin to reduce the risk of erosion; Abbreviations are as follows: OCi, obliquus capitis inferior; SsC, semispinalis capitis; and TM, trapezius.

[0092] FIGs. 55A-C shows a diagram of the nervous and vascular system of a human leg including the sciatic nen e, different embodiments of leads placed remote of the sciatic nerve, and an implantable pulse generator (e.g., IPG).

[0093] FIGs. 56A-D illustrates a multi-contact, open-coil percutaneous lead.

[0094] FIG. 56A is the distal portion of a lead with 3 contacts.

[0095] FIG. 56B is a sectioned view of insulated lead body (white),

[0096] FIG. 56C is a sectioned view of de-insulated (electrode contact; gray) portion of the lead.

[0097] FIG. 56D is a sectioned view of transitioning section of the lead (de-insulated to insulated section). The lead is designed to maintain the benefits of the existing single-contact lead design (i.e., percutaneous placement, infection resistance) while enabling delivery of stimulation from multiple contact locations, eliminating the need for testing stimulation at multiple lead locations during the lead placement procedure while also improving on the strength of the lead.

[0098] FIGs. 57A-C shows a flexible, self-anchoring coiled stimulating lead with a slim (0.7 mm diameter), pliable, and durable structure at A). The innovative lead design’s selective deinsulation forms long (e.g., 10 mm length) electrodes composed of multi-strand wires with redundant connections at B & C) for migration and fracture resistance. To enable remote selective targeting lead design here includes four long independent electrodes (channels) that are each created with selective de-insulation of the continuous multi-stranded stainless steel wire rope (i.e.. avoiding the need for a welded joint at the electrode, a common potential fracture point with existing neurostimulation leads).

[0099] FIGs. 58A-D illustrate embodiments of leads with different quantities of electrodes, illustrating insulated and uninsulated portions of the leads.

[00100] FIG. 58A illustrates the distal region of one embodiment of the multi-contact stimulation lead consisting of 4 electrodes or contacts configured to be implanted into a patient for peripheral nerve stimulation, in accordance with the teachings of this disclosure.

[00101] FIG. 58B illustrates the distal region of another embodiment of the multicontact stimulation lead consisting of 3 electrodes or contacts configured to be implanted into a patient for peripheral nerve stimulation, in accordance with the teachings of this disclosure.

[00102] FIG. 58C illustrates the distal region of another embodiment of the multicontact stimulation lead consisting of 2 electrodes or contacts configured to be implanted into a patient for peripheral nerve stimulation, in accordance with the teachings of this disclosure.

[00103] FIG. 58D illustrates the distal region of another embodiment of the multicontact stimulation lead consisting of 1 electrode or contact configured to be implanted into a patient for peripheral nerve stimulation, in accordance with the teachings of this disclosure.

[00104] FIG. 59A illustrates a sectional view of one embodiment of the multi-contact lead body consisting of four insulated and coiled multi-stranded or multi-filar conductors, in accordance with the teachings of this disclosure.

[00105] FIG. 59B illustrates a sectional view of another embodiment of the multicontact lead body consisting of three insulated and coiled multi-stranded or multi-filar conductors, in accordance with the teachings of this disclosure.

[00106] FIG. 59C illustrates a sectional view of another embodiment of the multicontact lead body consisting of two insulated and coiled multi-stranded or multi-filar conductors, in accordance with the teachings of this disclosure.

[00107] FIG. 59D illustrates a sectional view of another embodiment of the multicontact lead body consisting of one insulated and coiled multi-stranded or multi-filar conductors, in accordance with the teachings of this disclosure.

[00108] FIG. 59E illustrates a cross-sectional view of a multi-stranded or multi-filar conductor from FIG. 59B.

[00109] FIGS. 60A-C shows variations of wire configurations for an implantable multi-contact lead design including 7 filar, 19 filar and 37 filar cables with an insulation coating 230 to separate each conductor. All four conductors are wound in tandem to form a closed coil as shown in the figure. A highly flexible sleeve shown as transparent tubing is also used to protect and maintain the shape of the coil.

[00110] FIG. 61A illustrates iso-potential lines showing stimulation fields around different contact lengths demonstrating generation of a broad monopolar field with large contacts.

[00111] FIG. 61B This figure also illustrates iso-potential lines showing stimulation fields around contacts with different ratios of contact length to contact spacing demonstrating superposition of fields across multiple contacts.

[00112] FIG. 62 illustrates iso-potential lines showing stimulation fields around contacts with different ratios of contact length to contact spacing demonstrating superposition and uniformity of fields across multiple contacts.

[00113] FIG. 63 illustrates normalized peak activation function (e.g., activating function, “Act Fcn’’)comparing different electrode contact sizes and contact spacings.

[00114] FIG. 64A illustrates a cross-sectional view of conductors/channels showing filar arrangement in a conventional lead.

[00115] FIG. 64B illustrates a cross-sectional view of a conductor/channel showing one embodiment of the filar arrangement (37 filar conductors) in the multi-contact lead, in accordance with the teachings of this disclosure.

[00116] FIG. 64C illustrates a cross-sectional view of an example conductor/channel with higher filar count (49 filar conductors).

[00117] FIG. 64D illustrates a cross-sectional view of an example conductor or channel with higher filar count (133 filar conductors).

[00118] FIGs 65A-D illustrates sectional view of multi-contact leads with no outer jackets.

[00119] FIG. 65A illustrates a sectional view of another embodiment of the multicontact lead with no outer jacket or tubing and no spacing between coils at equilibrium, resting state or with no tension on the lead.

[00120] FIG. 65B illustrates a sectional view of another embodiment of the multicontact lead with no outer jacket or tubing, and with partial spacing between coils when the lead is pulled or stretched lengthwise.

[00121] FIG. 65C illustrates a sectional view of another embodiment of the multi-contact lead with no outer jacket or tubing, and with spacing between coils when the lead is pulled or stretched lengthwise.

[00122] FIG. 65D illustrates a lead with two conductors pulled or stretched lengthwise. [00123] FIGs. 66A-B illustrates the formation of coiled electrodes by fully or partially removing the insulation coating (deinsulating) the coiled conductors/channels in the lead body.

[00124] FIG. 66A illustrates fully insulated conductors.

[00125] FIG. 66B illustrates different percentages of deinsulation of coiled conductors, according to the teachings of this disclosure.

[00126] FIG. 67A illustrates a sectional view of an alternative embodiment of the multicontact lead with coaxial coil arrangement where all the conductors/channels alternate between the inner and outer layer of coil at different intervals and each conduct or/channel is coiled externally at least once to enable deinsulation (removal of insulation coating) and formation of electrodes/contacts for each conductor/channel.

[00127] FIGs. 67B-C illustrates a sectional view of an embodiment of an electrode on the multi-contact lead formed by removing the insulation coating of the coiled conductors at the distal end and coiling back the uninsulated conductors over the lead tubing toward the proximal end.

[00128] FIGs. 68A-C illustrates cross-sectional views of example conductors or channels wherein individual wires or filaments are made of a single material or two dissimilar materials (e.g., drawn filled tubes).

[00129] FIGs. 68D-F illustrate cross-sectional views of example conductors or channels in the multi-contact lead, where individual wires or filaments are made of multiple wire materials arranged in different orientations (e.g., variability in material between individual wires/filaments, multilayer arrangement of different materials in each wire).

[00130] FIG. 69 illustrates a lead with ring electrodes and/or flexible wire conductors accordingly to the teachings of this disclosure.

[00131] FIGs. 70A-B illustrates a sectional view of another embodiment of the outer tubing or jacket of the multi-contact lead which has a multi-layered jacket or tubing with a threaded outer layer (protruding spiral pattern) for mechanical securement (self-anchoring mechanism).

[00132] FIGs. 70C-D illustrates a sectional view of another embodiment of the outer tubing or jacket of the multi-contact lead which has a multi-layered jacket or tubing with a threaded outer layer (recessed spiral pattern) for mechanical securement (self-anchoring mechanism).

[00133] FIGs. 70E-G illustrates another sectional view of the outer tubing or jacket described in FIGs. 70A-B with tissue growth or formation around the lead enabling lead securement and a mechanism for withdrawal of the lead. [00134] FIGs. 70H-J illustrates another sectional view of the outer tubing or jacket described in FIGs. 71A-D with tissue growth or formation around the lead enabling lead securement and a mechanism for withdrawal of the lead.

[00135] FIG. 71 A and 71 C illustrate a sectional view of another embodiment of the outer tubing or jacket of the multi-contact lead which has an intermeshed outer layer for mechanical securement (self-anchoring mechanism). The lead is at equilibrium or resting state with no tension applied.

[00136] FIGs. 71B and 71 D illustrate a sectional view of the embodiment described in FIG. 30A when the lead is being pulled or stretched lengthwise causing the intermeshed outer layer to compress the lead body facilitating lead removal.

[00137] FIGS. 71 E-F illustrates an embodiment according to teachings of this disclosure.

[00138] FIGs. 72A-D illustrates a lead with 4 electrodes with different structures according to the teachings of this disclosure.

[00139] FIG. 72A illustrates an alternative embodiment of the distal tip of the multi-contact lead with two long electrodes or contacts flanked by two shorter electrodes/contacts.

[00140] FIG. 72B illustrates another embodiment of the distal tip of the multi-contact lead with two short electrodes or contacts flanked by two longer electrodes/contacts.

[00141] FIG. 72C illustrates another embodiment of the distal tip of the multi-contact lead with one long electrode or contact flanked by four shorter electrodes/contacts (two on each side).

[00142] FIG. 72D illustrates another embodiment of the distal tip of the multi-contact lead with three short electrodes or contacts flanked by two longer electrodes/contacts.

[00143] FIG. 73 illustrates a modular mandrel to construct the multi-contact coiled lead with segments or parts consisting of varying diameter and/or length and joined with a screw connection.

[00144] FIGs. 74A-C illustrates embodiments of anchors on the multi-contact lead, which are invertible or capable of reversing direction (e.g., anchors facing the proximal end of the lead at equilibrium or resting state may flip to the opposite direction facing the distal end of the lead when being pulled or stretched lengthwise.

[00145] FIG. 74A illustrates a lead with anchors facing the distal end of the lead.

[00146] FIG. 74B illustrates a lead with anchors facing the proximal end of the lead.

[00147] FIG. 74C illustrates a different view of the lead from FIG. 34B with anchors facing the proximal end of the lead. [00148] FIGs. 75A-E illustrates another embodiment of the anchors on the multi-contact lead, which includes flat and collapsible anchors that can fold or wrap around the lead body in the introducer needle and unwrap or expand (e.g., similar to a '‘blooming flower”) when deployed.

[00149] FIGs. 76A-D illustrates one embodiment of the lead retrieval/extraction tool for removing the multi-contact lead, which consists of a needle or percutaneous sheath that is inserted over the lead body during lead retrieval to cut/remove anchors or tines as it slides over the lead body from proximal to distal end of the lead.

[00150] FIG. 77A illustrates example embodiments of the distal tip of multi-contact lead with anchors slightly rotated, offset and/or asynchronously aligned at different points along the lead length to minimize unwanted migration in multiple axes (directions).

[00151] FIG. 77B illustrates a perspective view of the multi-contact lead with pairs of anchors facing away from each other along the lead body.

[00152] FIG. 77C illustrates a perspective view of the multi-contact lead with one pairs of anchors facing the proximal end of the lead and the other pair of anchors facing the distal end of the lead.

[00153] FIG. 77D illustrates a perspective view of the multi-contact lead as observed from the distal end to the proximal end showing the positioning of anchors along the lead body.

[00154] FIG. 77E illustrates a perspective view of the multi-contact lead as observed from the distal end to the proximal end showing the positioning of anchors along the lead body.

[00155] FIGs. 78A-C illustrates various configuration of anchors for use on a stimulation lead according to the teachings of the disclosure.

[00156] FIGs. 78D-E illustrates an embodiments of anchors that is a different shapes and dimension from earlier teachings.

[00157] FIGs. 79A-C illustrates another embodiment of the lead retrieval or extraction tool for removing the multi-contact lead, which consists of a stylet with one or more anchors, prongs, or barbs at the distal tip that can be inserted into the lumen of the lead and provide mechanical support for lead removal.

[00158] FIGs. 80A-C show an embodiment of the percutaneous and/or implantable multicontact lead design. They show a percutaneous lead and therefore the coiled conductors do not have an outer sleeve because tissue ingrow th in the open coil segment helps prevent lead migration and indw elling lead pistoning effects which could reduce infection. The most distal electrode is folded back to serve as an anchor. This figure is in accordance with aspects disclosed herein; [00159] FIGs. 80B and 80C show the cross-sectional view of the coil along the length of the lead as indicated. The stimulating electrodes have a closed coil configuration (B) and the spacing between electrodes has an open coil configuration (C).

[00160] FIGs. 81A-C show an embodiment of the percutaneous and/or implantable multicontact lead design. For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection. This figure is in accordance with aspects disclosed herein.

[00161] FIGs. 81B-C show the cross-sectional view of the coil along the length of the lead as indicated. The stimulating electrodes have a closed coil configuration (C) and the spacing between electrodes has an open coil configuration (B).

[00162] FIGs. 82A-B show an embodiment with the distal end of the percutaneous and/or implantable multi-contact lead design; FIG 82A shows 3 electrodes and the distal end of the lead. FIG. 82B shows a zoomed view with only the 2 most distal electrodes. The most distal end of the lead is folded back to serve as an anchor.

[00163] FIGs. 83A-C show an embodiment of the percutaneous and/or implantable lead design. FIG. 43B and C are cross-sectional views of the coil and two locations along the length of the lead. The stimulating electrodes have a closed coil configuration (top right) and the spacing between electrodes has an open coil configuration (top left). For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection. This figure is in accordance with aspects disclosed herein.

[00164] FIG. 84A-B shows the distal end of an embodiment of a percutaneous and/or implantable multi-contact lead design with 4 electrodes. 84A image shows the distal end of the lead with all 4 electrodes and the bottom image is a zoomed view with only the 2 most distal electrodes. The most distal end of the lead is folded back to serve as an anchor. This figure is in accordance with aspects disclosed herein.

[00165] FIGs. 85A-C show⁷ an embodiment of a percutaneous and/or implantable multicontact lead design with 2 electrodes. FIGs. 85B-C images show the cross-sectional view of the coil along the length of the lead. FIG. 85C shows the stimulating electrodes have a closed coil configuration (top right). FIG. 85B shows spacing between electrodes with an open coil configuration (top left). For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection, in accordance with aspects disclosed herein.

[00166] FIG. 86 shows distal end of the fourth variation of the percutaneous and/or implantable multi-contact lead design with 2 electrodes. The most distal electrode is folded back to serve as an anchor, in accordance with aspects disclosed herein;

[00167] FIGs. 87A-C show an embodiment of a percutaneous and/or implantable multicontact lead design. FIGs. 87B-C show the cross-sectional view of the coil along the length of the lead. The stimulating electrodes have a closed coil configuration (C; top right) and the spacing between electrodes has an open coil configuration (B; top left). For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection, in accordance with aspects disclosed herein.

[00168] FIG. 88 shows the distal end an embodiment of a percutaneous and/or implantable multi-contact lead design with 3 electrodes. The top image shows the distal end of the lead with all 3 electrodes and the bottom image is a zoomed view with only the 2 most distal electrodes. The most distal electrode is folded back to serve as an anchor, in accordance with aspects disclosed herein;

[00169] FIGs. 89A-C show an embodiment of a percutaneous and/or implantable multicontact lead design. The top two images show the cross-sectional view of the coil along the length of the lead. The stimulating electrodes have a closed coil configuration (C; top right) and the spacing between electrodes has an open coil configuration (B; top left). For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection, in accordance with aspects disclosed herein.

[00170] FIG. 90 show s the distal end of an embodiment of a percutaneous multi-contact lead design with 4 electrodes. The top image show s the distal end of the lead with all 4 electrodes and the bottom image is a zoomed view with only the 2 most distal electrodes. The most distal electrode is folded back to serve as an anchor, in accordance with aspects disclosed herein;

[00171] FIGs. 91 A-C show an embodiment of a percutaneous multi-contact lead design with 3 electrodes. The top tw o images show the cross-sectional view⁷ of the coil along the length of the lead. The stimulating electrodes which are the deinsulated conductors are coiled externally while the other two insulated conductors are coiled internally (top right) and the entire lead has an open coil configuration. For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection, in accordance with aspects disclosed herein;

[00172] FIG. 92 shows the distal end of another an embodiment of a percutaneous multicontact lead with 3 electrodes, in accordance with aspects disclosed herein;

[00173] FIG. 93 shows an embodiment of a multi-contact lead, in accordance with aspects disclosed herein;

[00174] FIGs. 94A-C show embodiments of a 4-contact multi-contact lead percutaneous with different contacts along the lead, in accordance with aspects disclosed herein;

[00175] FIG. 95A-B show embodiments of a lead and IPG according to teachings of this disclosure.

[00176] FIG. 96 show s embodiments of lead cross sections at the proximal end.

[00177] FIG. 97 shows embodiments of lead body tubing with anchors with the follow ing shapes: rectangular, trapezoidal, grooved, and rectangular with curved edge anchors.]

[00178] FIG. 98 shows an embodiment of a lead body tube with an indentation that accommodates an anchor.

[00179] FIG. 99 show s embodiments of anchors along a lead body.

[00180] FIG. 100 shows embodiments of anchors along a lead body.

[00181] FIG. 101A-G shows embodiments electrode configurations at the proximal and distal portions of the lead.

[00182] FIG. 102 illustrates conductive return electrodes with slots according to the teachings of this disclosure.

[00183] FIG. 103 illustrates an anchor tube consisting of a flap- sty le, foldable anchoring element, that is attached to the outer surface of the main lead body tubing.

[00184] FIG. 104 illustrates the full lead design with coiled electrodes and a flap-style anchoring tube at the distal end.

[00185] FIG 105 illustrates a single anchoring feature that prevents bidirectional lead migration (forward and backward) in two orthogonal planes.

[00186] FIG. 106A illustrates an embodiment of a segmented tubing assembly.

[00187] FIG. 106B illustrates an embodiment of a single lead tubing and an outer layer of molded tine with a large surface area of interface between the lead tubing and the anchor/tine body to address tine/anchor separation from the lead body during lead extraction.

[00188] FIG. 107A illustrates an embodiment of flap-style tine designed (new tine design) with a smaller tine width that folds along the lead body during insertion of the lead through a 7F introducer to address lead tines being too big and rigid to pass through a 7F introducer (2.2mm ID).

[00189] FIG. 107B illustrates an embodiment of flap-style tine designed (new tine design) with a smaller tine width that folds along the lead body during insertion of the lead through a 7F introducer to address lead tines being too big and rigid to pass through a 7F introducer (2.2mm ID).

[00190] FIGS. 108A and B depict one example of a tine design and FIGS. 108C and D embody an exemplary tine design, where such designs are consistent with what is described elsewhere in this specification.

[00191] FIGS 109A-D depicts exemplary embodiments of an introducer system that may be utilized with the lead and return electrode designs described in this specification.

[00192] FIGS. 110A-C depicts the lead introducer system utilized for implanting the lead and deploying the tines of the embodiments described in the specification.

[00193] FIGS. 111A-C depicts an embodiment of a lead introducer system utilized for implanting the lead and deploying the tines of the embodiments described in the specification.

[00194] FIGS. 112A-B disclose a lead as described in this specification elsewhere. The lead comprises electrodes and return electrodes and a tine or anchoring system. Also shown is a fixation sleeve.

[00195] FIG. 113A-B depicts a lead stylet in operation with a lead to be deployed.

[00196] FIG. 114 depicts a lead tunneling tool configured to be utilized in implanting the lead with return electrode described herein.

[00197] FIG. 115 depicts an embodiment of a lead that comprises a coiled body with proximal connectors, a fixation sleeve, tines, and electrodes that comprise non-insulated segments of the lead.

[00198] FIG 116 depicts an embodiment of a lead that comprises a coiled body with proximal connectors, a fixation sleeve, tines, and electrodes that comprise non-insulated segments of the lead.

[00199] FIG. 117 depicts an embodiment of a pulse generator. The pulse generator may be an implantable pulse generator that comprises a connector block and set screw, a receiver coil and lead connector to which the lead depicted in the specification may be operatively connected.

[00200] FIG. 118 depicts an embodiment of the lead implanted on a patient. The leads may be placed medial to lateral from the insertion site. [00201] FIG. 119 depicts an embodiment of the lead implanted on a patient.

[00202] FIG. 120 depicts a lead body comprising a terminal end for electrical connection to an IPG and shared connectors. The image also depicts embodiments of tensile testing and flex fatigue testing of the lead.

[00203] FIG. 121 depicts embodiments of migration and excitability' bench testing of the embodiments of the leads depicted herein.

[00204] FIG. 122 depicts an embodiment of a lead that comprises a coiled body with proximal connectors, a fixation sleeve, tines, and electrodes.

[00205] FIG. 123 depicts an embodiment of the lead implanted on a patient.

[00206] FIG. 124 depicts embodiments of IPG pocket incisions on a patient.

[00207] FIG. 125 depicts embodiments of lead insertion sites on a patient.

[00208] FIG. 126 depicts embodiments of IPG orientation and pocket incision on patients.

[00209] FIG. 127 depicts an example of the IPG and lead depth on a patient.

[00210] FIG. 128 are examples of lead pathways of the leads disclosed herein on a patient.

[00211] FIG. 129 depicts an example of lead tunneling from an IPG implanted on a patient.

[00212] FIG. 130 are examples of potential lead pathways for an IPG implanted in a lower back of a patient.

[00213] FIG. 131 are examples of potential lead pathways for an IPG implanted in a lower back of a patient.

[00214] FIG. 132 is an exemplary lead comprising an anchoring tube with a plurality of tines.

[00215] FIG. 133 is an exemplary⁷ lead comprising an anchoring tube with a plurality⁷ of tines.

[00216] FIG. 134 is an exemplary lead comprising an anchoring tube with a plurality of tines. The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims.

DETAILED DESCRIPTION

[00217] Reference will now be made in detail to exemplary⁷ embodiments of the present teachings, examples of which are illustrated in the accompanying drawings, wherein like numbered aspects refer to a common feature throughout. It is to be understood that other embodiments may be utilized and structural and functional changes may be made without departing from the respective scope of the present teachings. Moreover, features of the various embodiments may be combined or altered without departing from the scope of the present teachings. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments and still be within the spirit and scope of the present teachings. [00218] In this disclosure, numerous specific details provide a thorough understanding of the subject disclosure. It should be understood that aspects of this disclosure may be practiced with other embodiments not necessarily including all aspects described herein, etc.

[00219] As used herein, the words '‘example” and “exemplary” means an instance, or illustration. The words “example” or “exemplary” do not indicate a key or preferred aspect or embodiment. The word “or” is intended to be inclusive rather than exclusive, unless context suggests otherwise. As an example, the phrase “A employs B or C.” includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C). As another matter, the articles “a” and “an” are generally intended to mean “one or more” unless context suggest otherwise.

[00220] Further, as herein disclosed, the terms “substantially,” “about,” and variations thereof describe features that are equal or approximately equal to a value or characteristic, as desired, reflecting tolerances, conversion factors, rounding off, measurement error, acceptable variation thresholds, and the like. For example, unless context or this disclosure suggests otherwise, the term “substantially” includes values or characteristics that are exact or within 15% of exact (or what is stated), for example within 10% of exact, or within 5% of exact. In another example, unless context or this disclosure suggests otherwise, the term “about” includes values within .5 of a degree to 1 degree of exact (or what is stated).

[00221] Further, unless context or this disclosure suggests otherwise, descriptions of shapes (e.g., circular, rectangular, triangular, etc.) refer to shapes meeting the definition of such shapes and general representation of such shapes. For instance, a triangular shape or generally triangular shape may include a shape that has three sides and three vertices or a shape that generally represents a triangle, such as a shape having three major sides that may or may not have straight edges, triangular like shapes with rounded vertices, etc.

[00222] Disclosed is a peripheral nerve stimulation system, and devices and components thereof. In an embodiment, the system comprises a pulse generator (e.g., stimulator, neurostimulator, stimulation device, stimulating unit, signal generator, stimulation controller, waveform generator, stimulation engine, neural stimulator, peripheral nerve stimulator, current or voltage source) and one or more leads each with one or more electrodes. It is to be appreciated that the lead which is used may have one or more coiled components, and the lead may have a structure that is open coil or closed coil. It is understood that the stimulation output from a pulse generator may be pulses of electrical current, voltage, or charge of any shape (such as rectangular, square, trapezoidal, ramps, exponential, gaussian, stochastic, and/or biomimetic), alternating current (such as a sinusoidal wave, sawtooth wave), or direct current (such as where the pulse is on for several milliseconds, seconds, minutes, hours, or more). In an example embodiment, stimulation may be delivered between one or more stimulating electrodes (e.g.. cathodes, negative electrodes, current-delivering electrodes, driving electrodes, source electrodes, depolarizing electrodes, excitatory' electrodes, therapeutic electrodes, emitter electrodes, primary electrodes, active electrodes, stimulus delivery' site, output node, electrode contact, any of the previous terms with the word "electrode’' substituted with "contact") and one or more return electrodes (e.g., anodes, anodic electrode, reference electrode, ground electrode, common electrode, secondary electrodes, indifferent electrode, hyperpolarizing electrode, any of the previous terms with the word “electrode"’ substituted with “contact”). In an embodiment, the system comprises one or more return electrodes that are large in surface area and positioned distant from the stimulating electrodes and distant from the power receiving component(s) and/or distant from the pulse generating component(s). In an embodiment, this configuration can facilitate selective activation of large peripheral nerve fibers while avoiding or minimizing discomfort and/or unwanted responses (such as side effects, patient discomfort, pain, unintended muscle contractions, unintended bodily functions [hiccups, urinary incontinence, vasovagal response, headache, change in blood pressure], tissue irritation, and/or damage) by optimizing electrode size, placement, and/or spacing. For example, the electrode spacing may be non-uniform, with distal stimulating electrodes (e.g., electrodes closer to the terminal end of the lead, opposite to the connection point where the lead is mechanically and electrically coupled to the pulse generator, connection cable, adapter, etc.) placed close together to enable or ensure overlapping fields for comprehensive nerve activation, while the return electrodes are spaced farther away to create a uniquely advantageous stimulation field (e.g., electric field, current field, field of stimulation, activation field, electric potential field, current density field, charge distribution, volume or zone of tissue activated/stimulated/polarized, neural or axonal recruitment region, therapeutic field, stimulation zone, stimulation footprint, spread of stimulation, field distribution, depolarization/hyperpolarization/polarization field, any of the terms where “distribution”, “field”, “spread”, “zone”, and “gradient” may be used interchangeably) and/or reduce field overlap. The disclosed system may further comprise one or more of: coiled or patterned electrodes, and the use of multiple leads or segmented return electrodes to optimize surface area, the delivery of current density, and charge distribution while enhancing mechanical flexibility’, durability, and other characteristics.

[00223] In an example, the distance, spacing, and/or separation between the stimulating electrodes may be smaller than the distance, spacing, and/or separation between the one or more stimulating electrode(s) and the return electrode(s), and there may also be the distance, spacing, and/or separation between the return electrode(s) and the power receiving component(s) and/or the pulse generating component(s). In an example, the distance, spacing, and/or separation between the stimulating electrodes (e.g., the space between one stimulating electrode and the next nearest stimulating electrode) may be exactly, about, or approximately 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more millimeters, and the distance, spacing, and/or separation between the one or more stimulating electrode(s) and the return electrode(s) may be larger and/or may be exactly, about, or approximately 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 20-25, 25, 25-30, 30, 30-35, 35, 35-40, 40, 40- 45, 45, 45-50, 50, 50-60, 60-70, 70-80, 80-90, 90-100, 100-150, 100-200, 100-300, 100-400, 100-500, 100-600, 100-700. 100-800. 100-900, 100-1000, 10-100, 10-150, 10-200, 10-300, 10-400, 10-500, 10-600. 10-700, 10-800. 10-900, and/or 100-100 or more millimeters) and the distance, spacing, and/or separation between the return electrode(s) and the power receiving component(s) and/or the pulse generating component(s) may be larger and may be exactly, about, or approximately 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 20-25, 25, 25-30, 30. 30-35, 35, 35-40, 40, 40-45. 45. 45-50, 50, 50-60, 60-70. 70-80, 80- 90, 90-100, 100-150, 100-200, 100-300, 100-400, 100-500, 100-600, 100-700, 100-800, 100- 900, 100-1000, 10-100, 10-150, 10-200, 10-300, 10-400, 10-500, 10-600, 10-700, 10-800, 10-900, and/or 100-100 or more millimeters). In an example in which a lead has only one or at least one stimulating electrode, the return electrode may be positioned a significant distance from the stimulating electrode (e.g., approximately 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 20-25, 25, 25-30, 30, 30-35, 35, 35-40, 40, 40-45, 45, 45-50, 50, 50-60, 60-70, 70-80, 80-90, 90-100, 100-150, 100-200, 100-300, 100-400, 100-500, 100-600, 100-700, 100-800, 100-900, 100-1000, 10-100, 10-150, 10-200, 10-300, 10-400, 10-500, 10- 600, 10-700. 10-800, 10-900, and/or 100-100 or more millimeters from the stimulating electrode).

[00224] In another example, in addition or instead of measuring or designating the distance(s) or length(s) between the stimulating electrode and the return electrode and the power receive component, stimulation circuitry’, and/or pulse generator in terms of units of length (e.g., microns, micrometers, millimeters, centimeters, etc.), the distance, separation. and/or spacing may be measured or described in terms of full or partial multiples of the length of one or more electrodes and/or spacing between electrodes (e.g., the distance between the return electrode(s) and the stimulating electrode(s), may be at least or greater than one times (IX), two times (2X), three times (3X), four times (4X), five times (5X), six times (6X), seven times (7X), eight times (8X), nine times (9X), ten times (10X), or more the length or size of at least one stimulating electrode, an array or set of stimulating electrodes, the spacing between two stimulating electrodes, and/or a return electrode or an array or set of return electrodes).

[00225] In another example, the distance between the return electrode(s) and the power receive component, stimulation circuitry', and/or pulse generator, may be at least or greater than one times (IX). two times (2X), three times (3X). four times (4X). five times (5X), six times (6X), seven times (7X), eight times (8X), nine times (9X), ten times (10X), or more the length or size of at least one stimulating electrode, an array or set of stimulating electrodes, the spacing between two stimulating electrodes, and/or a return electrode or an array or set of return electrodes).

[00226] In one example the distance(s), spacing(s). separation(s), and/or length(s) between the stimulating electrode and the return electrode and the power receive component, stimulation circuitry⁷, and/or pulse generator may be measured along the length of the lead, device, or system, and in another alternative example, the distance(s). spacing(s), separation(s), and/or length(s) between the stimulating electrode and the return electrode and the power receive component, stimulation circuitry, and/or pulse generator may be measured not along the length of the lead, device, or system but rather in space or tissue. For example, in one embodiment if there is a loop or other formation or shape of the lead that is not in a straight line, the distance may be measured by (along) the length of lead (e.g., including the loop or other formation or shape of the lead), and in another example embodiment, the distance may⁷ be measured as the shortest distance between the points being measured (e.g., not including the loop or other formation or shape of the lead).

[00227] It is to be appreciated that units may be described in different or alternative words, meaning they may be converted from one term or word to another as needed (e.g., microns, micrometers, millimeters, centimeters, etc.).

[00228] Generally, disclosed is a peripheral nerve stimulation system 1000 configured to deliver precise and comfortable electrical stimulation to peripheral nerve fibers. In an embodiment, the system 1000 may comprise a pulse generator 1110. In an embodiment, the pulse generator 1110 may be configured to generate and control the electrical stimulation pulses and/or waveform(s). The pulse generator 1110 may be fully implanted, partially implanted, or external to the body. As described herein, the system 1000 may further include one or more leads 1120 (e.g. with coupling facilitated by corresponding lead ports or connectors 1150), stimulating electrodes 1130, and return electrodes 1 140. As described herein, components of the system 1000 (such as stimulating electrodes 1130 and lead 1120) may be placed at, near, proximal, or adjacent to a target 5 nerve and tissue, while other components of the system 1000 (such as return electrodes 1 140 and lead 1125) may be placed in excitable tissue, in non-excitable tissue 10 and/or on a patient’s skin 15. The placement of the other components of the system 1000 such as in non-excitable tissue 10 and skin 15 may be remote or distant from the target 5 nerve and tissue and/or distant from non-target nerve(s) or nerve fibers and/or off-target nerve(s) or nerve fibers. The non-excitable tissue may be physiologically non-excitable, such as bone or adipose tissue; or may be non-excitable due to the stimulation or type of stimulation being delivered or provided (e.g., using the stimulation waveform and/or at the stimulation levels output by the pulse generator) and/or due to or with the geometry of the electrodes (e.g., in an example where the tissue (e.g., non-target or off- target tissue) may have been excitable using the prior art, the use of the present invention overcomes that challenge of the prior art and causes the tissue to be non-excitable or the present invention avoids excitation of the tissue). The pulse generator may also deliver different stimulation waveforms to different electrodes (for example, FIG. 31 and FIG. 46), such that the stimulation waveform is charge balanced to avoid damaging tissue with repeated electrical stimulation so that the stimulation is reversible to maintain stability and biocompatibility at the electrode-tissue interface (for example, not producing electrochemical biproducts due to charge buildup on a metal surface), while also enabling stimulation that may selectively target nerve fibers and/or fascicles within a nerve and/or individual nen es at different depths to increase therapeutic efficacy. Different waveforms may also be delivered to different contacts (for example, waveform Bl to el, B2 to e2, B3 to 35 or Cl to e6 and C2 to e5, or any combination of waveforms and contacts shown herein) to promote selective stimulation while maintaining the safety of the device and optimizing stimulation programming to patient needs to maximize therapeutic efficacy.

