HK1242155B - Cable for conveying radiofrequency and/or microwave frequency energy to an electrosurgical instrument - Google Patents

Description

Cables for delivering radiofrequency and/or microwave frequency energy to electrosurgical instruments

Field of the Invention

The present invention relates to a cable for delivering radiofrequency and/or microwave frequency energy to an electrosurgical instrument. More particularly, the present invention relates to such a cable comprising a hollow tube and wherein an electrosurgical instrument connected to the cable is rotatable relative to the cable.

Background of the Invention

Electrosurgical instruments are used to deliver radiofrequency and/or microwave frequency energy to biological tissue for purposes such as cutting tissue or coagulating blood. Radiofrequency and/or microwave frequency energy is supplied to the electrosurgical instrument using an electrical cable. Conventional cables used for this purpose have a coaxial transmission line structure comprising a solid cylindrical inner conductor, a tubular layer of dielectric material surrounding the inner conductor, and a tubular outer conductor surrounding the dielectric material.

When operating many electrosurgical instruments, it is often necessary to provide the electrosurgical instrument with additional materials or components (e.g., control devices), such as liquid or gas feeds, liquids or gases, or wires or pull wires for manipulating (e.g., opening/closing, rotating, or extending/retracting) various parts of the electrosurgical instrument.

In order to provide these additional materials or components to the electrosurgical instrument, additional structures have been provided along with the conventional cable, such as additional tubes adjacent to the conventional cable. For example, it is known to provide additional tubes alongside the conventional cable to house the pull wires of the electrosurgical instrument, and it is known to house the conventional cable and the tube housing the pull wires in a single protective sheath/housing.

Summary of the Invention

The present inventors have recognized that conventional cables having the above-described coaxial transmission line structure for delivering radio frequency and/or microwave energy to electrosurgical instruments suffer from various disadvantages.

In particular, the inventors have recognised that with conventional arrangements that provide everything needed for an electrosurgical instrument when in use, including a conventional cable and other structures such as additional tubes for housing pull wires, a significant amount of space is wasted and that the maximum possible size (diameter) of the cable is limited for a given overall size (diameter) of the arrangement, which can result in significant power losses in the cable.

Furthermore, the present inventors have recognized that with conventional arrangements, additional components such as pull wires are positioned towards the edge of the arrangement, and that this off-center configuration may cause problems when using the additional components to operate an electrosurgical instrument.

The present inventors have recognized that one or more of these problems can be addressed by providing a hollow cable so that one or more additional components can be passed through the cable during use. By positioning the one or more additional components within the cable, the size (diameter) of the cable can be maximized, which can reduce power losses in the cable because the additional structure requires less space around the cable. Furthermore, by positioning additional components, such as pull wires, within the cable, actuation can be delivered to the electrosurgical instrument down the center of the cable (or closer to the center of the cable), which can improve actuation of the electrosurgical instrument.

The present inventors have also recognized that such hollow cables can be practically realized when transmitting microwave frequency energy due to the skin depth effect, which means that the microwave frequency energy travels only in the shallow surface area of the conductor. The present inventors have also recognized that radio frequency energy can be suitably transmitted along such hollow cables despite the increased resistance, losses, and heat caused by the use of thin conductors in such cables compared to the use of thicker conductors.

Furthermore, the present inventors have recognized that it would be desirable to provide a cable that enables an electrosurgical instrument connected to the cable to be rotated relative to the cable. Enabling relative rotation between the electrosurgical instrument and the cable can allow for more appropriate control of the electrosurgical instrument during operation of the electrosurgical instrument, for example, by allowing for more accurate or appropriate positioning or orientation of a portion or all of the electrosurgical instrument.

Thus, the present invention most generally provides a hollow cable for delivering radiofrequency and/or microwave frequency energy to an electrosurgical instrument, wherein a bipolar electrical connection to the electrosurgical instrument is configured such that the bipolar electrical connection is maintained when the electrosurgical instrument is rotated relative to the cable.

According to a first aspect of the present invention, there is provided a cable for delivering radiofrequency and/or microwave frequency energy to an electrosurgical instrument at a first end of the cable, the cable comprising:

a hollow tube comprising an inner conductive layer and an outer conductive layer separated by a dielectric material to form a transmission line;

a first terminal at the first end of the cable for making an electrical connection to the inner conductive layer;

a second terminal at the first end of the cable for making an electrical connection to the outer conductive layer;

a rotatable assembly at the first end of the cable, wherein the rotatable assembly includes a longitudinal passageway continuous with the hollow tube, and wherein the rotatable assembly is rotatable relative to the transmission line and comprises:

a first portion electrically connected to the first terminal, wherein the first portion and the first terminal are rotatable relative to each other and are configured to maintain electrical connection when rotated relative to each other;

A second portion is electrically connected to the second terminal, wherein the second portion and the second terminal are rotatable relative to each other and are configured to maintain electrical connection when rotated relative to each other.

Thus, the cable can be connected to the electrosurgical instrument via the rotatable assembly (which can, for example, be directly or indirectly connected to the electrosurgical instrument, or can be integral with the electrosurgical instrument) to form a bipolar electrical connection to the electrosurgical instrument. Furthermore, the bipolar electrical connection is maintained when the rotatable assembly (and thus the electrosurgical instrument) rotates because the electrical connection between the first and second portions and the first and second terminals is maintained during rotation of the rotatable assembly.

The longitudinal passage of the rotatable assembly may comprise an open passage, i.e., wherein at least a portion of the circumference of the passage is uncovered; or a closed passage, such as a hole or lumen. The longitudinal passage may be continuous with the hollow tube by being positioned at the first end of the hollow tube so that components fed through the hollow tube and exiting the first end of the hollow tube are also fed through the longitudinal passage. The longitudinal passage may be aligned with the central passage of the hollow tube. Alternatively, some or all of the longitudinal passages may be continuous with the hollow tube by some or all of the longitudinal passages overlapping with the central passage of the hollow tube (e.g., by some or all of the rotatable assembly being positioned around or within the hollow tube).

In some embodiments, the cable can be used to deliver only radiofrequency energy to the electrosurgical instrument. In other embodiments, the cable can be used to deliver only microwave frequency energy to the electrosurgical instrument. In still other embodiments, the cable can be used to deliver both radiofrequency and microwave frequency energy to the electrosurgical instrument.

The term "inside" means closer to the center of the hollow tube. The term "outside" means farther from the center of the hollow tube.

The tube may be a cylindrical tube in which the inner and outer conductive layers are concentric (coaxial) layers. In this case, the term inner means radially inside, and the term outer means radially outside.

The term hollow means that the tube has a hole or lumen extending along its length, for example centered in the center of the tube.

Unless the context dictates otherwise, the term conductive is used herein to mean electrically conducting.

An electrosurgical instrument may be any instrument or tool used during surgery and that utilizes radiofrequency or microwave frequency energy. As used herein, radiofrequency (RF) may refer to a stable, fixed frequency in the range of 10 kHz to 300 MHz and microwave energy may refer to electromagnetic energy having a stable, fixed frequency in the range of 300 MHz to 100 GHz. RF energy should have a frequency that is high enough to prevent the energy from causing nerve stimulation and low enough to prevent the energy from causing tissue blanching or unnecessary thermal overload or damage to tissue structures. Preferred nominal frequencies for the RF energy include any one or more of the following: 100 kHz, 250 kHz, 400 kHz, 500 kHz, 1 MHz, 5 MHz. Preferred nominal frequencies for the microwave energy include 915 MHz, 2.45 GHz, 5.8 GHz, 14.5 GHz, 24 GHz.

The hollow nature of the cable means that other components required when using the electrosurgical instrument, such as gas or liquid feeds, or pull wires or other control devices, can be fed through the interior of the cable. This means that the outer diameter of the cable can be maximized relative to an arrangement in which other components must be positioned around the outside of the cable. Maximizing the diameter of the cable reduces power losses in the cable relative to smaller diameter cables. The cable can therefore be able to deliver more power to the electrosurgical instrument relative to conventional cables. In addition, actuation components such as pull wires can be positioned closer to the center of the cable, which can improve actuation of the electrosurgical instrument.

Additional components that pass through the hollow tube of the cable (such as actuator controls or gas or liquid feeds) can be arranged concentrically within the hollow tube of the cable. This can optimize the use of space within the hollow tube of the cable. This can also facilitate rotating the rotatable assembly and the electrosurgical instrument at the first end of the cable by reducing or preventing tangling of additional components within the hollow tube of the cable during rotation.

The transmission line may be a coaxial transmission line in which the inner conductive layer and the outer conductive layer are coaxial.

The first end of the cable is the end of the cable for connection (directly or indirectly through another component or part) to the electrosurgical instrument. In other words, the first end of the cable is the distal end of the cable.

The opposite second end of the cable is used to connect the cable to a generator for supplying radiofrequency and/or microwave frequency energy to the cable. In other words, the second end of the cable is the proximal end of the cable. The second end of the cable can have a terminal or connector for connecting the second end of the cable to the generator. Thus, the cable can be used to deliver radiofrequency and/or microwave frequency energy from a generator connected to the second (proximal) end of the cable to an electrosurgical instrument connected to the first (distal) end of the cable.

The first terminal may include one end of the inner conductive layer, for example, an end of the inner conductive layer exposed on a face of the cable at the first end of the cable or on an annular surface of the inner conductive layer at the end of the inner conductive layer.

The second terminal may include one end of the outer conductive layer, for example, an end of the outer conductive layer exposed on a face of the cable at the first end of the cable or on an annular surface of the outer conductive layer at the end of the outer conductive layer.

An electrical connection between a terminal and a counterpart most generally refers to an interface between the terminal and the counterpart where an electrical signal can be transferred from the terminal to the counterpart. For example, there can be direct contact between the terminal and the counterpart so that current flows directly between them, or an indirect electrical connection through an intermediate conductive material or medium (e.g., a conductive adhesive or bonding material). Alternatively, the electrical signal can be transferred from the terminal to the counterpart through some other type of electrical coupling (e.g., inductive or capacitive coupling) or other type of magnetic and/or electrical coupling (e.g., a transformer).

The cable according to the first aspect of the invention may have any one of the following optional features, or, insofar as they are compatible, any combination of the following optional features.

The first portion or the second portion may be configured to maintain an electrical connection to the corresponding terminal during relative rotation by being configured to remain in direct physical contact with the corresponding terminal during relative rotation.

The first terminal may comprise a surface of an exposed portion of the inner conductive layer. The term exposed may mean, for example, free of covering or accessible on an annular surface of the cable. The surface of the exposed portion of the inner conductive layer may be an annular surface of the exposed portion of the inner conductive layer.

The exposed portion of the inner conductive layer may include an exposed tubular portion of the inner conductive layer. In other words, a short length of the tubular inner conductive layer may be exposed, for example at one end of the inner conductive layer. This can be achieved, for example, by not providing a covering layer (e.g., a tubular layer) on the surface of the inner conductive layer in this area.

The first terminal may be on an outer annular surface of the cable, and the first portion may be positioned around the outer annular surface of the cable. Thus, a surface (e.g., an inner surface or an outer surface) of the first portion may be adjacent to (opposite to) the first terminal, making it easy to establish an electrical connection therebetween.

Alternatively, the first terminal may be on an inner annular surface of the cable, and the first portion may be positioned inside the inner annular surface of the cable.

