CN1973918B - Implantable cluster-stimulating microelectrode arrays in the human nervous system - Google Patents

Abstract

The invention relates to a cluster stimulation micro-electrode array which can be implanted into human nervous system, belonging to the field of medical prosthesis. The invention includes: metal wire stimulating microelectrode, metal wire supporting microelectrode, metal wire stimulating microelectrode cluster, metal wire stimulating microelectrode cluster array, microelectrode substrate, Q metal wire stimulating microelectrodes bonded to the metal wire supporting microelectrode Metal wire stimulation microelectrode clusters are formed on the outer wall of the microelectrode base, and the microelectrode base is a three-layer structure. m*n metal wire stimulation microelectrode clusters are fixed on the microelectrode base to form a wire stimulation microelectrode cluster array, which is drawn out from the microelectrode base. The leads are connected to external devices. The material of the metal wire stimulating microelectrode and the metal wire microsupporting microelectrode is a metal material with good biocompatibility. The present invention can more effectively stimulate the nervous system in a limited space according to the anatomical and morphological features of the human nervous system.

Description

Implantable cluster-stimulating microelectrode arrays in the human nervous system

technical field

The invention relates to an implantable microelectrode in the technical field of medical prosthesis, in particular to a cluster stimulation microelectrode array which can be implanted into the human nervous system.

Background technique

The field of neuroprosthetics includes motor neuroprostheses, cochlear implants (cochlear implants) and optic neuroprostheses, among others. Motor neuroprostheses are microelectronic devices of the nervous system developed through deep brain stimulation to treat movement disorders such as Parkinson's disease (PD). Deep brain stimulation often uses an embedded electrical stimulation system, which generally consists of three parts: implanted electrodes, connecting wires to the subcutaneous receiver, and an electrical stimulator. After the electrodes are implanted, select certain stimulation parameters and different electrode stimulation contacts to observe the effect of implantation and record the parameters of different contacts at the same time for postoperative reference. During the experiment, it is necessary to ensure that the electrodes do not shift, so as not to affect the curative effect. Electrode design is therefore an important part of motor neuroprosthetic systems.

Hair cells in the human cochlea are sensory cells that receive sound. Severe deafness occurs when the damage to the hair cells of the cochlea is severe. The cochlear implant consists of two parts: external and internal devices. The external part includes microphones, speech converters, and transmitting coils; the internal part includes receiving coils, processors, stimulating electrodes, and reference electrodes. The more channels the stimulating electrodes use, the more electrodes can stimulate the auditory nerve fibers in the cochlea, and the natural structure of the patient's cochlea can be used to the greatest extent to establish a more complete auditory scale. The design of the electrode shape is also unique to the cochlear implant The essential.

Optic nerve prosthesis is a medical device to help patients with retinal or other visual organ lesions regain light and vision. Among them, the implanted electrode array directly acts on the central and peripheral nervous systems, simulating the process of normal vision formation, and transmits electrical signals to stimulate the microelectrode array in the form of specific pulses through encoding, acting on the visual cortex, retina or optic nerve. The pulse signal transmitted by the stimulating electrode should be large enough to cause an action potential to occur in the stimulating part, which is transmitted to the visual cortex through the nerve, and the imaging waveform is recorded by the recording electrode in the cerebral cortex. In the whole neuroprosthetic system, the stimulating microelectrode is crucial, and it must have good biocompatibility, easy processing, flexibility, and high space utilization.

After searching the existing technical documents, it is found that the patent application number is 03159801.3, the publication date is: March 30, 2005, and the patent name is: "multi-electrode array and its manufacturing method". This invention provides an easy-to-process , High-density electrode array, composed of microporous column, single electrode and fixed resin. Although this invention also considers the problem of achieving a high density electrode array, it only provides a four-electrode array. Since the electrodes have the same length, it does not take into account the stimulation of nerve fibers at different depths when used on nerve bundles, and does not fundamentally solve the efficiency and practical problems of electrical stimulation of the human nervous system. Therefore, the comprehensive performance of this type of electrode Still needs further improvement.

Contents of the invention

The object of the present invention is to address the deficiencies and defects of the prior art, to provide a clustered microelectrode array capable of effectively high-density electrical stimulation of the human nervous system, so that it can , can stimulate the nervous system more effectively in a limited space.

The present invention is achieved through the following technical solutions, and the present invention includes: a metal wire stimulating microelectrode, a metal wire supporting microelectrode and a microelectrode base, and Q metal wire microelectrodes with different lengths are bonded on the outer wall of the metal wire supporting microelectrode Metal microelectrode clusters are formed, and the microelectrode base has a three-layer structure. m*n metal wire microelectrode clusters are fixed on the microelectrode base to form m*n metal wire stimulation microelectrode cluster arrays. Lead wires are drawn from the microelectrode base to connect with external devices. The material of the metal wire stimulating microelectrode and the metal wire microsupporting microelectrode is a metal material with good biocompatibility. m represents the number of rows of the array, n represents the number of columns of the array, and Q represents the number of wire micro-stimulation electrodes on each wire micro-support electrode.