[00229] In an embodiment, the pulse generator 1110 may comprise a housing which may enclose or protect internal electrical circuitry from bodily fluids and tissue. For example, the pulse generator 1110 may contain within the housing electronic components to generate, shape, and control stimulation pulses, including microprocessors, current or voltage sources, and switching circuitry. In an embodiment, the housing may be biocompatible. For example. the housing may be constructed from materials such as titanium, ceramic, or medical-grade polymers. As described herein, it is noted that the housing may further include specialized features such as patterned or segmented conductive surfaces to serve as return electrodes which increase the surface area into which the current may return while minimizing unwanted heating during wireless power transfer such as by reducing eddy currents that can occur in unsegmented or more uniform areas of conductive surfaces when exposed to wireless power transfer (e.g., radiofrequency).

[00230] In an embodiment, the pulse generator 11 10 may be powered by an internal battery, such as a primary cell or a rechargeable battery, or may be designed for plug-in operation via a percutaneous connector or wireless power receiving component 1160. In rechargeable or wirelessly powered configurations, the housing may incorporate the power receiving component 1160 that is positioned to facilitate wireless transfer of energy from an external power source to the implanted device while minimizing tissue heating. The power receiving component 1160 may be incorporated into, or positioned within or adj acent to the housing of the pulse generator and may be constructed from non-magnetic, biocompatible, electrically conductive materials that are configured to provide efficient electromagnetic coupling.

[00231] In an embodiment, the power-receiving component (e.g., power receive coil, Rx coil, collector, receiver coil, energy receiver, power receiver module, rechargeable interface, charging coil, energy harvesting module, telemetry coil, inductive link, inductive coupling module, radiofrequency [RF] receiving antenna, ultrasonic transducer, photovoltaic cell, piezoelectric receiver) 1160 may capture energy (such as electromagnetic, AC electrical, DC electrical, heat, ultrasound, kinetic, physical, chemical, light) transmitted from an external power transmitter (such as a charging pad, recharging module, recharger, external powering transmitter [EPT], external powering unit [EPU], external powenng system, wearable transmitter, transmitter coil, Tx Coil, wireless powder transmitter, radiofrequency [RF] powering unit, ultrasound power transmitter, power link module, wearable powering unit, external charger, charging device, wearable transmitter, and/or power source delivering energy in any of the forms that the power-receiving component can convert into electrical energy,) placed on or near the skin surface. In an embodiment, the power-receiving component 1160 may convert this received energy into electrical energy' (through a direct conversion or by converting the received energy into intermediate form(s) of energy' and ultimately ending up as electrical energy), which is then used to power the internal circuitry of the pulse generator, recharge an internalized battery, and/or directly drive stimulation delivered to the patient, for example. As described herein, the power-receiving component 1160 may be located near the surface of the skin to reduce the distance between the external transmitter and the implanted power-receiving component. Further, the power-receiving component 1160 may be positioned such that the power-receiving component 11 0 is not directly under or over return electrodes (e.g., and is generally outside the radius of the return electrode plus a distance or margin or safety margin such as approximately or greater than or equal to 1 cm, 2 cm, 3 cm. or more). In an embodiment, the power-receiving component 1160 and return electrodes may also be positioned on or part of separate structures, to provide flexibility of placement. Such configurations may improve power transfer, reduce the risk of overheating and damaging electrical components such as circuitry, and/or reduce the risk of overheating surrounding tissue by increasing the energy transferred into the power receiving component and reducing energy transferred or lost in the return electrode(s).

[00232] In an embodiment, the pulse generator 1110 may also include a power switch or activation button, either on the housing itself or accessible via remote control, for example, to allow the user or clinician to turn the system on or off as needed. Additional features may include status indicators, including visual, auditory, and/or tactile indicators or alerts; stimulation intensity adjustments, pattern selection, or other selectable/adjustable stimulation parameters, such as amplitude, pulse duration, frequency, duty cycle, session duration, pattern, and waveform shape; telemetry modules for wireless communication including, for example, protocols for secure data transfer, remote programming, and real-time monitoring; memory and processing capabilities to log detailed usage data, stimulation history, device diagnostics, and patient-reported outcomes; adaptive charging and battery health monitoring; universal lead connections or interface capabilities with other medical devices; safetymechanisms to prevent overcurrent or overheating; and the like.

[00233] Generally, the peripheral nerve stimulation system 1000 may further comprise one or more leads 1120 (e.g. with coupling facilitated by corresponding lead ports 1150 and/or connectors 1155), stimulating electrodes 1130, and return electrodes 1140. In an embodiment, the pulse generator 1110 may be configured to interface, couple, or attach to one or more leads 1120 that extend from the pulse generator 1110 to the target anatomical region. The pulse generator 1110 may be configured to interface securely with one or more leads 1120 via lead ports 1150 and/or connectors 1155 on or attachable to the pulse generator 1110. For example, the lead ports 1150 may be integrated into the pulse generator 1110 as recesses configured to receive a corresponding pulse generator attachment end of the lead connectors 1155. The lead connectors 1 155 may comprise another opposite end that facilitates attachment with or to a lead (e.g., leads 1120, 1125). The lead attachment end of the lead connectors 1155 may allow for the coupling of different leads types to the pulse generator 1110 (e.g., as an adapter) or may extend the length of the lead (e.g., as an extender), may allow for multiple or two or more leads to connect through the same port 1150 of the pulse generator 1110 (e.g., as a splitter), and the like.

[00234] As described herein, the pulse generator 1110, in an embodiment, may comprise 1, 2, 3. 4, and/or more ports 1150. to each attach to a corresponding connector (e.g., so there are also 1, 2, 3, 4, and/or more connectors 1 155), which in turn, each attach to a corresponding lead (e.g., so there are also 1, 2, 3, 4, and/or more leads 1120, 1125). In an embodiment one lead 1120 may comprise the stimulating electrode(s) 1130 and a separate lead 1125 may comprise the return electrode(s) 1140. As described herein, other arrangements and variations in number of ports, connectors, leads, stimulating electrodes, and return electrodes, as well as the location and positioning thereof, are also herein contemplated and disclosed. The lead ports 1150 and/or connectors 1155, and the attachment facilitated thereby, can provide reliable electrical and mechanical connections throughout the duration of therapy.

[00235] While in one example embodiment there may be more than one or more than two (e.g., > 2) leads and/or ports or connections, in another embodiment, it may be advantageous to limit the number of leads and/or ports or connections (e.g., to maintain a desirably small size of the pulse generator such as an implantable pulse generator (e.g., IPG) and/or system and/or reduce or eliminate other potential challenges, complications, risk of failure, complexity, procedure skill required, invasiveness (e.g., to the patient), risk of tissue damage, risk of limitations or restrictions to the patient, or other potential problems), and the present invention may enable achievement of multiple goals simultaneously that are advantageous to the device or system and/or user(s), including the patient, care giver, physician, and/or medical provider(s).

[00236] In an embodiment, each lead 1120 may comprise a one or more or a plurality of electrodes, including at least one or more stimulating electrodes 1130 and one or more return electrodes 1140, for example. It is noted that the number of stimulating electrodes 1130 and return electrodes 1140 may be the same. It is noted that the number of stimulating electrodes 1130 and return electrodes 1140 may be different from one another. For example, the system 1000 may include more stimulating electrodes 1130 than return electrodes 1140. For example, the system 1000 may include more return electrodes 1140 than stimulating electrodes 1130. In an embodiment, the stimulating electrodes 1130 may be positioned at a distal end 1122 of the lead 1120 to deliver current to the target nerve fibers. In an embodiment, the return electrodes 1140 may be positioned at a proximal end or proximal half of the same lead 1120 as the stimulating electrodes 1130 (e.g., closer to the end of the lead in the direction of the pulse generator than the terminal end of the lead that travels away from the pulse generator), on a separate lead 1125 from the stimulating electrodes 1130, for example, on a proximal portion or distal end 1127 of the second lead 1125, on a lead connector 1150, on another portion of the system 1000. and the like. The lead(s) 1120 for the system may be the same or uniform or they may be distinct to enable unique features and to optimize stimulation to maximize activation of target fibers in a nerve trunk throughout the periphery while minimizing activation of non-target fibers and/or minimizing off-target effects. In a non-limiting example, one lead may be shorter and/or thicker in order to increase the electrical conductance or decrease the electrical impedance or resistance of the lead to reduce the current, voltage, and/or power required to operate the peripheral nene stimulation system 1000 and/or to improve the efficiency of stimulation, which can extend the life of a battery, increase the interval of time that the user can go between recharging, and/or extend the life of the battery which may only be able to be recharged a limited or finite number of times before it can no longer operate the device. In another non-limiting example, one lead may also be coiled or in the shape of a cylinder with electrodes along the length or ring electrodes or the like while another electrode is a paddle electrode and/or has an insulated surface or the like. The pulse generator that produces the electrical stimulation through the lead may be external to the body, where in one embodiment there is a return electrode that is placed on the skin; and in another embodiment there is no return electrode external to the body, and the return electrode(s) are within the body (e.g., within the body of (or internal to or inside of or in) the patient and not outside of or external to (or on) the body). In other embodiments, the pulse generator that produces the electrical stimulation through the lead may be implanted in the body, where in one embodiment a portion or all of the external casing or any other part of the pulse generator, IPG, receiver, receive coil, and/or other mechanism or device to receive energy or generate, transform or transmit electrical stimulation pulses serves as, is able to serve as. provides, is, or comprises (in whole or in part) a return electrode; and in another embodiment, no portion of the pulse generator, IPG, receiver, receive coil, and/or other mechanism or device to receive energy or generate, transform or transmit electrical stimulation pulses serves as (e.g., does not sen e as), is not able to serve as, cannot or does not provide, is not, or does not or cannot comprise (in whole or in part) as a return electrode, anode, reference electrode, ground electrode, and/or common electrode.

[00237] In an embodiment, as shown in FIGs. 23 and 40, for example, one or more electrodes, including stimulating 1130 and/or return electrodes 1140, may be recessed (or set back or sunken, such as with the electrodes having a smaller diameter than the outer jacket) within an electrically insulating portion of the lead 1120 or the pulse generator 1110. The recess may be uniform or non-uniform around the circumference of the electrode, with a preferred depth sufficient to smooth the current density profile and reduce edge effects (relative to the current density profile of a lead where the electrode is flush wi th the insulating jacket or the depth is much smaller than the length of the electrode) that can lead to unwanted activation of non-target nerve fibers while maintaining sufficient mechanical integrity of the lead to avoid damaging or breaking the lead; avoiding excessive tissue encapsulation surrounding the lead within the recess that would make removal of the lead difficult and may require surgical extraction down to the electrode to extract (that is, the lead cannot be removed by pulling on the lead prior to surgical extraction because the lead could break due to the tensile force, stress, and/or strain on the lead, and/or the lead could damage tissue as it is pulled out); and/or avoiding difficult lead removals or insertions where the recess is so deep that the edge of the jacket next to the electrode gets caught on or damages structures such as fascial planes, blood vessels, nerve fibers, etc. In another embodiment, the electrode may be formed with a bulged or conical or other geometry (e.g., protruding, projecting, raised, mounted such that it extends or sticks out), such that the thickness of the electrode increases (e.g., toward the middle between its proximal and distal ends or across the entire electrode or part of the electrode). This configuration further promotes a more uniform current density distribution, reducing the likelihood of discomfort or tissue irritation while not adding too much thickness to the lead that would create difficulties removing the lead due to snagging on or damaging anatomical structures; and/or require lead introduction into the body through a component (e.g., introducer needle, cannula, tunnel er) of a diameter that is larger or smaller than typical or than desirable e.g., approximately, or equal to or less than, or greater than or equal to 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21. 22, 23, 24, or 25 gauge) that could cause more tissue damage during insertion and/or inhibit delivery of the lead. The location and magnitude of the recess or protrusion or bulge may be selected based on the desired current density profile and anatomical placement. In an embodiment, as shown in FIGs. 24 and 41, for example, one or more electrodes, including stimulating 1130 and/or return electrodes 1140, may extend beyond or protrude from an electrically insulating portion of the lead 1120 or the pulse generator 1110. In an embodiment, electrodes may have a thickness that extends beyond or protrudes from the lead along part of the electrode and be recessed or sunken along other parts of the electrode.

[00238] In an embodiment, the return electrode(s) 1140 may be segmented, see FIG. 48, for example, such that each segment does not fully encircle the lead, connector, lead adapter, lead extension, or other supporting structure. The segmented electrodes 1140 may be oriented to face specific directions, for example, away from the skin surface or toward less sensitive tissue, to further minimize the risk of stimulating non-target fibers, which increases the versatility of the invention over the prior art where the directionality of the current returning to the return electrodes cannot be controlled (because the electrodes fully encircle or wrap around the lead), and thus, can only be placed in certain anatomical locations to avoid discomfort. The system 1000 may selectively activate one or more electrode segments (by themselves or in combination with the can of the pulse generator, surface return electrode in the case of an external pulse generator, and/or fully-encircling return electrodes on other leads or other system components) based on anatomical placement or patient feedback, providing greater control over the stimulation field and enhancing patient comfort. In one embodiment, the segmented electrode is constructed to be flexible or stretchy to enable directional focus of the current returning to the return electrode to avoid unwanted responses while allowing the lead to flex at the segmented electrode without causing gaps between the edge of the electrode and the insulating jacket, which may occur with rigid ring electrodes if segmented because the insulating jacket is more flexible than the ring electrodes. If you have a segmented electrode and one side is a rigid Pt-Ir segment and the other side is a flexible silicone/polyurethane jacket, the jacket side could bend while the segmented electrode side would be forced to bend or create gaps between the electrode and jacket

[00239] In an embodiment, the system 1000 may include leads 1120 with paddleshaped or flat, non-circular profiles, particularly suited for placement near the skin surface or in subcutaneous tissue. These leads may have an insulated portion(s) or side(s) facing or on the side closest to or near tissue that is advantageous to shield from stimulation, such as skin, muscle, nerve and/or nervous tissue or receptors or nerve endings innervating that tissue, skin, muscle, receptors, points, motor point, or end points, and electrodes facing away from the skin, muscle, nerve and/or nervous tissue or receptors or nerve endings innervating that tissue, skin, muscle, receptors, points, motor point, or end points, improving comfort and function by limiting or preventing activation of tissue, nervous tissue, or nerve tissue, or cutaneous nerve fibers, motor nerve fibers, sensory nerve fibers, improving securement, and minimizing the risk of protrusion, migration, or unwanted movement or displacement. In another embodiment, the leads may have an insulated side facing away from the skin or related nerve fibers and electrodes facing the skin or other superficial structures or nerve fibers, which is beneficial in specific anatomical or therapeutic contexts where the current is sufficiently distributed along the electrodes and/or lead to avoid activation of subdermal fibers and or other cutaneous fibers around the skin while also facing away from the nerve or deeper structures to prevent activation of non-target fibers, nerves, nerve endings or terminals, tissues, or anatomical regions (such as motor fibers, visceral sensory fibers, sensitive tissues, or others), while preserving or increasing activation of target fibers within the nerve body in the periphery. This embodiment may also improve securement of the lead by enabling securement along the dermal plane to effectively localize electrical stimulation and avoid deeper or lateral spread of current away from where the lead is placed, thereby avoiding patient discomfort while maximizing therapeutic efficacy. The use of targeted directional stimulation may also reduce power requirements, thereby improving the energy and/or power efficiency of electrical stimulation and/or avoiding unwanted responses or side effects such as tissue heating and/or eddy currents that may occur with wireless power transfer. The flexible paddle design may also allow the lead to be fixed, secured, sutured, sewn, stapled, and/or screwed on to different anatomical locations in the periphery, thereby allowing multiple target locations for a range of patient anatomies and nerve targets to improve patient-specific stimulation while reducing the risks of lead migration, discomfort, tissue damage, unwanted muscle contraction, or other unwanted side effects that may occur with systems in prior art with rigid, semi-rigid, or inflexible leads and/or electrodes placed along the lead.

[00240] Additionally, FIG. 16 illustrates an embodiment of an implantable multicontact lead design comprised of coiled conductors. The stimulating electrodes (right (or distal end of the lead)) and return electrodes (left (or proximal end of the lead)) have been formed by selectively removing the insulation coating of each coiled conductor at the distal and proximal portions of the lead body to expose the conductive wires, such that one or more or all of the electrodes are electrically isolated (e.g., not electrically connected). The electrodes may have a closed coil configuration and the spacing between electrodes has an open coil configuration. Alternatively, the electrodes may be closely wound (e.g., coils may be adjacent or nearly or approximately adjacent) but not fully closed (e.g., they may be fully open or partially open). In an example embodiment, the invention may also enable the electrodes to be electrically connected.

[00241] The present invention solves multiple problems that are present in peripheral nene stimulation (e.g., PNS), including PNS for pain relief, pain reduction, or improvement in quality of life and/or other domains) and are not present or not present to the same degree in other areas or fields or types of stimulation (e.g., the present invention solves problems, balances tradeoffs, and addresses needs that are not present in spinal cord stimulation, deep brain stimulation, central nervous system stimulation, stimulation of other sensory organs or functions, cochlear stimulation, stimulation related to hearing or auditory function, stimulation related to vision, cardiac or heart related stimulation, transcutaneous electrical nerve stimulation (TENS), stimulation devices that do not have an implanted component and/or are only surface stimulation devices that are entirely external, neuromuscular and muscular electrical stimulation (NMES) and other types of stimulation that are not peripheral nerve stimulation or specifically peripheral nerve stimulation for pain relief).

[00242] In an embodiment, the return electrode(s) 1 140 (e.g., anodes, reference electrode, ground electrode, common electrode) may comprise the same or different geometry (ies), shape(s), surface area(s), material(s) (e.g., which may be larger, smaller) (e.g., in comparison to each other (e.g., other return electrode(s) if there is more than one) and/or to the stimulating electrode(s) designed to optimize cunent density such that the cunent density or electric field is small enough to avoid, prevent, or minimize activating non-target fibers or local fibers to avoid or minimize patient discomfort, and avoid, prevent, inhibit, and/or reduce unwanted activation (e.g., direct and/or indirect activation) of non-target or off-target motor nerve fibers, muscle fibers, and/or muscle(s) while still directing or shaping the electric field from the stimulation electrode(s) to maximize activation of target fibers within one or more nerve bodies, trunks, or bundles. In an embodiment, the invention delivers, receives, returns or retrieves current via return electrodes 1140 with a design and/or in a way. method, or approach that desirably avoids activating non-target nerve fibers and/or causing unwanted physiological responses such as pain, muscle contraction, tissue irritation, and/or tissue damage. The invention solves multiple problems of the prior art to achieve this goal while achieving other goals (e.g. simultaneously). For example, present invention may use one or more return electrodes with size, shape, geometry and materials to avoid unwanted side effects (e.g., with a size of the return electrode that is large enough to deliver or receive current or charge with a charge density profile (e.g., both on or in the electrode(s) and/or also in the tissue (e.g., touching, adjacent, near, and/or far from the electrode(s))) but at the same time not so large (e.g., not large enough) to cause patient discomfort due to the anatomical placement of the return electrode, limit the potential location of lead placements due to the rigidity of the return electrode, and/or compromise the mechanical integrity of the return electrode(s) and/or lead(s). For example, FIG. 1 shows a single return electrode 1140 having a larger surface area than the combined total area for the four stimulating electrodes 1130. This design enables, facilitates, and/or ensures that the charge, flow of charge, and/or cunent returning from or produced by the one or more of the at least one or multiple (e.g., of the 1, 2, 3, 4, or more) stimulating electrodes is sufficiently dispersed, distributed, located, routed, forced, and/or directed so as to avoid, reduce or minimize the risk of unwanted side effects at, near, or far the return electrode site. This accomplishment is significant in many ways because failure to avoid these unwanted side effects can prevent the delivery of therapeutic stimulation. The invention enables the delivery of effective therapeutic stimulation because it avoids the production of unwanted effects (e.g., prevents or avoids side effects) that would prevent the delivery of therapeutic stimulation (e.g., therapeutic levels or types of stimulation), and thus the invention creates a therapeutic window that would not otherwise be possible by either raising the threshold for causing unwanted effects and/or ensuring both the delivery' and return of current (e.g., to and from the device through the tissue) avoids unwanted effects, enabling the delivery’ of therapeutic stimulation that yvas not previously possible in the prior art. FIG. 1 also shows the stimulating electrodes 1130 all located in proximity to one another (e.g., next to or adjacent to one another or within 1, 2, 3, 4, 5, 6, 7, 8, 9, and/or 10 mm of each other) on the distal end 1122 of a first lead 1120 yvhile the return electrode 1140 is located on the distal end 1127 of a second lead 1125, the distal end 1127 of the second lead 1125 including the return electrode 1140 which can be placed distant from the stimulating electrodes 1130 on the distal end 1 122 of the first lead 1120 when placed in the body. By locating the return electrode 1140 within non-excitable tissue distant from the target tissue and the stimulating electrodes 1130, the system minimizes the risk of unwanted nerve activation and enhances patient comfort and therapeutic effectiveness. Utilizing distal electrodes on a second lead as the return electrodes allows current to return farther away from the pulse generator than if the pulse generator case and/or return electrodes located on the proximal end of the lead or other system component located close to the pulse generator were used; this arrangement reduces the risk of discomfort or heating that could damage surrounding tissue that could arise if the current density around the case (which is serving as the anode, return electrode, ground, etc.) is concentrated or a high enough amplitude to cause discomfort or lead to activation of non-target fibers. In an embodiment, this separation of the return electrode distal to the pulse generator enables the use of a smaller, more compact pulse generator because the case is not returning current that can activate local nerve fibers that may cause unwanted nerve activation; and/or placement of the pulse generator close to the surface of the skin (e.g., less than 1 cm, 2 cm, 3 cm, or more under the skin) which facilitates fast (less than 5 minutes, 15 minutes. 30 minutes, or more minutes) , reliable (able to align external powering unit over the power-receiving component within a large radius in all directions such as greater than 3 cm, 5 cm, or more; and/or at multiple alignment angles such as up to 15 degree, 30 degrees, 45 degrees, or more. This reliability makes it easy for patients to place the external powering unit in the correct location for charging and/or increasing tolerance for slight movements of the external powering unit over the power-receiving component during power/recharging) and/or efficient wireless power transfer (for powering stimulation and/or recharging an internalized battery), which minimizes the risk of eddy currents, induced currents, or tissue heating around the pulse generator case while also decreasing the time that it takes patients to recharge the device (which may improve patient compliance and improve therapeutic outcomes) and/or enable the external powering unit to be placed in a range of locations to enable easier recharging (which may improve patient compliance, improve therapeutic outcomes, and/or enable the device to be used in a broader range of anatomical areas such as in the periphery where it is difficult for traditional, conventional, or prior art devices to wirelessly power the pulse generator because of the placement of the pulse generator and/or the placement of the external powering unit in locations that make it difficult to achieve efficient w ireless power transfer due to the presence of anatomical barriers or the depth of the pulse generator). In traditional, conventional, or prior art systems, the pulse generator may either be small but connected to a lead with smaller, inflexible electrodes that cannot generate a uniquely advantageous field (e.g., broad, monopolar to promote uniform, wide, and/or extensive activation of target nerve fibers while minimizing activation of non-target fibers that can cause discomfort, pain, abnormal/distracting sensations/bodily responses, and/or motor responses), or it may be larger and serve as the return electrode which may limit the anatomical locations where the pulse generator may be placed due to the risk of patient discomfort and/or of the pulse generator moving, rotating, or flipping within the body (resulting in possibly tangling or winding the lead up and causing lead migration; and/or movement of the power receiving component away from its original location) if it is not placed in the correct location (such as above the hip) due to its large size. The present embodiment, as an example, can be placed in multiple anatomical locations throughout the periphery while also enabling efficient wireless pow er transfer and shaping the stimulation field to enable activation of target-fibers within the nerve trunk to achieve significant reduction in pain, clinically significant pain relief, substantial pain relief, a percentage (such as approximately or greater than or equal to 30%, 40%, 50%, 60%, 70%, 80%, 90%, and/or 100%) pain relief compared to before treatment, majority pain relief, or complete pain relief while avoiding unwanted responses. Additionally, the present embodiment, for example, places the return electrodes distally away from the pulse generator and stimulating electrodes to avoid interference between the external powering unit, transmit coils, and/or receive coils, which may occur in some prior art systems, thereby generating unwanted eddy currents (e.g., induced electrical currents), which in turn can lead to tissue heating, energy loss, disruption in power transmission, and/or otherwise impair device function and/or lead to patient discomfort. The present embodiment, as an example, mitigates these risks and enables more stable and efficient wireless power transfer in multiple anatomical locations throughout the periphery and avoids unintended modulation of wireless power transfer and/or coupling effects between stimulation circuitry and power circuitry⁷ which could disrupt device function and compromise both safety (without proper controls to ensure proper device shut-off when therapy is disrupted) and therapeutic efficacy. In an embodiment, for example, the device may allow' current to flow through other regions of tissue before returning to the return electrode(s), anode(s), and/or ground electrode(s) to prevent edge effects and/or concentration of cunent around sensitive areas such as the pulse generator or superficial nen es, which might otherwise result in disruptions in the device function, uncomfortable paresthesia, and/or discomfort during therapy. As a result, the embodiments described herein, as examples, are more adaptable than systems in prior art or conventional systems for therapeutic use across a broader range of anatomical sites, patient anatomies, patient pain areas, and/or patient pain phenotypes and causes, while also overcoming limitations in size (by using a small pulse generator that can be placed in multiple locations including close to the skin to maximize efficiency of w ireless power transfer), patient needs (by enabling efficient wireless power transfer to enable consistent stimulation, e.g., with a wirelessly powered device, or rapid recharging, e.g., with a rechargeable device), minimize interference (e.g., between the power circuitry and stimulation circuitry ), and flexible placement locations, which uniquely supports reliable, precise and robust peripheral nerve stimulation throughout the periphery.

[00243] In an embodiment, the return electrodes 1140 may comprise a geometry, shape, material, and/or uniquely sized surface and/or surface area (e.g., a large or small surface area) designed to optimize current density, minimize patient discomfort, and reduce unwanted activation of non-target or off-target nerve fibers. In an embodiment, the return electrodes 1140 may comprise a surface area larger than the stimulating electrodes 1130, which reduces the current density which is inversely proportional to the electrode surface area and decreases the likelihood of activating non-target nerve fibers and/or causing unwanted physiological responses such as pain, muscle contraction, tissue irritation, and/or tissue damage. The surface area in the present embodiment minimizes these unwanted side effects but is not large enough to cause patient discomfort due to the anatomical placement of the return electrode, limit the potential location of lead placements due to the rigidity of the return electrode, and/or compromise the mechanical integrity of the return electrode. For example. FIG. 1 shows a single return electrode 1140 having a larger surface area than the combined total area for the four stimulating electrodes 1 130. This design ensures that the current returning from the four stimulating electrodes is sufficiently dispersed, minimizing the risk of unwanted side effects near the return electrode site. FIG. 1 also shows the stimulating electrodes 1130 all located in proximity to one another (e.g., next to or adjacent to one another) on the distal end 1122 of a first lead 1120 while the return electrode 1140 is located on the distal end 1127 of a second lead 1125, the distal end 1127 of the second lead 1125 including the return electrode 1140 which can be placed distant from the stimulating electrodes 1130 on the distal end 1122 of the first lead 1120 when placed in the body. By locating the return electrode 1140 within non-excitable tissue distant from the target tissue and the stimulating electrodes 1130, the system minimizes the risk of unwanted nerve activation and enhances patient comfort and therapeutic effectiveness. Utilizing distal electrodes on a second lead as the return electrodes allows current to return farther away from the pulse generator than if the pulse generator case and/or return electrodes located on the proximal end of the lead or other system component located close to the pulse generator were used; this allows the use of a smaller pulse generator without creating discomfort from the larger current density around the case and/or allows the pulse generator to remain near the surface of the skin for easier and faster recharging or wireless powering and have improved wireless communication with user interfaces.

[00244] For example, a single return electrode 1140 may be designed with a surface area larger than a single stimulating electrode 1130, a combined total plurality of (or one or more of) return electrodes 1140 may be designed with a combined total surface area larger than a combined total plurality (or one or more of) of stimulating electrodes 1130, a single return electrode 1140 may be designed with a surface area larger than a combined total plurality of (or one or more of) stimulating electrodes 1130, a combined total plurality of (or one or more of) return electrodes 1140 may be designed with a combined total surface area larger than a single stimulating electrode 1130, and the like. This design ensures that electrical current disperses across the electrodes surface as the current density is inversely proportional to the surface area of the electrode, reducing the risk of unintended stimulation of nearby non-target tissues.

[00245] In an embodiment, the return electrodes 1140 may be positioned at a distance from the stimulating electrodes 1130. In an embodiment, the return electrodes 1140 may be positioned at a distance from the power-receiving component 1160. In an embodiment, the return electrodes 1140 may be positioned at a distance from both the stimulating electrodes 1130 and the power-receiving component 1160. In each embodiment, the positioning enables and optimizes stimulation efficiency, patient comfort, and/or avoidance of unwanted effects (e.g., unwanted muscle activation, discomfort, and/or pain) by ensuring separation of the electric field (e.g., between the return electrodes 1140 and the power-receiving component 1160 and/or the return electrodes 1140 and the stimulating electrodes 1130) and preventing, avoiding or minimizing unwanted activation of non-target tissues, for example. Positioning the return electrodes 1140 away from the power-receiving component 1160 also avoids, eliminates, or reduces the potential for tissue heating around the power-receiving component which can be caused by generation or induction of eddy currents in conductive materials near the power-receiving component and localized heating during wireless charging or powering, posing safety risks due to heat damage of tissue and limiting the efficiency of power transfer due to the need to restrict the rate at which power is delivered to a safe level and/or require slower charging cycles. As shown in FIG. 1 and as described herein, for example, the return electrodes 1140 may also be positioned on a shorter lead 1125 (compared to the first lead 1120 with the stimulating electrodes 1130) and separate from the first lead 1125 to decrease or minimize electrical impedance to improve the overall efficiency and effectiveness of the stimulation system by reducing the maximum current, voltage, or power that needs to be delivered through the lead to activate target fibers within the nerve body. The return electrodes 1140 may also be positioned on a longer lead to increase the spacing between the return electrodes and the power-receiving component to enable or improve effectiveness of the stimulation system, avoid or reduce the risk of unwanted tissue heating and avoid or reduce the risk of patient discomfort.

[00246] In an example, the present invention uses or enables use of a lead with one or more (e g., at least one) return electrode that is selectively positionable such that it may be positioned in a location that is not on a path or pathway between the stimulating electrodes and the power receive component(s), stimulation generator, pulse generator, lead connection and/or lead exit site or location (e.g., the return electrode(s) are not on a straight line between the distal and proximal ends of the lead), and they are selectively positionable by the user during lead placement , and the lead delivery tools and instruments enable the position of the return electrode(s) to be chosen, tested, positioned, and/or repositioned as needed, and/or the lead(s) enables this ability, features, and characteristics, while maintaining resistance to or avoidance of unwanted migration, fracture, tissue, damage, treatment interruption, therapy interruption, unwanted movement, while enabling desirable flexibility' and ability to move, stretch, and bend in the tissue as the tissue and/or body moves. In an example, the lead may be placed by pushing, pulling, or other forces which may be applied directly or indirectly to the lead, including by the introducer or an aspect of the introducer or introducer tool set. The electrode(s) (e.g., stimulating and/or return electrode(s)), lead(s), introducer, and/or introducer part(s) may be formed into a range of shapes or formations before, during or after deployment of the electrode(s) and/or lead(s) (e.g., by the manufacturer or the user).