The first portion may include a conductive material on its inner or outer surface, the conductive material being in contact with the first terminal. Thus, an electrical connection is established between the first portion and the first terminal by the conductive material on the first portion physically contacting the first terminal. If the first portion is positioned within the annular surface on which the first terminal is located, the conductive material will be on the outer surface of the first portion.

Alternatively, where the first portion is positioned around an annular surface on which the first terminal is located, the conductive material will be located on the interior of the first surface.

The conductive material may comprise an annular strip of conductive material. This may facilitate maintaining an electrical connection to the first terminal when the first part is rotated.

Additionally, or alternatively, the first portion may include one or more conductive elements biased into contact with the first terminal.

The one or more conductive elements may include spring wings, spring leaves, spring washers or spring protrusions.

The one or more conductive elements may be made conductive by coating them with a conductive material.

The one or more conductive elements may be positioned on an inner surface or an outer surface of the first portion.

Therefore, a reliable spring electrical connection can be provided between the first part and the first terminal, which is maintained during relative rotation.

The first part may comprise a hollow tube. This may facilitate rotatable mounting of the first part on the cable.

In the case where the first terminal is on the outer annular surface of the cable and the first part is positioned around the outer annular surface of the cable, the first part may include first and second spring wings, which clamp the outer annular surface of the cable therebetween. Thus, a secure spring electrical connection can be achieved between the first part and the first terminal, which is maintained during relative rotation of the first terminal and the first part.

In a case where the first terminal is on the inner annular surface of the cable and the first part is positioned inside the inner annular surface of the cable, the first part may include first and second spring wings that press outward against the inner annular surface of the cable. Thus, a secure spring-loaded electrical connection can be achieved between the first part and the first terminal that is maintained during relative rotation of the first terminal and the first part.

The first portion may comprise a hollow tube of natural spring material from which axial strips have been removed from its circumference to form the first and second spring wings. Where the first portion is positioned around an outer annular surface of the cable, the hollow tube formed thereby by the first portion may have an initial diameter that is smaller than the diameter of the outer annular surface. Thus, the spring wings will flex outward when the first portion is positioned around the outer annular surface, and the resulting spring force will cause the spring wings to clamp the cable therebetween. Alternatively, where the first portion is positioned within an inner annular surface of the cable, the hollow tube formed thereby by the first portion may have an initial diameter that is larger than the diameter of the inner annular surface. Thus, the spring wings will flex inward when the first portion is positioned within the inner annular surface, and the resulting spring force will cause the spring wings to press outward against the inner annular surface.

The advantages of the following features of the second terminal may be the same as the above advantages of the corresponding first terminal.

The second terminal may include a surface of an exposed portion of the outer conductive layer.

The exposed portion of the outer conductive layer may include an exposed tubular portion of the outer conductive layer.

The second terminal may be on an outer annular surface of the cable, and the second portion may be positioned about the outer annular surface of the cable.

Alternatively, the second terminal may be on an inner annular surface of the cable, and the second portion may be positioned inside the inner annular surface of the cable.

The second portion may include a conductive material on an inner surface or an outer surface thereof, the conductive material being in contact with the second terminal.

The conductive material may comprise an annular strip of conductive material.

The second portion may include one or more conductive elements biased into contact with the second terminal.

The one or more conductive elements may include spring wings, spring leaves, spring washers or spring protrusions.

The second portion may comprise a hollow tube.

The second portion may include first and second spring wings that clamp the outer annular surface of the cable therebetween when the second terminal is on the outer annular surface of the cable and the second portion is positioned around the outer annular surface of the cable.

The second portion may include first and second spring wings that press outwardly against the inner annular surface of the cable when the second terminal is on the inner annular surface of the cable and the second portion is positioned inside the inner annular surface of the cable.

The second portion may comprise a hollow tube of natural spring material from the circumference of which axial strips have been removed to form the first and second spring wings.

The first part can be connected to the second part or integral with the second part. For example, the first part and the second part can be molded together from an insulating material such as plastic, which is then optionally coated with a conductive material. Alternatively, the first part and the second part can be formed from the same pipe, for example by laser cutting. Alternatively, the first part and the second part can be made separately and then connected together, for example by friction fit or by fastening or bonding them together.

The present inventors have also recognized that an alternative way to achieve rotation of the electrosurgical instrument relative to the cable is to rotate the inner conductive layer of the cable with the electrosurgical instrument such that there is relative rotation between the inner and outer conductive layers.

Thus, according to a second aspect of the present invention there is provided a cable for delivering radiofrequency and/or microwave frequency energy to an electrosurgical instrument, the cable comprising:

a first portion comprising an outer conductive layer disposed on the outside of a hollow tube of dielectric material;

a second portion comprising an inner conductive layer;

wherein the second portion is positioned inside the first portion such that the inner conductive layer and the outer conductive layer form a transmission line;

wherein the second portion is rotatable relative to the first portion;

The second portion includes another conductive layer electrically connected to the outer conductive layer in a region where the outer conductive layer is exposed, the other conductive layer being electrically insulated from the inner conductive layer, wherein the other conductive layer and the outer conductive layer are rotatable relative to each other and are configured to maintain electrical connection when rotated relative to each other.

Thus, a bipolar electrical connection to an electrosurgical instrument connected to the second part can be achieved and maintained during rotation of the electrosurgical instrument (and the second part) because the inner conductive layer has a fixed connection to the second part and because the electrical connection between the second part and the first part is maintained during relative rotation between the second part and the first part.

The second portion may also include an inner hollow material tube, and the inner conductive layer may be provided on the outside of the inner hollow material tube, for example by coating the outer surface of the inner hollow tube or material. In some embodiments, the inner conductive layer may be a solid conductive tube.

This arrangement has the advantage that the second part is also axially movable relative to the first part in addition to being rotatable relative to the first part.Thus, it may be possible to more accurately position or orient the second part (and thus the electrosurgical instrument).

The first and/or second aspects of the present invention may have any one of the following optional features, or any combination of the following optional features insofar as they are compatible.

The cable may comprise an actuating device fed through the hollow tube of the cable for rotating the rotatable assembly relative to the transmission line or rotating the second part relative to the first part.

The actuating means may comprise an actuator element such as a rod, a wire, a cable or a hollow tube. Alternatively, for example in a hydraulic actuation system, the actuating means may comprise a fluid, such as a liquid or a gas.

In one embodiment, the electrosurgical instrument can be rotated by connecting (fixing) the actuator element to the electrosurgical instrument and rotating the actuator to directly rotate the electrosurgical instrument. This may provide acceptable rotational control of the electrosurgical instrument in some cases.

However, the present inventors have recognized that, in some cases, this type of control can cause the rotation of the electrosurgical instrument to occur in a series of jumps (or jolts) or intermittent sudden changes, which may be undesirable in many applications. This is believed to be because the bending in the actuator causes friction and torque pressure during rotation of the actuator.

The present inventors have recognized that this problem can be overcome by causing rotation of the electrosurgical instrument by pushing or pulling an actuator element, such as a rod, wire, cable, tube, or pipe, to move it axially relative to the electrosurgical instrument, and providing an interface between the actuator and the electrosurgical instrument that converts this axial movement into rotational movement of the electrosurgical instrument. The present inventors have recognized that the axial pulling and pushing movement of the actuator can be smoothly transmitted along the cable even when the cable is bent, so that smooth rotation of the electrosurgical instrument can be achieved.

Thus, the actuator can be configured to move axially along the hollow tube of the cable, and the cable can include an interface disposed in the hollow tube of the cable for converting axial movement of the actuator into rotational movement of the rotatable assembly or second portion (and thus of the electrosurgical instrument). In other words, the actuator can be pushed or pulled (retracted) along the cable. With a fluid, the same effect can be achieved by varying the pressure or thrust applied to the fluid.

A further interface may be provided to prevent the actuator element from rotating relative to the cable, such that the actuator element can only move axially along the cable.

The actuator element may have a helical path provided on its outer surface, and the cable may include a rotator having a follower that follows the helical path when the actuator element moves axially, thereby rotating the rotator. Thus, the axial movement of the actuator element is converted into rotational movement of the rotator.

Alternatively, the actuator element may include a follower on its outer surface, and the cable may include a rotator having a helical path provided on its inner surface, the follower following the helical path when the actuator element moves axially, thereby causing the rotator to rotate. Thus, the axial movement of the actuator element is converted into a rotational movement of the rotator.

The rotator may be a hollow cylinder or a tubular body.

The helical path may comprise a convex helical path.

Alternatively, the helical path may comprise a helical channel, a helical groove or a helical slot.

The follower may include: a protrusion; a pin; a fin; a recess; a groove; a channel; or a slot.

The rotator may be connected to or integral with the electrosurgical instrument (directly or indirectly through another part or component) such that rotation of the rotator causes rotation of the electrosurgical instrument.

When the cable comprises the rotatable assembly, the rotator may be connected to or integral with the rotatable assembly (directly or indirectly through another part or assembly) such that rotation of the rotator causes rotation of the rotatable assembly.

In one embodiment, the interface for preventing the actuator from rotating relative to the cable can include a follower (e.g., a pin or fin) on the actuator that follows a linear axial path (e.g., a groove or slot) on the wall of the cable or the shank of the cable. Alternatively, the interface can include a follower (e.g., a pin or fin) on the cable or the shank of the cable that follows a linear axial path (e.g., a groove or slot) on the surface of the actuator. In either case, the actuator can move axially relative to the cable but is prevented from rotating relative to the cable.

The cable may be configured to deliver radiofrequency energy to the electrosurgical instrument using the transmission line and another conductor positioned in and extending along the hollow tube, and the other conductor may be electrically insulated from the transmission line within the hollow tube of the cable.

A potential problem with sending both RF and microwave frequency energy down the same transmission line of the cable is that the high voltage RF energy can cause dielectric breakdown, particularly in porous, low-loss materials that are particularly well-suited for use when transmitting microwave frequencies. Therefore, in some embodiments, RF signals can instead be transmitted using the transmission line and conductors positioned within and extending along the hollow tube. This can significantly reduce the risk of dielectric breakdown.

The cable may be configured to deliver radiofrequency energy in this manner by having a terminal or connector at its second (proximal) end for connection to a generator for supplying radiofrequency energy to the further conductor and the transmission line.

Electrically insulating the further conductor from the transmission line within the hollow cable can prevent electrical breakdown of the air between the further conductor and the transmission line, which would otherwise damage the cable or increase power losses in the cable. For example, this can be achieved using an insulation layer around the further conductor (e.g., provided on a surface of the further conductor) or an insulation layer provided on the innermost surface of the cable.

The cable can be configured to deliver radiofrequency energy to the electrosurgical instrument using (only) the inner conductive layer and the further conductor, or using (only) the outer conductive layer and the further conductor, or using the inner conductive layer, the outer conductive layer and the further conductor, wherein the inner conductive layer and the outer conductive layer are electrically connected at a second (proximal) end of the cable.

The conductor positioned in the hollow tube may be a conductive rod or tube specifically designed for this purpose. Alternatively, the further conductor may comprise another tubular conductive layer of the cable, such as the innermost tubular layer of the cable. Alternatively, an additional component passing through the hollow tube may serve as the center conductor. For example, the outer casing of a tube or wire or puller wire used to supply liquid or gas to the electrosurgical instrument may be formed of a conductive material or coated with a conductive material and may serve as the center conductor. A generator may then be used to input the radio frequency signal separately from the microwave frequency signal into the cable using the transmission line and the further conductor, the microwave frequency signal being input only to the inner and outer conductive layers of the transmission line.