[00247] In an embodiment, the system 1000 may comprise one or more additional leads, see FIG. 19, for example, each equipped with one or more electrodes configured to sen e as return electrodes 1140 that are designed to optimize, disperse, and/or spread out the distribution of current to enable comfortable activation of target nerve fibers or tissue while avoiding unwanted responses from activation of non-target fibers. These additional leads may be designed with larger surface areas and/or optimized shapes to facilitate broader current dispersion, thereby minimizing or reducing current density and lowering the risk of activating non-target nerve fibers. The additional leads may also be designed with multiple electrodes with smaller area that can be used to return current independently or in some combination (part or all of the group of electrodes) to disperse the current throughout non-excitable tissue and/or disperse the current in multiple locations to minimize the risk of activation of non- target nerve fibers and/or other unwanted side effects. The additional leads may be placed in non-excitable tissue, such as adipose or connective tissue, or in deeper anatomical locations to avoid cutaneous discomfort and reduce the likelihood of activating non-target nerve fibers while enabling the use of higher stimulation intensities, use of a smaller implantable pulse generator, and/or placement of an implantable pulse generator superficially (near cutaneous fibers). The system may dynamically and/or automatically select which lead(s) and electrode(s) serve as return electrodes, allowing for patient-specific configurations, settingspecific combinations (such as when used in a configuration to generate comfortable sensations like paresthesia and/or in a setting intended to generate comfortable muscle contractions through activation of motor fibers), electrode-specific configurations (such as using a combination of return electrodes when a set of stimulating electrodes are used to deliver stimulation, and a different combination of return electrodes when a different set of stimulating electrodes are used), and/or anatomy-specific configurations (such as custom combinations of return electrodes if the system is used to target specific nerves and/or the pulse generator is located in a specific anatomical location), which will maximize patient comfort and the versatility of the system to work across a broad range of patients.

[00248] In an embodiment, the system 1000 may include a lead connector, adaptor, or extension that incorporates one or more return electrodes 1140, see FIG. 23, for example. These integrated electrodes may be positioned on the connector body, allowing the return path for stimulation current to be established at a location distant from both the stimulating electrodes and the power-receiving component. In an embodiment, the placement of the lead connector or connection component incorporating one or more return electrodes is outside the radius of the external powering unit (e.g., beneath the perimeter of the external powering unit located on or above the skin) to minimize unwanted side effects (as described previously) while being far enough away from the stimulating electrodes to enable them to deliver monopolar or pseudo-monopolar stimulation and avoid unwanted responses around the return electrode. The connector-based return electrodes may be designed with a large surface area and may be recessed or segmented as described above in order to effectively shape the stimulation field around the return electrode to minimize unwanted side effects such as activation of non-target fibers The connector-based return electrode may also feature a larger surface area to minimize current density, multiple return electrodes with smaller surface areas to effectively distribute cunent. and/or a combination of large/small surface areas with the recessed/segmented design. These configurations provide additional flexibility and adaptability for implantation in system design and can further reduce the risk of heating during wireless power transfer, effectively balancing and enabling simultaneously therapeutic efficacy, patient comfort, and the safety of the stimulation system. Lead connectors, adaptors, or extensions with return electrodes may enable a system without (e.g., avoids the need for) proximal electrodes on the stimulating lead and/or an electrically conductive implantable pulse generator case to deliver stimulation through the distal electrodes of the lead similar to monopolar stimulation, without having (e.g., avoiding the need for) to be in a bipolar configuration where the return electrode is close to the stimulating electrode. In an embodiment, the system is powered through electrical (e.g., DC) coupling where electrical current is passed through the skin and collected by a power-receiving component such as a receiver, and the return electrode(s) on the lead connector, adaptor, and/or extension allow the return electrode(s) to be positioned away from the receiver to prevent inadvertent transfer of power to the return electrode(s), which could cause unintended stimulation of non-target fibers, stimulation of target fibers at different intensities and/or parameters as intended, and/or decreased energy and/or power efficiency of stimulation.

[00249] In an embodiment, the system 1000 may further include aspects such as non- uniform electrode spacing 1130, 1140, coiled or ring-shaped electrodes 1130, 1140, segmented or multiple return electrodes 1140, and flexible lead bodies 1120, 1125. These design aspects, individually or in any combination may contribute to mechanical flexibility, improve current dispersion, and allow for versatile implantation options, including both percutaneous and fully implantable configurations. These design aspects also enable flexible use of the system across multiple patients, maximizing therapeutic efficacy for a variety of patient anatomies, pain regions, and/or other patient factors described herein. As described herein, the system 1000 may also utilize lead connectors 1155 (of varying lengths and adapters) to facilitate versatile electrical and mechanical coupling between the leads 1120, 1125 and the pulse generator 1110, through ports 1150. These design features also ensure optimal system performance and patient-specific customization for different anatomies, pain regions, and/or other patient factors described herein.

[00250] In an embodiment, the materials selected for the return electrodes 1140 and leads 1120 may be selected for compatibility with wireless power transfer. The return electrodes may be positioned at a distance from the power-receiving component, with a preferred multiple, distance, margin, and/or safety margin (e.g., approximately or equal to or greater than 1 .2. 3, 4, 5. 6, 7, 8. 9, 10, 11, 12, 13, 14, 15, 16, 17, 18. 19. 20. or 1-2. 1-3, 1-4, 1-5, 1-10, 3-10, 5-10, 1-20, 1-30 or more) to avoid undesirable effects, mitigate heating risks, enhance transmission, receipt, reception, of power and/or communication signals, and/or enable use of a desirable small device (e.g., enable use or placement of the internal and/or external device(s), component(s), and/or system in anatomical locations that require a small or thin size, such as in or near an extremity, leg, arm, or part of the torso or other body part). Non-magnetic (e.g., conductive polymers or metals), non-inductive, and/or patterned electrically conductive materials may be used to minimize the formation of eddy currents and reduce localized heating during wireless charging or powering, allowing the distance between the power-receiving component(s) and the leads and/or electrodes to be reduced while still maintain safe levels of tissue heating, speed of recharging an implantable battery in the pulse generator, and/or increase the amount of the battery capacity recharged in a given time interval. In some embodiments, the power-receiving component and return electrode are located on separate structures, allowing for optimal placement of each component to maximize safety and efficiency, see FIG. 25, for example. [00251] In an embodiment, the system 1000 is configured to allow user-defined or automated programming of the proportion of current returned through each of multiple return electrodes 1140, including those on the proximal portions of leads, distal electrodes on other leads, distal electrodes on the same lead delivering stimulation (when not being used to deliver stimulating current), the case of the pulse generator, a surface return electrode (in the case of an external pulse generator), and/or return electrodes on any other components of the system. The circuitry within the pulse generator may dynamically or automatically adjust the amount or proportion of current at each return electrode based on pre-set parameters, realtime measurements, and/or patient feedback, optimizing comfort and therapeutic efficacy across a range of patient anatomies, pain areas, and/or other patient factors described herein; and these features overcome challenges in the prior art where patients may experience discomfort due to the inability to select return electrodes and/or they must wait until they are seen by someone who can reprogram their system, such as a caregiver that understands how to operate the system, a clinician, and/or technician. The system may also automatically redistribute current if discomfort or unwanted effects are detected at a particular return electrode, thereby enhancing safety and versatility.

[00252] Generally, the peripheral nerve stimulation system 1000 may further comprise one or more anchors (such as tines, anchoring tines, securement points, barbs, lead body protrusions, and/or fixation elements) on one or both leads 1120, 1125 to securely maintain the lead position within the body. Anchors 170 may be used with either lead 1120, 1125 or any other lead or component as desired within system 1000 to prevent lead migration, enabling precise lead and electrode placement with minimal loss of efficacy while the system is implanted to ensure consistent therapeutic performance. In an embodiment, anchors 170 may be used with implantable leads 1120, securing them in place and preventing undesired movement of the lead within the body. The leads 1120 may also anchor themselves through various means including but not limited to tissue ingrowth around parts or sections or the entirety⁷ of the lead to minimize lead migration and maximize therapeutic efficacy. One or more section or parts of the lead may also form and/or be formed into an anchor or anchor shape such as a loop(s). hook(s). barb(s), tine(s), expandable element(s), and/or other elements to minimize lead migration. These anchor(s), anchor feature(s), and/or lead design(s) in the form of anchor(s) enable both ease of initial placement and ease of removal for the lead if required, enabling both reliable function and safe and effective placement and removal of the lead with or without the anchor(s), anchor feature(s). and/or lead design (s) in the form of anchor(s) during use. In an embodiment, the anchors 170 may be located at the distal end, proximal end, interspersed between electrode contacts, or at both ends of the electrode array. For example, and as shown in FIG. 2, the anchors 170 may be located at the distal end 1122, 1127 of the leads 1 120, 1125 proximal the electrodes 1130, 1140. In certain configurations, anchors 170 are positioned proximal to each electrode, between contacts, or at strategic locations along the lead to optimize fixation relative to the target nen e and surrounding anatomical structures. The placement of anchors 170 may be selected based on the intended clinical application, the type of tissue in which the lead is to be implanted (e.g., muscle, bone, fascia, adipose tissue, or connective tissue), and the need to maintain the position of stimulating electrodes 1130 and/or return electrodes 1140. The anchors and/or anchor components or shapes may be pre-formed and/or formed prior to placement of the lead(s) and/or the anchors and/or anchor components or shapes may be formed during and/or after placement of the lead(s).

[00253] As described herein, one or more of the leads may be intended to be placed in non-excitable tissue (e g., adipose tissue, connective tissue, body parts that lack or have fewer pain/sensory fibers such as the back of elbow, etc.). For example, this lead 1125 may include the return electrodes 1140 and may be placed in non-excitable tissue so as to avoid and/or minimize undesired effects. In an embodiment, the lead 1125 may have anchor(s), tine(s), an anchoring system 170, and/or be shaped into a hook, anchor, tine or other feature and/or be self-anchoring in the tissue due to tissue ingrowth around the lead 1125, with the lead 1125 secured in place (e.g., muscle, bone, fascia) even though the electrodes, (e.g., return electrodes 1140), may reside in non-excitable tissue and/or other tissue to which it is challenging to secure a lead (e.g., fat/adipose tissue). Positioning the return electrode 1140 within non-excitable tissue and/or other tissue to which it is challenging to secure a lead minimizes risk of undesirable side effects such as activation of non-target fibers that can cause discomfort, pain, unwanted sensations, undesired sensory perceptions, and/or unwanted bodily functions. In an embodiment, the lead 1125 may have tines or an anchoring system 170 where the tines or anchoring system 170 can be adjusted along the length of the lead 1125. It is noted that these types of tines or anchoring system 170 may also be used with lead(s) 1120 having stimulating electrode(s) 1130. It is further noted that embodiments of lead 1125 and return electrode(s) 1140 may not be intended to be placed in non-excitable tissue, but may be positioned on the surface of the skin, or the like, as described herein. It is further noted that the embodiments of lead 1125 and return electrode(s) 1140 may be selfanchoring in the tissue due to tissue ingrowth around the lead 1125 and/or the return electrode(s) 1140 and/or the lead(s) 1125 and/or return electrode(s) 1140 may be formed into one or more hooks, loops, tines, or other anchor-like shapes to minimize lead migration while maximizing therapeutic efficacy.

[00254] In an embodiment, the shape, number, and design of the anchors 170 may be varied based on a particular purpose or desired outcome, e.g., to enhance securement, minimize tissue trauma, and facilitate both implantation and explantation and/or removal of the associated lead. In an embodiment, the anchors 170 may be cylindrical, trapezoidal, rectangular with curved edges, flat, collapsible, or multi-layered. In an embodiment, the anchors 170 may comprise multi-layer cylindrical or intermeshed/cross-hatched outer layers, providing a self-anchoring mechanism that increases mechanical securement within tissue. The number of anchors 170 may range from a single anchor to multiple anchors distributed along the lead, and in embodiments, the anchoring system may include adjustable tines or anchoring elements that can be repositioned along the length of the lead to accommodate different anatomical sites or tissue types. For example, the tines or anchoring system may be adjustable to allow securement to tissue capable of maintaining lead position, even when the electrodes reside in tissue that is otherwise challenging for fixation, such as fluid-filled spaces, fat. or adipose tissue.

[00255] In an embodiment, the anchors 170 may be collapsible or invertible, configured to fold or wrap around the lead body during insertion and/or removal and to deploy or expand upon placement within the tissue. Such anchors may be designed to return to a tangential or expanded position, similar to a "blooming flower," when released from a delivery sheath or introducer. This configuration can provide secure fixation while permitting straightforward removal by retracting or collapsing the anchors during explantation, therefore improving patient safety and the ability of the device to deliver consistent stimulation while implanted. In an embodiment, the anchors 170 may be slightly rotated, offset, or asynchronously aligned along the lead to minimize unwanted migration in multiple axes or directions (such as lateral, medial, right, left, superior, inferior, rostral, caudal, deep, superficial, distal, proximal, x, y, and z). The anchoring mechanisms described herein collectively serve to maintain the stability of the lead within the body, reduce the risk of migration, and allow for atraumatic removal, thereby minimizing tissue damage and patient discomfort.

[00256] The system 1000 may be implemented in a variety of embodiments, including but not limited to: leads with coiled conductors or multiple filars for enhanced flexibility : leads with conductive jackets to increase return electrode surface area or to have multiple smaller return electrodes along the lead to minimize side effects such as unwanted stimulation of non-target fibers or to distribute the electrical current density along the surface area of the return electrode to enable placement of the return electrode in different anatomical regions and/or to minimize discomfort; and systems with multiple leads or connectors providing distributed return paths. These configurations may provide clinical advantages such as improved patient comfort, reduced risk of tissue damage, enhanced selectivity⁷ for large- diameter nerve fibers, and greater versatility in anatomical placement. The ability to tailor electrode size, shape, spacing, and placement to individual patient needs further distinguishes the system from conventional designs

[00257] As described herein, the disclosed peripheral nerve stimulation (PNS) system 1000 may improve patient comfort, selectivity of target fibers, minimize activation of nontarget fibers and/or versatility in neuromodulation therapies. In an embodiment, the system 1000 may comprise a pulse generator (implantable, see FIG. 2, for example, or external, see FIG. 5, for example), and one or more leads equipped with multiple electrodes, including stimulating and/or return electrodes. The configuration, placement, relative size, and design of return electrodes as described herein may help to address limitations and adverse effects in conventional systems. For example, the peripheral nerve stimulation system 1000 may comprise with leads and distant, large-surface-area, and/or flexible return electrodes, supporting both monopolar and multipolar stimulation, and designed for improved comfort, safety, and adaptability in various anatomical locations.

[00258] In an embodiment, the system 1000 may comprise distant and flexible return electrodes to strategically position the electrodes across diverse anatomical locations, such as the limbs or torso, to enhance effectiveness while minimizing unwanted side effects. Unlike previous systems in prior art that often rely on closely positioned electrodes with rigid designs that do not enable flexible stimulation configurations, such as monopolar or pseudo monopolar stimulation, this system may comprise configurations that allow return electrodes to be positioned far from stimulating electrodes and/or power-receiving components, effectively dispersing current around the return electrodes to minimize side effects such as stimulation of non-target fibers, muscle contractions, or other unwanted stimulation described herein while maximizing ease of placement and the ability to place the system in diverse anatomical locations. This example configuration also ensures comfortable and uniform nen e activation, particularly beneficial for stimulating larger nerve trunks where broad activation throughout the nerve is needed to achieve effective pain relief, while many systems in prior art have closely spaced electrodes with rigid designs that do not enable monopolar or pseudo-monopolar stimulation, cannot generate uniform stimulation fields to activate a large nene trunk and/or are not designed for use in the periphery'. This configuration ensures that stimulation is effective and comfortable by distributing current evenly and creating a broad, uniform stimulation field, enabling selective activation of large-diameter nerve fibers while minimizing the risk of discomfort, pain, or unwanted muscle contractions caused by stimulation of non-target fibers.

[00259] In an embodiment, the system 1000 may comprise an introducer (see FIG. 29 for an example), with return electrode(s) and or stimulating electrode(s) placed along the introducer as conductive parts of the insulated introducer and/or with slats or spacing or a gap along the introducer to shape the field from the stimulation lead and shape the path of current from the stimulating electrode(s) to the return electrode(s) such that placement of the lead is made easier during a procedure to implant the lead and/or place the lead percutaneously. While a flexible, non-rigid lead is beneficial for contouring to the body, the introducer may make it easier to place the lead deeper in the body and/or precisely target hard to reach locations within the body. Placing stimulating electrode(s) and/or return electrode(s) along the introducer and/or placing slats, windows, openings, and/or other spacing along the introducer to expose the return electrode(s) on the lead make it easier to test out multiple locations while placing the lead and enable physicians to target an ideal location for a specific nerve target that maximizes activation of target fibers within the nerve while minimizing discomfort for the patient and enabling the lead to be placed in a variety of locations throughout the periphery that are difficult to reach for conventional systems that have rigid, non-flexible lead(s), small electrode(s) and/or rigid electrode(s) that are designed for placement in a specific location (rather than multiple locations throughout the periphery as in the present invention) or are designed to target sensory' organs and may not be able to activate a large peripheral nerve. In a non-limiting example, the introducer allows stimulation to be tested dunng the lead implant procedure while the lead is still located within or inside the lead introducer using a combination of stimulating electrode(s) and return electrode(s) that would not be possible with a solid introducer that did not include slats or electrodes along the length of the introducer because the introducer may cover up one or more electrodes and block current from transferring to/from the electrode and tissue. In a non-limiting example, the introducer allows stimulation using proximal electrodes, including proximal stimulating electrodes and/or proximal return electrodes, without having to deploy the lead and exposing anchor(s), tine(s), and/or anchoring component(s) into the tissue, which enables proximal electrodes to be tested in multiple locations without having to reinsert the lead into the introducer needle, which may not be possible after the anchor(s) or tine(s) have deployed in the tissue.

[00260] In an embodiment, the system 1000 may comprise electrodes having variable relative placement to achieve precise, effective, and/or efficient activation of target fibers within the nen e. In an embodiment, stimulating electrodes at the distal end of the leads are positioned closely together, enabling overlapping electrical fields and providing consistent activation of target fibers within the nerve. In an embodiment, proximal return electrode(s) may be spaced far enough from the stimulating electrode(s) that stimulation is monopolar, effectively monopolar, or pseudo-monopolar such that the placement of the return electrode(s) does not affect or has a minimal effect on activation of target nerve fibers, nontarget nerve fibers, and/or off-target nerve fibers within the nerve body or within the tissue or body; and/or the effect of stimulation (such as physiologically, electrically, on energy consumption, and/or safety) is indistinguishable using the proximal return electrode(s) compared to using a return electrode located much farther away from the stimulating electrode, such as the can of the pulse generator or a theoretical return electrode located an infinite distance away. In this embodiment, the variable, versatile, or user-controllable placement of the stimulating electrodes and the return electrodes (e.g., independent of the location of other aspects or components of the device or system, such as independent of the location of the stimulating electrode(s) or distal end of the lead and also and/or independent of the location of the proximal end of the lead, stimulator, lead exit site or external stimulator (e.g., in the example of a percutaneous system), and/or IPG. receiver, coil, or power receive unit or component (e.g., in the example of an internalized, implantable, fully implantable system, and/or partially or mostly implanted or implantable system) enables efficient and effective activation of target fibers in the nen e and enables targeting of a wide range of different target nerves in different locations, or target nerves with different sizes, shapes, or different distnbution patterns of fascicles within the nerve (e.g., producing desirable and/or therapeutic effects, which may include pain relief, comfortable muscle tension, direct or indirect activation of afferent fibers to cause desirable effects in the nervous system or part of the nervous system causing pain relief which may cause other desirable effects) while also desirably avoiding unwanted effects and/or unwanted activation of non-target fibers or nerves and/or off-target fibers or nerves (e.g., avoiding discomfort, pain, and/or muscle activation, contraction, tension in examples where it is desirable to avoid one or more of these undesirable effects). The spacing of return electrode(s) within and/or along the lead also enables monopolar stimulation, effective monopolar stimulation, or pseudo-monopolar stimulation with efficient activation of the target nerves within the axon while also enabling the lead to be placed in different regions of the body such as smaller anatomical regions where stimulation systems in prior art, for example, have leads that are too rigid to contort or conform to or move with or function with (or avoid inhibit or impairing) the natural movement of the body while delivering effective stimulation of target fibers within the peripheral nerve or where the systems are designed for stimulation of sensory organs and are too small to deliver effective stimulation that relieves pain by stimulating target fibers within a peripheral nerve. The desirable flexible arrangement of electrodes of the present invention allows the system to adapt seamlessly to anatomical regions in the periphery that are challenging and/or not possible for or with other systems in prior art due to their rigidity or design features that are designed specifically for other locations, such as near sensory organs; therefore, the present system offers a versatile and effective solution for effective pain relief throughout the periphery.

[00261] In an embodiment, the system 1000 may comprise multiple and segmented return electrodes, designed to significantly enhance effective pain relief while also improving patient comfort during stimulation and minimizing unwanted side effects. In an embodiment, the system 1000 may comprise multiple return electrodes, with each return electrode strategically oriented to direct electrical current, charge, current density' or shape the electrical stimulation field from the stimulating electrodes to the return electrodes in such a way that avoids or minimizes unwanted side effects of stimulation while maximizing the efficacy of the stimulating electrodes to activate target fibers within the nerve. In an embodiment, multiple return electrodes may be used to increase the total surface area and/or increase the spacing between the stimulating electrodes and the return electrodes to offer personalized stimulation fields for a specific patient anatomy, nerve target, or other patient/nerve factors described herein. The increased number of return electrodes, for example with at least two return electrodes on a lead or with at least one return electrode on multiple leads, increases the overall surface area of the return electrodes, reducing concentrated areas of high current density that can cause discomfort of unintended effects. In an embodiment, the strategic segmentation and orientation of the return electrodes enables more fine-grained control of stimulation intensity and direction, which while systems in prior art may be capable of control of stimulation intensity and direction, it is at a smaller scale, is not designed for placement throughout the periphery, and/or uses less flexible traditional electrode designs that are not capable of flexible stimulation configurations such as monopolar or pseudomonopolar stimulation with leads placed throughout the periphery across a range of patient anatomies to optimize patient-specific therapeutic outcomes and comfort. [00262] In an embodiment, the system 1000 may employ highly flexible lead and electrode designs, essential for maintaining patient comfort and device integrity across a variety of anatomical locations. For example, the leads may incorporate coiled or ring-shaped electrodes and/or utilize multiple fine strands or filars to enhance mechanical flexibility and durability while also enabling a range of stimulation configurations and placement of the leads in a variety of anatomical locations. This highly flexible lead design, as an example, also ensures that the lead comfortably conforms to anatomical movements and natural body contours and variability across a range of patient anatomies and/or nen e targets in the periphery', thereby reducing the risk of lead migration, device failure, or tissue irritation commonly observed with rigid leads or semi-rigid leads used in prior art. The highly flexible lead design, as an example, also allows effective use for both percutaneous and fully implanted configurations (with or without wireless power transfer), enabling reliable therapeutic performance for effective pain relief even in challenging anatomical areas, such as in the upper extremity areas of the periphery, around the shoulder, or other highly mobile areas where rigid leads and/or rigid electrode designs may experience mechanical failure and/or cause patient discomfort.

[00263] In an embodiment, the system 1000 may be used for varying applications to provide improvements in patient comfort and outcomes. This PNS system is intended for therapeutic, curative, or enhancing effects, such as pain relief or functional improvement, by targeting peripheral nen e fibers. It is distinct from systems designed for hearing or vision restoration. The innovations described enable more comfortable, effective, and versatile neuromodulation, overcoming common challenges in prior art related to unwanted stimulation, device rigidity, and limitations in electrode placement and power transfer. The present invention is designed and sized for use in the periphery’, allowing peripheral nerve stimulation in any part of the body such as the head, neck, shoulder, torso, back, abdomen, groin, pelvic region, upper extremity, lower extremity, hands, feet, and/or knee, compared to systems designed for specific areas of the body and/or in small spaces, for example, near sensory organs, where the systems are too small to comfortably activate sufficient numbers of nerve fibers for pain relief, and with leads that would be too rigid if scaled up to a large enough size to activate peripheral nerves. In an embodiment, the electrodes on the leads are large enough and/or spaced close enough such that broad activation of nerve fibers can be achieved within a nerve trunk through activation of one or more electrodes, avoiding challenges in the prior art with systems designed for sensory restoration that use small electrodes and intentionally space electrodes along the lead or electrode array far apart to create small areas of activation to avoid overlap of stimulation fields and thus more distinct sensations. Other systems in the prior art designed for specific areas of the body are not versatile enough to be used outside of their intended areas of the body, for example, some systems in the prior art may be designed for placement within a bony structure such as the sacrum, which provides mechanical protection, or non-mobile areas of the body such as the cochlea; and thus, the system may not be robust enough to withstand conditions outside of their intended area where it may be subject to greater compression, torsion, flexion, tensile, and other types of forces.

[00264] In an embodiment and as described herein, the disclosed nerve stimulation system 1000 is configured to and able to deliver a broader spectrum of stimulation than conventional systems, which are typically limited to highly targeted or focal stimulation fields. By employing one or more stimulating electrodes 1130 positioned in close proximity to the target nerve fibers and one or more return electrodes 1140 that are distant and of larger surface area, for example, the system 1000 may be capable of generating a more expansive and uniform electric field. This broad-field configuration can enable the selective activation of a greater proportion of large-diameter nerve fibers within a peripheral nerve trunk, thereby achieving more comprehensive therapeutic effects, such as pain relief or functional improvement, across a wider anatomical region. In contrast, conventional systems with closely spaced or small return electrodes often produce undesirably highly localized fields, resulting in incomplete nerve activation and gaps in therapeutic coverage.

[00265] In an embodiment and as described herein, the system 1000 may comprise non-uniform electrode spacing, e.g., where stimulating electrodes 1130 are placed close together and return electrodes 1140 are positioned at a greater distance, which may increase the range of the stimulation field and enable sufficient activation of target nerve fibers. This arrangement and variations thereof, can be used to manipulate the range of each stimulation field per each stimulating electrode 1 130 and the effects of the return electrodes 1140. This arrangement, for example, may reduce the overlap of stimulation fields between the stimulating 1130 and return 1140 electrodes, creating a more monopolar field that extends across a larger volume of tissue. As described herein, the spacing between the most distal stimulating electrodes 1130 may be small to reduce the gap in the stimulation fields generated by each electrode individually, while the spacing between the proximal return electrode(s) 1140 and the distal stimulating electrodes 1130 may be intentionally larger to reduce field overlap and create a broad, uniform field. The proximal return electrodes 1140 may also be larger in size than the distal stimulating electrodes 1130, which can reduce current density and minimize the risk of activating non-target nerve fibers that could cause discomfort, pain, or unwanted motor responses. Additionally, the use of multiple or segmented return electrodes 1140 increases the total surface area and perimeter, further dispersing current and reducing edge effects. The ability to place return electrodes 1140 in non-excitable or less sensitive tissue, or even on separate leads 1125 or connectors 1155, allows for further customization of the stimulation field to match patient-specific anatomical and therapeutic needs, a flexibility not available in conventional, more targeted systems.

[00266] In an embodiment and as described herein, the system 1000 may incorporate one or more aspects to facilitate and optimize this broad-field stimulation based on the practical application. For example, the use of flexible, coiled, or ring-shaped electrodes, e.g., formed by winding conductors around the lead 1120 or using a series of ring electrodes, may allow for a large total surface area for the return electrodes 1140 while maintaining mechanical flexibility. This design may overcome the rigidity and risk of device migration or breakage that are susceptible to conventional systems that use single, rigid metal rings as return electrodes. The system also supports the use of multiple leads 1120, 1125, with one or more leads dedicated to return electrodes 1 140 that can be placed in desired anatomical locations, including deeper tissue or non-excitable regions, to further reduce the likelihood of discomfort or unwanted effects. The circuitry within the system 1000 may allow for dynamic selection and programming of which electrodes serve as stimulating or return electrodes, including the ability to adjust the proportion of current returned through each electrode, either manually or automatically, to optimize comfort and efficacy. This level of control and adaptability is not present in conventional systems, for example, which are often limited by fixed electrode configurations and uniform current distribution.

[00267] In an embodiment and as described herein, the broader stimulation field provided by the system 1000 can offers clinical advantages. By ensuring that a majority of the target nerve fibers within a peripheral nerve are activated before discomfort or unwanted effects arise, the system 1000 can deliver more effective and comfortable therapy. This is particularly beneficial in cases, for example, where comprehensive nerve activation is required for desired therapeutic outcomes, such as in the management of chronic pain or restoration of function. The system 1000 may avoid one or more (or all) limitations such as: incomplete coverage, higher risk of lead migration affecting efficacy, and increased likelihood of patient discomfort.

[00268] The breadth and uniformity of the stimulation field generated by the disclosed peripheral nerve stimulation system are visually represented in several figures, including FIGs. 30 and 37-46. These figures provide detailed illustrations of how the system’s electrode configuration — specifically the arrangement of stimulating electrodes 1130 and return electrodes 1140 on lead 1120 — creates a broad and controlled electric field within the targeted tissue. For example, FIG. 30 depicts the spatial relationship between distal stimulating electrodes 1130 and proximal return electrodes 1140, highlighting how the increased distance and larger surface area of the return electrodes 1140 contribute to a more monopolar and expansive field. This configuration ensures that the electric field encompasses a greater volume of the nen e trunk, reducing gaps in activation and supporting the selective stimulation of large-diameter nene fibers.

[00269] FIGs. 37 through 46 further illustrate the technical aspects of field shaping and current distribution. These figures show various electrode geometries, such as coiled, ringshaped, or segmented return electrodes 1140, and demonstrate how these designs influence the dispersion of current and the uniformity of the stimulation field. For instance, FIGs. 38 and 39 compare the current density' profiles along electrodes of different lengths and configurations, emphasizing the reduction in peak current density and edge effects achieved by using larger or multiple return electrodes 1140. FIGs. 40 and 41 illustrate the impact of recessed or bulged electrode designs on current density uniformity', showing how these features help to minimize unwanted activation of non-target fibers. FIGs. 42 and 43 provide additional detail on how electrode radius and shape affect the maximum and minimum current densities, further supporting the system’s ability to deliver comfortable and effective stimulation. FIGs. 44-46 demonstrate the programmability and dynamic selection of return electrodes 1140, including the use of segmented or directionally oriented electrodes to tailor the field to specific anatomical requirements. Collectively, these figures underscore the system’s innovative approach to generating a broad, uniform, and customizable stimulation field, setting it apart from conventional, more focal systems.

[00270] In an embodiment, the peripheral nerve stimulation system is configured to provide significant flexibility in the initial placement of its components, particularly through the arrangement of stimulating electrodes 1130 and return electrodes 1140, as well as the construction of the lead 1120, 1125. The system 1000 comprises one or more stimulating electrodes 1130 positioned at the distal end 1 122 of the lead 1 120, which are intended to be placed at, near, or adjacent to the targeted nen e or area of stimulation. This configuration allows clinicians to precisely target specific nen e fibers or anatomical regions, thereby maximizing therapeutic efficacy. In an embodiment, the return electrodes 1140 are positioned distant from the stimulating electrodes 1 130 — often on the proximal end of the same lead 1120 or on a separate lead 1125. This separation enables the creation of a broad, monopolar stimulation field, facilitating selective activation of large-diameter nerve fibers while providing clinicians with greater latitude in selecting anatomical sites for both stimulation and current return, thus accommodating patient-specific anatomy and clinical needs.

[00271] In an embodiment and as described herein, one or both the leads 1120, 1125 are mechanically flexible. In an embodiment, one or both the leads 1120, 1125 comprise coiled or patterned conductors. In an embodiment, one or both the leads 1120, 1125 comprise segmented or ring-shaped electrodes 1 130, 1140. In an embodiment, these described aspects, alone or in any combination, may allow one or both the leads 1120, 1125 to conform to the natural curves and physiology of a particular user and position of the target area of stimulation relative the user's specific physiology, like muscles, bones, depth of the nerve to be stimulated, and the like. The flexibility of the leads 1120, 1125, for example, can allow the physician to navigate around sensitive anatomical structures, avoid areas of high tissue density, and secure the leads 1120, 1125 in desired positions without causing trauma, discomfort, or high risk of being dislodged. Additionally, the physical separation of stimulating electrodes 1130 and return electrodes 1140 onto different leads 1120, 1125 or on the same lead 1120 at an extended distance, can facilitate greater flexibility of placement of the return electrodes 1140 into non-excitable tissues or areas while still allowing desired placement of the stimulating electrodes 1130 near the target nerve and in the stimulating tissue.

[00272] In an embodiment, these described aspects, alone or in any combination, may allow one or both the leads 1120, 1125 to conform and react with the movements of the user’s body, both during implantation of the lead(s) 1120, 1125 as well as over time and during stimulation of the system 1000. In an embodiment, the use of multiple or segmented return electrodes 1140 can be manipulated, for example, to increase the total surface area and perimeter available for current return, which may not only reduce current density and the risk of unwanted stimulation but also can enhance the ability of the leads 1120, 1125 to flex and adapt to the movements of the body.