With an arrangement such as this, it may be necessary to provide a configuration such as a duplexer at the first end of the cable to prevent higher voltage radio frequency signals from traveling backward along the inner and outer conductors and/or to prevent microwave signals from traveling backward along the further conductor. Alternatively, the further conductor may be configured so that it is physically disconnected when the cable is used to deliver only microwave energy. This may be achieved, for example, by pulling the further conductor axially away from the electrosurgical instrument so that it no longer contacts the corresponding terminal of the electrosurgical instrument.

The cable may include a conductor positioned within and extending along the hollow tube to deliver radio frequency energy to the electrosurgical instrument using the transmission line.

The dielectric material may comprise a solid tube of dielectric material; or a tube of dielectric material having a porous structure. Being a solid tube of dielectric material may mean that the dielectric material is substantially homogeneous. Having a porous structure may mean that the dielectric material is substantially inhomogeneous, having a significant number or amount of air pockets or voids.

For example, the porous structure may mean a honeycomb structure, a network structure, or a foam structure.

The dielectric material may include PTFE or another low-loss microwave dielectric.

For example, the dielectric material may comprise a tube having a thickness greater than 0.2 mm, such as a tube having a thickness of 0.3 mm or 0.4 mm. In one embodiment, the dielectric material may be a PTFE tube having an inner diameter of 1.6 mm and an outer diameter of 2.4 mm.

The inner conductive layer and/or the outer conductive layer may include: a conductive coating on the inside or outside of the material tube; a solid conductive material tube positioned against the inside or outside of the material tube; or a braided conductive material layer formed on or embedded in the material tube.

The conductive coating or the conductive material may be a metal, such as silver, gold, or copper. Alternatively, the conductive coating or the conductive material may comprise a different type of conductive material, such as graphene. The conductive coating and the conductive material are preferably good conductors, i.e., low-loss conductors at microwave or radio frequencies, for example, not steel.

The inner conductive layer and/or the outer conductive layer may include a silver coating.

The inner conductive layer and/or the outer conductive layer may have a thickness of about 0.01 mm.

In the case where the cable is used to deliver only RF energy to the electrosurgical instrument and not microwave frequency energy, the dielectric material is not necessarily a good microwave dielectric. Alternatively, in these embodiments the dielectric material may be a good RF dielectric material, for example a material that provides a stand-off voltage or breakdown voltage that is sufficiently greater than the voltage of the RF signal, i.e. a material with a sufficiently high dielectric strength. The dielectric material may also be selected at least in part based on its mechanical properties, such as its hardness, strength or ease of electroplating. A suitable material may be Kapton, for example a Kapton polyimide film having a breakdown strength of approximately 3000 KV/mm. Therefore, PTFE may be replaced with Kapton or Kapton polyimide or another suitable RF dielectric hereinafter when the cable is to be used to deliver only RF energy to the electrosurgical instrument.

Where only radiofrequency energy is being delivered, reflections of energy due to impedance mismatch at the region where the cable connects to the electrosurgical instrument are significantly less than when microwave frequency energy is being delivered. Consequently, connecting the cable to the electrosurgical instrument may be simpler and can be achieved, for example, using two suitable connecting wires (in addition to the connection arrangements discussed below).

In some embodiments, a single conductor monopole tool may be introduced into the cable and connected only to the inner conductive layer.

A protective covering or liner may be provided on the inside of the inner metal layer to protect the inner metal layer, for example, from damage caused by components or tools passing through the hollow cable. In one embodiment, the protective liner may comprise an inner tubular layer, and the inner metal layer may be coated on the outer surface of the inner tubular layer. The inner tubular layer may comprise an insulating or dielectric material.

In one embodiment, the first end of the cable can be detachable or otherwise separate from the remainder of the cable, such as so that different first ends having different configurations of the first and second terminals can be used with the cable by attaching them to the same cable. In another embodiment, the first end of the cable can be integral with or fixed to the cable.

A protective outer jacket or outer coating (e.g., a spray coating) may be present on the outer surface of the cable to protect the outer surface of the cable. This may include, for example, an insulating material, and/or a material selected for its mechanical properties (such as strength and/or hardness).

In one configuration, the cable may include a hollow inner tubular layer; a tube of the inner conductive layer on the outer surface of the hollow inner tubular layer; a tube of dielectric material on the outer surface of the tube of the inner conductive layer; and a tube of the outer conductive layer on the outer surface of the tube of dielectric material. The structure may or may not include air gaps between some or all of these layers. The advantage of avoiding air gaps is that losses in the cable can be minimized. In one example, this structure can be made by sequentially applying each subsequent layer to the previous (inner) layer. Alternatively, this structure can be made by forming one or more of the layers into a first part and one or more of the layers into a second part and then sliding one part inside the other part. The hollow inner tubular layer may include PTFE or polyimide. The hollow inner tubular layer may have a thickness of 0.1 mm.

The inner conductive layer may protrude beyond an edge of the tubular dielectric material so that the inner conductive layer is exposed at the first end of the cable. This may facilitate connection of the electrosurgical instrument at the first end of the cable.

In an alternative configuration, the cable may include a hollow tube for the inner conductive layer; a tube of dielectric material on the outer surface of the hollow tube for the inner conductive layer; and a tube for the outer conductive layer on the outer surface of the tube of dielectric material. Furthermore, air gaps may or may not exist between one or more of the layers. In one example, such a configuration may be manufactured by coating the inner and outer conductive layers on the inner and outer surfaces of the dielectric material, respectively.

The cable may further comprise a protective outer tubular layer on the outer surface of the tube of the outer conductive layer. The outer tubular layer may comprise PTFE or polyimide. The protective outer tubular layer may be an insulating layer.

The outer conductive layer may protrude beyond the edge of the dielectric material tube so that the outer conductive layer is exposed at the first end of the cable. This may facilitate connection of the electrosurgical instrument.

The outer diameter of the cable may be smaller over a portion of its length adjacent to the first end of the cable. In other words, the cable may be narrower at the first end. This may facilitate connecting the cable to the electrosurgical instrument.

The outer diameter of the cable can be made smaller in said portion by reducing the inner diameter of the cable. In other words, the walls of the cable can be nudged or moved inwardly so that they are closer to the central axis of the cable for the section of the cable at said first end.

Alternatively, or in addition, the outer diameter of the cable can be made smaller in the portion by reducing the thickness of the dielectric material or another component of the cable. In this case, the inner diameter of the cable can remain unchanged, but the outer diameter is reduced. For example, the thickness of the dielectric material or another component can be reduced by machining the region to a smaller thickness or by using a heat shrink material.

Radio frequency energy and/or microwave frequency energy can be input into the cable using a side feed positioned at or adjacent to the second (proximal) end of the cable. This can allow for unobstructed passage of the cable through various other components and instrument controls. In order for the RF energy not to short-circuit, the inner and outer conductive layers can be connected without leaving the dielectric material of the cable across the hollow passage. Microwave energy can be prevented from leaking from the open end of the cable by a coaxial filter or choke. The distance of the choke or filter from the side feed can be selected so that the impedance of the generator device matches the impedance of the hollow cable and the side feed.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be discussed, by way of example only, with reference to the accompanying drawings, in which:

FIG1 is a schematic illustration of a portion of a cable according to an embodiment of the present invention;

FIG2 is a schematic illustration of a portion of a cable according to an alternative embodiment of the present invention;

FIG3 is a schematic illustration of a portion of a cable according to an alternative embodiment of the present invention;

FIG4 is a schematic illustration of a portion of a cable according to an alternative embodiment of the present invention;

FIG5 is a schematic illustration of a portion of a cable according to an alternative embodiment of the present invention;

FIG6 is a schematic illustration of a portion of a cable according to an alternative embodiment of the present invention, wherein the outer diameter of the cable is narrower near one end thereof;

7 is a schematic illustration of a portion of a cable according to an alternative embodiment of the present invention, wherein the outer and inner diameters of the cable are narrower near one end thereof;

8 is a schematic illustration of a cable according to an embodiment of the present invention in which radio frequency energy is delivered using a conductor inside a hollow cable;

FIG9 illustrates a first configuration for connecting an electrosurgical instrument to a cable such that the electrosurgical instrument is rotatable relative to the cable, according to an embodiment of the present invention;

FIG10 illustrates a second configuration for connecting an electrosurgical instrument to a cable such that the electrosurgical instrument is rotatable relative to the cable, according to an embodiment of the present invention;

FIG11 illustrates a third configuration for connecting an electrosurgical instrument to a cable such that the electrosurgical instrument is rotatable relative to the cable, in accordance with an embodiment of the present invention;

12A-12F are schematic illustrations of concepts for forming a rotational electrical connection to a metal tubular layer, according to an embodiment of the present invention;

FIG13 is a schematic illustration of a rotator shaft for providing relative rotation between an electrosurgical instrument and a cable connected to the rotator shaft, in accordance with an embodiment of the present invention;

FIG14 illustrates another configuration of a cable in accordance with an embodiment of the present invention wherein the electrosurgical instrument is rotatable relative to the cable;

FIG15 illustrates an arrangement for converting axial movement of an actuator into rotational movement of an electrosurgical instrument, according to an embodiment of the present invention;

FIG. 16 illustrates an alternative configuration for converting axial movement of an actuator into rotational movement of an electrosurgical instrument, according to an embodiment of the present invention;

17A to 17C illustrate an arrangement for enabling a bipolar rotational connection between a cable and an electrosurgical instrument and for converting axial movement of an actuator into rotational movement of the electrosurgical instrument.

DETAILED DESCRIPTION

Where features of the embodiments described below are equivalent, the same reference numerals are used and detailed descriptions thereof are not repeated.

A schematic illustration of a portion of a cable according to an embodiment of the present invention is illustrated in Figure 1. Figure 1 shows only selected details of the cable regarding its general construction and not the connection to an electrosurgical instrument. The dashed line in Figure 1 is intended to illustrate the central axis of the cable.

The cable 1 illustrated in Figure 1 comprises an inner tubular layer 3 which may comprise PTFE or polyimide or another material providing sufficient mechanical strength (the electrical properties of this layer are less important). In this embodiment the inner tubular layer has a thickness of 0.1 mm.

An inner metal layer 5 (which corresponds to an inner conductive layer) is provided on the outer surface of the inner tubular layer 3 to form a tube around the inner tubular layer 3. In this embodiment, the inner metal layer 5 is made of silver and has a thickness of 0.01 mm.

A dielectric layer 7 (which corresponds to a dielectric material) is provided on the outer surface of the inner metal layer 5 to form a tube around the inner metal layer 5. In this embodiment, the dielectric layer 7 includes PTFE and has a thickness of 0.4 mm.

An outer metal layer 9 (which corresponds to an outer conductive layer) is provided on the outer surface of the dielectric layer 7 to form a tube around the dielectric layer 7. In this embodiment, the outer metal layer 9 is made of silver and has a thickness of 0.01 mm.

Of course, in other embodiments, the thickness of any layer can be different from that described above, and the material of any layer can also be different. For example, dielectric layer 7 can include a different low-loss microwave dielectric material or a different radio frequency dielectric material instead of PTFE, and inner metal layer 5 and/or outer metal layer 9 can be formed of a metal other than silver.

The inner metal layer 5 , the dielectric layer 7 and the outer metal layer 9 form a coaxial transmission line for delivering radio frequency and/or microwave frequency energy to an electrosurgical instrument connected thereto.

The inner tubular layer 3 can serve to protect the inner metallic layer 5 from any components inserted through the hollow interior of the cable 1 during use of the cable. In this sense, the inner tubular layer can be considered a liner. The inner tubular layer 3 can also provide mechanical strength to the cable.

In other embodiments, another insulating sleeve or coating may be provided on the outer surface of the outer metal layer 9 to prevent wear of the outer metal layer 9 during use of the cable and to electrically insulate the outer metal layer 9 .

Edge 11 of dielectric layer 7 (and outer metal layer 9) is set back relative to edge 13 of inner tubular layer 3 (and inner metal layer 5) so that an area of inner metal layer 5 is exposed between edges 11, 13. This can facilitate connection of an electrosurgical instrument at one end of the cable.

In some embodiments, the edge of the outer metal layer 9 can be set back relative to the edge 11 of the dielectric layer 7 to increase the air gap between the outer metal layer 9 and the inner metal layer 5. This can reduce the risk of electrical breakdown of the air between the outer metal layer 9 and the inner metal layer 5.

Alternatively, or in addition, in some embodiments an insulating fluid or grease or other material may be applied at or around the edges of the outer metal layer 9 and/or in other areas of the cable to reduce the risk of electrical breakdown of air in the cable.

In one embodiment, the structure shown in FIG1 can be constructed by sequentially forming each layer on the outer surface of the previous (inner) layer. For example, the outer surface of the inner tubular layer 3 can be coated with metal to form the inner metal layer 5. For example, the setback position of the edge 11 can be achieved by machining this edge backward. Alternatively, this configuration can be made by forming the inner metal layer 5 on the outer surface of the inner tubular layer 3, forming the outer metal layer 9 on the outer surface of the dielectric layer 7, and then inserting the inner tubular layer 3 inside the dielectric layer 7.

The cable shown in FIG. 1 has a central passage, bore or lumen 15 through which components, such as liquid or gas feeds or pull wires or other control devices, can be fed and supplied to an electrosurgical instrument connected to the cable.

A schematic illustration of a portion of a cable according to an alternative embodiment of the invention is illustrated in Figure 2. Figure 2 shows only selected details of the cable relating to its general construction and not the connection to the electrosurgical instrument. The dashed line in Figure 2 is intended to illustrate the central axis of the cable.

The cable 17 illustrated in Figure 2 comprises an inner tubular metal layer 19 (which corresponds to the inner conductive layer). In this embodiment, the inner tubular metal layer 19 is made of silver and has a thickness of 0.01 mm.

A dielectric layer 21 (which corresponds to a dielectric material) is provided on the outer surface of the inner tubular metal layer 19 to form a tube around the inner tubular metal layer 19. In this embodiment, the dielectric layer 21 includes PTFE and has a thickness of 0.4 mm.

An outer metal layer 23 is provided on the surface of the dielectric layer 21. The outer metal layer 23 comprises silver and has a thickness of 0.01 mm in this embodiment.

The outer tubular layer 25 is provided on the surface of the outer metal layer 23. The outer tubular layer 25 comprises PTFE or polyimide and has a thickness of 0.1 mm in this embodiment.

Of course, in other embodiments, the thickness of any layer may be different than that described above, and the material of any layer may also be different. For example, dielectric layer 21 may include a different low-loss microwave dielectric material or a different radio frequency dielectric instead of PTFE, and inner metal layer 19 and/or outer metal layer 23 may be formed of a metal other than silver.

The inner metal layer 19 , the dielectric layer 21 , and the outer metal layer 23 form a coaxial transmission line for delivering radio frequency and/or microwave frequency energy to an electrosurgical instrument connected thereto.

Edge 27 of dielectric layer 21 (and inner metal layer 19) is set back relative to edge 29 of outer metal layer 23 (and outer tubular layer 25) so that an area of outer metal layer 23 is exposed between edges 27, 29. This facilitates connection of an electrosurgical instrument at one end of the cable.

In one embodiment, the structure can be manufactured by sequentially coating each layer on the previous (inner) layer. For example, the setback position of edge 27 can be achieved by machining the edge backward. Alternatively, the structure can be manufactured by forming inner metal layer 19 on the inner surface of dielectric layer 21, forming outer metal layer 23 on the inner surface of outer tubular layer 25, and then inserting dielectric layer 21 inside outer tubular layer 25.

A schematic illustration of a portion of a cable according to an alternative embodiment of the invention is illustrated in Figure 3. Figure 3 shows only selected details of the cable relating to its general construction and not the connection to the electrosurgical instrument. The dashed line in Figure 3 is intended to illustrate the central axis of the cable.

The cable 31 illustrated in Figure 3 includes an inner tubular metal layer 33 (which corresponds to the inner conductive layer). In this embodiment, the inner tubular metal layer 33 is made of silver and has a thickness of 0.01 mm.

A dielectric layer 35 (which corresponds to a dielectric material) is provided on the outer surface of the inner tubular metal layer 33 to form a tube around the inner tubular metal layer 33. In this embodiment, the dielectric layer 35 includes PTFE and has a thickness of 0.4 mm.

An outer metal layer 37 (which corresponds to an outer conductive layer) is provided on the surface of the dielectric layer 35. The outer metal layer 37 includes silver and has a thickness of 0.01 mm in this embodiment.

Of course, in other embodiments, the thickness of any layer may be different than that described above, and the material of any layer may also be different. For example, dielectric layer 35 may include a different low-loss microwave dielectric material or a different radio frequency dielectric material instead of PTFE, and inner metal layer 33 and/or outer metal layer 37 may be formed of a metal other than silver.

The inner metal layer 33 , the dielectric layer 35 , and the outer metal layer 37 form a coaxial transmission line for delivering radio frequency and/or microwave frequency energy to an electrosurgical instrument connected thereto.

In one embodiment, this structure can be manufactured by coating inner metal layer 33 and outer metal layer 37 on the inner and outer surfaces, respectively, of dielectric layer 35. Alternatively, inner metal layer 33 and/or outer metal layer 37 can comprise a solid metal tube positioned on the inner or outer surface of dielectric layer 35.

A schematic illustration of a portion of a cable according to an alternative embodiment of the invention is illustrated in Figure 4. Figure 4 shows only selected details of the cable relating to its general construction and not the connection to the electrosurgical instrument. The dashed line in Figure 4 is intended to illustrate the central axis of the cable.

The cable 39 illustrated in Figure 4 comprises a non-uniform porous structure of a dielectric material 41. The non-uniform porous structure may be, for example, a honeycomb structure, a mesh structure or a foam structure formed of a foam material. The dielectric material 41 may comprise PTFE.

Inner metal layer 43 is disposed on an inner surface of dielectric material 41 and outer metal layer 45 is disposed on an outer surface of dielectric material 41 .

The inner metal layer 43, the dielectric layer 41 and the outer metal layer 45 form a coaxial transmission line for delivering radio frequency and/or microwave frequency energy to an electrosurgical instrument connected thereto.

The non-uniform porous structure of the dielectric material 41 can improve the microwave dielectric properties of the dielectric material 41. In other words, the dielectric material 41 can be a more efficient low-loss microwave dielectric.

In this embodiment, one or both of the inner metal layer 43 and the outer metal layer 45 can be a solid metal tube rather than a metal coating. This can improve the mechanical strength and structural integrity of the cable.

Alternatively, one or both of the inner metal layer 43 and the outer metal layer 45 may be a metal coating and may be formed on an additional tubular layer provided on the inner surface of the inner metal layer 43 or on the outer surface of the outer metal layer 45 to provide mechanical support to the cable. For example, such an additional tubular layer may be formed of PTFE or polyimide.

A schematic illustration of a portion of a cable according to an alternative embodiment of the invention is illustrated in Figure 5. Figure 5 shows only selected details of the cable relating to its general construction and not the connection to the electrosurgical instrument. The dashed line in Figure 5 is intended to illustrate the central axis of the cable.

The cable 47 illustrated in Figure 5 comprises an inner metal layer 49 and a dielectric layer 51 provided on the outer surface of the inner metal layer 49. The cable further comprises a braided metal structure 53 embedded in the dielectric layer 51 (which corresponds to the outer conductive layer).

In one embodiment, this construction can be manufactured by extruding or otherwise forming a portion of the dielectric layer 51 on the surface of the inner metal layer 49, weaving the braided metal structure 53 on the portion of the dielectric layer 51, and then extruding or otherwise forming the remaining portion of the dielectric layer 51 on the braided metal structure 53.

In alternative embodiments, the material coated atop the braided metal structure 53 may be different than the material underneath (inside) the braided metal structure 53. For example, the braided metal structure 53 may be formed on a dielectric layer 51, and then a different material may be extruded or otherwise formed over the braided metal structure 53. This different material may not be a dielectric material and may instead be an insulating material such as polyimide.

The inner metal layer 49 may include a solid metal tube, or alternatively may be a metal coating, for example a silver coating, formed on the outer surface of another tubular layer (not shown), such as a tubular layer of PTFE or polyimide.

In this embodiment, the braided metal structure is formed by braiding copper or steel wire coated with silver. Of course, other metals can be used in other embodiments.

In this embodiment, the dielectric material comprises PTFE.

Any of the configurations disclosed above may be used in the present invention. Variations of the described embodiments may also be used. For example, in embodiments, the metal coating on the surface of the material tube may be replaced with a solid metal tube, and vice versa.

In some embodiments of the present invention, the outer diameter of the cable may be reduced for a portion of its length near or at the end of the cable where the cable is attached to the electrosurgical instrument. This may facilitate connecting the cable to the electrosurgical instrument.

As an example, this is illustrated in FIG. 6 for a cable having the configuration illustrated in FIG. 1 . In the cable 55 illustrated in FIG. 6 , the thickness of the dielectric layer 7 is reduced over a portion 57 of the length of the cable 55 adjacent to one end of the cable 55 . For example, the thickness of the dielectric layer 7 can be reduced from 0.4 mm to a thickness of 0.2 mm or 0.1 mm in the reduced thickness portion, such that the overall diameter of the cable 55 is reduced by 0.4 mm or 0.6 mm without changing the inner diameter of the cable 55 . Although not shown, the edges of the dielectric layer 7 can still be set back as illustrated in FIG. 1 . In one embodiment, the thickness of the dielectric layer 7 can be reduced over a length of 20 mm adjacent to one end of the cable. For example, this reduction in thickness can be achieved by machining downward along the dielectric layer 7 . For example, the length of the portion of the cable having the reduced thickness can be 20 mm. The maximum length of the reduced thickness portion that can be used in practice (in terms of acceptable power loss in the cable) depends on the specific thickness of the dielectric material and the electrical properties of the dielectric material. This can be determined for a specific configuration through simulation and/or measurement.

The same effect can be achieved in other embodiments by reducing the thickness of one or more of the dielectric material and other tubular layers (if present) to reduce the outer diameter of the cable at the end of the cable to which the electrosurgical instrument is connected.

Alternatively, or in addition, the outer diameter of the cable may be reduced in the portion near the end where it is connected to the electrosurgical device by reducing the inner diameter of the cable.

As an example, this is illustrated in FIG7 for a cable having the configuration illustrated in FIG1. In the cable 59 illustrated in FIG7, the inner diameter of the cable is reduced over a portion 61 of the length of the cable 59 by deflecting or moving the outer wall of the cable 59 inward in this portion 61 so that the inner diameter of the cable 59 is reduced. For example, the length of the cable having the reduced thickness may be 20 mm.