[00273] In an embodiment and as described herein, the system 1000 further comprises anchoring mechanisms 1170, such as tines or adjustable anchors, positioned along the length of the lead 1120, 1125. These anchors 1170 may be located at the distal end 1122, proximal end, or interspersed between electrode contacts to secure the lead within various tissue types, including muscle, fascia, or non-excitable tissues such as adipose tissue. The anchoring system 1170 is designed to prevent migration or dislodgement of the lead during and after implantation, even as the patient moves or engages in daily activities. In an embodiment, collapsible or invertible anchors 1170 can be deployed during placement and retracted during removal, minimizing tissue trauma and facilitating both implantation and explantation procedures.

[00274] In an embodiment and as described herein, the combination of flexible lead construction, versatile electrode placement, and secure anchoring mechanisms ensures that the system remains comfortable and effective after implantation. The lead’s ability' to bend and flex with the body’s natural movements avoids and/or reduces the risk of mechanical irritation, device migration, or patient discomfort, e.g., issues commonly associated with more rigid or less adaptable systems. Furthermore, the system’s design allows for the return electrodes 1140 to be placed in less sensitive or non-excitable tissues, further minimizing the risk of discomfort or unwanted sensations. This adaptability not only can improve patient outcomes and satisfaction but also expands the range of anatomical sites where the system 1000 can be effectively deployed, making it suitable for a wide variety of clinical scenarios and patient anatomies.

[00275] In an embodiment, the flexibility in placement and configuration of stimulating electrodes 1130 and return electrodes 1140 is further exemplified by the system diagrams and illustrations provided in FIGs. 1-15. For example, FIG. 1 depicts a system in which multiple stimulating electrodes 1130 are clustered at the distal end 1122 of lead 1120, while a single, large-surface-area return electrode 1140 is positioned on the distal end 1127 of a separate lead 1125, allowing for distant placement in non-excitable tissue. FIG. 2 demonstrates an alternative configuration where both stimulating electrodes 1130 and return electrodes 1140 are located on the same lead 1120, with the return electrodes 1140 occupying the proximal half of the lead, thus enabling a broad range of placement options along the lead’s length. FIG. 3 and FIG. 4 illustrate the use of separate leads specifically designed for return electrode 1140 placement near the skin or in other remote anatomical locations, further enhancing the system’s adaptability to patient-specific needs.

[00276] Additional figures, such as FIGs. 5-7, show configurations where the return electrode 1140 is positioned closer to the implantable pulse generator (IPG) 1110 or the power receive coil 1160, but still distant from the stimulating electrodes 1 130, thereby supporting both monopolar and multipolar stimulation paradigms. FIGs. 8-10 highlight the use of flexible lead connectors 1155 and extensions, which facilitate the routing of leads 1120, 1125 to optimal anatomical sites while minimizing impedance and mechanical strain. FIGs. 11-13 present embodiments with short, separate leads for return electrodes 1140, designed to minimize impedance and allow for secure placement in non-excitable tissue, while also illustrating the use of anchors 1170 for enhanced fixation.

[00277] Furthermore, FIGs. 14 and 15 demonstrate the system’s ability to target different anatomical regions, such as the sciatic nerve, by allowing the stimulating electrodes 1130 to be placed at the nerve target and the return electrodes 1140 to be positioned in non- excitable tissue or other locations that avoid sensitive structures. Collectively, these figures underscore the system’s modularity and the wide range of possible configurations, which enable clinicians to tailor the placement of both stimulating and return electrodes to the unique anatomical and therapeutic requirements of each patient. The illustrated flexibility in electrode and lead placement, combined with features such as segmented electrodes, coiled or ring-shaped designs, and versatile anchoring mechanisms, ensures that the system can be adapted for optimal performance and patient comfort across a broad spectrum of clinical scenarios.

[00278] Provided are sy stems and methods for a multi-contact lead for electrical stimulation of the nervous system and, in an example, provided are systems and methods for a lead with multiple electrode contacts for providing electrical stimulation to tissue to relieve neuropathic pain. The disclosed systems and methods may be used to deliver neurostimulation using one or more multi-contact leads and may optimize the region of therapeutic benefit, patient experience, and/or simplify the procedure for placing the electrode.

[00279] Conventional neurostimulation systems may rely on patient feedback to guide the placement or implant of a lead used to delivered electrical stimulation to the nervous system. For example, stimulation may generate a “buzzing” or “tingling” sensations experienced by the patient called paresthesia, and stimulation parameters and/or the location of stimulation and return electrodes relative to the nen e target may be adjusted so that paresthesia overlaps with the region where a patient experiences pain to generate pain relief. In an embodiment, sensations generated by stimulation may also result as comfortable tension of muscles as a result of motor nerve stimulation or non-paresthesia stimulation. However, this process to achieve the desired response from stimulation can involve significant trial and error for the patient, physician and other personnel involved in the implant procedure, slowing down the procedure and increasing the discomfort for the subject. Additionally, the sensations generated by stimulation at the stimulating and return electrode can be highly sensitive to and/or dependent on the size, configuration, and location of the stimulating and return electrodes, as well as the orientation and distance of these electrodes from the target and off- target neural structures. [00280] In an embodiment, the electrode contacts may be configured to generate a broad, monopolar field such that the field from each contact, which can be used individually or combined to optimize activation of a nen e. In another embodiment, an electric field approaching the size and therapeutic effects of a monopolar stimulation configuration may be created with the use of multiple electrode contacts to generate a similar (i.e., monopolar-like) electric field. Each electrode contact, in an example, may be used to generate the same broad, monopolar fields, thus minimizing the need to adjust the lead location or stimulation parameters, and therefore speeding up the stimulation procedure. In an embodiment, the stimulating electrode may remain the same while the return electrode configuration is adjusted to maintain the desired stimulation response. The described systems and methods may provide improved abilities to conventional methods to eliminate the trial and error of the placement of conventional methods thereby minimizing the need for adjustments of lead location or stimulation parameters, resulting in minimizing discomfort of the patient, thus speeding up the procedure and improving the efficacy of the procedure.

[00281] In an embodiment, the device may be used to activate multiple nerves simultaneously through one or multiple contacts. There are many different anatomical regions where activation of multiple nerves could provide additional therapeutic benefits including, but not limited to: simultaneous activation of the axillary nerve and the suprascapular nerve in the quadrangular space, simultaneous activation of the medial branch of the dorsal ramus at multiple levels along the spine, simultaneous activation of the greater occipital nerve, lesser occipital nerve, and/or third occipital nerve in the neck, simultaneous activation of the sciatic nerve and posterior femoral cutaneous nerve in the subgluteal area, activation of the illiohypogastric, ilioinguinal nerve, and/or genitofemoral nerve in the genital area, activation of the tibial nerve, saphenous nerve, and/or common peroneal nerve in the lower leg, activation of the ulnar nerve, medial nerve, and/or radial nerve in the arm, and many other targets. Each of these targets may improve pain relief by stimulating multiple dermatome areas or neural pathways and activating sensory' fibers in multiple nerves thus improving pain relief

[00282] In an embodiment, the device may be used to activate an individual nerve at multiple points or orientations, for example by wrapping around the nerve to generate stimulation fields on multiple sides of the nerve. In an embodiment, the combination of electrical fields delivered either synchronously or asynchronously from multiple stimulation contacts may lower the threshold for target nerve fibers. [00283] In an embodiment, the device may be used to preferentially activate target fibers compared to nontarget (or non-target) fibers using multiple stimulation leads placed at different distances away from the nerve or at different orientations with respect to the nerve. For example, one or more leads may be placed perpendicular to the nerve with one or more other leads placed parallel to the nerve to selectively activate different fibers along the nerve.

[00284] In an embodiment, the multi-contact lead may be deployed to use different stimulation parameters through each of the electrode contacts or electrode configurations. For example, 12 Hz stimulation may be used for intramuscular stimulation through one or more electrode contacts in combination with neurostimulation of an individual nerve through additional contacts. As another example, one or more stimulation contacts may be activated at a lower proportion of the current of another stimulation contact to facilitate a stronger field under a desired contact. It is noted that other stimulation frequencies and percentages may also be used with the disclosed multi-contact lead and systems and methods thereof.

[00285] In an embodiment, the multi-contact lead and return electrode configuration may be used to adapt stimulation parameters over time if the lead migrates or if the primary region of pain changes over time, reducing or eliminating the need to reposition the lead (such as through surgery and/or clinical visit) to regain or improve pain relief and/or other desired effects of stimulation.

[00286] It is noted that combination of techniques and/or electrode configurations disclosed herein may be used for different nerve targets and different locations in the body.

[00287] In an embodiment, the multi-contact lead in the present disclosure can improve the deployment and decrease procedure time compared to existing single contact leads. In an embodiment, the lead may be comprised of coiled wires with insulated sections and exposed electrical contacts. The multi-contact lead may be used with the described methods and facilitate the described methods, and vice versa.

[00288] In an embodiment, the electrode contacts on the multi-contact lead may be different sizes. For example, multiple smaller contacts may preferentially activate different areas, while activation of multiple contacts simultaneously could mimic, approximate, replicate, and/or be physiologically indistinguishable from the field generated from a single larger contact. In an embodiment, the various stimulating electrode configurations can be coupled with adjustable return electrode configurations, which may be used to selectively activate target structures and/or avoid activation of off target structures.

[00289] In an embodiment, the one or more leads may also be bent or curved along different sections of the lead to alter the shape of the electric field generated by the one or more electrode contacts. The lead may be shaped to bend around the nerve or to target multiple nerves with one or more contacts. For example, in the head/neck. the lead could be bent to target both the greater occipital and lesser occipital, potentially eliminating the need to place two leads to target both nerves.

[00290] In an embodiment, the lead and/ or system may include an introducer that can be bent to aid in the delivery of the desired shape of the lead. The introducer could be bent prior to inserting the lead or during the procedure to correctly place the lead or electrodes around the nerve or make the entry angle easier. In an embodiment, the introducer may be flexible to enable it to be bent without compromising mechanical strength and/or reducing the interior diameter or lumen, which may cause the lead to snag or catch within the introducer, preventing deployment and/or damaging the lead. In an embodiment, the flexibility of the introducer may be achieved through a series of closely spaced annular ridges and grooves or corrugations formed in the wall of the tube, similar to a bendy straw but made out of a durable material that can withstand having a lead inserted through it and/or hard enough to be inserted through tissue to the desired location. In an embodiment, the flexibility of the introducer may be achieved through an open-coil structure and/or using a bendable material that can be formed into a certain shape while still being hard enough to be inserted through tissue to the desired location.

[00291] In an embodiment, the lead may include one or more anchoring devices placed along the lead to prevent lead migration. These anchoring devices may be placed at various locations along the lead, such as between each electrode contact to facilitate keeping the lead bent or curved along a path. The anchoring device may consist of a screw, a hook, and/or a tube to place the lead in specific tissue. For example, the lead may use a hook at the end of each contact to help deploy the lead and keep it in place during testing and lead deployment. In an embodiment, one anchor can be used for multiple contacts. In an example, the lead may include a screw/corkscrew shape as an anchor that prevents axial movement (e.g., dislodgement or other undesired movement), but if the lead body is twisted during removal, it can disengage and come out more easily. In an example, the lead may include a lead body with screw threads where the lead can be removed more easily if twisted in the right direction but otherwise is prevented from axial movement, dislodgement, or other undesired movement.

[00292] In an embodiment, one or more contacts may be used for stimulation while one or more contacts are used for recording. In an example, the recording contacts could be used for closed loop stimulation (e.g. by recording an evoked compound action potential from stimulation), to inform lead placement (e.g. by recording local muscle activation surrounding the lead), or a combination of both approaches. In an example, the recording contacts could be distal electrodes (towards the tip of the lead) and/or proximal electrodes (on the half of the lead closer to the pulse generator than the terminal tip).

[00293] In an embodiment, the device may include a pulse generator required to provide neurostimulation through the one or more electrodes and leads. In an example, the pulse generator may be capable of delivering stimulation through each of the contacts individually through multiple contacts on up to multiple different leads.

[00294] In an embodiment, the device includes the cables and connectors required to connect the pulse generator to the one or more multi-contact leads. In an embodiment, the cables can be used as a switchboard to control the configuration of stimulation and return electrodes. In an embodiment, the pulse generator can be programmed to create the electrical coupling for the configuration of stimulation and return electrodes.

[00295] In an embodiment, the device includes an introducer needle with stimulating and/or return electrode contacts that may be used to replicate the fields generated by the multicontact lead upon deployment. The introducer needle may replicate the stimulation field of any contact individually or multiple contacts together. In an example, the introducer needle geometry' mimics the geometry' of the multi-contact lead, but the field can be shaped to replicate specific contacts either by using a sheath to cover contacts that are not used, or by deploying the introducer to the specific position of one or more individual contacts.

[00296] In an embodiment, the introducer may be rigid to enable deployment in the target area and switch to non-rigid after deployment to enable the introducer to shape or curve the lead. In an example, the introducer may be made of a flexible mesh but have rods or sty lets in place to keep it rigid (e.g., insertable or maneuverable) during deployment. When the rods are removed, the flexible mesh introducer can be shaped to create the custom field from the multi -contact lead.

[00297] In an embodiment, the lead may be coiled inside the introducer and use a spring device to deploy the lead into tissue once the stimulating or return electrodes are in the desired location. In an example, the device may be coiled around a spring or tightly wound so that it naturally expands when the lead is released from the introducer, which may allow use of a lead that has a diameter when deployed within the tissue that is larger than the interior lumen of the introducer, which allows a smaller introducer to be used that causes less tissue damage and/or requires a smaller incision or needle insertion site. [00298] In an embodiment, the introducer may be used to evaluate or identify optimal electrode configurations, including selectively choosing contact sizes and spacings during the procedure. In an embodiment, the introducer may include a deployable sharp edge to either remove portions of the lead (e.g. remove a single contact from the tip) or remove insulation surrounding a contact on the lead (e.g. to turn a 4 mm contact into a 6 mm contact), which may allow customization of electrode and/or lead geometry without having to remove the lead from the body or replacing a lead with static or unchangeable geometry with another lead with the desired geometry.

[00299] In an embodiment, the one or more leads with multiple electrodes may be deployed percutaneously with an external pulse generator or deployed and tunneled subcutaneously to an implanted (e.g.. internal) pulse generator. In an embodiment, the lead configuration may be connected to an external pulse generator for the treatment of one type of pain and an internal pulse generator for another type of pain. For example, the lead may be placed with an internal pulse generator for stimulation of the low back but placed percutaneously for stimulation of the deltoid with the external pulse generator placed on the arm. In an embodiment, a percutaneously placed lead with multiple stimulation and return electrode contacts may be used for temporary trial stimulation with an external pulse generator and then later connected to an implantable pulse generator.

[00300] The stimulation lead in this invention is designed to overcome the limitations of the devices to generate stimulation fields from leads in the prior art which may be limited, irregular, small, and/or non-uniform by modifying the ratio of electrode or contact length to the spacing or gaps between them, altering the edge-to-edge distance between contacts, and/or increasing the electrode or contact lengths, which creates a broad, wide, inclusive, even and/or uniform stimulation field and/or activation region along the length of the electrode and/or electrode array due to sufficient overlap of fields between tightly spaced electrodes or contacts, (e.g., a broad monopolar field generated by a single larger contact, a broad and uniform field generated by multiple large contacts that are tightly spaced)

[00301] The stimulation lead in this invention also may be used to avoid, limits, and/or decreases activation of non-target fibers which may increase pain (including smaller diameter non-myelinated fibers) through a novel lead design involving multiple electrodes with the option to select an electrode or a combination of stimulating electrodes and return electrodes to promote, increase, and/or drive selective activation of target fibers which may drive pain relief The stimulation lead with multiple contacts and return contact configurations is designed to optimize or balance several tradeoffs that include generating a broad stimulation field to extend the activation area beyond prior art neurostimulation leads, enabling selective activation of neural targets while avoiding non-targets. and preserving the flexibility’ and durability' of the electrodes.

[00302] The neurostimulation lead in the present invention takes an alternate approach from prior art neurostimulation leads, which may limit, minimize, or constrain stimulation fields with the anode and cathode in proximity (e.g., multiple contacts on the same lead); a close proximity between the cathode and anode in bipolar stimulation may shunt current away from tissue (e.g., field around electrodes is small, positive and negative fields cancel each other out, and/or superposition between fields from adjacent contacts may cancel each other out). Increasing the spacing between two or more contacts can increase the area of activation and/or span of activation but also leads to an increase in the area between electrodes where no activation of target nerve fibers may occur due to the field between electrodes being too small to generate activation and/or lack of superposition of fields across contacts. Decreasing the spacing between contacts (e.g., increasing the ratio of electrode contact length to electrode contact spacing) or reducing the length of electrode contacts (e.g.. decreasing the ratio of electrode contact length to electrode contact spacing) shrinks the span of the lead and decreases the activation area, (e g., decreases the number of nerve target fibers and/or the number of nen e trunks within the activation area). The activation area or lead span between the most proximal and distal contacts may be expanded or enlarged by increasing the number of stimulating or return contacts, but this adds additional challenges with programming all leads or all contacts, and stimulation fields may cancel out and/or fields from contacts may be smaller. The neurostimulation lead in the present invention is designed using long electrode contacts with short gaps between the contacts to enable broad stimulation fields and/or activation of multiple nerve targets without a large gap between the electrode contacts. Using long electrode contacts with short gaps between electrodes may make electrodes more difficult to manufacture and/or may increase the rate of fracture without the correct manufacturing technique for long, flexible, electrode contacts or de-insulated portions of the lead. Most conventional neurostimulation leads use an electrode contact length to electrode contact spacing ratio of 1 : 1 and add additional electrodes to generate the same activation area; however, additional electrodes may result in additional manufacturing expense and an excessively thick lead due to the extra circuitry and/or a lead that is more prone to fracture due to thinner wires and increased failure points. The present neurostimulation lead overcomes the challenge of adding electrodes without compromising the integrity of the lead or the activation area around the lead with long, flexible electrodes that are designed to be resistant to fracture. Increasing the contact length with short electrode spacing requires flexible electrode contacts but provides broad stimulation fields and an increased activation area without leaving gaps (or minimizing gaps) where no activation will occur.

[00303] The present invention overcomes limitation of the prior art. Prior art neurostimulation leads have used shorter contact lengths because they are made with electrodes with limited flexibility of the electrodes or contacts because they are made of solid metal rings or cylinders that are rigid, inflexible, and/or inextensible, restricting the positioning, orientation and/or the maneuverability of the electrodes and/or lead near the neural target. The present neurostimulation lead overcomes the challenge of shorter contact lengths with longer contacts and/or deinsulated portions of the lead for stimulation or return of stimulation while maintaining the lead flexibility’, pliability, and stretchability to maintain the positioning, orientation, and/or maneuverability of the electrodes and/or lead near the neural target. Additionally, the design of the present neurostimulation lead overcomes the challenge of existing neurostimulation leads that may tend to have shorter electrodes or contacts to minimize the stiffness of the lead in that region while preserving the maneuverability of the lead, which is crucial for use with neurostimulation systems, including permanently implanted peripheral nerve stimulation systems for treating pain as a nonlimiting example, which require the system and lead to be comfortable and avoid migration or dislodgment for patients during movement.

[00304] The present neurostimulation lead will also enable field shaping with bipolar or multipolar (e.g., more than two electrodes are used simultaneously) stimulation while expanding the stimulation fields to maintain or increase the activation area below the nerve target. Bipolar stimulation using multiple contacts with the opposite polarity may generate more complex fields, particularly close to the electrode, so spacing electrode contacts with bipolar stimulation may shrink the effective area of stimulation and may also leave gaps where no activation of neural elements occurs w ithout proper lead design. Bipolar stimulation with long electrode contacts and short gaps betw een electrodes may still enable complex field shaping between electrodes while expanding the overall electric field to ensure greater activation of target fibers.

[00305] The present neurostimulation lead may be used with various types and configurations of return electrodes for monopolar stimulation and the benefits of monopolar stimulation, such as a broad, uniform stimulation field with negligible effects from the return electrode, are ideal for the design of the present neurostimulation lead, which has long stimulation contacts designed to generate broad, uniform stimulation fields. A limitation of the prior art is the challenge of unintended activation of tissue or nerve fibers at the location of the return electrode when using monopolar stimulation, which can cause uncomfortable sensations for the patient. The present invention enables the return electrode(s) to be configured (i.e., located, oriented, or shaped) in sufficient way to maintain monopolar stimulation field and simultaneously minimize undesirable sensations by the patient, improving patient tolerability of the stimulation, reducing need for the physician to reposition or adjust lead positioning, and enhancing patient experience and pain relief outcomes.

[00306] Prior art neurostimulation leads may be designed to be placed in close proximity and/or adjacent to the neural target to generate sufficient activation of target fibers which may also result in activation of nontarget neural fibers. The proposed neurostimulation lead overcomes this challenge by enabling remote placement of the one or more electrodes away from the neural target which increases the resolution in activation threshold of different neural elements allowing selective activation of target nen e fibers while avoiding non-target fibers. Remote placement may require increased power or current to deliver stimulation, and higher amplitudes may cause pain, discomfort or tissue damage either around the stimulating electrode or the return electrode, but the large contact size of the neurostimulation lead in this invention along with the placement of the one or more return electrodes sufficiently far from the active electrode (monopolar stimulation) enables safe delivery' of stimulation while also promoting selective activation of nerve targets.

[00307] Use of multiple contacts or deinsulated portions of the lead helps with remote placement of the neurostimulation lead with respect to the neural target by enabling increased flexibility with where electrodes are placed. Flexibility with where stimulating and return electrodes are placed simplifies the procedure by enabling testing of each electrode contact individually to determine optimal placement and minimizing need to reimplant or revise a prior implant in the event of lead migration and/or physiological or anatomical changes that alter the response to stimulation. As a non-limiting example, the neurostimulation lead may be placed along the same axis as a nerve, at an angle such that contacts are different (i.e., multiple) distances away from the nerve. Stimulation through any of the contacts or deinsulated portions of the lead may enable stimulation of the same fibers, and having multiple options for the contacts or deinsulated portions of the lead enables testing of optimal placement.

[00308] The present neurostimulation lead creates a broad, wide, inclusive, and/or uniform stimulation field and/or activation region across and/or between contacts by increasing the ratio of electrode/contact size to electrode/contact spacing (e.g., increasing from approximately 1 : 1 in prior art to 5 : 1 as a non-limiting example). The present neurostimulation lead increases the size/length of the electrode contacts and maintains or decreases the size/length of electrode spacing to generate a more broad, wide, inclusive, and/or uniform stimulation field and/or activation region. The broad, wide, inclusive and/or uniform stimulation field and/or activation region generated by the lead optimizes or increases the proportion of activation of target fibers in nerve trunks across, adjacent to, and/or between electrode contacts while minimizing activation of non-target fibers that may cause unwanted responses such as pain. The broad, wide, inclusive, and/or uniform stimulation field and/or activation region overcomes limitations in prior art that may require specific programming to achieve activation of target fibers in the nerve.

[00309] The present invention may reduce the trial and error involved with existing lead implant procedures by using a multi-contact lead with a larger ratio of electrode length-to- spacing that is designed to generate a broad stimulation field covering a larger activation region with a uniform and/or continuous stimulation field between electrodes/contacts such that the field from each contact can be used individually or in combination with other adjacent and/or nearby contacts to activate or stimulate the target nerve(s) efficiently with minimal adjustment of lead position and/or stimulation parameters, which may increase patient safety, reduce the skills and training required of practitioners to perform the implant procedures, desirably minimize the time to perform the procedure, and minimize need for revision procedures while avoiding loss of therapeutic benefit in the event of lead migration.

[00310] Broad stimulation fields create an even spatial distribution of current density’ to generate more uniform activation of a nerve target. Axons fire when the depolarization is greater than a threshold value, and the broad uniform fields helps maximize the number or percentage of target axons that are activated. Nontarget fibers have a higher threshold due to their smaller diameter, so a broad uniform stimulation field helps maximize the number or percentage of target fiber activation in comparison to nontarget fibers. Monopolar stimulation helps create a consistent broad uniform field because the return electrode is far away and thus does not alter the shape of the field. With bipolar stimulation, placing the return electrode in close proximity to the stimulating electrode minimizes activation around the return electrode. Monopolar stimulation overcomes this limitation with the one or more return electrodes placed far away to increase the uniformity of the field. Omnidirectional stimulation, or stimulation in all directions out of the electrode contacts, also helps generate a broad uniform field, and may be employed in the current invention. Some neural stimulation leads employ directional stimulation to only stimulate out of a portion of the electrode contact. In an embodiment, The current invention uses omnidirectional stimulation in combination with multiple stimulation and return electrode contact sizes and shapes to generate a broad stimulation field. Prior art lead designs require physicians to place leads and get feedback from patients to determine if they are in the correct position, and minute adjustments in lead positioning (e.g., due to lead migration) may shift the number of target fibers activated in a given nerve.

[00311] The lead described here may generate a stimulation field through one or more contacts that can be used individually or in combination with adjacent contacts to increase the size of the stimulation field while maintaining a broad and uniform field approximately within the region of the target nerve trunk, maximizing activation of target fibers. Additionally, the lead may generate a stimulation field to target multiple nerve targets using multiple stimulation contacts with broad uniform stimulation fields. An alternative benefit is the lead maximizes activation of the nerve target(s) while minimizing discomfort during the procedure. Additionally, initial placement of the lead during the procedure requires careful positioning and may require multiple placement attempts in order to correctly position the lead, so multiple contacts, each of which may deliver a broad and uniform field individually or combined with other contacts, may increase the ease of the initial placement procedure and beneficially reduce procedure time. After placement, the lead may also shift or migrate in position over time, which may alter the region of activation within the target nerve(s). This lead design incorporating multiple contacts that can be used for monopolar stimulation may prevent loss of coverage in the target nerve(s) by enabling a different electrode contact or a different combination of currents through each contact, and either the physician or a trained user may be able to make changes to the stimulation fields.

[00312] Reprogramming stimulation on the lead to use one or more different stimulating or return electrode contacts may prevent the need for additional procedures to reposition the lead or to place one or more new leads, optimizing the use for the patient. Although combining multiple adjacent contacts to create a broad, uniform stimulation field may have similar effect as the stimulation from a single larger contact when activating a larger nerve trunk or multiple nerves in the same region, it is possible to inadvertently stimulate nontarget fibers with a single larger contact while the multi-contact lead in this invention offers flexibility in selecting the contact(s) for stimulation, making it easier to avoid nontarget fibers while maximizing activation of target fibers. Sudden changes in position or changes in the fiber activation within the target nerve(s) may also present a safety risk to the patient as they may receive undesirable side effects such as uncomfortable stimulation from activation of nontarget fibers, but the broad uniform stimulation fields generated in the proposed lead may reduce these side effects while enabling easier use, allowing physicians more programming options, and increasing safety for patients by minimizing procedure risk.

[00313] These options enabled by the selection of multiple contacts in close proximity to each other optimizes the procedure by enabling easier lead placement, which reduces patient discomfort and simplifies the procedure for physicians, overcoming the challenge of physicians potentially not knowing optimal procedure protocols and/or how best to deploy or use neural stimulation leads and/or how to program multicontact leads with complicated designs, therefore increasing adoption. The lead described in the present invention may also decrease patient discomfort during therapy by reducing or eliminating the need to reposition the lead since there are fewer areas surrounding the lead where the stimulation field does not reach the target nerve trunk, overcoming the challenge of needing to reposition the lead during the procedure to find optimal location. Adding additional options for the lead during use with multiple contacts optimizes the design for the patient and may also prevent the need for additional surgeries to reposition the lead or place a new lead.

[00314] The present multi-contact lead enables activation of one or more nerve targets to optimize programming needs for physicians and trained users by using flexible, stretchable, and pliable electrodes made of coiled wires with larger electrode/contact size, reduced spacing between electrodes/contacts, and a higher intensity and/or amplitude of stimulation enabled by the larger surface area of electrode contacts which may collectively allow activation of multiple, large nerve targets or nerve trunks without a gap or discontinuity of fields between electrodes/contacts, thus minimizing the need to implant multiple leads to accomplish the same outcome and/or minimizing loss of therapy or change in stimulation if the lead changes positions over time, which may help reduce complications and improve efficiency of implant procedures. Increasing the stimulating or return electrode contact size and reducing the spacing between electrodes may increase the overall area and/or span of the stimulation field enabling activation of multiple nerve trunks using a single lead while avoiding non-target/pain fibers by individually selecting the contacts to deliver stimulation. However, increasing the contact size of either stimulating or return electrodes can also be challenging because there is a potential to inadvertently stimulate nontarget or off-target fibers that could cause discomfort and/or pain to the patient. On the other hand, reducing the electrode spacing or gap may also lead to practical challenges with manufacturing the lead with sufficient spacing to allow transitioning from one electrode or contact to another electrode or contact while avoiding crosstalk between electrodes/contacts. [00315] The lead in this invention addresses this challenge through the use of a variety of different sizes of electrodes or contacts on the same lead allowing different sizes to be selected depending on the target for stimulation (e.g., larger or longer electrodes can be created and used to stimulate large nerve trunks and/or multiple nerve targets while smaller or shorter electrodes can be used to stimulate smaller, narrower or discrete nerve targets). As a non-limiting example, the lead in this invention may have an electrode or contact length of 2mm - 15mm and a spacing or gap of l-3mm. Contacts with lengths shorter than 2 mm may produce smaller fields which are undesirable for placement of the lead remote to the nen e target. Contacts with lengths longer than 15 mm may not provide additional benefit, as these contacts will already cover the span of most human nerve targets including larger peripheral nerves like the sciatic or femoral nerve. Therefore, in some anatomies, adding additional length to the individual contacts may not provide additional benefit beyond 15 mm that could not be achieved by adding additional contacts to the lead. Contact spacings or gaps between 1-3 mm avoid gaps in the stimulation fields that may occur with larger gaps while differentiating between contact areas for multiple electrodes.

[00316] There are many different anatomical regions where activation of multiple nerves could provide additional therapeutic benefits for certain pain indications including but not limited to: simultaneous activation of the axillary nen e and the suprascapular nerve in the quadrangular space, simultaneous activation of the medial branch of the dorsal ramus at multiple levels along the spinal cord, simultaneous activation of the lumbar medial branch of the dorsal ramus and the lumbar spinal nerve, simultaneous activation of the greater occipital nerve, lesser occipital nen e, and/or third occipital nen e in the neck, simultaneous activation of the sciatic nerve and posterior femoral cutaneous nerve in the subgluteal area, activation of the illiohypogastric, ilioinguinal nerve, and/or genitofemoral nerve in the genital area, activation of the tibial nerve, saphenous nerve, and/or common peroneal nerve in the lower leg, activation of the ulnar nerve, medial nerve, and/or radial nen e in the arm, and many other targets. Each of these targets, as well as other peripheral nerve targets, may improve pain relief by stimulating multiple areas of the body and activating nerve fibers (e.g., sensory fibers, motor fibers, etc.) in one nerve at one location, in one nen e at multiple locations, or in multiple nen es thus improving pain relief. Existing neurostimulation leads have stimulating and return electrodes/contacts with too large of spacing between electrodes/contacts resulting in gaps or regions where stimulation fields are inadequate to activate a nerve because the fields generated by adjacent contacts do not sufficiently overlap in the spacing between contacts. Existing neurostimulation leads may have stimulating and return electrodes/contacts with insufficient spacing between electrodes/contacts resulting in uncomfortable stimulation sensations when stimulation fields activate a nerve because the fields generated by adjacent contacts activate small diameter afferent nerve fibers.

[00317] The present invention overcomes limitations of the prior art which would not be able to achieve activation of nerve targets while maintaining comfortable sensations because of reduced selectivity between small diameter, large diameter, and/or mixed nerve fibers. Additionally, modifying existing neural stimulation leads of the prior art to employ the approach described in the present invention (e g., long contacts with short spacing), would not be feasible for nerve targets where it is necessary to activate more target fibers to get a positive therapeutic effect. As an example, having the return electrode close to the stimulating electrode (e.g., bipolar stimulation) limits superposition of fields from adjacent contacts and are not be able to activate multiple nerve targets. As an example, leads and return electrodes with small contacts and small spacing between contacts would not be able to achieve activation of nerve targets without unwanted activation of off target or non-target nerve fibers. As an example, leads and return electrodes with small contacts and small spacing between contacts would not be able to achieve sufficient activation of nerve targets to generate pain relief before activation of non-target fibers generating unwanted responses. As an example, leads and return electrodes with small contacts and small spacing between contacts restricts the span of activation to the stimulation fields generated by individual electrodes/contacts which are generally smaller in size for most neurostimulation leads (e.g., 3mm contact length), limiting the stimulation intensity and/or amplitude and/or charge that can be delivered through the small surface area of the electrodes/contacts without exceeding the safe charge injection limit and/or stimulating the small nontarget fibers.

[00318] The stimulating lead and return electrode in this invention overcomes the limitations gaps or regions where stimulation fields are inadequate to activate a nerve by involving multiple leads and/or return electrodes to activate multiple nerve targets by using mechanically and electrically robust electrodes made of coiled wires with larger contact size, reduced spacing between contacts or electrodes, and a higher intensity and/or amplitude of stimulation enabled by the larger surface area of electrode contacts which may collectively enable activation of multiple nerve trunks concurrently with a broad, uniform and/or continuous stimulation field, to improve pain relief across multiple areas of the body. The stimulating lead and return electrode in this invention overcomes the limitations of reduced selectivity of small diameter and large diameter nen e fibers by involving multiple leads to activate multiple nerve targets by using mechanically and electrically robust electrodes made of coiled wires with larger contact size, reduced spacing between contacts or electrodes, and a higher intensity and/or amplitude of stimulation enabled by the larger surface area of electrode contacts which may collectively enable activation of multiple nerve trunks concurrently with a broad, uniform and/or continuous stimulation field, to improve pain relief across multiple areas of the body. In an embodiment, the stimulating lead and return electrode in this invention avoids the need for using multiple leads in multiple locations by using a single lead, thus minimizes the time to perform the procedure and reducing complications from having to place two or more separate leads in the body.

[00319] In an embodiment, the present multi-contact lead and/or return electrode with long, flexible coiled electrodes activates individual nerves or nerve trunks at multiple points, segments, distances and/or orientations around and/or along the length of nerve trunk with an in-line design and/or non-cuff design that permits percutaneous implant and/or implant with just a needle and/or introducer, for example by wrapping around the nerve without intimate contact and/or while maintaining distance/spacing away from the nerve trunk to enable remote selective activation of target nerve fibers on multiple sides of the nerve trunk, and the combination of electrical fields from multiple stimulation electrodes may lower the activation threshold for target nen e fibers allowing selective activation of large diameter, target nerve fibers while avoiding small nontarget fibers in the nerve trunk. In another embodiment, the present multi-contact lead and/or return electrode has 1, 2, 3, 4, 5, 6, 7. 8, or more contacts with the same, varying, uniform, repeated, or quasi-random spacing and/or orientation around and/or along the length of nerve trunk with an in-line design and/or non-cuff design that permits percutaneous implant and/or implant and/or permanent implant with just a needle, for example by wrapping around the nerve without intimate contact and/or while maintaining distance/spacing away from the nerve trunk to enable remote selective activation of target nerve fibers on multiple sides of the nerve trunk, and the combination of electrical fields from multiple stimulation electrodes may lower the activation threshold for target nerve fibers allowing selective activation of large diameter, target nerve fibers while avoiding small nontarget fibers in the nerve trunk. In an embodiment, the multi-contact lead and/or return electrode in this invention enables activation of different fascicles at different points due to differences in fascicle position along the nerve. In an embodiment, the multi-contact lead and return electrode in this invention enables activation of one, multiple, many, all, or some fascicles at the same or different points due to differences in fascicle position along the nerve and/or differences in lead and/or return electrode configuration (e.g., positioning, orientation, size, shape, and/or composition). [00320] Nerve trunks may have a distinct somatotopic organization (e.g., the sciatic nerve has distinct divisions for the peroneal and tibial nerve with an antero-posterior and medial- lateral organization). Activation of target fibers within a nerve may require accounting for the somatotopy of the nen e trunk (e.g., activation of the medial component of the nerve). Conventional nen e cuff electrodes may be placed such that they cannot activate individual portions of the nerve. Conventional cylindrical electrodes may also not be able to activate sections of the nerve due to the close proximity to the nerve trunk, which limits selective activation. The present invention overcomes limitations of distance dependent selectivity (i.e., whereby proximity limits selective activation) by enabling placement around the entire nerve trunk with multiple contacts to stimulate different portions of the nerve. In an embodiment, the lead(s) and/or return electrode(s) have multiple contacts that are sufficiently separated to activate one or more portions of the nerve and/or one or more nen e fibers or bundles of fibers with selective activation that promotes pain relief and avoids activation of non-targeted fibers (e.g., small diameter fibers or bundles of fibers). Additionally, many nerves have unknown somatotopic organization or an organization with high variability. In an embodiment, the multiple contacts on the lead and/or return electrode in the present invention enables testing of different portions of the nerve trunk to activate target fibers from the corresponding somatotopic area.

[00321] In an embodiment, the lead and return electrode with multiple contacts not only optimizes pain relief, but also simplifies the procedure for the benefit of both the physician and the patient. For example, with the lead running along the sciatic nerve, contact A and/or B may activate fascicles from the tibial nerve while contacts C and/or D activates fascicles from the peroneal nerve. Conventional nen e cuff electrodes may enable stimulation at different locations around the perimeter of a nerve trunk electrode, but the electrodes/contacts are often in close proximity (e.g., 0-2 mm) to the nen e trunk, which limits the selective activation of large diameter nerve fibers (e.g., sensory nerve fibers, motor nerve fibers) for pain relief over smaller non-target nene fibers; and nerve cuffs require invasive surgery' to dissect tissue and expose the nerve trunk for placement of the cuff (and explant of the cuff when needed), and typically a suture or other method to secure the cuff. In an embodiment, the present invention enables activation of multiple locations around the nerve by combining the stimulation fields from multiple larger electrodes/contacts and/or return electrodes with minimal spacing while increasing the distance between the electrodes/contacts and nerve trunk (e.g.. -5-30 mm away) and allowing percutaneous placement and removal without surgery (e.g., placement through a needle without an incision, removal by pulling on the lead). In an embodiment, the lead and/or return electrode is permanently implanted.

[00322] The present multi-contact lead with long, flexible coiled electrodes may be used to activate individual nerves or nerve trunks at multiple points, segments, distances and/or orientations around and/or along the length of nerve trunk with an in-line design. Conventional cylindrical leads are often placed in close proximity (e.g., 0-2 mm) to the nerve trunk, which limits the selective activation of large diameter nerve fibers (e.g., sensory nerve fibers, motor nerve fibers) for pain relief over smaller non-target nen e fibers). In an embodiment, the present invention enables activation of multiple locations around the nerve by combining the stimulation fields from multiple larger electrodes/contacts with minimal spacing while increasing the distance between the electrodes/contacts and nerve trunk (e.g., -5-30 mm away) and allowing percutaneous placement and removal without surgery (e.g., placement through a needle without an incision, removal by pulling on the lead). In an embodiment, placing the lead and/or return electrode closer to the nerve enables activation of target fibers but may not enable rescue of stimulation when leads migrate. Additionally, placing the leads closer to the nerve may not enable the physician to stimulate with multiple contacts due to the superposition of the fields. Placing the leads further away from the nen e may not enable stimulation of target fibers without causing uncomfortable stimulation in surrounding tissue.

[00323] As an example, cylindrical leads and/or other similar conventional neurostimulation leads also may not enable activation of multiple nerve targets and/or multiple fascicles within a nerve because of the stiff lead bodies and rigid electrodes or contacts which prevent placement of the lead around a nen e. Conventional leads are also often placed in close proximity (e.g., 0-2 mm) to the nerve trunk, which limits the selective activation of large diameter nerve fibers (e.g., sensory nerve fibers, motor nerve fibers) for pain relief over smaller non-target nerve fibers. As an example, conventional cylindrical leads are not as flexible as the proposed lead, by which the proposed lead and return electrode optimizes placement around the nerve(s) to activate multiple target nerve(s) and/or multiple target fascicles within nerve(s).

[00324] Prior art neurostimulation leads may lose efficacy over time if the lead and/or return electrode migrates because the parameters of the stimulation current delivered by the lead cannot be reprogrammed to recapture stimulation, but the present invention has multiple contacts with broad, uniform fields which may be used to adapt stimulation parameters over time if the lead migrates or if the primary region of pain changes over time without having to adjust the position of electrodes or remove and replace the lead. As a non-limiting example, the system can be reprogrammed so that stimulation can be moved to be delivered through a new contact and/or stimulation can be combined across new contacts and/or new return electrodes to generate a new stimulation field and/or area of activation around the lead. The present invention overcomes limitations of conventional leads, which may be limited by the large spacing between electrodes/contacts relative to the size/length of the electrodes/contacts, which may leave areas between the contacts where the target nerve cannot be activated by either of the contacts individually or together (without unacceptable and/or undesired activation of non-target nerve fibers). In the present invention, the selection of stimulating and return electrodes/contacts through which to deliver stimulation and the stimulation levels/intensities through each contact may be controlled (e.g., by an algorithm, script, user interface, manual controls, artificial intelligence, etc.) to test stimulation around each individual contact and between the contacts in a logical manner. For example, stimulation may be delivered first through contacts individually to identify the two adjacent electrodes/contacts that provide the best effect on the patient (e.g., paresthesia coverage of regions of pain, pain relief, activation of motor fibers). In an embodiment, one or multiple return electrode may be used to identify the stimulating and return electrode configuration that provide the best effect on the patient (e.g., paresthesia coverage of regions of pain, pain relief, activation of motor fibers). In an embodiment, the invention incorporates, uses, and/or is used with a program (and/or other method of control) that adjusts the levels of stimulation through both contacts with different ratios of intensities and/or other stimulation parameters between the two contacts and/or one or multiple return electrodes or return electrode configurations until the effect on the patient is optimized (e.g.. most paresthesia coverage of regions of pain, greatest pain relief, strongest activation of motor fibers, least discomfort from inadvertent activation of non-target fibers).

[00325] As another non-limiting example, the program may have a ‘’location parameter” that spans across the length of an electrode array including all the electrodes/contacts on the lead and/or return electrode, with the spacing between electrodes at certain interv als corresponding to the distal or proximal edge or the center of each electrode/contact on the lead, which makes adjustment of the stimulation and electrodes through which stimulation is delivered less complicated for the user and provides more consistent stimulation as different locations are selected. Adjusting the location parameter may correspond to the adjusting which electrode/contacts are active and/or the stimulation intensities, amplitude and/or pulse width going through the electrodes/contacts, return electrode spacing, and/or return electrode configuration.

[00326] In an embodiment, the algorithm for the location parameter is designed to take a simple input from the user and convert the input automatically to a distribution of stimulation parameters that optimizes stimulation in a given region under or around where the electrode is placed. As an example, the algorithm may take into account additional information about the location or position of neural targets and/or stimulation areas to avoid. In an embodiment, the algorithm synthesizes or combines this information to determine optimal stimulation parameters for each individual contact using the available information and weights information according to importance. For example, activation of the nerve target may be the primary goal, but avoiding activation of other nontarget areas and unwanted responses may also inform stimulation choices. The algorithm may stimulate through individual contacts to derive information. For example, stimulation through 1 contact with 1 return electrode may provide information about how well stimulation is activating the target nerve. In an embodiment, stimulation is programmed for a specific location base on anatomical landmarks or information from the procedure. In an embodiment, the algorithm overcomes limitations with existing leads and programming algorithms which may only be able to determine the intensity of stimulation for each contact. While functional, individually programming each contact is time consuming and may not determine the optimal solution for pain relief for the patient.

[00327] As a non-limiting example, the intervals corresponding to the electrodes/contacts may be whole numbers, 10s, 100s, etc. For example, “0”, “1”, “2”, “3” may correspond to the center of each contact/electrode on a 4-contact lead with one or more return electrodes. For a given stimulation intensity, a location parameter set exactly to an interval for a given contact results in all the stimulation current going through that contact/electrode and return electrode. In an embodiment, a location parameter betw een two intervals divides the stimulation intensity and/or amplitude and/or other stimulation parameters between the electrodes or contacts based on how close the selected location parameter is to either of the two intervals. For a location parameter selected between two adjacent contacts or electrodes, higher stimulation intensity wall go to the electrode or contact that is closer to the selected location parameter and the proportion of the stimulation intensity that is distributed between the two contacts or electrodes is determined by the distance of each electrode or contact to the location parameter. As a non-limiting example, '’1.25" may correspond to more stimulation going to “contact 1” than “contact 2”, for example, 75% going to “contact 1” and 25% going to "contact 2”, assuming a location parameter of “1” corresponds to the center of ‘‘contact 1” and a location parameter of “2” corresponds to the center of “contact 2”, whereas “1.25” is located a quarter of an interval away from “contact 1 ” and three quarters of an interval away from “contact 2”, indicating a stimulation ratio of 3: 1 between contact 1 and 2, respectively. As an additional example involving activation of more than two contacts, “0.75” corresponds to the point of peak current density being in between contact 0 and contact 1 (e.g., 75% of the way to contact 1 from contact 0). In this nonlimiting example, more current would go to “contact 0” and some going to “contact 1” and/or “contact 2”. The present invention addresses limitations in existing methods of controlling stimulation through multicontact leads which may be limited by manual setting of stimulation parameters through each contact, such as stimulation on (delivering current) vs. off (not delivering current), polarity (positive vs. negative, anodic vs. cathodic), amplitude (charge, cunent, and/or voltage), pulse width (pulse duration), symmetry’ (symmetric vs. asymmetric), waveform phases (monophasic, biphasic, triphasic), waveform shape (triangular/ramp, rectangular, sinusoidal, exponential, and/or custom); and the existing methods are time-consuming, confusing to the user, and/or do not guarantee a broad, uniform field for consistent activation of the nerve. For example, manual control may result in users adjusting settings on only 1 electrode/contact at a time, which does not allow⁷ the combination of fields across electrodes to create a larger broad stimulation field to target nerve fibers between the electrodes. The present invention overcomes these limitations by enabling automatic (e.g.. through an algorithm, script, artificial intelligence, etc.) or manual (e.g., through manual controls or a user interface) control of stimulation parameters such as stimulation on (delivering current) vs. off (not delivering current), polarity (positive vs. negative, anodic vs. cathodic), amplitude (charge, current, and/or voltage), pulse width (pulse duration), symmetry (symmetric vs. asymmetric), waveform phases (monophasic, biphasic, triphasic), waveform shape (triangular/ramp, rectangular, sinusoidal, exponential, and/or custom), or any combination of the above. Furthermore, the present invention enables automatic control or manual control of each of these elements individually or in combination with a simple, intuitive user interface to generate consistent control over the stimulation output from the present neurostimulation lead. While existing prior art leads may have control systems for stimulation outputs, the stimulation controls for prior art are designed for rigid, small contacts placed close to the neural target; the present invention overcomes these limitations with manual and/or automatic stimulation controls that are designed for a stimulation lead to generate broad, uniform stimulation fields placed remotely from the nerve to increase the activation of target fibers while limiting the activation of nontarget fibers.

[00328] Prior art neurostimulation leads may also be limited by false responses while the present invention overcomes these limitations by enabling both automatic and manual control of stimulation parameters for stimulating and/or return electrodes. For example, prior art neurostimulation leads may generate false responses (e.g.. false negative responses), where the user fails to activate target nerve fibers located around the electrodes (e.g., between 2 adjacent electrodes) not because the electrodes and range of stimulation parameters were incapable of stimulating them, but rather because the proportions of stimulation intensity, charge, polarity, current, voltage, waveform shape, and/or pulse duration were not set among the electrodes correctly (e.g., to generate a broad stimulation field that selectively activates target nerve fibers over non-target fibers). The present invention addresses this challenge by enabling both automatic control of stimulation parameters such as charge, polarity, current, voltage, waveform shape, frequency, and/or pulse duration between multiple electrodes or contacts, that reduces the trial-and-error and the number of steps required to accurately place the lead and/or return electrode, while also offenng the ability to adjust settings manually for certain situation where independent control of stimulation parameters may be needed.

[00329] In an embodiment, the current invention is designed to overcome the challenges of the prior art related to lead fatigue, fracture and/or damage by using a stimulation lead composed of one or more insulated and coiled conductors, channels or conducting wires which are made of multi-filar, multi-stranded and/or bundled wires with unique filar arrangements involving wire filaments that are small enough to produce robust flexibility but large in number and compact in filar arrangement to create strong mechanical and electrical performance. In an embodiment, the present invention optimizes flexibility, elasticity and/or pliability of the lead by using smaller filaments, strands, or individual wires while also achieving the conflicting goals of maintaining or enhancing the mechanical, electrical, magnetic, magnetic resonance imaging and/or other physical performance of the device (e.g., including but not limited to tensile, bending, rotary, rotational, torsion, and/or shear performance or strength; electrical conductivity) by increasing the filar count and/or using a large or increased number of filaments or strands in each conductor or conducting element and/or using a compact arrangement of filaments while preserving if not reducing the overall lead diameter and/or size of the lead relative to conventional leads.

[00330] In an embodiment, the lead in the present invention overcomes multiple limitations of conventional neurostimulation leads, which may be limited in fatigue resistance, fatigue life, and/or prolonged mechanical performance due to the inflexible cylindrical electrode design and the large number of electrodes and hence conductors used to generate large and/or bipolar stimulation field, by implementing coiled electrode design which enables increasing the surface area of stimulating and/or return electrodes to create large stimulation field with fewer electrodes or contacts corresponding to a smaller number of conductors in the lead body, allowing conductors and electrodes to be coiled tightly and/or with reduced pitch which increases flexibility and stretchability of the lead especially when placed in highly mobile regions of the body such as the periphery where the lead is subject to a range of different stresses (e.g., tensile, shear, flex, and/or torsional stress) and varying repetition of these stresses (e.g., high stress-low frequency cycles from arm movement, low stress-high frequency cycles from muscle contraction).

[00331] In an embodiment, the present invention overcomes the limitations of most conventional leads which may only have single filar (solid) conductors (e.g., each conductor is composed of a single large wire or filament) or multi-filar conductors with a limited number of wires, filaments, or strands within each conductor because large or thick wires have higher tensile strength. However, large solid wires are more rigid and less flexible than stranded, multi-filar wires and have lower fatigue resistance under repetitive flexing and shearing. In an embodiment, the stimulation lead in this invention is designed to optimize both tensile strength and fatigue resistance by using multi-filar and/or multi -stranded conductors with smaller wire filaments or strands, and a higher filar count or number of wire filaments or strands with a unique filar arrangement 120 that maximizes compactness of wire filaments or strands by reducing air gaps or spacings to increase the flexibility’, elasticity and/or pliability and potentially the fatigue performance of the lead while maintaining the tensile strength, electrical conductivity and overall diameter/size of the lead relative to conventional leads.

[00332] In an embodiment, the coiled configuration of the multi-filar conductors or channels described in this invention along with the reduced filar size (i.e., diameter of individual wire filament) overcomes the limitations of prior art with lead flexibility , stretchability and fatigue life by offering strain relief or minimizing tensile strain on individual wire strands or filaments, and balancing the need for flexibility which is accomplished by reducing filar size with the need for fracture resistance which is achieved by the stretchable, coiled design and high filar count and compact filar arrangement 120. In an embodiment, reducing the filar size or the diameter of individual wires, filaments, or strands may result in a more flexible, pliable, yielding and/or maneuverable conductor or channel but it may also reduce the tensile strength of the lead making it more susceptible to fracture when pulled or stretched along the length which is common in the body due to tightening and lengthening of muscles and other tissues. However, the stretchiness of the coiled conductors/channels described in this invention reduces the tensile strain on individual wire filaments making it less prone to fracture from stretching in the body while also improving the flexibility of the lead due the reduced filar size/ diameter. Although reduction in filar size or diameter along with a coiled design may be sufficient to improve mechanical performance of the lead, the ability to remove the lead intact and in a minimally invasive way whenever necessary (e.g., at the end of treatment) is critical, which requires pulling the lead lengthwise and applying significant amount of tensile stress on the lead, potentially uncoiling and increasing the tensile strain on the multi-filar or multi -stranded conductors. Therefore, in an embodiment minimizing filar size or diameter may be balanced by increasing the filar count (e.g., the number of individual wires, filaments or strands) to collectively increase the tensile strength of the lead by spreading or distributing the tensile stress across multiple wires filaments or strands and reducing the strain or burden on each wire filament or strand. Although multi-filar or multistranded conductors/channels may be more flexible, malleable, and maneuverable than solid conductors/channels (e.g., a single filar or wire per conductor/channel), they often have lower electrical conductivity compared to solid conductors of the same size or diameter because the more strands or filaments there are in a conductor or channel the larger the surface area for current dissipation with each filament due to air gaps between filament or strands. In an embodiment, the lead in this invention minimizes this conductivity loss by using specific filar arrangement or arrangement of individual wires, filaments, or strands that minimizes these air gaps and increases the density of wire filaments or strands to form a more compact or compressed arrangement. For example, individual wire filaments, or strands may be arranged in concentric circles around a single center which increases the metal density in the lead and minimizes the air gaps or space between wire filaments or strands, thus optimizing electrical conductivity by increasing the cross-sectional area of the metal conductors and reducing the surface area for current dissipation, while also increasing the tensile strength of the lead because of the higher metal density in the conductor. One embodiment of this is a 1x37 filar arrangement where 1 represents the number of centers or inner cores for circular configuration and 37 stands for the number of individual wires/fil aments arranged in layers around each center or inner core as shown in FIG. 61B. Unlike other configurations involving multiple inner cores with such as 7x7 (e.g., 7 centers or groups each consisting of 7 wire filaments arranged in small concentric circles as shown in FIG. 61C) which has 49 filaments or strands, the 1x37 configuration with only 37 filaments or strands may have better tensile strength and electrical conductivity because of the compact filar arrangement 120. Other example embodiments of this invention include 1x19 and 1x7 filar arrangement 120, with 19 and 7 wire filaments arranged in layers around a single center or inner core, respectively. The tensile strength can also be further increased by using multiple multi-filar or multi-stranded conductors or channels. For example, a multi-contact lead consisting of 2. 3 or 4 conductors or channels each consisting of 37 filaments will result in a total of 74, 11 1. and/or 148 wire filaments in the lead, further enhancing the tensile strength of the lead. Another example of the lead in this invention may include a multi-centric filar arrangement 120 within each conductor in the lead. Although a concentric filar arrangement 120 around multiple centers or inner cores may offer less tensile strength than a single core or center due to the increased air gaps and reduced metal density in each conductor, a multi-center filar arrangement 120 (e.g., 7x7, 7x19, 3x19) may still offer enhanced flexibility and tensile strength for a multi-contact lead that consists of multiple conductors, which increases the tensile strength of the lead by distributing or spreading the tensile stress across multiple conductors and across multiple wire filaments in each conductor as shown in FIGs. 69C-D.

[00333] In another embodiment of the present invention, the stimulation system may use one or more additional return electrode configurations, including one or more lead(s) with electrode(s) capable of acting as return path(s) for the delivered stimulation current from one or more electrode(s) on a primary lead to overcome challenges in the prior art associated with delivering monopolar stimulation using the pulse generator case or surface electrodes on the skin as the return electrode.

[00334] Using one or more additional lead(s) or electrode configurations to serve as the return electrode(s) provides more flexible options to the user for the location of the return electrodes, and the user may be able to place the additional electrode(s) or lead(s) in parts of the body that may be ideal or better suited for return electrodes than where the pulse generator is implanted.

[00335] In the present invention, the circuitry within the system (e.g., in the pulse generator) may use electrical switches to control which one or more electrode(s) is the stimulating electrode(s) and which one or more electrode(s) (e.g., electrode or conducting surface of the IPG) will serve as the return electrode(s), with the option of selecting electrodes on another lead (other than the one on which the stimulating electrode is located) to act as the return electrode. [00336] In a non-limiting example, the additional electrode(s) or lead(s) may not be identical to the first lead and may be designed specifically to be configured as a return electrode. As a non-limiting example, the electrodes on any of the additional leads may be larger in surface area than the electrodes on the first lead to minimize uncomfortable sensations, pain, unwanted tingling or muscle contractions. In another embodiment, the electrode(s) on any of the additional leads may consist of multiple smaller electrodes that can be configured together (i.e., electrically coupled) as a return electrode and the selection of which electrodes are used as a return can be optimized to improve patient comfort and avoid off target stimulation or sensations.

[00337] Turning to FIGs. 58A-D, shown are embodiments of a stimulation lead 10. The stimulation lead 10 may be generally referred to as a multi-contact or multi -electrode stimulation lead 10 in embodiments having multiple, at least one, or more than one contact or electrode. The stimulation lead 10 may generally comprise an elongated body 13 having a proximal end 16 and a distal end or tip 19. The stimulation lead 10 may be generally cylindrical, having generally circular cross-sections, or be otherwise rounded. The distal tip 19 may be generally rounded or hemispherical. As described here, the stimulation lead 10 may include one or more anchors. As described here, the stimulation lead 10 may include an outer sleeve or jacket. In an example, FIG. 58A shows the stimulation lead 10 comprising four electrodes 50. FIG. 58B shows the stimulation lead 10 comprising three electrodes 50, FIG. 58C shows the stimulation lead 10 comprising two electrodes 50, and FIG. 58D shows the stimulation lead 10 comprising one electrode 50. It is noted that the stimulation lead 10 may include any number of electrodes 50 as desired, including at least one electrode, more than one electrode, at least two electrodes, more than two electrodes, a plurality of electrodes, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, etc., electrodes, including at least or more than each of the foregoing, and the like.

[00338] The electrodes 50 may be any length and width as desired and may be different lengths and/or widths as described herein. For example, FIG. 61 illustrates iso-potential lines 5 showing stimulation fields around different contact lengths demonstrating generation of a broad monopolar field with larger or longer contacts. FIG. 62 illustrates iso-potential lines 5 showing stimulation fields around contacts with different ratios of contact length to contact spacing demonstrating superposition of fields across multiple contacts.

[00339] Generally, the number of electrodes 50, in an embodiment, may correspond to the number of conductors or channels 100. The number of conductors or channels 100, in an embodiment, may similarly correspond to the number of electrodes 50. For example, a stimulation lead 10 having four conductors 100 may have four electrodes 50. see FIG. 58A; a stimulation lead 10 having three conductors 100 may have three electrodes 50. see FIG. 58B; a stimulation lead 10 having two conductors 100 may have two electrodes 50, see FIG. 58C; and a stimulation lead 10 having one conductor 100 may have one electrode 50, see FIG. 58D. A single electrode or contact may also correspond to multiple conductors or channels but the number of electrodes or contacts may not exceed the number of conductors or channels in a lead. FIGs. 58A-D similarly shows stimulation leads 100 having four, three, two, and one conductor(s) 100 respectively as well as an enlarged cross-sectional view of the conductor(s) 100. As described herein, the electrodes 50 may be formed by or from the corresponding conductor 100 and may comprise an uninsulated or de-insulated portion of the corresponding conductor 100 as shown in FIG. 58. The inner materials, e.g.. the wire strands 110, of the corresponding conductor 100 may be exposed in the uninsulated or de-insulated portion and may facilitate the application or return of electrical stimulation, thereby serving as a stimulating electrode or return electrode for electrical stimulation. The extent of deinsulation (i.e., the percentage of uninsulated portion of the conductor) may be optimized to increase the surface area of the electrode for stimulation while also providing structural support to the electrode portion of the lead and preventing fraying of wire filaments.

[00340] For example, and as shown in FIG. 59, each conductor 100 may comprise wire strands or wire filaments 110. Each conductor 100 may be generally referred to as a multistranded or multi -filar conductor(s) 100 in embodiments having multiple, at least one. or more than one wire strand or filament. In an embodiment, each conductor 100 may include a bundle or a plurality of wire strands 110. In an embodiment, each of the wire strands may have a same diameter, shape, and cross-section. It is noted that different diameters, shapes, and cross-sections, may also be used.

[00341] In an embodiment, each conductor 100 may include 37 wire strands with smaller filar size or diameter, see FIG. 64B. In an embodiment, each conductor 100 may include 49 wire strands, see FIG. 64C. In an embodiment, each conductor 100 may include 133 wire strands, see FIGs. 64D-E. It is noted that each conductor 100 may include any number of wire strands 110 as desired, including at least one wire strand, more than one wire strand, at least 19 wire strands, more than 19 wire strands, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20 wire strands, 7, 37, 49, 133, wire strands, etc., including at least or more than each of the foregoing, and the like. In an embodiment, each conductor 100 in the stimulation lead 10 may have the same number of wire strands 100 or may have a different number of wire strands 100. As shown in FIG. 64A, conventional stimulation leads may generally utilize a single larger filament or 7 larger wire filaments. The described stimulation leads 10, on the other hand, can accommodate several times the number of wire strands with smaller diameter.

[00342] In an embodiment, the wire strands 1 10 may be arranged in layers of wire strands around an inner or center core of wire strands. For example, a single wire strand (or more wire strands) may sen e as a central core 130 and a layer of wire strands may circumscribe this center wire strand. For example, a first layer of 6 wire strands 140 may circumscribe the center wire strand and another layer of wire strands may circumscribe this first layer 140. For example, a second layer of 12 wire strands may circumscribe the first layer of wire strands 140 and another layer of wire strands may circumscribe this second layer 150. For example, a third layer of 18 wire strands 160 may circumscribe the second layer of wire strands 150. The center wire strand and three layers may result in a conductor 100 having 37 wire strands, see FIG. 64B. Additional layers may be added after the third layer 160, each subsequent layer circumscribing the prior layer. In an embodiment, successive layer(s) of wire strands may be wound in an opposite direction relative a preceding layer of wire strands.

[00343] It is noted that the wire strand(s) comprising the central core 130 may be referred to as center wire strand(s). the outmost layer of wire strands may be referred to as the outer layer of wire strands, and layers between the center wire strand(s) and the outer layer of wire strands may be referred to collectively as the inner layer(s) of wire strands.

[00344] In an embodiment, the wire strands 110 may be arranged in sections and bundled together. For example, a single wire strand 110 (or more wire strands) may serve as a central core 130 and a layer of wire strands 110 may circumscribe this center wire strand 110. For example, a layer of 6 wire strands 110 may circumscribe the center wire strand 110. This central core 130 and layer of wire strands may comprise a first bundle of wire strands. In an embodiment, the central core 130 and outer layer of wire strands 110 may have 7 wire strands total. The first bundle of wire strands may be positioned in the middle of the conductor 100 or at the center of the conductor. Additional bundles, including a central core 130 and layer of wire stands circumscribing the central core 130, may themselves circumscribe the first bundle of wire strands. All of the bundles including the first bundle and additional bundles may be the same or identical. It is also noted that the bundles may be different and include a different number of layers and/or wire strands. For example, 6 additional bundles of wire strands may circumscribe the first bundle of ware strands. Each additional bundle may have, in an example, 7 wire strands total including the central core 130 and outer layer of wire strands (identical to the first bundle). The first bundle and 6 additional bundles, each having 7 wire strands, may result in a conductor 100 having 49 wire strands, see FIG. 64C. [00345] In an embodiment, each the first bundle and additional bundles may include a second layer circumscribing the central core 130 (e.g.. may have two layers circumscribing the central core 130). For example, a second layer of 12 wire strands may circumscribe the first layer of 6 wire strands, which in turn, circumscribes the single wire strand as the central core 130. In an embodiment, each bundle may include 19 wire strands total. The bundles may be positioned the same as described for FIG. 64C, only including the second additional layer on each bundle, see FIG. 64D. For example, 6 additional bundles of wire strands may circumscribe the first bundle of wire strands, which serves as a center point. Each additional bundle may have, in an example, 19 wire strands total including the central core 130, inner layer, and outer layer of wire strands (identical to the first bundle). The first bundle and 6 additional bundles, each having 19 wire strands, may result in a conductor 100 having 133 wire strands, see FIG. 64D.

[00346] In an embodiment, a second layer of additional bundles may be added. For example, the center bundle 170 and first layer of bundles 180 be positioned the same as described for FIG. 64C and may include the same number of wire strands in each bundle, e.g.. a single center wire strand and an outer layer of 6 wire strands. The conductor 100 may similarly include a center bundle 170 and a first layer of 6 additional bundles 180 circumscribing the center bundle, but the conductor 100 may further include another layer circumscribing the first layer of additional bundles. For example, a second layer of 12 additional bundles 190, each also including the same number of wire strands in each bundle, e.g., a single center wire strand and an outer layer of 6 wire strands, may further circumscribe the first layer of additional bundles. The center bundle 170, first layer of additional bundles 180, and second layer of additional bundles 190. each having 7 wire strands, may result in a conductor 100 having 133 wire strands, see FIG. 64D. As described, it is noted that the embodiments and conductors 100 in FIGs. 64D, while each having 133 wire strands, may have the wire strands oriented differently as described. Each bundle may have a certain number of layers wire strands and each conductor may have a certain number of layers of bundles.