The same effect can be achieved with the other embodiments described above by moving the walls of the cable inward to reduce the inner diameter of the cable.

In any of the described embodiments, if the cable is used to transmit only RF energy, the dielectric material may be a suitable RF dielectric material such as Kapton or Kapton polyimide, ie, a dielectric material having a breakdown strength sufficiently greater than the voltage of the RF energy.

In some embodiments of the present invention, both RF and microwave frequency energy are delivered using the inner and outer metal layers. However, there may be a risk in some situations where the higher voltage RF signal causes electrical breakdown of the dielectric material. Therefore, in some embodiments of the present invention, the RF signal can be delivered to the electrosurgical instrument separately from the microwave frequency signal. This can be achieved by delivering the RF energy using the inner and/or outer metal conductors, as well as a conductor positioned within and extending along the hollow bore of the cable.

This is illustrated in FIG8 for a cable having the configuration illustrated in FIG1 . However, the same concept also applies to the other configurations described above, i.e., conductors can be positioned in the hollow core of other configurations and used to deliver RF energy. In the cable 63 illustrated in FIG8 , conductor 65 is positioned in the hollow core of cable 63 and extends along cable 63 to an electrosurgical instrument (not shown). In some embodiments, conductor 65 can be a metal rod or tube provided for this purpose. However, in other embodiments, conductor 65 can be a conductive outer surface of a portion or component of an electrosurgical instrument, such as a tube or wire for supplying liquid or gas or a housing for a pull wire or other control device.

The conductor 65 is insulated from the inner and outer metal layers of the cable by the inner tubular layer.For example, the inner tubular layer may comprise an insulating material.

The cable 63 may be connected to a generator configured to supply a radio frequency signal to the cable through the conductor 65 and the inner and/or outer metal layers and to supply a microwave frequency signal through the inner and outer metal layers. Thus, the dielectric material may not experience sufficient voltage to cause it to electrically breakdown because it may only be exposed to the lower voltage microwave frequency signal.

When both the inner and outer metallic layers are used to carry RF energy with the center conductor 65, the inner and outer metallic layers may be electrically connected together at the second (proximal) end of the cable.

With this arrangement, it may be necessary to provide one or more components at the end of the cable where it is connected to the electrosurgical instrument to prevent radio frequency signals from being able to travel back along the microwave transmission paths of the inner and outer metal layers, and/or to prevent microwave signals from traveling back along conductor 65. Otherwise, the dielectric material may still be exposed to the high voltage signal and may still be at risk of breakdown.

Alternatively, or in addition, in one embodiment the cable can be configured such that the conductor 65 can be pulled axially rearwardly along the cable to disconnect the electrical connection between the conductor 65 and the electrosurgical instrument when only microwave frequency energy is being delivered to the electrosurgical instrument to prevent microwave frequency energy from traveling along the conductor 65.

To reduce the risk of electrical breakdown of the dielectric or air gap in any of the above-described embodiments, a low-loss fluid or grease or other material may be provided around one or more portions of the cable (e.g., in areas where breakdown is likely, such as at each end of one or more layers) to reduce the risk of electrical breakdown.

FIG9 illustrates a first configuration for connecting an electrosurgical instrument to a cable so that the electrosurgical instrument can rotate relative to the cable, according to an embodiment of the present invention. The cable illustrated in FIG9 has a configuration based on that illustrated in FIG1 (although the materials and/or thicknesses of the various layers may be different). The cable further includes a protective sheath or covering or coating 67 disposed on the outer surface of the outer metal layer 9 to protect and electrically insulate the outer metal layer 9.

The electrosurgical instrument can be connected to the cable so that it can be rotated relative to the cable using a rotator shaft 69. The rotator shaft 69 includes a first portion 71 having a smaller inner diameter and a second portion 73 having a larger inner diameter. In this embodiment, the first portion 71 and the second portion 73 have the same outer diameter, but this is not required. The rotator shaft 69 can include a section of tubing (a portion or a short piece of tubing). However, as discussed below, in other embodiments, the rotator shaft 69 may not include a section of tubing.

The rotator shaft 69 is positioned about the exterior of the first end of the cable.

The rotator shaft 69 is positioned on the first end of the cable so that the inner surface of the first portion 71 faces the inner metallic layer 5, which is exposed in the area between the edge 11 of the dielectric layer 7 (and the outer metallic layer 9) and the edge 13 of the inner tubular layer 3 (and the inner metallic layer 5). The inner surface of the first portion 71 is configured so that at least a portion of the inner surface of the first portion 71 contacts the inner metallic layer 5 to achieve an electrical connection between at least a portion of the inner surface of the first portion 71 and the inner metallic layer 5, and so that the inner surface of the first portion 71 can rotate (e.g., slide) relative to the inner metallic layer 5 while still maintaining the electrical connection.

For example, this can be achieved by having an inner surface of the first portion 71 having an inner diameter corresponding to (i.e., the same as or slightly larger than) the outer diameter of the inner metal layer 5 and by partially or completely coating the inner surface of the first portion 71 with a conductive material. Alternatively, this can be achieved by having an inner surface of the first portion 71 having a diameter larger than the outer diameter of the inner metal layer 5 and including one or more conductive elements (such as spring washers, spring wings, spring leaves, or spring protrusions) that are biased to contact the inner metal layer 5, such that the one or more conductive elements form a spring electrical connection to the inner metal layer 5 and can maintain this electrical connection while sliding/rotating.

Furthermore, the rotator shaft 69 is positioned on the first end of the cable so that the inner surface of the second portion 73 faces the outer metal layer 9. The inner surface of the second portion 73 is configured so that at least a portion of the inner surface of the second portion 73 contacts the outer metal layer 9 to achieve an electrical connection between at least a portion of the inner surface of the second portion 73 and the outer metal layer 9, and so that the inner surface of the second portion 73 can rotate (e.g., slide) relative to the outer metal layer 9 while still maintaining the electrical connection.

For example, this can be achieved by having an inner surface of the second portion 73 having a diameter corresponding to (i.e., the same as or slightly larger than) the outer diameter of the outer metal layer 9 and by partially or completely coating the inner surface of the second portion 73 with a conductive material. Alternatively, this can be achieved by having an inner surface of the second portion 73 having a diameter larger than the outer diameter of the outer metal layer 9 and including one or more conductive elements (such as spring washers, spring wings, spring leaves, or spring protrusions) that are biased to contact the outer metal layer 9, such that the one or more conductive elements form a spring electrical connection to the outer metal layer 9 and can maintain this electrical connection while sliding/rotating.

FIG10 illustrates a second configuration for connecting an electrosurgical instrument to a cable so that the electrosurgical instrument can rotate relative to the cable, according to an embodiment of the present invention. The cable illustrated in FIG10 has a configuration based on the configuration illustrated in FIG2 (although the materials and/or thicknesses of the layers may be different). The cable also includes a protective sheath or covering or coating 67 disposed on the outer surface of the outer tubular layer 25 to protect the outer tubular layer 25.

The electrosurgical instrument can be connected to the cable so that it can be rotated relative to the cable using a rotator shaft 75. The rotator shaft 75 includes a first portion 77 having a larger outer diameter and a second portion 79 having a smaller outer diameter. In this embodiment, the first portion 77 and the second portion 79 have the same inner diameter, but this is not required. The rotator shaft 75 can include a section of tubing (a portion or a short piece of tubing), but as described below, this may not be the case in some embodiments.

The rotator shaft 75 is positioned on the first end of the cable with the rotator shaft 75 being substantially contained within the interior of the cable.

The rotator shaft 75 is positioned on the first end of the cable so that the outer surface of the first portion 77 faces the outer metallic layer 23, with the outer metallic layer being exposed in a region between the edge 29 of the outer metallic layer 23 (and the outer tubular layer 25) and the edge 27 of the dielectric layer 21 (and the inner metallic layer 19). The outer surface of the first portion 77 is configured so that at least a portion of the outer surface of the first portion 77 contacts the outer metallic layer 23 to achieve an electrical connection between at least a portion of the outer surface of the first portion 77 and the outer metallic layer 23, and so that the outer surface of the first portion 77 can rotate (e.g., slide) relative to the outer metallic layer 23 while still maintaining the electrical connection.

For example, this can be achieved by having an outer surface of the first portion 77 having a diameter corresponding to (i.e., the same as or slightly smaller than) the inner diameter of the outer metal layer 23 and by partially or completely coating the outer surface of the first portion 77 with a conductive material. Alternatively, this can be achieved by having an outer surface of the first portion 77 having a diameter smaller than the inner diameter of the outer metal layer 23 and including one or more conductive elements (such as spring washers, spring wings, spring leaves, or spring protrusions) that are biased to contact the outer metal layer 23, such that the one or more conductive elements form a spring electrical connection to the outer metal layer 23 and can maintain this electrical connection while sliding/rotating.

Furthermore, the rotator shaft 75 is positioned on the first end of the cable so that the outer surface of the second portion 79 faces the inner metal layer 19. The outer surface of the second portion 79 is configured so that at least a portion of the outer surface of the second portion 79 contacts the inner metal layer 19 to achieve an electrical connection between at least a portion of the outer surface of the second portion 79 and the inner metal layer 19, and so that the outer surface of the second portion 79 can rotate (e.g., slide) relative to the inner metal layer 19 while maintaining the electrical connection.

For example, this can be achieved by having an outer surface of the second portion 79 having a diameter corresponding to (i.e., the same as or slightly smaller than) the inner diameter of the inner metal layer 19 and by having the outer surface of the second portion 79 partially or completely coated with a conductive material. Alternatively, this can be achieved by having an outer surface of the second portion 79 having a diameter smaller than the inner diameter of the inner metal layer 19 and including one or more conductive elements (such as spring washers, spring wings, spring leaves, or spring protrusions) that are biased to contact the inner metal layer 19, such that the one or more conductive elements form a spring electrical connection to the inner metal layer 19 and maintain this electrical connection while sliding/rotating.

FIG11 illustrates a third configuration for connecting an electrosurgical instrument to a cable so that the electrosurgical instrument can rotate relative to the cable, according to an embodiment of the present invention. The cable illustrated in FIG11 has a configuration based on the configuration illustrated in FIG3 (although the materials and/or thicknesses of the layers may be different). The cable also includes a protective sheath or covering or coating 67 disposed on the outer surface.

11 , the outer metal layer 37 includes a portion 37b that extends beyond the edge of the dielectric material 35 so that it is exposed on the inner annular surface of the cable. For example, the portion 37b may include a hollow solid metal tube or cylinder. In the case where the outer metal layer 37 is a hollow solid metal tube or cylinder, the portion 37b may be an integral extension of the outer metal layer 37. Alternatively, in the case where the outer metal layer 37 is a metal coating, the portion 37b may be a separate conductive portion that is electrically connected to the outer metal layer 37, for example, by physical contact with the outer metal layer 37. In one embodiment, the portion 37b may be disposed (e.g., coated) on the inner surface of the protective jacket 67.

The electrosurgical instrument can be connected to the cable so that it can be rotated relative to the cable using a rotator shaft 81. The rotator shaft 81 includes a first portion 83 having a larger outer diameter and a second portion 85 having a smaller outer diameter. In this embodiment, the first portion 83 and the second portion 85 have the same inner diameter, but this is not required. The rotator shaft 81 can include a section of tubing (a portion or a short piece of tubing), but as discussed below, this may not be the case in some embodiments.