[00347] Turning to FIGs. 68D-F, each wire strand 100 may have a specific composition. For example, as shown in FIG. 68D, each (or all) of the plurality of wire strands 110 may comprises a mechanically robust core 112 surrounded by a highly conductive material shell 114. For example, as show n in FIGs. 68E-F, each of the plurality of wire strands 110 may be formed from either a highly conductive material or a mechanically robust material so that a single conductor 110 may comprise a plurality of highly conductive wire strands 116 each formed entirely from a highly conductive material and a plurality of mechanically robust wire strands 118 each formed entirely from a mechanically robust material. As shown in FIGs. 68A-B. other stimulation leads may utilize a single conductor or wire strand (FIG. 68A) or may utilize wire stands all comprising a single material (FIG. 68B). As shown in FIG. 68C, other stimulation leads may generally utilize an opposite orientation of two dissimilar materials such as a highly conductive core and a mechanically robust shell. In an example, all wire strands in the stimulation leads may generally have the same composition in the same conductor and in the same stimulation lead.

[00348] The described stimulation leads 10, on the other hand, can include opposite material configurations (mechanically robust core and highly conductive shell), which is important for the electrical performance of the electrodes because of the highly conductive outer layer which lowers interface impedance and offers high charge injection capacity, or a variety of material configurations of the wire strands 110 in the same conductor 100 and stimulation lead 10, more wire strands, and the like, which enables various arrangements of wire filaments to optimize electrical and mechanical performance.

[00349] It is noted that the highly conductive wire strands 116 and the mechanically robust wire strands 118 may be positioned within the conductor 100 in a pattern. For example, the plurality of highly conductive wire strands 116 may form an inner core of the conductor 100 and the plurality of mechanically robust wire strands 118 may surround the inner core of the plurality of highly conductive wire strands 116. For example, the plurality of highly conductive wire strands 116 may form an inner core of the conductor 100 and the plurality of highly conductive wire strands 1 16 may form several '‘spokes” extending from the core to the outer surface of the wire strands 110 and the plurality’ of mechanically robust wire strands 118 may fill in between the “spokes.” In an embodiment, the conductor 100 may comprise more highly conductive wire strands 116 than mechanically robust wire strands 118. In an embodiment, the conductor 100 may comprise more mechanically robust wire strands 118 than highly conductive wire strands 116. It is noted that each conductor 100 in the stimulation lead 10 may have the same or different composition and patterning of the corresponding w ire strands 110.

[00350] In an embodiment, the conductors 100 (individually and together in embodiments having more than one conductor) may generally comprise a coiled body. The conductors 100 may have a generally circular, cylindrical, or rounded shape. The conductors may be generally coiled 300 horizontally or linearly, coaxially, from the proximal end 16 of the stimulation lead and toward the distal tip 19, vice versa, and the like. The conductors 100 may be coiled at different tensions. For example, as shown in FIG. 65 A, the conductors 100, such as two conductors, may be close coiled and the conductors 100 may contact each other on both sides of each conductor 100 as the conductors 100 are wound together, e.g., so that there is no space in between each successive coil 300 at equilibrium or resting state with no tension on the conductors 100.

[00351] However, the close coiled lead may become open coil when pulled or stretched lengthwise which may result in conductors not contacting each other on both sides, as shown in FIG. 65C and 65D, or on one side of each conductor as shown in FIG. 65B e.g.. as a pair or group, but leaving space between each successive coil of the pair or group. Although embodiments in FIGs. 65A-D show two conductors, it is noted that any number of conductors 100 may be used as herein described.

[00352] As described herein, the conductors 100 are insulated across the length of each conductor 100 (e.g., having insulated portions 60) and the conductor may further include uninsulated portions - also called non-insulated, exposed, or de-insulated portions - that sen es as the electrode 50 for that conductor 100. Generally, uninsulated portions and electrodes 50 may be used interchangeably unless context or this disclosure suggests otherwise. For example. FIGs. 66-67 show the formation of coiled electrodes 50 by fully or partially removing an insulating material (e g., de-insulating or uninsulating) the coiled conductors 100 in the stimulation lead 10. The inner materials of the corresponding conductor 100, e.g., the wire strands 110, may be exposed in the non-insulated portion and may facilitate the application of electrical stimulation to a patient. In an embodiment, the insulating material may encapsulate or coat the wire strands 110 or may permeate through the wire strands 110, or coils thereof. In an embodiment, and as shown in FIG. 66, the noninsulated portion may be completely non-insulated and may not include any insulation material in the portion. In an embodiment, and as shown in FIG. 66, the non-insulated portion may be partially non-insulated, e.g., wherein a cross-section of the wired strands 110 includes an insulated surface 63 including insulating material and an exposed surface 66 not including insulating material. The non-insulated portions may be coated with a highly conductive and corrosion resistant material, such as platinum iridium.

[00353] For example, approximately half of a circumference of the wire strands 110 may have the insulated surface 63 including insulating material and the remaining approximately other half of the wire stands 110 may have the exposed surface 66 not including insulating material. It is noted that other ratios of insulated and non-insulated portions may also be incorporated into the conductor 100, including 1:2, 1 :3. 1:4, 1:5, vice versa, and the like. It is also noted that the non-insulated portions may be patterned, not continuous, and the like. In an embodiment, the insulated surface 63 may face an interior of the conductor 100 as the conductor is coiled and the exposed surface 66 may be on the exterior of the conductor 100 to serve as an electrode 50 and facilitate the application of electrical stimulation.

[00354] In an embodiment, the conductors 100 may transition between inner coil 310 layers and outer coil 320 layers, see FIG. 67. FIG. 67 shows a coaxial coil arrangement where the conductors 100 may alternate between inner and outer layers of the coil at different intervals. In an embodiment, each conductor 100 may be coiled externally (e.g.. may be the outer coil 320) at least once to enable de-insulation (e g., removal of insulation coating 230) and formation of electrodes 50 for each conductor 100. For example, a conductor 100 may be provided as an inner coil 310 on the stimulation lead 10. When an inner coil 310, the conductor 100 may be fully insulated across this length or portion of the inner coil 310. When an inner coil 310, the conductor 100 may not be non-insulated. For example, the noninsulated portion and electrodes 50 may not overlap or serve as an inner coil 310. When an outer coil 320, the conductor 100 may have insulated and non-insulated portions or may have only non-insulated portions. As an outer coil 320, the position of the conductor 100 may enable de-insulation of the outer coils 320 to form electrodes 50.

[00355] In an embodiment, the size or length of the electrodes 50 or non-insulated portions may be varied based on the type or distance of the electrical stimulation desired and the proximity to the target nerve site. For example, FIG. 72A shows a stimulation lead 10 comprising four coiled conductors and four corresponding electrodes, wherein two electrodes are longer and flanked by two shorter electrodes. For example, FIG. 72B shows a stimulation lead 10 comprising four coiled conductors and four corresponding electrodes, wherein two electrodes are shorter and flanked by two longer electrodes. For example, FIG. 72C shows a stimulation lead 10 comprising five coiled conductors and five corresponding electrodes, w herein one long electrode is flanked by four shorter electrodes, with two on each side of the longer electrode. For example, FIG. 72D shows a stimulation lead 10 comprising five coiled conductors and five corresponding electrodes, wherein three shorter electrodes are flanked by two longer electrodes.

[00356] As another non-limiting example, the lead described above, where the conductors may be coiled in tandem or in parallel to form a close wound lead or close coiled lead with no spacing and/or optimal spacing between coil to minimize, prevent, control, optimize, and/or avoid excessive, unhelpful, unwanted, and/or undesirable tissue growth or formation or fibrotic growth and/or ingrowth within, around, near, adjacent to. and/or contoured to the coil which could complicate lead explant procedures due to the risk of fracture or tissue damage (e.g., avoiding unwanted tissue adherence to the electrode, contact, lead, and/or any part thereof) when removing (e.g., pulling out) the lead while also simultaneously encouraging desirable tissue grow th or formation or fibrotic growth and/or ingrowth within, around, near, adjacent to, and/or contoured to the coil which could desirably help stabilize the electrode, contact, lead, and/or any part thereof in an optimal location and enabling the invention to perform in a mechanically and electrically challenging and heterogenous environment (e.g., receiving, mitigating, minimizing, deflecting, sustaining, enduring, and/or overcoming multiple competing mechanical stresses and factors such as multiple, simultaneous, repeating, repetitive, variable, continuous, and/or changing vector(s) of mechanical force and/or mechanical characteristics and/or multiple, variable, and/or changing electrical conductance(s), impedance(s), and/or electrical characteristics of the surrounding, nearby, and/or distant tissues). Additionally, the close-coiled lead may not have (and/or may avoid needing to have) an additional outer sleeve which means a gap or space may be formed between coils when the lead is stretched along the length of the body which also enables some tissue encapsulation around the lead, thus anchoring or securing the lead in place without the need to add. build, attach, and/or append anchors, tines 420, and/or fins around it. as shown in the figures.

[00357] As a non-limiting example, the stimulating and return electrodes or contacts in the present stimulation lead may be formed from the same coiled conductors in the lead body but with the insulation coating 230 fully or partially removed or deinsulated and the conducting material exposed to deliver stimulation (as shown in the figures). Partial de-insulation may involve removing the insulation coating 230 on the exterior side of the coil that is intended to face or be in contact with the body while leaving the inside of the coil insulated. Partial deinsulation may help maintain the overall structure of the lead in the distal end and minimize the likelihood of fracture and fraying of the filars or wires since the wires are partially held together or supported by the insulation coating 230 while also enabling electrical stimulation through the exposed side of the coil. Most conventional leads may have coiled conductors in the lead body and ring- or cylinder-shaped solid electrodes welded to the distal end of the conductors to deliver stimulation, the transition from the more flexible lead body to the rigid or inflexible electrode at the distal end may be a potential point of mechanical or electrical failure or source of fracture when the lead is being stretched, bent, and/or pulled along the length. The current invention overcomes this risk of failure or fracture by using the same multi-filar and multi-stranded wires in the conductors to form the stimulating and/or return electrodes or contacts, thus resulting in a smooth transition from the lead body to the electrode.

[00358] One embodiment of this involves a coiled electrode formed by removing the insulation coating 230 of the coiled conductors at the distal end and coiling back the uninsulated conductor over the outer tubing, sleeve or j acket toward the proximal end of the electrode as shown in the figures. Similarly, multiple electrodes may be formed by stripping or removing the insulation coating 230 of each conductor at different distance away from the distal end of the coil to avoid crosstalk between conductors and coiling them over the outer tubing, jacket or sleeve at different segments to form each electrode coil as shown in the figures. However, the process of forming electrodes from the wires in the lead body becomes very challenging for a multi-contact lead that require selectively deinsulating each coiled conductor or channel (e.g., selectively removing the insulation of each conductor or channel) while maintaining independent channels and/or contacts (e.g., not electrically connected).

[00359] Another embodiment of the current invention addresses the challenge of making multiple coiled electrodes or contacts by transitioning from a large diameter mandrel 260 to a smaller diameter mandrel 260 when winding the segments of the lead where the electrodes or contacts need to be formed, as shown in FIG. 73. The insulated conductors may be coiled on the small diameter mandrel while leaving out one conductor that may be deinsulated or stripped to form an electrode or contact. Once the insulated conductors are tightly coiled on a smaller mandrel 260 and a sleeve, jacket or tubing is inserted or molded over the coiled insulated conductors, then the remaining uncoiled conductor can be deinsulated or stripped and wound over the inner coil 310 of insulated conductors, creating a second layer of coiled electrode or contact while maintaining the same and/or consistent lead diameter in the transition from lead body to electrode, contact or uninsulated conductor. Then, the coiled electrode may be terminated by cutting the conductor and attaching it to the sleeve/jacket/tubing underneath (e.g., using liquid silicone rubber) and the inner insulated conductors may transition back to a large diameter mandrel when forming the spacing between electrodes or contacts (similar to the lead body). The same steps may be used to continue deinsulating or exposing each conductor and forming or creating coiled electrodes. In another embodiment, the current invention may incorporate an alternative design involving two layers of coiled conductors arranged coaxially with one or more conductors wound internally and others coiled externally and each conductor alternates between the inner and outer layer at different segments of the lead body to enable de-insulation of each conductor as they are externally coiled and expose each stimulating electrode or contact along the lead body as depicted in the figures.

[00360] Turning to FIGs. 69 through 71, the stimulation lead 10 and conductors 100 may include an outer sleeve, jacket, or tubing 200 that surrounds, circumscribes, or encapsulates the body 13 of the stimulation lead 10 and the conductors 100. In an embodiment, the sleeve 200 surrounds all of the conductors 100 (e.g., 1, 2, 3, 4, 5, 6, 7, etc. conductors) in the stimulation lead 10. The sleeve 200 may surround all of the conductors 100 toward the proximal end 1 of the stimulation lead 10 or on a portion of the body 13 of the stimulation lead 10 and may terminate or have a terminal end 210 toward the distal tip 19 of the stimulation lead 10. The sleeve 200 and terminal end 210 thereof may end and allow the coiled conductors 100 and electrodes 50 to be exposed. The sleeve 200 may generally protect the stimulation lead 10 and may prevent excessive or undesirable tissue growth into, around, near, and/or between the coiled conductors 100 in the area that the sleeve 200 is present to facilitate intentional lead withdrawal at the end of treatment.

[00361] The sleeve 200 may include an outer surface 220. The outer surface 220 may include patterns, protrusions, indents, and the like to provide mechanical securement of the stimulation lead 10 to the tissue of the patient. For example, as shown in FIG. 69, the sleeve 200 may include a threaded outer layer (spiral pattern) for mechanical securement (selfanchoring mechanism). For example, as shown in FIG. 71, the sleeve 200 may include an intermeshed or cross-hatched outer layer for mechanical securement (self-anchoring mechanism). Similar to the conductors 100, the sleeve 200 may have different tensions applied. The tension applied may change the expansion of the conductors 100 and the sleeve 200 or the sleeve 200 may have a tension that is separate or independent from the tensions applied to the conductors 100. For example, FIG. 71 A shows the sleeve 200 and stimulation lead 10 at an equilibrium or resting state with no tension applied. FIG. 7 IB shows the sleeve 200 and stimulation lead 10 being pulled or stretched lengthwise. The sleeve 200 and outer surface 220 may facilitate removal of the stimulation lead 10 by compressing the lead body 13 when being pulled.

[00362] Another embodiment of this sleeve 200 includes a lead anchoring mechanism where the height, width, spacing, and angle of the anchoring elements on the lead body are variables that can be optimized, selected, tuned to retain the lead in tissue and resist migration and unwanted displacement but enables desirable movement with the tissue while avoiding unwanted displacement relative to the nerve while enabling intentional withdrawal when desired and pulled with a higher force. For example, the lead may have multi-layered outer tubing that lengthens or stretches and pulls in the threaded outer layer (to a thinner diameter) while also shrinking the diameter of the rest of the lead and the overall diameter, such that it reduces resistance against tissue (e.g., the threaded outer layer is no longer protruding into tissue and is no longer in the '‘grooves”, indentations and/or recessed areas of the tissue making it easy to slide out as shown in the figures.

[00363] A non-limiting embodiment of the multi-contact lead described in the current invention overcomes the limitations of prior art leads with regards to flexibility of electrodes by utilizing coiled electrodes or contacts that may be formed by deinsulating or removing the insulation of the coiled conductors in the electrode portion of the lead and coating (or making) the uninsulated portion of the conductor with a highly conductive and corrosion resistant material such as platinum-iridium which enables optimal and safe stimulation of nerve targets through the electrodes while maintaining the flexibility, stretchability and/or fatigue performance of the lead due to the coil configuration and the superior mechanical properties of the alloys used as conductors (e.g., 316L, 316LVM) underneath the coating. The stimulating electrodes for most conventional neurostimulation leads are made up of inflexible metal rings or cylinders that are welded to the conductors in the distal end of the lead body. The stiffness of the metal ring electrode minimizes the maneuverability of the electrode during placement and increases the risk of fracture at the transition from the lead body conductor to the welded metal ring- or cylinder-shaped electrode. Platinum-iridium alloy is used in many stimulating electrodes because of its excellent biocompatibility, corrosion resistance, lower impedance, and higher charge transfer capacity. Although the iridium content of the alloy greatly improves mechanical hardness, the tensile strength and fatigue resistance is lower than other alloys such as 316L, MP35N or 35NLT which are often the preferred choice to make the conductors in the lead body. The lead described in the present invention overcomes this limitation by using the same coiled conductors used in the lead body to form the core of the electrodes and replacing the insulation coating 230 by a metal coating with high electrical performance. For example, the conductor in the lead body may be made of 316L stainless steel, MP35N, 35NLT or other materials that have a good balance of tensile strength and flexibility which will likely improve the fatigue performance of the lead, but the same coiled conductor may be de-insulated in the electrode segments and coated with Platinum-iridium alloy to enable safe and optimal electrical stimulation.

[00364] In a non-limiting example, the conductive materials in the lead(s), electrode(s), conductor(s). and/or other components, may be made of any biocompatible material, including platinum, platinum indium, steel, and/or stainless steel, and/or any combination. [00365] In a non-limiting embodiment, the lead described in the present invention optimizes the tradeoff between fatigue and/or fracture resistance and optimal electrical performance of stimulating and/or return electrodes or contacts by using the same coiled conductors used in the lead body to form the core of the electrodes but replacing the insulation coating 230 by a metal coating with high electrical performance. For example, the conductor in the lead body may be made of 316L stainless steel, MP35N. 35NLT and/or other materials that have a good balance of tensile strength and flexibility which will likely improve the fatigue performance of the lead, but the same coiled conductor may be de-insulated in the electrode segments and coated with a highly conductive and biocompatible material such as Platinum-Iridium alloy to enable safe and optimal electrical stimulation. The stimulating and/or return electrodes or contacts for most conventional neurostimulation leads are made up of inflexible metal rings or cylinders 70 that are welded to the conductors in the distal end of the lead body. The stiffness of the metal ring electrode minimizes the maneuverability of the electrode during placement and increases the risk of fracture at the transition from the lead body conductor to the welded metal ring- or cylinder-shaped electrode. Although using the same conductive material in the lead body to form the electrodes/contacts may minimize fracture at the junction between the insulated lead body and the uninsulated electrodes, it may be challenging to find a material that is mechanically robust to withstand fatigue while also maintaining superior electrical properties and biocompatibility profile to be used as an electrode. Platinum-iridium alloy is used in many stimulating electrodes because of its excellent biocompatibility, corrosion resistance, lower impedance, and higher charge transfer capacity. Although the Iridium content of the alloy greatly improves mechanical hardness, the tensile strength and fatigue resistance is lower than other alloys such as 316L, MP35N or 35NLT which are often the preferred choice to strengthen the conductors in the lead body. As a non-limiting embodiment of the lead described in this invention, the electrodes may be formed from the same conductor as the lead body but uninsulated (e.g., insulation coating 230 removed) and coated with a highly conductive and corrosion resistant material such as Platinum-iridium which enables optimal and safe stimulation of nerve targets through the electrodes while maintaining the flexibility, stretchability and/or fatigue performance of the lead due to the coil configuration and the superior mechanical properties of the alloys used as conductors (e.g., 316L, 316LVM) underneath the coating.

[00366] Another non-limiting example of the stimulation lead in this invention addresses the challenges of making flexible and stretchable electrodes to enable maneuverability during placement and fatigue resistance during use by employing coiled electrodes that are formed by deinsulating or removing the insulation coating 230 of each coiled conductor at the distal end and joining the uninsulated portion to an external conductive metal coil that is placed over the lead. For instance, this may involve having a separate metal coil that is inserted over the lead tubing, sleeve, or jacket at the distal portion of the lead and welding it to the stripped and/or uninsulated end of inner coiled conductors. In another embodiment, this may involve an array of thin, external conductive metal rings 72 that are placed over the lead body and connected to the stripped and/or uninsulated end of the inner coiled conductors, wherein a single electrode is made up of an array of interconnected metal rings 70 that enable robust mechanical performance and maneuverability of electrodes during lead placement in tissue.

[00367] As another non-limiting example, the lead conductor may be designed from a combination of high-performance alloys such as MP35N, 35NLT, 316LVM and/or Nitinol that result in increased strength, ductility, biocompatibility, electrical conductivity, and/or fatigue resistance as each alloy has a unique set of properties that enhance the electrical and mechanical performance of the lead. The conductors in most conventional leads may use a single material or two materials (e.g., drawn-filled tube (DFT) wires, which consist of a highly conductive or less resistive core material and a mechanically robust and pliable outer material) for each wire filament or strand in the conductors. Although DFT wire strands or filaments may offer good electrical and mechanical performance, it may be challenging to use them for the coiled electrodes or contacts described in this invention which are formed from the same material as the coiled conductors in the lead body because the material on the outer layer of DFT wires has lower conductivity (higher impedance) and lower charge transfer capacity compared to the inner core which is not ideal for electrodes or contacts. This may not be a challenge for most conventional leads because the electrodes are metal cylinders or rings with a higher conductivity and charge injection capacity’ such as Platinum-Iridium. One embodiment of this invention includes lead conductors or channels composed of wires, filaments and/or strands that may have a very flexible and fatigue resistant core (e.g., 35NLT) and an outer surface or coating that is highly conductive with higher charge injection capacity, enabling a highly conductive stimulating electrodes while also maintaining mechanical durability.

[00368] In another embodiment, individual wires, filaments, and/or strands made of different materials may be combined, interleaved, interwoven and/or interlaced in multiple configurations within each conductor with careful selection of materials to avoid unintended effects such as corrosion and/or creation of an electric potential. For example, wire filaments or strands located centrally within the conductor may consist of one type of material and/or alloy and the outer most filaments or strands may have a different material and/or alloy, or various materials and/or alloys could be interspersed throughout the cross-section of the lead conductor (e.g., each filament or strand may use different material) to improve both electrical and mechanical performance of the lead in the body. Tube drawing process to make individual wires or filaments from two dissimilar materials, one in the core and another in the outer layer, may involve a complicated and costly manufacturing process. The current embodiment of this invention may minimize the manufacturing challenges of DFT wires by using wire filaments made of different material instead of layering different or dissimilar materials in each wire filament within a conductor, which enables more options for material variation (e.g., more than 2) since each conductor or channel is composed of many wire filaments or strands as opposed to the two layers of dissimilar materials that each individual DFT wires can have. Furthermore, the multitude of arrangements of different and/or dissimilar wires within a conductor can enable further optimization of electrical and mechanical performance of the lead by arranging highly conductive wires externally (e.g., on the external layers of the concentric filar arrangement) and mechanically robust and fatigue resistant wires internally within the core of the lead conductor or channel (the figures). Alternatively, the wires or filaments that provide mechanical support could be interspersed between the wires or filaments that optimize electrical performance within a conductor, as shown in the figures.

[00369] In another non-limiting example, the lead in the current invention may have a multilayered sleeve, tubing, jacket, casing and/or cover, where the outer layer may be textured, uneven, patterned, meshed, threaded, rough and/or ridged throughout the lead body or in certain segments to allow some tissue encapsulation or desirable tissue growth or formation or fibrotic growth and/or ingrowth within, around, near, adjacent to, and/or in between creases on the sleeve which could desirably help stabilize the location of the one or more stimulation and/or return electrode(s), contact(s), lead(s), and/or any part thereof in an optimal location to minimize migration while also concurrently reducing, minimizing, preventing, controlling, and/or avoiding excessive, unnecessary, and/or unwanted tissue growth or formation or fibrotic growth and/or ingrowth within, around, near, adjacent to, and/or between the coil by maintaining an inner layer of solid sleeve to enable or facilitate lead extraction and reduce the risk of fracture or tissue damage during lead removal or explant. One embodiment of this feature may be an outer sleeve, tubing, jacket and/or cover with a threaded spiral pattern on the external surface to allow some tissue encapsulation or desirable tissue growth or formation or fibrotic growth and/or ingrowth around the sleeve. tubing, jacket and/or cover while maintaining full coverage of the coiled lead to prevent tissue ingrowth within the coil, thus minimizing complications during lead extraction. Tissue encapsulation of the lead is important to prevent lead migration and to maintain the position of the lead in the body throughout treatment. Existing neurostimulation leads use tines 420, barbs, fins, and/or protuberances to anchor the lead within tissue and minimize migration of electrodes from the target nerve. However, excessive fibrotic ingrowth around, within and/or adjacent to the lead and/or anchors could make the lead explant or removal procedure challenging and time-consuming and may sometimes involve an invasive surgery to remove the lead without fracturing it. The lead described in this invention optimizes the tradeoff between lead extractability and lead securement by using a multi-layer sleeve, jacket and/or tubing where the outer layer(s) is textured, meshed, threaded and/or ridged to enable desirable tissue encapsulation without the need to use conventional anchors, tines 420 and/or fins to minimize lead migration due to the self-anchoring property of the textured sleeve while also mitigating the challenges of extracting the lead. Another embodiment may include a stimulation lead with the same multi-layer sleeve, jacket and/or tubing described above along with small and/or flexible anchors, fins and or tines 420 on the lead to provide additional securement while reducing the burden of lead extractability.

[00370] Turning to FIGs. 74-79, the stimulation lead 10 may include one or more anchors 400. The anchors 400 may serve as “spacers'’ between the electrodes 50 or the anchors 400 may be positioned on the insulated portions 63 of the coiled conductor, which serve as “spacers” between the electrodes 50. It is noted that the stimulation lead may include any number of anchors 400 as desired, including at least one anchor, more than one anchor, at least two anchors, more than two anchors, a plurality of anchors, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, etc., anchors, including at least or more than each of the foregoing, and the like. The anchors 400 may be positioned on the body 14 of the stimulation lead 10 and may generally surround the coiled conductors 100 or be positioned on the outer surface of the coiled conductors 100. In an embodiment the anchors 400 may be positioned on or toward the distal tip 19 of the stimulation lead 10. In an embodiment, the anchors 400 may be positioned on the insulated portions or surface 64 of the coiled conductors 100. In an embodiment, the at least one anchor 400 may be provided on each and all of the insulated portions or surface 64 of the coiled conductors 100, see Figs. 72A-D, for example.

[00371] As shown in FIG. 74A-C, in an example, the anchors 400 may be invertible or capable of reversing direction. The anchors 4000 may be invertible or capable of reversing direction based on the tension or force applied. For example, the anchors 400 may be backward facing at an equilibrium or resting state. In the backward-facing position (e.g., pointed away from the distal tip 19 of the stimulation lead 10 or toward the proximal end 16) at an equilibrium or resting state, the anchors 400 may provide stabilization and anchoring into the tissue of the patient to prevent movement or migration of the stimulation lead 10 in a backward direction. For example, the anchors 400 may be invertible or reversible to an opposite forward-facing direction (e.g.. pointed toward the distal tip 19 of the stimulation lead 10 or away from the proximal end 16) when being pulled or stretched lengthwise. In the forward-facing position at a tension or pulled state, the anchors 400 may allow the stimulation lead 10 to be pulled backward and removed from the patient.

[00372] As shown in FIG. 75A-C, a removal sheath 250 may also be used to detach or remove the anchors 400 from the lead body 13 of the stimulation lead 10 when the stimulation lead 10 is ready for removal from the patent. The sheath 250 may be inserted over the lead body 13 of the stimulation lead 10 during lead retrieval to cut or remove the anchors 400 as the sheath slides over the body 13 of the stimulation lead 10 from proximal 16 to distal end 19 of the stimulation lead 10. It is noted that the anchors 400 may be slightly rotated, misaligned, and/or offset at different points along the length of the stimulation lead 10. The different positioning may minimize unwanted migration in multiple axes (directions). As shown in FIG. 75 D-E tines 420 may have different arrangements.

[00373] As shown in FIG. 75D-E. in an example, the anchors 400 may be collapsible or expandable. The anchors 400 may be collapsible or expandable based on the use of an introducer or casing that can hold or push the anchors 400 into a collapsed state and release the anchors 400 to an expanded state when removed. For example, the anchors 400 can collapse, fold, or w rap around the body 13 of the stimulation lead 10 so that the anchors 400 may be generally flat when the introducer or casing covers the anchors 400. The anchors can expand, unfold, or unwrap to extend from the body 14 of the stimulation lead 10 so that the anchors 400 may be protruding when the introducer or casing is removed. The collapse and expansion of the anchors 400 may be similar to a “blooming flower” when deployed into an expanded state. The anchors 400 may be deployed into an expanded state once the simulation lead 10 is implanted or positioned into a desired position of the patient. The anchors 140 may be retracted into a collapsed state when the stimulation lead 10 is ready for removal from the patient.

[00374] The lead 10 described in this invention is designed to overcome the limitations of prior art and achieve multiple conflicting goals by optimizing lead securement, lead extractability, fluid ingress protection, and mechanical durability with an outer tubing, sleeve and/or jacket made of a combination of materials arranged in a unique configuration and/or orientation such as in a multi-layer structure where the inner layer could be made of a very flexible, stretchable and/or pliable material (e.g., silicone) and the outer layer could be made of a stronger, harder and/or abrasion resistant material (e.g., polyurethane) which may be a solid layer or a threaded, meshed, interwoven, ridged, fibrous, and/or cross-hatched layer, as shown in FIGs. 29-30. to provide additional strength and/or support and also enable compression of the lead body when being pulled which reduces the overall diameter of the lead and allows the lead to be explanted easily (FIG. 71 for example). The current invention addresses the challenges with conventional anchoring systems by using a self-anchoring lead with a textured, uneven, patterned and/or ridged outer sleeve that allows desirable tissue encapsulation and possible compression of the lead body when stretched and/or pulled along the length, and minimizes excessive tissue or fibrotic growth and/or ingrowth associated with conventional anchoring systems and facilities lead removal or explant. The present invention overcomes the limitations of conventional leads, which may only have a single outer sleeve to cover the conductors or conducting wires in the leads, and/or may have a continuous solid tubing or sleeve without any opening, hole, break, indentation, and/or groove along its length to minimize exposure of the conductors or wires to bodily fluid and/or tissues and fluid and/or contaminant ingress through the lumen and/or spaces along the shaft of the lead traveling to the pulse generator and/or the electrodes/contacts. The inner sleeve of the present invention protects against this exposure to the body while maintaining the mechanical flexibility of the lead.

[00375] The lead described above, where the stimulating or return contacts or electrodes may be different sizes/lengths to preferentially activate different targets requiring different electrode/contact sizes. For example, individual smaller contacts may preferentially activate different areas, while activation of multiple contacts simultaneously could mimic the field from a single larger contact. Another example is the use of smaller contacts to target smaller nerve trunks, where a broad uniform stimulating field that is too large may cause unwanted activation of non-target fibers in nearby non-target nen e trunks and/or local fibers located in tissues surrounding the target nerve; while the same lead could also have longer contacts to target larger nerve trunks if needed. The user could test the different contact sizes on the lead over the target nerve to determine which provides better responses (e.g., comfortable stimulation without causing discomfort) without having to switch leads. Another example is a lead with a long contact (approximately 5-15 mm or longer) with shorter contacts (approximately 1-4 mm) on either side of the long contact. The long contact may be the primary contact used for stimulation, and the shorter adjacent contacts may be activated, turned on, start delivering stimulation along with the long contact to grow the broad uniform stimulation field in smaller amounts compared to activating, turning on, or starting to deliver stimulation from another long contact, which may grow the field too much and activate nontarget fibers (e.g., in non-target nerve trunks or in local surrounding tissue). In another embodiment, the long distal stimulating contact may be coupled with various configurations of proximal return electrode(s) (i.e.. size, shape, orientation) to increase the size of the broad stimulation field while optimizing patient comfort and enhancing therapeutic benefit (e.g., pain relief).

[00376] In another non-limiting example, the lead described above may also be bent, curved, undulating, or wound along different sections of the lead to alter the field's shape. The lead could be shaped to bend around the nerve trunk, be implanted between branches of a nerve, and/or to target multiple nerves with separate electrodes/contacts, which may enable the electrodes to be oriented in an optimal direction with respect to the target nerves. For example, in the head and neck, the lead could be bent, routed, or curved to target both the greater occipital and lesser occipital nerve(s). Another non-limiting example includes targeting the branches of the sciatic nerve, including the tibial nerve and common peroneal (fibular) nerve by bending, routing, or curving the lead between the branches and/or orienting the electrodes in an optimal orientation, including perpendicular, parallel, and/or at an angle to the nerve trunk. The bent, curved, or undulating lead may also be helpful to allow the lead to be implanted and remain in place through specific parts of the body to minimize stresses on the lead (flexing, bending, shearing), which would reduce the risk of lead fracture, breakage, and migration. For example, the lead may be bent or curved to travel within a tissue plane, neurovascular bundle, bony canal or fissures, notches, etc. Existing conventional leads cannot be bent too sharply or acutely and remain in that shape without damage to the lead conductors and/or insulating jacket. Also, existing conventional leads can target multiple nerve trunks but may require placement at an orientation with respect to one or more of the target nerves that reduces or eliminates the ability to selectively activate the target nerve fibers in the trunk while avoiding activation of non-target fibers in the trunk and/or surrounding tissue.