The rotator shaft 81 is positioned on the first end of the cable with the rotator shaft 81 being substantially housed within the interior of the cable.

Rotator shaft 81 is positioned on the first end of the cable so that the outer surface of first portion 83 faces portion 37b of outer metal layer 37. The outer surface of first portion 83 is configured so that at least a portion of the outer surface of first portion 83 contacts portion 37b to achieve an electrical connection between at least a portion of the outer surface of first portion 83 and portion 37b, and so that the outer surface of first portion 83 can rotate (e.g., slide) relative to portion 37b while still maintaining the electrical connection.

For example, this can be achieved by having an outer surface of the first portion 83 having a diameter corresponding to (i.e., the same as or slightly smaller than) the inner diameter of portion 37b and by partially or completely coating the outer surface of the first portion with a conductive material. Alternatively, this can be achieved by having an outer surface of the first portion 83 having a diameter smaller than the inner diameter of portion 37b and including one or more conductive elements (such as spring washers, spring wings, spring leaves, or spring protrusions) that are biased to contact portion 37b, such that the one or more conductive elements form a spring electrical connection to portion 37b and maintain this electrical connection while sliding/rotating.

Furthermore, the rotator shaft 81 is positioned on the first end of the cable so that the outer surface of the second portion 85 faces the inner metal layer 33. The outer surface of the second portion 85 is configured so that at least a portion of the outer surface of the second portion 85 contacts the inner metal layer 33 to achieve an electrical connection between at least a portion of the outer surface of the second portion 85 and the inner metal layer 33, and so that the outer surface of the second portion 85 can rotate (e.g., slide) relative to the outer metal layer 33 and can maintain the electrical connection while rotating.

For example, this can be achieved by having an outer surface of the second portion 85 having a diameter corresponding to (i.e., the same as or slightly smaller than) the inner diameter of the inner metal layer 33 and by partially or completely coating the outer surface of the second portion 85 with a conductive material. Alternatively, this can be achieved by having an outer surface of the second portion 85 having a diameter smaller than the inner diameter of the inner metal layer 33 and including one or more conductive elements (such as spring washers, spring wings, spring leaves, or spring protrusions) that are biased to contact the inner metal layer 33.

In any of the above configurations, the rotator shaft can be an integral part of the electrosurgical instrument. Alternatively, the rotator shaft can be connected (electrically and mechanically) to the electrosurgical instrument. For example, the rotator shaft and the electrosurgical instrument can include one or more corresponding protrusions and/or recesses for connecting the electrosurgical instrument to the rotator shaft. Alternatively, the electrosurgical instrument can be connected to the rotator shaft by, for example, fixing one or more parts of the electrosurgical instrument to the rotator shaft via welding or via an adhesive or bonding material. Alternatively, or in addition, the rotator shaft can have electrical connection terminals for electrically connecting to corresponding terminals of the electrosurgical instrument so as to provide a bipolar electrical connection between the rotator shaft and the electrosurgical instrument. Thus, by rotating the electrosurgical instrument and the integral or connected rotator shaft relative to the cable, the electrosurgical instrument can be rotated relative to the cable.

In any of the configurations described above, electrical connection between a portion of the rotator shaft and the corresponding metal layer can be achieved at multiple different locations on the portion of the rotator shaft, for example, by physical contact between the portion of the rotator shaft and the corresponding metal layer at multiple different locations. For example, an advantage of achieving electrical connection at multiple locations is that capacitance can be reduced relative to an arrangement having electrical connection at only one location.

Additionally, or alternatively, conductive grease may be present between any gaps between portions of the spinner shaft and the corresponding metal layers to provide a more uniform electrical connection between the portions of the spinner shaft and the corresponding metal layers.

The rotator shaft may include an insulating material that is selectively coated with a conductive material to form a sliding electrical connection with the inner and outer metal layers. For example, portions of the rotator shaft may be selectively coated on an inner or outer surface with one or more annular bands and/or axial strips of conductive material to form a sliding electrical connection with the corresponding metal layer.

Where the rotator shaft comprises a section of tubing, electrical connection to the metal layer can be achieved by providing an annular ring or strip of conductive material around the inner or outer surface of a portion of the rotator shaft (depending on the particular configuration of the cable). These conductive strips can then be electrically connected to terminals on the end face of the rotator for electrical connection to the electrosurgical instrument via the path of conductive material positioned on the inner or outer surface of the rotator shaft.

The rotator shaft may comprise an insulating material that is selectively coated with a conductive material to leave suitable connection terminals for connection to an electrosurgical instrument.

Selective coating of the spinner shaft with conductive material may be achieved by first applying a uniform coating and then by removing (eg by etching) appropriate areas of material.

In all of the above embodiments, the rotator shaft includes a longitudinal passageway (a central closed channel or bore in these embodiments) that is continuous with the central passageway of the hollow tube of the cable.

In some embodiments, the first and/or second portions of the rotator shaft (i.e., the portions having different inner or outer diameters) can be segments of a hollow tube (or pipe). In other words, the outer surface of the portion can span an angle of 360 degrees around the central axis of the portion to form a closed loop (or circle) around the central axis.

However, in other embodiments the first and/or second portions of the rotator shaft may include segments of a hollow tube (or pipe) in which portions of the hollow tube have been omitted or removed such that the outer surface of the portion spans an angle of less than 360 degrees around the central axis of the portion and does not form a closed loop.

For example, FIG12A illustrates the basic concept of forming a rotational electrical connection to a tubular metal layer using a tube (or pipe) with a portion removed or omitted (e.g., cut, such as by laser cutting). Of course, in other embodiments, a first portion having a configuration based on the configuration illustrated in FIG12A can be made in a manner other than removing a portion of an existing tube. For example, a first portion having a configuration based on the configuration illustrated in FIG12A can be made by molding or otherwise forming the shape of the first portion, rather than forming a tube and then removing portions of it.

In Figure 12A, a metal layer 87 is disposed on the outer surface of a hollow material tube 89. For example, the material tube 89 may be the inner tubular layer 3 and the metal layer 87 may be the inner metal layer 5 of Figures 1 and 9, or the material tube 89 may be the dielectric material 7 and the metal layer 87 may be the outer metal layer 9 of Figures 1 and 9.

In FIG12A , a rotational electrical connection to the metal layer 87 is achieved using a partial tube 91 (a tube in which axial strips have been removed or omitted from the circumference of the tube so that the outer circumference of the tube does not form a closed loop around the central axis of the tube). In this embodiment, the partial tube 91 comprises a tube having an initial diameter similar to (i.e., the same or smaller than) the outer surface of the metal layer 87, from which the axial strips have been cut outside the circumference so that the outer surface of the partial tube no longer forms a closed loop (or circle) around the central axis of the partial tube 91. In FIG12A , the partial tube 91 has been elongated to fit around the outer surface of the metal layer 87 to provide a spring-secure and rotational connection between the partial tube 91 and the metal layer 87. The partial tube 91 presses inwardly onto the metal layer 87 in multiple locations (e.g., in the central region of the partial tube 91 and at the edges of the partial tube 91 that extend in the axial direction).

The faces of the partial tube 91 can be thought of as spring wings that clamp the outer surface of the metal layer.

Portions of the tube 91 may be formed from a natural spring material such as polyimide.

The partial tube 91 includes, on its inner surface, a conductive strip 93 extending axially along the partial tube 91. The conductive strip 93 is positioned at a central location of the partial tube 91 where the partial tube 91 contacts the metal layer 87. Thus, when the partial tube 91 rotates relative to the metal layer 87, a secure electrical connection is always formed between the conductive strip 93 and the metal layer 87.

Figure 12B is a schematic illustration of a portion of a tube 91 positioned around the inner metallic layer 5 of the cable arrangement illustrated in Figure 1. Figure 12C is a schematic illustration of the inner surface of a portion of a tube 91 showing conductive strips 93 on the inner surface.

Figures 12A to 12C illustrate only a rotatable electrical connection formed to a single metal layer. Of course, in embodiments of the present invention, two such partial tubes 91a, 91b may be provided to form a rotatable electrical connection to the inner and outer metal layers of the cable. For example, in Figure 12B, a second partial tube 91b having a larger diameter than the first partial tube 91a can be positioned around the outer metal layer 9 to form a rotatable electrical connection to the outer metal layer 9. The two partial tubes may be integrally formed or may be mechanically connected or attached together.

Figures 12D and 12E illustrate an example of a rotator shaft including a first portion tube 91a for forming a rotatable electrical connection to the inner metal layer and a second portion tube 91b for forming a rotatable electrical connection to the outer metal layer. The first portion tube 91a and the second portion tube 91b are integrally formed of the same insulating material (e.g., polyimide) and are selectively coated with a conductive material for forming an appropriate electrical connection to the metal layer.

As described above, the partial tubes can be positioned around the exterior of the corresponding metal layer to form a spring connection to the metal layer. Alternatively, in other embodiments, an equivalent rotatable electrical connection to the metal layer on the interior of the material tube can be achieved by providing a partial tube 91 formed from a tube having an initial diameter greater than the inner diameter of the metal layer, such that the partial tube 91 is compressed to fit inside the metal layer and presses outwardly against the metal layer in multiple locations. This arrangement is illustrated in FIG. 12F , which shows the partial tube 91 compressed to fit inside the tube so that the wings of the partial tube 91 press outwardly against the interior of the tube, thereby forming a spring connection to the interior of the tube.

The partial tubes illustrated in Figures 12A to 12E all have a longitudinal passage in the form of an open channel, which is bonded over only some of its circumference by the wall of the partial tube which is continuous with the central passage of the hollow tube of the cable.

13 is a schematic illustration of an alternative configuration of a rotator shaft for enabling electrical connection and relative rotation between an electrosurgical instrument and an electrical cable connected to (or integral with) the rotator shaft.

The rotator shaft 95 has a configuration similar to that illustrated in Figures 10 and 11. In other words, the rotator shaft 95 includes a first portion 97 having a larger outer diameter and a second portion 99 having a smaller outer diameter. The rotator shaft 95 is primarily formed of an insulating material. For example, it can be at least partially made of molded plastic. The first portion 97 of the rotator shaft 95 includes one or more inseparable spring pads 101a and the second portion 99 includes one or more inseparable spring pads 101b. The spring pads 101a, 101b protrude or extend from the outer surface of the first portion 97 or the second portion 99 in their natural (or resting) state and can be displaced backward toward the corresponding outer surface against the action of a spring force, which acts to return them to their natural (or resting) state. The outer surfaces of the spring pads 101a, 101b are coated with a conductive material.

Thus, when the rotator shaft 95 is positioned on one end of the cable with the second portion 99 housed within the inner metal layer and the first portion 97 housed within the outer metal layer, as illustrated in Figures 10 or 11, the spring pad 101b on the second portion 99 will contact the inner metal layer and (due to its backward pressure and the resulting spring force) will be biased toward the inner metal layer. A safe and reliable spring connection is thus formed between the rotator shaft 95 and the inner metal layer, which enables rotation between the rotator shaft 95 and the inner metal layer and electrically connects the rotator shaft 95 and the inner metal layer via the conductive material coated on the spring pad 101b. A corresponding connection is formed between the rotator shaft 95 and the outer metal layer by the spring lug 101a of the first portion contacting and biasing toward the outer metal layer.

One or more paths (i.e., lines or sections) of conductive material may be formed on the rotator shaft 95 to electrically connect the conductive material on the spring pads 101a, 101b to terminals for connecting the rotator shaft to an electrosurgical instrument, which terminals may be located on an end surface of the rotator shaft. For example, these paths may run down the inner or outer annular surface of the rotator shaft 95.