[00377] In another embodiment, the lead described above with a pliable conductor material in the bent or curved sections of the lead such as shape-memory alloys (e.g., nitinol) and a very flexible material on the outer sleeve such as silicone to improve flexibility and/or to maintain shape. [00378] In another embodiment, the lead described above where the bent or curved section can be manufactured by adjusting the winding tension or heat treatment in those sections or by winding it around a mandrel that has an arc/bend to it so that the coiled lead will maintain the shape of the mandrel. Existing conventional leads are either straight conductors/channels or are coiled using a straight uncurvcd mandrel, resulting in a straight lead.

[00379] In an embodiment, the present invention also includes modular mandrels, shafts and/or spindles that may be used to construct the multi-contact coiled lead described in this invention, where mandrel segments of different diameters, length, size, shape, and/or curvature can be attached to each other (e.g., screwed together) for variable winding or coiling diameters and/or lengths along the length of the lead. In a non-limiting example, the modular mandrels may be used with a mandrel component having a larger diameter with multiple conductors wound or coiled around it: then one or more of the conductors is separated or pulled out from the other conductors to form one of the electrodes while the remaining conductors continue to be coiled along a mandrel component with smaller diameter that is attached to the larger diameter mandrel; then the one or more conductors that were separated or pulled out are wound around and over the other conductors that had been wound around the smaller-diameter mandrel to form the electrode. The construction of a multi-contact coiled lead may be challenging, difficult to automate for manufacturing, and time-consuming due to the need to change the winding diameter, selectively deinsulate or remove insulation coating 230 of conductors to form or expose electrodes or contacts, swap out mandrels, and/or terminate the end of the coiled conductor while ensuring seamless and/or consistent transition between each segment at different points along the length of the lead. This invention minimizes this challenge by using modular mandrels that have various lengths, diameters and assemblies or connections which fits into existing coiling machine fixtures and enables efficient, time- and cost-effective manufacturing of the multi-contact coiled lead in this invention while enabling the flexibility to change different parameters of the lead as needed.

[00380] In another non-limiting example, the lead described above, including an introducer which may be a needle with a cutting edge on one side that tapers toward the distal end, so it dilates the tissue it passes through rather than cutting through it. Existing introducers for leads may cause significant tissue damage or trauma during the procedure, and may lead to additional post-operative pain.

[00381] In another non-limiting example, the lead described above, including an introducer that can be bent to the shape of the lead without fracturing and while maintaining the proper diameter to allow the lead to be deployed (e.g., lead does not get stuck at a bend due to reduced diameter). The introducer could be bent prior to inserting the lead or during the procedure to correctly place the lead around the nerve or make the entry angle easier. The introducer may include a fibrous support structure or mesh to enable bending to the shape of the lead while preventing it from kinking. Existing introducers for conventional leads cannot guarantee that the diameter will remain large enough for the lead if the introducer is bent and/or the introducer may kink, preventing the lead from being inserted through the introducer and/or preventing the lead from being deployed because the bend/kink in the introducer has reduced the diameter to the point that the lead can no longer pass through the lumen of the introducer.

[00382] In another non-limiting example, the lead described above is used where one or more contacts are used for stimulation while one or more contacts are used for recording. The recording contacts could be used for closed loop feedback stimulation (e.g., by recording an evoked compound action potential from stimulation or electromyogram), to inform lead placement (e.g., by recording local muscle activation and/or evoked compound action potentials surrounding the lead), or a combination of both approaches. For example, the lead may be placed parallel to the target nerve trunk, and the evoked compound action potential from the nerve could be measured using one or more contacts from the lead (e.g., the nonstimulating contacts) and used to determine if and how adjustment is needed to stimulation parameters and/or which electrodes to use for stimulation. Another example is if stimulation is delivered through one or more electrodes to activate motor fibers, and electrodes on the same lead located within or near the muscle activated by those motor fibers can be used to record the electromyogram signal. The electromyogram signal can then be used to determine if and how adjustment is needed to stimulation parameters and/or which electrodes to use for stimulation. Adjustment of these factors may be manual by the user/patient and/or automatic based on an algorithm within the other system components (e.g., pulse generator, user interface [patient remote, clinician controller]). The electrical impedances, resistance, conductance, capacitance, and/or inductance of the electrodes intended for recording may be different from those intended for stimulation (e.g., higher electrical impedance to improve localization/noise reduction of recorded signal). Conventional leads with multiple electrodes/contacts have the same or similar electrical properties (resistance, conductance, capacitance, inductance) across the electrodes and cannot record bioelectric signals (e.g., evoked compound action potentials, electroneurograms, electromyograms, and/or electrocardiograms) accurately/precisely and/or have low energy efficiency when try ing to stimulate through the electrode with high impedance due to the resistive energy loss.

[00383] In an embodiment, the lead and/or return electrode may be fully implanted. In an embodiment, the lead may be fully implanted, and the return electrode may be external. In an embodiment, the lead and return electrode may be fully implanted with an external control unit outside the skin. In an embodiment, the lead and/or return electrode includes an anchoring system placed or secured along one or more different sections of the lead to prevent migration. For example, these anchoring devices may be placed between one or more contacts to facilitate keeping the lead bent or curved along a path. The anchoring system may consist of a screw, coil, hook, and/or tube and it may be curved, bent, hollow and may have sharp comers to place the lead in specific tissue. For example, the lead and/or return electrode may use a hook at the end of one or more contacts to help deploy the lead and keep it in place during testing and lead deployment. A coiled anchor may help keep the lead and/or return electrode in place when inadvertent tension is applied to the lead while unwinding when a stronger intentional tension is applied to remove the lead and/or return electrode.

[00384] One embodiment of the lead body in the present invention involves making anchors on the lead by removing material from the lead body/sleeve and creating a hole, groove and/or indentation on or along the distal tip of the lead body to facilitate tissue/fibrotic growth or ingrow th around, within, over, and/or adjacent to these holes, grooves, indentations and uneven surfaces on the lead body and reduce unwanted movement or migration of electrodes/contacts and lead while also minimizing the need to have big anchors protruding from the lead body, making lead removal easier and also allowing the lead to fit within a smaller size or gauge needle. Most conventional anchoring methods involve attaching additional material to the lead body which complicates the lead explant procedure because the anchors are physically located outside the lead body and within surrounding tissues making the lead explant or removal process challenging and time-consuming since it may not be easily removed by pulling out the lead without lead fracture or disruption of surrounding tissues. In addition, conventional anchors increase the overall diameter of the lead, which requires the use of larger introducer needles, which are more painful and challenging to insert percutaneously and/or require an incision to implant.

[00385] The lead described above, including additional groove or indentation at different points along the length of the lead. For example, a spiral groove along the entire length or segments of the lead body may increase desirable tissue encapsulation. Or, selectively including groves between each contact and/or at the distal tip near, around, surrounding and/or between the electrodes, and/or at the proximal end near the IPG 500 connector. Alternatively, the lead body may have an outer jacket that is threaded like a screw along parts of the length or along the entire length, helping the lead minimize migration while facilitating lead removal by allowing the user to unscrew/twist the lead out.

[00386] In a non-limiting example, lead securement may be achieved with a mechanical design that allows the physician to control anchor deployment and retrieval based on the amount of pull force applied on the lead. For example, a pull force of approximately between 10N -15N can cause the anchors to retract or fold back making it easy to remove the lead. In an example, if the pull force is under approximately 10N, the anchors will remain deployed and if it is over approximately 15N, the lead will permanently deform. One non-limiting embodiment of this involves anchors that invert back when sufficient pull force is applied (similar to an inverted umbrella) allowing the lead to be removed easily. An alternative embodiment may involve a lead with two layers of sleeve where the anchors are connected to the inner layer through an opening on the outer sleeve allowing the anchors to slide in when the inner sleeve is pulled during lead removal. Conventional leads may have anchors that do not fold or retract are challenging to remove intact without fracturing along the lead body and/or at the anchors due to tissue encapsulation and growth around the anchors, and the anchors help keep the lead in place even when the user and/or clinician is intentionally try ing to remove or explant the lead.

[00387] Lead anchoring mechanism that enables physicians to customize anchor positions depending on target nen e and surrounding tissues. This may be achieved by having multiple anchors along the lead body and providing a means/tool to remove anchors during procedure as needed, thus allowing physicians to choose anchor points for lead securement. One embodiment of this tool includes a percutaneous sheath that cuts/removes anchors as it slides over the lead body and the physician can control which anchors to remove by controlling how far the percutaneous sheath travels over the lead body.

[00388] Lead anchoring mechanism that enables the lead to be contained within an introducer needle without significantly increasing the overall diameter of the needle. This may be possible by using anchors that are flat along the length of the lead and may wrap (fold) around the lead body when loaded in the introducer and unwrap when the lead is deployed in the body providing anchor to surrounding tissues. For example, the anchors may emerge from the inner layer of the sleeve/jacket/tubing and extend tangentially from the cross section of the lead body allowing them to collapse on or wrap around the sleeve/jacket/tubing when rotating the lead body opposite to the direction the anchors are exiting the sleeve. jacket, or tubing allowing easier lead removal and also enabling it to remain compactly wrapped within an introducer needle until the anchors are deployed and return to their tangential position securing the lead in tissue. In another non-limiting example, the lead body may have slots or channels in which the anchor fits when loaded in an introducer such that the anchor does not significantly increase the diameter of the lead and the lead can fit into the introducer.

[00389] The lead anchor in the present invention may be made of a biodegradable or bioabsorbable material such as PGA, PLA, PCL, or their copolymers that breaks down and is absorbed into the body over a period of time (e.g., 2 months to 2 years) beyond which tissue growth, ingrowth or encapsulation will be sufficient to hold the lead in place while also facilitating lead removal at the end of treatment when the anchors are fully absorbed or degraded. Most conventional leads have a tine 420 system to anchor or secure the lead within tissue and minimize migration of electrodes from the target nerve. However, tissue/fibrotic growth or ingrowlh around these tines 420 or anchors 400 makes lead removal or explant very challenging and time-consuming due to the risk of lead fracture when pulling the lead with a significant force or complications from tissue damage when portion of the tissue surrounding, around, within, and/or adjacent to the anchor is removed or moved by the anchors when the lead is being pulled.

[00390] Another non-limiting embodiment includes a lead anchor that may disconnect, detach, disengage, uncouple, or disjoin from the lead body over the course of months beyond which tissue encapsulation assisted by the stretchiness and flexibility of the lead will be sufficient to hold, secure, or fasten the lead in tissue. This may be achieved by using dissimilar materials for the anchor and the lead body sleeve/tubing such as silicone sleeve and polypropylene anchors to reduce the natural tendency to adhere to one another and using a loose or shallow mechanical anchoring and/or attachment to temporarily bond the anchor to the lead for approximately 2-9 months and detaches upon prolonged cyclic stresses in the body, and the lead anchor material may be biocompatible, MR Conditional (e.g., at least 1.5T) or MR Safe, and safe to remain in the body indefinitely once the lead is removed or explanted.

[00391] In an embodiment, the system has a lead anchor that will disconnect, detach, disengage, uncouple, or disjoin from the lead body during lead retrieval when a certain amount of pull force is applied. This may be achieved with a lead anchor material that is biocompatible and safe to remain in the body indefinitely once the lead is removed. This may be achieved by adjusting the bond strength of the anchor to the lead body to sufficiently retain the position of the lead within tissue but also lower than the pull force required to completely remove the lead, thus enabling removal of anchors from the lead body prior to pulling the lead out which minimizes tissue damage.

[00392] In an embodiment, the system has a needle with a sharp, razor-like edge that is inserted over the lead body during lead retrieval to cut/remove lead anchors 400 or tines 420 as it slides over the lead body and enables easier removal of the anchor-free lead without having to apply excessive force that could cause lead fracture or tissue damage. This may be achieved with a lead anchor material that is biocompatible and safe to remain in the body indefinitely once the lead is removed. Also, the needle is designed to cut through the lead anchors without cutting through the lead body or electrodes (e.g., controlling sharpness of needle, protective guide to prevent cutting through lead).

[00393] Another embodiment includes a lead anchor that is visible under imaging to facilitate lead removal. For example, a lead anchor that is radiopaque and/or echogenic may enable physicians to easily identify anchor points or the location of anchors on the lead and in the body to enable lead extraction by dissecting near those anchor points and avoiding the need for large incision, which could complicate the procedure and the recovery of the patient. [00394] The lead anchor described above, where the radiopacity and echogenicity does not significantly impact MRI compatibility. This can be accomplished by using biocompatible materials that have relatively low magnetic susceptibility indices such as metal alloys containing Titanium and Tungsten or other materials (e.g., calcium, hydroxyapatite)

[00395] The lead anchors at different points along the length of lead body may be slightly rotated, asynchronously aligned and/or offset at a certain angle (e.g., 90° or 45°) to minimize unwanted movement or migration of electrodes/contacts and lead in more than one direction and/or dimensions.

[00396] The current invention also incorporates lead removal tool(s). One embodiment of the lead removal tool may be a percutaneous sheath with a cutting edge that is inserted over the lead during lead removal and cuts the anchors or tines as it slides over the lead body. Another example of the lead removal tool may be a stylet with one or more anchors, hooks, prongs, and/or barbs at the distal tip that is inserted into the lumen of the lead and hooked to one of the coiled conductors at the distal end and enable easier removal of the lead without uncoiling. The lead removal tool may also be an external device with a DC motor that binds to the coiled conductors and either unwinds or tightly winds the coil to reduce the diameter of the lead and enable easier lead removal for potential embodiments of the stimulation lead without anchor or tines and/or with no tubing or sleeve over the coiled conductors. [00397] As another non-limiting example, the present invention embodies a lead removal tool that may fit within the lumen of the lead and secure, fasten, hook, tie, and/or clip itself to one or more points within the lead body (e.g., the tool may have anchors that slide between coil within the lead body and secure the tool to the lead) which provides support for lead removal and minimizes uncoiling of lead during explant. This will enable the lead to be removed easily and/or entirely (either intact or all pieces of the lead if the lead does fracture). For example, the lead removal tool may be a stylet that fits within the lumen of the lead and has one or more directional barbs, prongs, anchors and/or hooks that allow for insertion into the lead but cannot be w ithdrawn without engaging the interior wall of the lead. Conventional leads are removed by pulling and creating tension along lead length. This causes tension/stress, stretches the jacket and conductors/ wires, causes lead to fracture during removal, explant or extraction, requiring invasive surgery to remove the remnant. Alternatively, physicians perform invasive surgery to loosen lead from tissue encapsulation prior to lead removal or explant. The lead removal tool in this invention provides support within the lumen, minimizing or preventing the lead from stretching, reducing tension on wires, allowing lead to come out intact.

[00398] A lead and a lead removal tool where the removal tool (e g., needle) is inserted into the lumen of the lead, partway or entirely to the distal tip, and a material that can harden (e.g., polymer, liquid silicone rubber) may be injected within the lumen of the lead. The material will provide mechanical strength to the lead and help keep the lead intact upon removal.

[00399] Lead removal tool that attaches, fastens, hooks, and/or clips to the conductors within the lead body at one or more points along the length of the lead either by penetrating through the external sleeve, tubing or jacket enclosing the lead or by inserting the tool into the lumen of the lead and unwinds the coil by spinning in the direction opposite to the coiling direction, or straightens the coil by spinning perpendicular to the cross section of the coil, thus pulling the conductors longitudinally, which reduces the diameter of the lead and allows the anchors and lead to separate from the tissue encapsulating the lead and facilitating lead removal. As non-limiting examples, the unwinding, spinning, and/or rotating may be accomplished using a rotating DC motor, a separate torque wrench that fits into the end of the portion inserted into the lead, a small knob at the end of the tool for manual rotation that only allows rotation in the correct direction for lead removal. Alternatively, a lead removal tool that attaches, fastens, hooks, and/or clips to the conductors within the lead body at one or more points along the length of the lead and winds the coil more tightly by spinning in the same direction as the coiling direction, which may reduce the diameter of the coiled lead body, and potentially facilitate lead extraction.

[00400] FIG. 60 shows variations of wire configurations for an implantable multi-contact lead design including 7 filar, 19 filar and 37 filar cables with an insulation coating 230 to separate each conductor. All four conductors are wound in tandem to form a closed coil as shown in the figure. A highly flexible sleeve shown as transparent tubing is also used to protect and maintain the shape of the coil.

[00401] FIG. 71 shows one variation of the implantable multi-contact lead with four electrodes. The electrodes are the deinsulated segments of each conductor as indicated in the magnified images. The inter-electrode spacing is insulated and has the same protective sleeve as the lead body. A variation may have electrodes pulled out and coiled over the protective sleeve instead of removing the sleeve to expose electrodes.

[00402] FIG. 80 shows one variation of the percutaneous and/or implantable multi-contact lead design with 2 electrodes. The top two images show the cross-sectional view of the coil along the length of the lead. The stimulating electrodes have a closed coil configuration (top left) and the spacing between electrodes has an open coil configuration (top right). For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection. The most distal electrode is folded back to serve as an anchor, tine, and/or securing element. In a non-limiting example, the lead may not have an anchor, tine, and/or securing element at the end..

[00403] FIG. 81 shows another variation of the percutaneous and/or implantable multicontact lead design with 3 electrodes. The top two images show' the cross-sectional view' of the coil along the length of the lead. The stimulating electrodes have a closed coil configuration (top right) and the spacing between electrodes has an open coil configuration (top left). For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection.

[00404] FIG. 82 shows the distal end of the second variation of the percutaneous and/or implantable multi-contact lead design with 3 electrodes. The top image shows the distal end of the lead w ith all 3 electrodes and the bottom image is a zoomed view w ith only the 2 most distal electrodes. The most distal electrode is folded back to serve as an anchor, tine, and/or securing element. In a non-limiting example, the lead may not have an anchor, tine, and/or securing element at the end. [00405] FIG. 83 shows a third variation of the percutaneous and/or implantable multicontact lead design with 4 electrodes. The top two images show the cross-sectional view of the coil along the length of the lead. The stimulating electrodes have a closed coil configuration (top right) and the spacing between electrodes has an open coil configuration (top left). For a percutaneous lead, the coiled conductors do not have an outer sleeve such as a cylindrical electrically insulating sleeve along the length of the lead (but the coiled conductors still have an electrically insulating layer around them except, for example, because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection.

[00406] FIG. 84 shows the distal end of the third variation of the percutaneous and/or implantable multi-contact lead design with 4 electrodes. The top image shows the distal end of the lead with all 4 electrodes and the bottom image is a zoomed view with only the 2 most distal electrodes. The most distal electrode is folded back to serve as an anchor, tine, and/or securing element. In a non-limiting example, the lead may not have an anchor, tine, and/or securing element at the end..

[00407] FIG. 85 shows a fourth variation of the percutaneous and/or implantable multicontact lead design with 2 electrodes. The top two images show the cross-sectional view of the coil along the length of the lead. The stimulating electrodes have a closed coil configuration (top right) and the spacing between electrodes has an open coil configuration (top left). For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection.

[00408] FIG. 86 shows the distal end of the fourth variation of the percutaneous and/or implantable multi-contact lead design with 2 electrodes. The most distal electrode is folded back to serve as an anchor, tine, and/or securing element. In a non-limiting example, the lead may not have an anchor, tine, and/or securing element at the end.

[00409] FIG. 87 shows a fifth variation of the percutaneous and/or implantable multi-contact lead design with 3 electrodes. The top two images show the cross-sectional view of the coil along the length of the lead. The stimulating electrodes have a closed coil configuration (top right) and the spacing between electrodes has an open coil configuration (top left). For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrow th in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection. [00410] FIG. 88 shows the distal end of the fifth variation of the percutaneous and/or implantable multi-contact lead design with 3 electrodes. The top image shows the distal end of the lead with all 3 electrodes and the bottom image is a zoomed view with only the 2 most distal electrodes. The most distal electrode is folded back to serve as an anchor, tine, and/or securing element. In a non-limiting example, the lead may not have an anchor, tine, and/or securing element at the end.

[00411] FIG. 89 shows a sixth variation of the percutaneous and/or implantable multicontact lead design with 4 electrodes. The top two images show the cross-sectional view of the coil along the length of the lead. The stimulating electrodes have a closed coil configuration (top right) and the spacing between electrodes has an open coil configuration (top left). For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection.

[00412] FIG. 90 shows the distal end of the sixth variation of the percutaneous and/or implantable multi-contact lead design with 4 electrodes. The top image shows the distal end of the lead with all 4 electrodes and the bottom image is a zoomed view with only the 2 most distal electrodes. The most distal electrode is folded back to serve as an anchor, tine, and/or securing element. In a non-limiting example, the lead may not have an anchor, tine, and/or securing element at the end.

[00413] FIG. 91 shows a seventh variation of the percutaneous and/or implantable multicontact lead design with 3 electrodes. The top two images show the cross-sectional view of the coil along the length of the lead. The stimulating electrodes which are the deinsulated conductors are coiled externally while the other two insulated conductors are coiled internally (top right) and the entire lead has an open coil configuration. For a percutaneous lead, the coiled conductors do not have an outer sleeve because tissue ingrowth in the open coil segment helps prevent lead migration and indwelling lead pistoning effects which could reduce infection.

[00414] FIG. 92 shows the distal end of the seventh variation of the percutaneous and/or implantable multi-contact lead design with 3 electrodes.

[00415] FIG. 93 shows an example drawing of the multi-contact lead.

[00416] FIG. 94 shows an example activation of different contacts along a 4-contact multicontact lead.

[00417] The concepts as shown in FIG. 112A-F incorporate the use of a unique lead design (with possible implementations within the setting of a fully implantable system or a percutaneous system) with one or more electrodes incorporated into the lead such that distal electrode(s) (e.g., which may serve as the cathode and/or anode, may be near, adjacent to, away from, and/or remote to or from a nerve, such as a target nerve or peripheral nerve, and/or may be away from or close to the IPG 500) on the lead utilize the proximal electrode(s) (e.g., at the other end of the lead) on the lead as a return path for the delivered stimulation current. For example, the preferred location for the distal electrodes is remote from a nerve (-0.5-1 cm away), and the preferred location for the proximal electrodes is next to the connection point between the lead and IPG 500. The spacing between electrodes on the lead may be uniform and/or intentionally non-uniform. For example, the spacing between the most distal electrodes may be small to reduce the gap in the stimulation fields generated by each electrode individually while the spacing between the electrode that may be used as the return electrode and the other electrodes may be greater to reduce the overlap of fields generated by the stimulating and return electrodes, creating a more monopolar field.

[00418] Tight spacing of distal electrodes: Each of the distal electrodes may be activated individually to deliver stimulation to target nerve fibers, and there is a volume of tissue around an electrode over which nerves may be activated for a given pulse generator's stimulation parameters. The parts of tissue not covered by any of the electrodes’ volumes of tissue are where the lead and its electrodes cannot activate nerve fibers. If the electrodes are spaced too far apart, then there may be gaps along the length of the electrode where nerve fibers cannot be activated. If the electrodes are spaced close enough together such that the volumes of tissue overlap, then these gaps are reduced or eliminated.

[00419] Use of proximal electrode as return electrode: The overall stimulation field generated from every active electrode is the superposition of the fields generated by the individual electrodes. Electrodes that are closer to one another will have a greater change on the overall stimulation field (relative to their individual fields) because electric potential in a conductive medium decreases proportionally to the square of the distance from the source. Electrodes that are sufficiently far away from each other with one acting as anode and the other as cathode may be considered monopolar because the field generated by one electrode is approximately zero near the other electrode and vice versa, and thus, the field around each electrode is approximately the same as if the other electrode was not active.

[00420] Non-uniform spacing is preferred because the spacing between the distal stimulating electrodes (which themselves may or may not be spaced uniformly) is expected to be much smaller than the space between the proximal electrode and the distal electrodes to enable the monopolar stimulation as descnbed above. [00421] The concept shown in FIG. 101 incorporates the use of one or more additional lead(s) with electrode(s) capable of acting as return path(s) for the delivered stimulation current from one or more electrode(s) on a primary lead. Conventional systems use the IPG can or electrodes on the same lead as the stimulating electrode to serve as the return electrode. To do this, the circuitry⁷ within the system (e.g., in the pulse generator) may use electrical switches to control which electrode(s) is the stimulating electrode(s) and which electrode(s) (or the IPG can) will serve as the return electrode(s). In this concept, the switches select electrodes on another lead (other than the one on which the stimulating electrode is located) to act as the return electrode.

[00422] If more than one lead is being used to deliver stimulation to target nerve(s), then stimulation pulses may be interleaved such that when stimulation is being delivered through 1 lead and/or electrode, the electrode(s) on the other lead(s) act as the return electrode(s); and when a stimulation pulse is not being delivered through a lead, then its electrode(s) may serve as a return electrode for the lead delivering the stimulation pulse. It should be understood that this can apply to each of the embodiments disclosed previously and hereafter.

[00423] When a single return electrode is used, the amplitude of the stimulation pulse at the return electrode must equal the amplitude of the primary stimulation pulse. When multiple return electrodes are used, the sum of the amplitudes of the stimulation pulses at the return electrodes equals the amplitude of the primary stimulation pulse. The amplitudes at the return electrodes may or may not be equal. This may be accomplished by a user programming the proportion of the stimulating current to be returned to each of the return electrodes (e.g., 0.5, 0.2, 0.3 to 3 different return electrodes), and the circuitry within the system (e.g., in the IPG 500) adjusting the current at each return electrode accordingly. This may also be accomplished automatically with the IPG 500 making some measurement (e.g., voltages and current at each return electrode) and adjusting the proportions of current returned to each electrode according to some optimization function (e.g., minimizing overall power, which is the sum of the pow er at each return electrode, which can be calculated by Ii*Vi where “i" is a return electrode, I is the current, and V is the voltage. This may also be accomplished through a combination of user programming and automation by the system. For example, the IPG 500 may make automatic adjustments of the proportion of current going to each return electrode, and the user may indicate to the system if they are experiencing discomfort at a return electrode (causing the system to decrease the intensity at that return electrode and increase the intensity accordingly at the other return electrodes). It should be understood that this can apply to each of the embodiments disclosed previously and hereafter. [00424] The charge recovery may be equal or non-equal, and/or balanced or un-balanced. The preferred approach is equal and balanced so that any charge delivered to the body by the stimulating electrode is returned back during the charge recovery phase (e.g., biphasic pulse). If a net charge is delivered to the body, this can corrode the electrode and/or cause tissue damage. It should be understood that this can apply to each of the embodiments disclosed previously and hereafter.

[00425] Some systems have net DC (direct current) on the stimulation pulse, and the recovery phase may not have exactly the same charge recovery as the stimulating phase to account for the net DC signal - see FIG. 112.

[00426] The additional lead(s) may not be identical to the first lead and may be designed specifically to act as a return electrode. The electrodes may be larger in surface area than the electrodes on the first lead to minimize uncomfortable sensations, pain, unwanted tingling or muscle contractions. The proposed system addresses several challenges and problems with the present state of the art. As an example, it addresses a common challenge and complaint that has previously been reported and observed with the prior art when the outer metal can of an IPG 500 is used as the return electrode and unwanted responses, such as uncomfortable sensations, pain, undesirable muscle contractions, unwanted activation or stimulation of off- target or non-target nerve fibers, and/or other undesirable effects, around and/or near the can due to its size and proximity to structures and nerves, such as peripheral nerves, cutaneous nerves, off-target nerves or nerve fibers, non-target nerves or nerve fibers, the surface of the skin, subcutaneous tissue, other tissue, and/or other layers of tissue below the skin, such as where cutaneous nerve fibers and other non-target fibers are located, and/or in or near muscle tissue where efferent (motor) fibers and nen es may be present. Increasing the size of the return electrode(s) and making it or them larger than the stimulating electrodes on the primary' stimulating lead, and/or locating it or them in another location, may prevent, avoid, mitigate, and/or reduce the unwanted responses and/or chance of causing discomfort, pain and/or undesirable muscle activation, tension, or contraction. For a given stimulating current amplitude, as surface area increases, the current density' decreases. This weakens the field close to the electrode and reduces the likelihood of activating local nerve fibers that can cause discomfort, unwanted sensations, and/or motor activation. Discomfort around the return electrode(s) may be caused by the specific ty pes of local nerve fibers and specific locations with respect to the electrode. Moving the return electrode(s) to another location may result in different local nerve fibers and/or different locations with respect to the electrode. For example, moving the return electrode from close to the skin (e.g., < 1 cm to the surface) to deeper in the tissue (e.g., >3 cm to the surface) moves the return electrode away from cutaneous nerve fibers located near the surface of the skin and decreases the chance of their activation because the current threshold to activate nerve fibers increases with distance. Another example is moving the electrode from within muscle to within connective tissue, which may move the electrode away from motor fibers within the muscle and decrease the likelihood of activating them.

[00427] The lead(s) and/or electrode(s) intended to be used as return electrodes may have shapes designed specifically to be implanted in certain parts of the body.

[00428] For example, lead(s) and/or electrode(s) may be designed specifically to be implanted near the surface of the skin. The lead(s) may include a paddle electrode(s) with an insulated side facing the skin surface and the electrodes facing away from the skin surface. The paddle may be flexible to contour to the body and avoid discomfort or protrusion. The lead body may have a flat or non-circular profile to improve comfort and avoid protrusion through the skin.

[00429] Another example is a lead designed to be placed in non-excitable tissue (e.g., adipose tissue, connective tissue, body parts that lack pain/sensory fibers [back of elbow]). The lead may have tines or an anchoring system where the lead is secured to tissue that can keep the lead in place (e.g., muscle, bone, fascia) even though the electrodes may reside in tissue to which it is challenging to secure a lead (e.g., fat/adipose tissue). One example of such a lead is where the tines or anchoring system can be adjusted along the length of the lead.

[00430] The additional leads may be long and/or short to allow the return electrode to be distant from the power receive coil in implantable pulse generators (IPG 500s) that do and/or do not contain a battery, a primary cell battery, a rechargeable battery, and/or other power or charge storage ability or capacity. The long lead may be used with the activation stimulation and the short lead may be used as the return electrode or more specifically a lead with a return electrode. A long lead may be used when 1) heating during wireless powering/charging is a concern (e g., limits rate of wireless powering), and/or 2) need to move return electrode away to avoid discomfort (e.g.. deeper in the tissue, another location in the body). A short lead may be used when 1) impedance is a concern, which may limit maximum stimulating amplitude and/or increase energy consumption, because a shorter lead has lower impedance than a longer lead, 2) physician/patient doesn’t want an excessively long lead, which can be hard to implant due to excess lead and/or be uncomfortable, and/or 3) keeping return electrode close to IPG 500 is desired (e.g., certainty of location, easier to manage). When

I l l power is transferred wirelessly from the surface of the skin to the IPG 500 (e.g., either to deliver energy to output the stimulation or to charge a rechargeable battery), certain materials around the power receive coil may be exposed to the field generated by the external power transmit coil, generating heat in the body. This heat limits the rate at which power can be transferred safely. By placing the return electrode distant from the power receive coil (e.g., outside the radius of the return electrode plus some safety factor [e.g., ~5 cm] to account for potential misalignment by user), the amount of heat generated may be reduced substantially and enable more efficient power transfer (e.g., faster power transfer, smaller transmit/ receive coils, ability to transfer power over greater distances between the receive and transmit coils, more forgiving placement, alignment, and/or misalignment of the IPGs 500, external power unit(s) (EPU), charging unit(s). charger(s), coil(s), transmit coil(s), receive coil(s), and/or related devices).

[00431] The short lead acting as the return electrode may allow it to be easier to implant within the patient. The short lead need only to be spaced so that no unintentional stimulation of a nerve or other part thereof occurs while still allowing monopolar stimulation. This may then allow placement of the IPG 500 to be easier. The IPG 500 would not need a return electrode on it (the short lead provides such) and as such, placing the IPG 500 within the patient is easier as it does not need to be placed to avoid unwanted electrical stimulation. Not having the return electrode built into the IPG 500 also will allow the IPG 500 to have a reduced footprint and to be smaller than those IPGs 500 that have a return electrode. This is particularly effective for peripheral nerve stimulation described herein that is monopolar. Monopolar PNS tends to require higher intensity than other electrical stimulation systems, including, without limitation, spinal cord stimulation. The current and voltage being higher for monopolar PNS can result in unwanted stimulation around the IPG 500. This does not occur in spinal cord and other types of electrical stimulation. The short lead prevents this unwanted stimulation that is unique to monopolar PNS.

[00432] The return electrode and lead may also be designed using materials that are biocompatible and electrically conductive but do not heat up when subjected to radiofrequency (RF), and/or with shapes that minimize heating. Wireless (e.g.. RF) powering may induce eddy currents in certain materials, and the degree of eddy currents is influenced by the type of material and its shape.

[00433] The concept shown in Figure 61 incorporates the implementation of electrode(s) into lead connector(s) / lead connection point(s) that are capable of acting as return electrode(s) such that the distal electrode(s) on the lead(s) utilize the electrode(s) on the lead connector(s), adaptor(s), lead connection device, apparatus, and/or point(s) as the return path for the delivered stimulation current. The locations of the return electrodes may be distant enough away (e.g., outside the radius of the return electrode plus some safety factor [e.g., ~5 cm] to account for potential misalignment by user) from the power receive coil to avoid generating heat during wireless power transfer from an external powering unit.