A corresponding rotator shaft having a configuration such as that illustrated in Figure 9 can be used, in which the first and second metal layers are provided on the outer surface of the tubular layer and the first and second parts of the rotator shaft are provided on the outside of the metal layers. In that case, the spring washers can, in their natural (or resting) state, protrude or bulge inwardly from the inner surface of the first or second part, respectively, so as to form a spring connection between said part and the corresponding metal layer positioned inside said part.

In any of the embodiments described above, the axial position of the rotator shaft can be fixed to prevent the rotator shaft from moving axially (and thereby disconnecting the electrical connection). This can be achieved in one embodiment by providing one or more protrusions and/or corresponding projections on the rotator shaft and the cable, wherein the one or more protrusions and/or corresponding projections interact to prevent the rotator shaft from moving axially. In one embodiment, the cable can have one or more apertures extending across the entire width of the cable, such as laser-cut apertures. The rotator shaft can have one or more annular channels or recesses in its surface that align with the one or more apertures when the rotator shaft is in the correct axial position. A stopper can be fitted into the one or more apertures so that it protrudes through the aperture and enters the corresponding annular channel or recess in the rotator shaft. Thus, when the block is in place, the rotator shaft can rotate freely because the block is contained in the annular channel or recess and can move along it during rotation. However, the rotator shaft is prevented from moving axially because the block abuts the axial wall of the annular recess or channel.

An outer protective sheath may be provided on the cable to prevent the blocks from being removed from the apertures during operation of the cable.

In one embodiment, one or more blocks can also be used to transmit electrical signals from the inner or outer metal layer to the outside of the cable.Thus, the blocks can perform dual functions, which can reduce the number of components required.

In any of the embodiments described above, the cable may be narrowed at its first end as shown in Figures 6 and 7. This may provide more space for connecting a rotating part such as a rotator shaft at the first end of the cable.

FIG14 shows another configuration of a cable according to an embodiment of the present invention in which an electrosurgical instrument is rotatable relative to the cable. In the embodiment illustrated in FIG14 , the cable is divided into two main components. The first component comprises a dielectric material layer 103 with an outer metal layer 105 disposed (e.g., coated) on its outer surface and a protective layer 107 disposed on the outer surface of the outer metal layer 105.

The second element includes an inner tubular layer 109 having an inner metal layer 111 disposed (e.g., coated) on its outer side. The inner tubular layer 109 is positioned inside the dielectric material layer 103 such that the inner metal layer 111 is adjacent to the dielectric material layer 103. However, the inner metal layer 111 is not attached or connected to the dielectric material layer 103 and is able to slide relative to the dielectric material layer, such that the second element can rotate relative to the first element.

The second element also includes an electrosurgical instrument 113 attached at a first end of the second element. In an area adjacent to the electrosurgical instrument 113, another dielectric material layer 115 is disposed on the inner metal layer 111, adjacent to the dielectric material layer 103 and one end of the outer metal layer 105. The other dielectric material layer 115 has a thickness greater than the combined thickness of the dielectric material layer 103 and the outer metal layer 105. Furthermore, another outer metal layer 117 is disposed on the outer surface of the other dielectric material layer 115 such that it extends axially in opposite directions from the edge of the other dielectric material layer 115 toward the electrosurgical instrument so as to overlap with the exposed portion of the outer metal layer 105. The other outer metal layer 117 contacts the outer metal layer 105 in the overlapping area, thereby forming an electrical connection between the outer metal layer 105 and the other outer metal layer 117. The other outer metal layer 117 is slidable relative to the outer metal layer 105, allowing the second element to rotate relative to the first element while still maintaining an electrical connection.

Thus, the connection between the first and second elements is such that the electrosurgical instrument and the second element can be rotated relative to the first element (ie, the outer portion of the cable) while maintaining a bipolar electrical connection to the electrosurgical instrument.

With this configuration, the electrosurgical instrument can be both rotated and axially moved relative to the cable. This can allow for good control of the orientation and positioning of the electrosurgical instrument.

Some specific example configurations of how to rotate an electrosurgical instrument connected at one end of a cable will now be discussed.

In one embodiment, an electrosurgical instrument can be rotated by connecting an actuator, such as a rod, wire, cable, or tube, to the electrosurgical instrument and rotating the actuator to directly rotate the electrosurgical instrument. This can provide acceptable rotational control of the electrosurgical instrument in some cases. However, the inventors have recognized that in some cases, this type of control can cause the rotation of the electrosurgical instrument to occur in a series of jumps (or jolts) or intermittent sudden changes, which may be undesirable in many applications. This is believed to be because the flexure in the actuator causes friction and torque pressure.

The present inventors have recognized that this problem can be overcome by causing rotation of the electrosurgical instrument by pushing or pulling an actuator, such as a rod, wire, cable, tube, or pipe, to move it axially relative to the electrosurgical instrument, and by providing an interface between the actuator and the electrosurgical instrument that converts this axial movement into rotational movement of the electrosurgical instrument. The present inventors have recognized that the axial pulling and pushing movement of the actuator is smoothly transmitted along the cable even when the cable is bent, thereby enabling smooth rotation of the electrosurgical instrument.

In one embodiment, as shown in Figure 15, this is achieved by providing a raised helix 119 on the outer surface of the actuator 121, which is a hollow flexible tube in this embodiment. A corresponding rotator 123 is provided above the helix 119 that is connected to the electrosurgical instrument (directly or indirectly through other parts or components). The rotator 123 comprises a hollow tube or pipe. The rotator 123 has a device or structure for making the rotator 123 follow the path of the raised helix 119. For example, the rotator 123 can have a curved channel or groove for accommodating the raised helix 119. The rotator 123 is prevented from moving axially with the actuator 121 by a device not shown in Figure 15, which will be discussed in more detail below. Therefore, when the actuator 121 moves axially relative to the rotator 123, the rotator 123 is maintained in the same axial position and rotates relative to the actuator 121 by the interaction between the raised helix 119 and the rotator 123.

15 , the raised helix 119 comprises a wire that bends in a spiral pattern around the actuator 121. However, in other embodiments the raised helix 119 may be configured differently. For example, in one embodiment the raised helix 119 may comprise a tube that is cut (e.g., laser cut) to create a spiral shape and then attached (e.g., bonded) to the exterior of the actuator 121. Alternatively, the raised helix 119 may be formed on the exterior surface of the actuator 121 by selectively removing material from the exterior surface of the actuator 121, such as by laser etching, such that the actuator 121 and the raised helix 119 are formed from a single tube.

In this embodiment, the raised helix 119 comprises a single very small low pitch thread. This allows the rotator 123 to have a good bearing on the actuator 121, giving it a smooth rotating action.

Because the actuator 121 is a hollow tube in this embodiment, other components such as liquid or gas feeds or pull wires or other actuators can be passed through the hollow tube when the cable is in use. Therefore, the actuation for rotating the electrosurgical instrument does not significantly limit the provision of other components through the hollow cable.

The rotator 123 illustrated in Figure 15 can be integral with or connected to any of the previously described rotational configurations, such as the rotational shaft illustrated in Figures 9 to 13 or the second element illustrated in Figure 14, thereby enabling the electrosurgical tool to be accurately rotated in any of these embodiments.

In some embodiments, the spinner 123 can be significantly longer in the axial direction than the spinner 123 shown in Figure 15. This can provide additional space for providing a seal.

In other embodiments, the interaction between the actuator and the rotator to convert the linear motion of the actuator into the rotation of the rotator can be different from the interaction illustrated in Figure 15. For example, instead of having a raised helix, the actuator can instead have a helical groove or slot on its outer surface, and the rotator can have a follower (e.g., a protrusion such as a pin) that is received in the helical groove or slot so that it follows the path of the groove or slot. Thus, when the actuator moves axially and the axial position of the rotator is fixed, the rotator is caused to rotate.

In an alternative embodiment, the rotator may instead include a helical groove or slot and the actuator may include a follower that is received in the helical groove or slot of the rotator. Thus, when the actuator moves axially and the rotator is prevented from moving axially, the rotator is caused to rotate. This is illustrated in FIG. 16 , where the actuator 121 includes a follower 125 and the rotator 123 has a helical groove 127 on its inner surface for receiving the follower 125.

As discussed above, in order to achieve rotation of the rotator in the above configuration, the rotator is prevented from moving axially. In some embodiments, this can be achieved by providing a stop (such as a ring or protrusion) at one end of the cable to prevent the rotator from moving axially further than the stop. In other embodiments, an external cover or sleeve can be fitted over the cable, the cover or sleeve having a stop, such as a ring or protrusion, for preventing the rotator from moving axially further than the stop.

In other embodiments, the diameter of the cable end may be reduced as illustrated in FIG. 7 and/or by other means such as crimping or heat shrinking to prevent the rotator from escaping the cable end or by forming a flange or ring at one end of the cable.

In some embodiments, the actuator can also be configured to interact with the cable or with the handle of the cable so that the actuator is prevented from rotating relative to the cable. This can improve the rotation of the rotator and/or make it easier to rotate the rotator. This can be achieved, for example, by providing a linear axial groove or slot in the surface of the actuator that accommodates a follower (e.g., a protrusion such as a pin) on the inner surface of the cable or handle. Alternatively, a linear axial groove or slot can be formed in the surface of the cable or handle that accommodates a follower (e.g., a protrusion or pin) on the surface of the actuator.

In order to impart axial motion to the actuator, a second helical interface may be provided at the proximal end of the cable, whereby rotation of a control knob or the like is converted into axial movement of the actuator.

In some configurations the previously described rotator shaft and the previously described rotator may be combined (eg, attached together) to form a single component.

FIG17A illustrates an example in which the rotator shaft and rotator are combined. The arrangement illustrated in FIG17A includes a first portion 129 and a second portion 131. First portion 129 comprises a material tube coated with a conductive material on the exterior. As previously discussed with respect to the rotator shaft, first portion 131 further comprises a partial tube 133 spaced apart from one end of the material tube so as to be positioned around the outer surface of the outer metal layer of the cable. Partial tube 133 has a conductive coating on its interior for achieving an electrical connection to the outer metal layer.

The second part 131 comprises a tube of material coated with a conductive material on the outside. A helical slot has been cut from the tube of material to allow interaction with a follower (not shown) on the actuator. The second part 131 thus acts as a rotator as described above.

As previously discussed with respect to the rotator shaft, the second portion 131 has a portion of the tube 135 adjacent the tube of material so as to be positioned around the outer surface of the inner metallic layer of the cable.

As shown in FIG. 17B , the second portion 131 may be a slideway inside the first portion 129 and secured inside the first portion 129 to form a combined spinner shaft and helix (spinner).

As shown in Figure 17C, the combined rotator shaft and helix can then be connected to a cable having a configuration corresponding to that illustrated in Figure 1. Thus, a rotatable bipolar electrical connection is formed between the combined rotator shaft and helix and the cable, and the combined rotator shaft and helix can be rotated by axially moving an actuator, which can be an axially sliding sleeve or the like extending through a hollow passage in the cable.

The electrosurgical tool can then be connected to the free end of the combined rotator shaft and helical wire (the left end in FIG17C ). FIG17C does not show an electrical connection interface to the electrosurgical instrument. However, the connection interface may include, for example, corresponding conductive recesses and/or protrusions on the cable and on the electrosurgical instrument, such as metal foil tabs, pins or wires and corresponding holes or openings, or corresponding electrical connection terminals on the cable and electrosurgical instrument that make direct physical contact or electrical contact (e.g., using wires).

In some cases, it may be necessary to convert a cable having the configuration illustrated in FIG1 , in which the metal layer is disposed on the outer surface of the inner tubular layer and the dielectric material tube, to a configuration in which the metal layer can be recessed from the interior of these layers. In one embodiment, this can be achieved by providing a solid metal tube of corresponding size at each end of the inner tubular layer and the dielectric material tube. Conductive foil can be used to mechanically and electrically connect the solid metal tube to the corresponding metal layer, thereby allowing electrical connection to the metal layer from the inner surface of the solid metal tube. Thus, a rotator shaft as illustrated in FIG10 can be used with a cable having the configuration illustrated in FIG1 .

The same concept can also be used to convert a cable having the configuration illustrated in FIG. 2 , where the metal layer is provided on the inner surface of the dielectric material and the outer tubular layer, to a configuration where the metal layer is recessed from the exterior of those layers.

Alternatively, a ceramic ferrule having a metallic coating on the interior can be connected to the inner tubular layer end so that electrical connection to the inner metallic layer can be obtained from the interior of the ceramic ferrule. Additionally, an outer sheath having an inner metallic coating at the electrosurgical instrument connection end and a metallic ring at that end can be positioned opposite the outer metallic layer, and electrical connection to the outer metallic layer can be obtained from the interior of the metallic ring.

In one embodiment, an electrical signal from an inner metal layer coated on the exterior of the inner tubular layer can be transmitted to a metal ring to be used as a sliding electrical connection. This can be achieved by positioning the distal end of the inner tubular layer so that it is set back from the distal end of the dielectric layer (on whose outer surface the outer metal layer is coated). A portion of the interior of the dielectric layer extending from the proximal side of the distal end of the inner tubular layer to the distal side of the distal end of the inner tubular layer can be coated with a conductive material. Therefore, the electrical signal from the inner metal layer is transmitted to the portion on the interior of the dielectric layer because this portion is in contact with the inner metal layer. The metal ring (or tube) can be slid to the distal end of the dielectric layer so that it is adjacent to the distal end of the inner tubular layer. Because the metal ring is in contact with the portion on the interior of the dielectric layer coated with the conductive material, the metal ring is electrically connected to the inner metal layer even when the metal ring slides away from the inner tubular layer (provided that at least a portion of the metal ring remains in contact with the portion on the interior of the dielectric layer). Thus, the metallic ring includes a sliding electrical connection to the inner metallic layer, which may allow an electrosurgical instrument connected (directly or indirectly) to the metallic ring to slide axially relative to the inner metallic layer while still maintaining electrical contact with the inner metallic layer.

Claims (49)

1. A cable for delivering radio frequency and/or microwave frequency energy to an electrosurgical instrument at a first end of a cable, said cable comprising: A hollow tube comprising an inner conductive layer and an outer conductive layer separated by a dielectric material to form a transmission line; A first terminal is provided at the first end of the cable to form an electrical connection to the inner conductive layer. A second terminal is provided at the first end of the cable to form an electrical connection to the outer conductive layer. A rotatable assembly at the first end of the cable, wherein the rotatable assembly includes a longitudinal passage continuous with the hollow tube, and wherein the rotatable assembly is rotatable relative to the transmission line and includes: A first portion electrically connected to the first terminal, wherein the first portion and the first terminal are rotatable relative to each other and are configured to maintain electrical connection when rotated relative to each other; A second portion electrically connected to the second terminal, wherein the second portion and the second terminal are rotatable relative to each other and are configured to maintain electrical connection when rotated relative to each other. 2. The cable of claim 1, wherein the first terminal includes the surface of the exposed portion of the inner conductive layer. 3. The cable of claim 2, wherein the exposed portion of the inner conductive layer comprises an exposed tubular portion of the inner conductive layer. 4. The cable according to any one of the preceding claims, wherein: The first terminal is located on the outer annular surface of the cable; and The first portion is positioned around the outer annular surface of the cable. 5. The cable according to any one of claims 1 to 3, wherein: The first terminal is located on the inner annular surface of the cable; and The first portion is positioned inside the inner annular surface of the cable. 6. The cable of claim 1, wherein the first portion comprises a conductive material on its inner or outer surface, the conductive material being in contact with the first terminal. 7. The cable according to claim 6, wherein the conductive material comprises an annular strip of conductive material. 8. The cable of claim 1, wherein the first portion includes a conductive element biased to contact the first terminal. 9. The cable according to claim 8, wherein the conductive element comprises a spring wing, a spring sheet, a spring pad, or a spring protrusion. 10. The cable of claim 1, wherein the first portion comprises a hollow tube. 11. The cable of claim 1, wherein the first terminal is located on the outer annular surface of the cable, and the first portion is positioned around the outer annular surface of the cable; and The first portion includes first and second spring wings that clamp the outer annular surface of the cable therebetween. 12. The cable of claim 1, wherein the first terminal is located on the inner annular surface of the cable, and the first portion is positioned inside the inner annular surface of the cable; and The first portion includes first and second spring wings that press outward against the inner annular surface of the cable. 13. The cable of claim 11 or claim 12, wherein the first portion comprises a hollow tube of natural spring material, and an axial strip has been removed from its circumference to form the first and second spring wings. 14. The cable of claim 1, wherein the second terminal includes the surface of the exposed portion of the outer conductive layer. 15. The cable of claim 14, wherein the exposed portion of the outer conductive layer comprises an exposed tubular portion of the outer conductive layer. 16. The cable according to claim 1, wherein: The second terminal is located on the outer annular surface of the cable; and The second portion is positioned around the outer annular surface of the cable. 17. The cable according to claim 1, wherein: The second terminal is located on the inner annular surface of the cable; and The second portion is positioned inside the inner annular surface of the cable. 18. The cable of claim 1, wherein the second portion comprises a conductive material on its inner or outer surface, the conductive material being in contact with the second terminal. 19. The cable of claim 18, wherein the conductive material comprises an annular strip of conductive material. 20. The cable of claim 1, wherein the second portion includes a conductive element biased to contact the second terminal. 21. The cable of claim 20, wherein the conductive element comprises a spring wing, a spring sheet, a spring pad, or a spring protrusion. 22. The cable of claim 1, wherein the second portion comprises a hollow tube. 23. The cable of claim 1, wherein the second terminal is located on the outer annular surface of the cable, and the second portion is positioned around the outer annular surface of the cable; and The second part includes first and second spring wings that clamp the outer annular surface of the cable therebetween. 24. The cable of claim 1, wherein the second terminal is located on the inner annular surface of the cable, and the second portion is positioned inside the inner annular surface of the cable; and The second part includes first and second spring wings that press outward against the inner annular surface of the cable. 25. The cable of claim 23 or claim 24, wherein the second portion comprises a hollow tube of natural spring material, and an axial strip has been removed from its circumference to form the first and second spring wings. 26. The cable of claim 1, wherein the first portion is connected to or integral with the second portion. 27. The cable of claim 1, wherein the cable includes an actuation device fed through the hollow tube of the cable for rotating the rotatable component relative to the transmission line. 28. The cable of claim 27, wherein the actuating device is configured to move axially along the hollow tube of the cable, and wherein the cable includes an interface disposed in the hollow tube of the cable for converting the axial movement of the actuating device into rotational movement of the rotatable component. 29. The cable of claim 27, wherein the actuation device comprises an actuator element, and wherein the actuator element comprises a rod, a wire, a cable, or a hollow tube. 30. The cable according to claim 29, wherein: The actuator element has a helical path disposed on its outer surface; and The cable includes a rotator with a follower that follows the helical path as the actuator element moves axially, thereby causing the rotator to rotate. 31. The cable according to claim 29, wherein: The actuator element includes a follower on its outer surface; and The cable includes a rotator having a helical path disposed on its inner surface, and the follower travels along the helical path as the actuator element moves axially, thereby rotating the rotator. 32. The cable according to claim 30 or claim 31, wherein the helical path includes a raised helical path. 33. The cable according to claim 30 or claim 31, wherein the helical path includes a helical channel, a helical groove, or a helical slot. 34. The cable of claim 30 or claim 31, wherein the follower comprises: Protrusion; pins; Fins; concavity; Groove; Channel; or Narrow slot. 35. The cable of claim 30 or claim 31, wherein the rotator is connected to or integrated with the electrosurgical instrument, such that rotation of the rotator causes rotation of the electrosurgical instrument. 36. The cable of claim 30 or claim 31, wherein the rotator is connected to or integrated with the rotatable assembly such that rotation of the rotator causes rotation of the rotatable assembly. 37. The cable of claim 1, wherein the dielectric material comprises: Solid dielectric tube; or Dielectric material tube with a porous structure. 38. The cable of claim 1, wherein the inner conductive layer and/or the outer conductive layer comprises: Conductive coating on the inside or outside of the material tube; A solid conductive material tube positioned internally or externally by the material tube; or A braided conductive material layer formed on or embedded in a material tube. 39. The cable of claim 1, wherein the cable comprises: Hollow inner tubular layer; The tube of the inner conductive layer on the outer surface of the hollow inner tubular layer; The dielectric material tube on the outer surface of the inner conductive layer tube; and The outer conductive layer on the outer surface of the dielectric material tube. 40. The cable of claim 39, wherein the inner conductive layer protrudes beyond the edge of the dielectric tube such that the inner conductive layer is exposed at the first end of the cable. 41. The cable of claim 1, wherein the cable comprises: The hollow tube of the inner conductive layer; The dielectric material tube on the outer surface of the hollow tube of the inner conductive layer; and The outer conductive layer on the outer surface of the dielectric material tube. 42. The cable of claim 41, wherein the cable further comprises a protective outer tubular layer on the outer surface of the tube of the outer conductive layer. 43. The cable of claim 41 or claim 42, wherein the outer conductive layer protrudes beyond the edge of the dielectric material tube such that the outer conductive layer is exposed at the first end of the cable. 44. The cable of claim 1, wherein the outer diameter of the cable is smaller over a portion of its length adjacent to the first end of the cable. 45. The cable of claim 44, wherein the outer diameter of the cable is made smaller in the portion thereof by reducing the inner diameter of the cable. 46. The cable of claim 44 or claim 45, wherein the outer diameter of the cable is made smaller in the portion thereof by reducing the thickness of the dielectric material. 47. A cable for delivering radio frequency and/or microwave frequency energy to an electrosurgical instrument, the cable comprising: The first part includes an outer conductive layer disposed on the outside of a hollow tube of dielectric material; The second part includes an inner conductive layer; The second part is positioned inside the first part, such that the inner conductive layer and the outer conductive layer form a transmission line; The second part can be rotated relative to the first part; The second portion includes another conductive layer electrically connected to the outer conductive layer in the region where the outer conductive layer is exposed, the other conductive layer being electrically insulated from the inner conductive layer, wherein the other conductive layer and the outer conductive layer are rotatable relative to each other and are configured to maintain electrical connection when rotated relative to each other. 48. The cable of claim 47, wherein the cable includes an actuation device fed through the hollow tube of the cable for rotating the second portion relative to the first portion. 49. The cable of claim 48, wherein the actuating device is configured to move axially along the hollow tube of the cable, and wherein the cable includes an interface disposed in the hollow tube of the cable for converting the axial movement of the actuating device into rotational movement of the second portion.