[00434] Another embodiment incorporates a return electrode on the implantable pulse generator (e.g.. outer metal can) and includes a separate power receive coil that can be placed distant from the IPG 500.

[00435] A further embodiment as shown in Figure 62 incorporates an IPG 500 with an outer can made primarily from a non-electrically conductive material (e.g., ceramic, silicone). A return electrode is incorporated into the outer can such that unwanted, undesirable and/or eddy currents or other effects generated from an external wireless power transmitter are minimized. For example, one or more thin metal line(s) that does not form any loops may be embedded in the can. This design maintains a high surface area while limiting the formation of unwanted, undesirable and/or eddy currents or other effects in, near, and/or around the can. This design reduces heating generated from the eddy currents, allowing greater efficiency of wireless power transfer. The shape of the return electrodes limits the size of potential eddy currents by precluding the formation of loops of current with large areas on the conductive surface.

[00436] Additionally, and/or alternatively, metal(s) and/or material(s) that are biocompatible and can serve as a return electrode but do not heat up when subjected to a radiofrequency (RF) field during wireless power transfer may be used.

[00437] The electrode(s), conductor(s), and/or other components may or may not be made of a specific metal(s), material(s), and/or any biocompatible material (and/or any combination) that is acceptable and safe for the intended purpose (e.g., serving as electrode(s), conductor(s), and/or other components) and may or may not include or be made, manufactured, and/or composed (in whole, ratio(s), percentage(s), combination(s), and/or in part(s)) of metal(s), material(s) and/or alloy(s), which may or may not be medical grade and/or acceptable for human use and/or surgical or percutaneous placement, implant, or implantation, such as platinum, platinum iridium, stainless steel, stainless steel, stainless steel 316LVM, nitinol, nickel titanium alloy(s), MP35N, nickel-cobalt based alloy(s), cobalt- chromium-nickel alloy (s), nickel, cobalt, chromium, molybdenum, iron, titanium, manganese, silicon, phosphorus, carbon, boron, and/or sulfur. [00438] Any combination or permutation and/or all of the concepts may or may not be used in any combination and/or conjunction of the other concepts. In addition, any combination of the concepts may also be used conjunction with the use of a return electrode incorporated into and/or integral with an implantable pulse generator case/can or an external return electrode used with an external pulse generator and/or any combination

[00439] What has been described above includes examples of the present specification. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present specification, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present specification are possible. Each of the components described above may be combined or added together in any permutation to define embodiments disclosed herein. Accordingly, the present specification is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes'’ is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising'’ is interpreted when employed as a transitional word in a claim.

[00440] The system and method of the present disclosure overcomes multiple challenges associated with the prior art and provides systems and/or methods to enable monopolar or pseudo-monopolar stimulation for effective treatment of pain, providing or enabling pain relief, improvement in function, and/or treatment of disease(s) and/or disorders of the body, body parts, peripheral nervous system, and/or central nervous system using stimulation and/or electrical stimulation. The use of the present system enables more effective and forgiving treatment, meaning that results and outcomes that w ere not previously possible with the prior art will now be possible with the present system, which can make effective results and/or treatment available and/or more widely available regardless of and/or able to overcome challenges associated with patient body habitus, shape, size, anatomy, anatomical irregularities, and/or physician and/or healthcare provider skill or skill level and/or practice setting or environment, including urban and/or rural settings, and/or academic, private practice(s). for-profit and non-profit institution(s), center(s), hospital(s), and/or practice(s). It enables use of a small IPG 500 (e.g., sufficiently small to enable optimal and easy placement with a minimally-invasive procedure that is easily learned and performed by the physician or provider) with desirable characteristics in combination with a lead(s) and/or electrode(s) with desirable characteristics as part of a system that may or may not be used in combination with external components (e.g., components or parts of the system which are outside or manufactured to be used outside of the body), which may communicate with and/or power the internal components (e.g., components or parts of the system which are inside or manufactured to be used inside of the body and/or under the skin, in tissue, and/or subcutaneously), where the external components of the system may include a w ireless power unit(s) or external power unit(s) (EPU), a communication device(s) and/or circuitry. programmer(s), remote(s), and/or other tools and/or components which may be used prior to, during, and/or after a procedure or surgery to implant one or more components of the system. [00441] A lead anchor or tine attachment method involving a solid single lead body tubing with a molded anchoring tube that is attached to the outer surface of the main lead body tubing. One method of assembling the anchor tube to the lead body tubing involves segmented assembly where the anchoring tube (i.e., a cylindrical tube with prongs or barbs protruding from the tube) is inserted between two adjacent lead body tubing segments that are flush against each other. These segments are laterally adjoined using an adhesive applied on the edges of these tubes. While this segmented method reduces the diameter of the lead hence requiring a smaller needle to percutaneously implant it in the body, the surface area of adhesion is limited to the adjoining edges and may compromise the structural integrity of the lead. The current design overcomes these conflicting challenges by employing the layered approach where the anchoring tube is attached to the outer surface of the lead body tubing but the flap-style protruding elements of the anchoring tube (i.e., anchor, prong, barb) is designed to have the same width as the tube’s thickness and are located on the proximal edge of the tube allowing it to fully fold back when inserted through an introducer needle. A foldable tine or anchor effectively reduces the lead's diameter as it is advanced through the introducer sheath, thereby minimizing trauma to the patient during the lead implantation procedure.

[00442] A lead anchor or tine attachment method involving dissimilar materials that do not naturally adhere to each other. Dissimilar materials may be used in combination to achieve a certain mechanical performance. For instance, silicone may be a great choice for lead body tubing because of its softness and elasticity, which may enhance patient comfort and help reduce lead migration. On the other hand, polyurethane, with its stiffness and tensile strength, may be an ideal choice for anchoring tines as it is resistant to movement. Combining these two dissimilar materials can be challenging since the two do not naturally adhere to each other. One way to overcome the adhesion issue is using silicone primer which can be applied to the polyurethane anchoring tube to enhance adhesion to the silicone adhesive. While primers enhance adhesion, they are typically a last resort as they come dispersed in a solvent and have a limited active time between drying and silicone application. This method requires immersing the lead or anchor tubing in the primer, followed by wicking the primer from the inside of the tubing to prevent a thick layer from forming, as this could reduce adhesion, particularly in the lumen of small-diameter tubes. To address this challenge, a compression technique can be employed to mechanically secure these two materials instead of relying on adhesive alone. A compression technique involves using an anchoring tube with a slightly smaller diameter than the lead body, allowing for mechanical securement. Additionally, a fillet can be added to each side of the anchoring tube to withstand axial movement, and a notch can be added in the anchoring tube and filled with an adhesive to mechanically secure the anchors in place and prevent rotational movement.

[00443] A method for securing the conducting wires (i. e. , coils) inside the lead body to the lead body tubing. Some materials such as silicone can be readily available in an adhesive that is 100% solids, while other materials such as polyurethane may not, which is why a solventbased glues are created by dissolving polyurethane pellets in a solvent to create a lacquer which only has a small percentage of polyurethane. When used to bond polyurethane lead body tubing to polyurethane anchor tubing, the solvent-based glue works by dissolving the polyurethane lead body tubing and the anchor tubing to achieve a bond. The solvent glue must be applied in small amounts and built up in several layers, which otherwise will dissolve and distort the lead body tubing and anchor tubing. The limitation with the solvent-based glue is that it does not have any bonding ability to the lead coil at the distal end and it does not have backfilling capabilities (i.e.. it is not capable of filling a large gap). This is because, once the solvent evaporates, only a thin film of dissolved polyurethane remains, which is only suitable for butt joining. Without a plug or a mechanical anchoring at the distal end of the lead body, the lead coil would simply slide out. The present invention overcomes this challenge with other assembly methods such as thermal bonding or reflow that requires molds and fixtures or by directly molding to the lead body. The thermal reflow method requires significant fixture design and can create stresses in the polyurethane if not annealed afterwards. Molding directly to the lead body may address this challenge by inserting the lead body tubing into the mold and injecting the molten material into the mold. However, this method is more complicated with polyurethane than silicone because polyurethane is a thermoplastic material whereas silicone is a thermoset material that can handle the heat of molding without melting. The polyurethane melt is highly viscous, so the mold must be heated to prevent the melt from solidifying in the runners and to ensure it flows further into the mold. The smaller the orifices the harder it is to make the polyurethane flow and the higher the mold temperature that is needed. This method involves precisely controlling the mold temperature to ensure smooth injection and flow of the molten polyurethane, while also preventing distortion of the lead body tubing due to the mold temperature. A lead design involving a wire configuration that optimizes mechanical and electrical performance. Decreasing the size of wire filaments while increasing the number (e.g., count) of wire filaments can potentially increase flexibility' and durability of the lead under repetitive stress. According to the mechanical and electrical performance analysis performed on various wire variations, increasing the wire count from 7-filar to 19-filar while maintaining the same outer diameter resulted in a notable improvement in fatigue life without compromising tensile strength. However, moving from 19-filar to 32-filar did not enhance the fatigue life and caused a significant reduction in tensile strength. Therefore, 19-filar wire appears to offer an optimal balance between tensile strength and fatigue life.

[00444] Another embodiment of an anchoring feature that prevents bidirectional lead migration (forward and backward) in two orthogonal planes. This embodiment features a single anchoring tube with a set of two tines facing backward (i.e., the proximal end of the lead) and orthogonal to another set of two tines facing forward (i.e., the distal end of the lead), and vice versa. This may significantly reduce the risk of lead migration in multiple directions and orientations, while facilitating lead explant procedure by reducing the number of anchoring features on the lead.

[00445] In reference to FIG. 105, a single anchoring tube with a set of two tines facing backward (i.e., the proximal end of the lead) and orthogonal to another set of two tines facing forward (i.e., the distal end of the lead), and vice versa. This significantly reduces the risk of lead migration in multiple directions and orientations, while facilitating lead explant procedure by reducing the number of anchoring features on the lead.

[00446] In reference to FIG. 116, flexible electrodes constructed from the same wires as the lead body conductors; safe charge density enabling electrode surface area of > 30cm², 1.3mm lead body' diameter. Outer tubing to prevent fluid ingress and excessive tissue ingrow th, and to enhance the fatigue life. Designed to reduce migration risks via anchoring features (tines), and elastic lead body tubing.

[00447] FIG. 103 embodies a lead as further described in the specification. The lead may comprise an anchor tube consisting of a flap- style, foldable anchoring element, which is attached to the outer surface of the main lead body tubing. The lead comprises a butt-joint assembly: the lead body tubing segments and the anchor tubing segment aligned and secured using adhesive. One of the leads shown embodies a layered assembly: molded anchor tubing is attached to the outer surface of the lead body tubing. The lead may also comprise a flap- style anchoring element at the proximal edge of the anchor tube, which enables it to fold back onto the lead body tubing during insertion through an introducer sheath. The anchoring elements fold back onto the lead body tubing when advanced through an introducer sheath.

[0044S] FIG 104 embodies a full lead design with coiled electrodes and a flap-style anchoring tube at the distal end. The lead may comprise proximal connectors with a fixation sleeve, tines, and electrodes. A section view of the lead is shown wherein an embodiment comprises a conductor with a 1x19 filar configuration.

[00449] FIG 105 embodies a single anchoring feature that prevents bidirectional lead migration (forward and backward) in two orthogonal planes. A single anchoring tube with a set of two tines facing backward (i.e., the proximal end of the lead) and orthogonal to another set of two tines facing forward (i.e., the distal end of the lead), and vice versa. This may significantly reduce the risk of lead migration in multiple directions and orientations, while facilitating lead explant procedure by reducing the number of anchoring features on the lead. [00450] FIG 106 A depicts one example of a tine design and FIG. 106B embodies an exemplary tine design, where such designs are consistent with what is described elsewhere in this specification.

[00451] FIG 107A depicts one example of a tine design and FIG. 107B embodies an exemplary tine design, where such designs are consistent with what is described elsewhere in this specification.

[00452] FIGS. 108A and B depict one example of a tine design and FIGS. 108C and D embody an exemplary tine design, where such designs are consistent with what is described elsewhere in this specification.

[00453] FIGS 109A-D depicts exemplary embodiments of an introducer system that may be utilized with the lead and return electrode designs described in this specification. This may comprise an introducer sheath with an insertion needle position within the introducer sheath. A lead stylet may be insertable into the introducer sheath. The lead may be deployed from the introducer sheath. A lead tunneling device may be utilized, which may comprise a tunneling rod and a passing straw. FIGS. 110A-C depicts the lead introducer system utilized for implanting the lead and deploying the tines of the embodiments described in the specification.

[00454] FIGS. 111A-C depicts an embodiment of a lead introducer system utilized for implanting the lead and deploying the tines of the embodiments described in the specification. [00455] FIGS. 112A-B disclose a lead as described in this specification elsewhere. The lead comprises electrodes and return electrodes and a tine or anchoring system. Also shown is a fixation sleeve.

[00456] FIG. 113A-B depicts a lead stylet in operation with a lead to be deployed.

[00457] FIG. 114 depicts a lead tunneling tool configured to be utilized in implanting the lead with return electrode described herein.

[00458] FIG. 115 depicts an embodiment of a lead that comprises a coiled body with proximal connectors, a fixation sleeve, tines, and electrodes that comprise non-insulated segments of the lead.

[00459] FIG 116 depicts an embodiment of a lead that comprises a coiled body with proximal connectors, a fixation sleeve, tines, and electrodes that comprise non-insulated segments of the lead. The lead comprises flexible electrodes constructed from the same wires as the lead body conductors. The lead comprises a safe charge density enabling electrode surface area of > 30 cm2. The lead comprises a 1.3mm lead body diameter. The outer tubing of the lead prevents fluid ingress and excessive tissue ingrowth and enhances the fatigue life. The lead is designed to reduce migration risks via anchoring features (tines) and a body comprising an elastic lead body tubing.

[00460] FIG. 117 depicts an embodiment of a pulse generator. The pulse generator may be an implantable pulse generator that comprises a connector block and set screw, a receiver coil and lead connector to which the lead depicted in the specification may be operatively connected.

[00461] In reference to FIG. 117. An example follows:

[00462] FIG. 118 depicts an embodiment of the lead implanted on a patient. The leads may be placed medial to lateral from the insertion site. A minimum of 1 strain relief loop is placed at the lead insertion site before tunneling both leads superficially to one side of the lower back (i.e., IPG implant location). The lead may comprise a length of 30 - 35cm.

[00463] FIG. 119 depicts an embodiment of the lead implanted on a patient. The lead pathway varies based on the nerve target, body habitus and patient’s shoulder mobility. Lateral deltoid (upper arm) and upper back IPG locations require shorter lead pathways. If the IPG is placed in the pectoral space or lower back, longer lead pathways are required. The lead may comprise a length of 20 - 60cm.

[00464] FIG. 120 depicts a lead body comprising a terminal end for electrical connection to an IPG and shared connectors. The image also depicts embodiments of tensile testing and flex fatigue testing of the lead.

[00465] FIG. 121 depicts embodiments of migration and excitability bench testing of the embodiments of the leads depicted herein.

[00466] In reference to FIG. 121, an example follows:

[00467] FIG. 122 depicts an embodiment of a lead that comprises a coiled body with proximal connectors, a fixation sleeve, tines, and electrodes.

[00468] FIG. 123 depicts an embodiment of the lead implanted on a patient.

[00469] FIG. 124 depicts embodiments of IPG pocket incisions on a patient.

[00470] FIG. 125 depicts embodiments of lead insertion sites on a patient. [00471] FIG. 126 depicts embodiments of IPG orientation and pocket incision on patients.

[00472] FIG. 127 depicts an example of the IPG and lead depth on a patient.

[00473] FIG. 128 are examples of lead pathways of the leads disclosed herein on a patient.

[00474] FIG. 129 depicts an example of lead tunneling from an IPG implanted on a patient.

[00475] FIG. 130 are examples of potential lead pathways for an IPG implanted in a lower back of a patient.

[00476] FIG. 131 are examples of potential lead pathways for an IPG implanted in a lower back of a patient.

[00477] FIG. 132 is an exemplary' lead comprising an anchoring tube with a plurality of tines.

[00478] FIG. 133 is an exemplary lead comprising an anchoring tube with a plurality of tines.

[00479] FIG. 134 is an exemplary' lead comprising an anchoring tube with a plurality' of tines.

[00480] Now referring to FIG. 127 A which illustrates an embodiment of a segmented tubing assembly. FIG. 127B illustrates an embodiment of a single lead tubing and an outer layer of molded tine with a large surface area of interface between the lead tubing and the anchor/tine body to address tine/anchor separation from the lead body during lead extraction (labeled “New Tine Design’").

[00481] FIG. 128 A. illustrates an embodiment of flap-style tine designed (labeled “New Tine Design”) with a smaller tine width that folds along the lead body during insertion of the lead through a 7F introducer to address lead tines being too big and rigid to pass through a 7F introducer (2.2mm ID).

[00482] FIG. 128B illustrates an embodiment of flap-style tine designed with a smaller tine width that folds along the lead body during insertion of the lead through a 7F introducer to address lead tines being too big and rigid to pass through a 7F introducer (2.2mm ID). Silicone primer may be applied to the Polyurethane anchor or polyurethane lead body tubing to enhance adhesion to silicone adhesive which is used to join the silicone lead body tubing to the polyurethane anchor tube or the polyurethane lead body tubing to the silicone anchor, since inadequate adhesion between the lead body tubing and the anchor/tine can occur (especially for dissimilar materials that do not naturally adhere to each other, such as silicone lead body to polyurethane tines, or polyurethane lead body to silicone tines). An additional consideration for this approach is that while primers enhance adhesion, they come dispersed in a solvent and have a limited active time between drying and silicone application. This method would also require immersing the lead tubing or anchor tubing in the primer, then the primer is wicked from the inside of the tubing to avoid a thick layer of primer, which can reduce adhesion especially in the lumen of a small diameter tube. An additional approach to address this includes a compression technique that can be used to put a polyurethane lead body into a molded silicone anchor. The intent is that the silicone anchor tube is smaller than the lead body. Generally, silicone and polyurethane are mechanically anchored rather than rely on adhesive alone. In the case of a polyurethane anchor to silicone lead, a fillet may be added to each side of the anchor body to withstand axial movement and a notch may be added in the anchor body and filled with silicone adhesive to mechanically secure the anchors in place and prevent rotational movement.

[00483] In continued reference to FIGS 127-128. alternative assembly methods such as thermal bonding or reflow (that will require molds and fixtures or by directly molding to the lead body) may be used to address backfilling the distal end of a polyurethane lead body tubing to secure the lead coil. Unlike silicone, polyurethane is not readily available in an implant grade polyurethane adhesive that is 100% solids. Solvent-based polyurethane glues are created by dissolving pellets in a solvent to create a lacquer which is low solids and works by dissolving the polyurethane lead body tubing and anchor to achieve a bond. The solvent glue must be applied in small amounts and built up in several layers otherwise it will dissolve and distort the lead body and anchor. The limitation with the solvent-based glue is that it does not have any bonding ability to the lead coil at the distal end. Once the solvent evaporates, a thin film of the dissolved polyurethane is all that is left. It does not have backfilling capability (i.e., it is not capable of filling a large gap).

[00484] The invention can desirably create a sufficiently broad, uniform, and/or selectively stimulating or activating field such that target nerve fibers of a certain class, type, function, group, innervation pattern, size, and/or diameter are activated (e.g., type I and/or II nerve fibers, tactile sensory fiber(s), A alpha and/or A beta fibers, muscle sensory fibers, A alpha and/or A beta fibers, motor fibers or alpha fibers) or fibers of a certain size such as greater than or equal to 5 .6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, and/or 25 microns or micrometers in diameter are activated) while avoiding activation of non-target and/or off-target nerve fibers of a certain class, type, function, group, innervation patter, size, and/or diameter (e.g., type I and/or II nerve fibers, tactile sensory fiber(s), A alpha and/or A beta fibers, muscle sensory⁷ fibers, A alpha and/or A beta fibers, motor fibers or alpha fibers) or fibers of a certain size such as less than or equal to 1. 2, 3, 4. 5 ,6, 7. 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, and/or 24 microns or micrometers in diameter are not activated (e.g., activation of which is avoided)). The non-target fibers and/or off-target fibers may be located near or far from any one or more of the electrodes of the present invention, and/or the electrodes of present invention may be located adjacent, touching, near or far away from any one or more of the non-target fibers and/or off-target fibers. For example, an electrode serving as the return electrode may be located adjacent, touching, near or far away from any one or more of the non-target fibers and/or off-target fibers, while enabling the stimulating electrode to create a sufficiently broad, uniform, and/or selectively stimulating or activating field to achieve the desired effects while avoiding the undesirable effects.

[00485] The present invention enables the use of a system that does not require (e.g., it avoids the use of or avoids the requirement of) a return electrode to be a part of the IPG, pulse generator, or power receive unit (e.g., it avoids the need for the IPG to be integrated with the return electrode or the can to serve as the return electrode), enabling the use of a desirably small IPG and/or desirably small external unit (e.g., external power unit) while enabling the system to be forgiving of significant misalignment (e.g., displacement, linear displacement, angular, and/or tilt) in either relative or absolute measurements, or amounts between the internal unit (e.g., IPG, pulse generator, receiver, or powder receive component) and the external unit (e.g. external power unit, external power transmission unit, etc.). It is also to be appreciated that the present invention may enable enhanced use of a system with an IPG, pulse generator, or power receive unit that has one or more return electrodes and/or is integrated with an electrode that can serve as the return electrode), and which return electrode(s) or combination of return electrodes are used can be selected or chosen by the user to maximize and/or achieve the desirable effects or features of the system and avoid and/or reduce undesirable effects. In a non-limited example, the present invention enables selective stimulation or activation of target fibers, avoidance of activation or stimulation or non-target fibers and/or off-target fibers, placement of the lead(s), pulse generator(s), and/or pow er receive and/or transmission units, in comfortable and functional locations that enable intended and uninterrupted delivery of treatment, while avoiding treatment interruption, avoidance of damage to tissue or the system, avoidance of erosion of tissue (e.g.. avoidance of skin erosion), avoidance of unwanted muscle activation, avoidance of activation of cutaneous afferent pain fibers, avoidance of patient discomfort, avoidance of patient pain, and providing and/or enabling pain relief and/or resultant improvement in quality of life.

[00486] Although the embodiments of the present teachings have been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be understood that the present teachings are not to be limited to just the embodiments disclosed, but that the present teachings described herein are capable of numerous rearrangements, modifications and substitutions without departing from the scope of the claims hereafter. The claims as follows are intended to include all modifications and alterations insofar as they come within the scope of the claims or the equivalent thereof.

Claims

CLAIMS What is claimed is:

1. A peripheral nerve stimulation system comprising: a pulse generator; a lead comprising a distal end, a proximal end, and a plurality of electrodes, wherein the plurality of electrodes comprise at least one distal stimulating electrode configured to deliver electrical stimulation to a target peripheral nerve and at least one return electrode positioned distant from the distal stimulating electrode; and wherein the at least one return electrode has a larger surface area than the distal stimulating electrode and is configured to return current to the pulse generator.

2. The peripheral nerve stimulation system of claim 1, wherein the at least one return electrode comprises a plurality of return electrodes.

3. The peripheral nerve stimulation system of claim 1, wherein the at least one return electrode is located distant from the pulse generator.

4. The peripheral nerve stimulation system of claim 1. wherein the at least one return electrode is located on the proximal end of the lead.

5. The peripheral nerve stimulation system of claim 1, further comprising at least one additional lead comprising at least one electrode configured to serve as a return electrode.

6. The peripheral nerve stimulation system of claim 5, wherein the additional lead comprising the return electrode is positionable distant from the lead comprising the stimulating electrode.

7. The peripheral nerve stimulation system of claim 5, wherein the additional lead comprising the return electrode is positionable distant from the pulse generator.

8. The peripheral nerve stimulation system of claim 5, wherein the additional lead is positionable to avoid causing activation of excitable tissue.

9. The peripheral nerve stimulation system of claim 5, wherein the additional lead the additional lead is positionable in non-excitable tissue.

10. The peripheral nerve stimulation system of claim 1, wherein the plurality of electrodes, including the at least one distal stimulating and the at least one return electrode, are not all a same size.

11. The peripheral nerve stimulation system of claim 1, wherein the at least one return electrode is larger than the distal at least one stimulating electrode.

12. The peripheral nerve stimulation system of claim 1, wherein spacing between the plurality of electrodes is not uniform.

13. The peripheral nerve stimulation system of claim 1, wherein spacing between the at least one distal stimulating electrode and the at least one return electrode is greater than a spacing between adjacent distal stimulating electrodes.

14. The peripheral nerve stimulation system of claim 1, wherein the lead comprises a plurality of return electrodes having a total surface area greater than a surface are of the at least one distal stimulating electrode.

15. The peripheral nerve stimulation system of claim 1, wherein the lead comprises a plurality⁷ of return electrodes having a perimeter greater than a perimeter of the at least one distal stimulating electrode.

16. The peripheral nerve stimulation system of claim 1, wherein the at least one return electrode is formed by a coiled conductor or a series of ring electrodes.

17. The peripheral nerve stimulation system of claim 1, further comprising a lead connector or adaptor having at least one return electrode electrically coupled to the pulse generator.

18. The peripheral nerve stimulation system of claim 1, wherein the at least one return electrode is recessed within an electrically insulating portion of the lead.

19. The peripheral nerve stimulation system of claim 1, wherein the at least one return electrode extends beyond an electrically insulating portion of the lead.

20. The peripheral nerve stimulation system of claim 1, wherein a proportion of current returned through each of multiple return electrodes is programmable or automatically adjustable to minimize patient discomfort.

21. The peripheral nerve stimulation system of claim 1, wherein the lead is fully implantable within a patient's body.

22. The peripheral nen e stimulation system of claim 1, wherein the lead is percutaneous and exits skin to connect to the pulse generator.

23. The peripheral nerve stimulation system of claim 1, wherein the return electrode is located on or forms a pad.

24. The peripheral nerve stimulation system of claim 1, wherein the return electrode is located on an open-coil lead or a closed-coil lead.

25. A peripheral nerve stimulation system comprising: a pulse generator; a lead comprising a distal end, a proximal end and a plurality⁷ of electrodes, wherein the plurality of electrodes comprise a distal stimulating electrode configured to deliver electrical stimulation to a target peripheral nerve and a return electrode positioned distant from the distal stimulating electrode; and wherein the return electrode is configured to return current to the pulse generator and is positioned such that it is distant from both the stimulating electrode and a power-receiving component of the system.

26. The peripheral nerve stimulation system of claim 25, wherein the power-receiving component of the system is the pulse generator.

27. The peripheral nerve stimulation system of claim 25, wherein the return electrode is located on the proximal end of the lead.

28. The peripheral nen e stimulation system of claim 25, further comprising at least one additional lead with an electrode configured to serve as a return electrode.

29. The peripheral nerve stimulation system of claim 28, wherein the additional lead comprising the return electrode is positionable distant from the lead comprising the stimulating electrode.

30. The peripheral nerve stimulation system of claim 28, wherein the additional lead comprising the return electrode is positionable distant from the pulse generator.

31. The peripheral nerve stimulation system of claim 28, wherein the additional lead is positionable to avoid causing activation of excitable tissue.

32. The peripheral nerve stimulation system of claim 28, wherein the additional lead is positionable in non-excitable tissue.

33. The peripheral nerve stimulation system of claim 25, wherein the plurality of electrodes, including the distal stimulating and return electrodes, are not all a same size.

34. The peripheral nerve stimulation system of claim 25, wherein the return electrode is larger than the distal stimulating electrode.

35. The peripheral nerve stimulation system of claim 25, wherein spacing between the plurality of electrodes is not uniform.

36. The peripheral nerve stimulation system of claim 25, wherein spacing between the distal stimulating electrode and the return electrode is greater than spacing between adjacent distal stimulating electrodes.

37. The peripheral nerve stimulation system of claim 25, wherein the lead comprises a plurality of return electrodes having a total surface area greater than a surface area of the distal stimulating electrode.

38. The peripheral nerve stimulation system of claim 25, wherein the lead comprises a plurality of return electrodes having a perimeter greater than a perimeter of the distal stimulating electrode.

39. The peripheral nerve stimulation system of claim 25, wherein the return electrode is formed by a coiled conductor or a series of ring electrodes.

40. The peripheral nerve stimulation system of claim 25. further comprising a lead connector or adaptor having at least one return electrode electrically coupled to the pulse generator.

41. The peripheral nerve stimulation system of claim 25, wherein the return electrode is recessed w ithin an electrically insulating portion of the lead.

42. The peripheral nerve stimulation system of claim 25, wherein the return electrode extends beyond an electrically insulating portion of the lead.

43. The peripheral nerve stimulation system of claim 25, wherein a proportion of current returned through each of multiple return electrodes is programmable or automatically adjustable to minimize patient discomfort.

44. The peripheral nerve stimulation system of claim 25, wherein the lead is fully implantable within a patient’s body.

45. The peripheral nerve stimulation system of claim 25, wherein the lead is percutaneous and exits skin to connect to the pulse generator.

46. The peripheral nerve stimulation system of claim 25, wherein the return electrode is located on or forms a pad.

47. The peripheral nerve stimulation system of claim 25, wherein the lead is an open-coil lead.

48. The peripheral nerve stimulation system of claim 25, wherein the lead is a closed-coil lead.

49. A peripheral nerve stimulation system comprising: a pulse generator; a lead comprising a distal end, a proximal end and a plurality of electrodes, wherein the plurality of electrodes comprise a distal stimulating electrode configured to deliver electrical stimulation to a target peripheral nerve; and one or more return electrodes wherein the one or more return electrodes are configured to return current to the pulse generator, and are positioned distant from the stimulating electrode.

50. The peripheral nerve stimulation system of claim 49, wherein the one or more return electrodes are positioned distant from the pulse generator.

51. The peripheral nerve stimulation system of claim 49, wherein the one or more return electrodes are located on the proximal end of the lead.

52. The peripheral nerve stimulation system of claim 49, further comprising at least one additional lead with at least one electrode configured to serve as a return electrode.

53. The peripheral nerve stimulation system of claim 52, wherein the additional lead comprising the return electrode is positionable distant from the lead comprising the stimulating electrode.

54. The peripheral nerve stimulation system of claim 52, wherein the additional lead comprising the return electrode is positionable distant from the pulse generator.

55. The peripheral nerve stimulation system of claim 52, wherein the additional lead is positionable to avoid causing activation of excitable tissue.

56. The peripheral nerve stimulation system of claim 52, wherein the additional lead is positionable in non-excitable tissue.

57. The peripheral nerve stimulation system of claim 49, wherein the plurality of electrodes, including the distal stimulating and return electrodes, are not all the same size.

58. The peripheral nerve stimulation system of claim 49, wherein the one or more return electrodes are larger than the distal stimulating electrodes.

59. The peripheral nerve stimulation system of claim 49, wherein spacing between the plurality of electrodes is not uniform.

60. The peripheral nerve stimulation system of claim 49, wherein spacing between the distal stimulating electrode and the one or more return electrodes is greater than spacing between adjacent distal stimulating electrodes.

61. The peripheral nerve stimulation system of claim 49, wherein the lead comprises a plurality of return electrodes having a total surface area greater than a surface area of the distal stimulating electrode.

62. The peripheral nerve stimulation system of claim 49, wherein the lead comprises a plurality⁷ of return electrodes having a perimeter greater than a perimeter of the distal stimulating electrode.

63. The peripheral nerve stimulation system of claim 49, wherein the return electrode is formed by a coiled conductor or a series of ring electrodes.

64. The peripheral nerve stimulation system of claim 49, further comprising a lead connector or adaptor having at least one return electrode electrically coupled to the pulse generator.

65. The peripheral nerve stimulation system of claim 49, wherein the one or more return electrode is recessed within an electrically insulating portion of the lead.

66. The peripheral nerve stimulation system of claim 49, wherein the one or more return electrodes extends beyond an electrically insulating portion of the lead.

67. The peripheral nerve stimulation system of claim 49, wherein a proportion of current returned through each of multiple return electrodes is programmable or automatically adjustable to minimize patient discomfort.

68. The peripheral nerve stimulation system of claim 49, wherein the lead is fully implantable within a patient's body.

69. The peripheral nerve stimulation system of claim 49, wherein the lead is percutaneous and exits skin to connect to the pulse generator.

70. The peripheral nerve stimulation system of claim 49, wherein the one or more return electrodes are located on or forms a pad.

71. The peripheral nerve stimulation system of claim 49, wherein the lead is an open-coil lead.

72. The peripheral nerve stimulation system of claim 49, wherein the lead is a closed-coil lead.