The metal material with good biocompatibility refers to one of tungsten wire, gold wire and platinum-iridium alloy wire.

The rods of the metal wire stimulating microelectrode and the metal wire supporting microelectrode are subjected to insulation treatment, and the tip is exposed to the microelectrode.

The material for insulating the wire stimulating microelectrode and the wire supporting microelectrode is C-type parylene.

The tips of the metal wire stimulating microelectrode and the wire supporting microelectrode are exposed with strong laser light.

The diameter of the metal wire stimulating microelectrode is 10-20 μm.

The tip diameter of the wire stimulating microelectrode is about 1 μm.

The diameter of the metal wire supporting the microelectrode is 50-80 μm.

The length range of the metal wire stimulating microelectrodes is 300-1000 μm.

The tip diameter of the wire stimulating microelectrode is about 3 μm.

The length of the metal wire supporting the microelectrode is 1.2 mm.

The total diameter of the metal wire stimulating microelectrode cluster is 70-120 μm.

The metal wire stimulating microelectrode cluster is that Q metal wire stimulating microelectrodes with different lengths adhere to the outer wall of the metal wire supporting microelectrode according to a distribution strategy of a certain length. The length of the stimulating electrodes is designed to be different in length, in order to stimulate nerve fibers at different depths and realize multi-site stimulation. The wire stimulating microelectrodes with different lengths are staggered in a certain order to ensure the stability and mechanical strength of each wire stimulating microelectrode cluster in the entire wire stimulating microelectrode cluster array.

The adhesive used for bonding the wire stimulating microelectrode and the wire supporting microelectrode is: cyanoacrylate adhesive.

The distribution strategy of the length of the metal wire stimulating microelectrode is: set the length of the metal wire stimulating microelectrode as l _p = l _l + (p-1)*Δl, a total of p, that is, the electrode length is from l _l to l _p , the adjacent length difference is Δl.

The arrangement strategy of the described metal wire stimulation microelectrode cluster array is: set the array as A={m*n}, the element l _{i of A, j(k)} is located in the i-th row of the wire stimulation microelectrode array, the jth The length of the kth metal wire microstimulation electrode in the row of metal wire microelectrode clusters, l _{i, j(k)} = l _l + [(i-1)*m+(j-1)]*Δl+m*n* (k-1)*Δl (i=1, 2...m, j=1, 2...n, k=1, 2...Q). l represents the length of the metal wire micro-stimulation electrode, A represents the electrode array (Array), m represents the number of rows of the array, n represents the number of columns of the array, Q represents the number of metal wire micro-stimulation electrodes on each metal wire micro-support electrode, p=m*n*Q.

The row spacing of the wire stimulating microelectrode cluster array is 0.35-1.2 mm, and the column spacing is 0.35-1.2 mm.

The composition of the three-layer electrode base is: a silicon rubber layer on the surface, a conductive layer in the middle, and a silicon rubber layer on the bottom layer.

The silicon rubber layer thickness of the surface layer is 0.5-1mm.

The thickness of the middle conductive layer is 0.5-1mm.

The silicon rubber layer thickness of the bottom layer is 1-2mm.

Compared with the prior art, the main innovative point technology of the present invention is as follows:

1) Fully considering the characteristics of the human nervous system, aiming at the defects of the existing nerve stimulation electrode technology, the cluster stimulating microelectrode array that can be implanted into the human nervous system is designed. Since the micro-stimulation electrodes designed in the present invention have different lengths and are regularly arranged and combined, nerve fibers of different depths can be efficiently stimulated. At the same time, more experimental schemes can be designed to allow more information input and output in the experiment, improve the success rate of the experiment, and allow people to grasp more relationships between external stimuli and human nervous tissue responses.

2) The biocompatibility and electrical properties of the selected electrode materials are fully considered: metal microelectrodes have the advantages of low electrical resistance, high mechanical strength, and low electrical noise. Metal microelectrodes are especially beneficial to the needs of chronic implantation experiments, and are ideal stimulating electrodes. Metal wires such as tungsten wire, gold wire, and platinum-iridium alloy wire can be used as raw materials. Tungsten wire has good biocompatibility, high strength, low price, and convenient manufacture. It is the earliest and most commonly used electrode material in experiments and scientific research. Platinum-iridium alloy has excellent biocompatibility and stable physical and chemical properties, and is especially suitable for implantation in vivo, and is the most ideal electrode material. Animal experiments have proved that stainless steel wire, tungsten wire, platinum, and platinum-iridium alloy have less toxicity, and platinum-iridium alloy causes the least tissue inflammation in the body, followed by tungsten wire and stainless steel wire.

3) For the insulation problem of the metal wire electrode, the biocompatibility problem between the insulating material and the tissue has been fully considered, and the selected insulating material does not cause tissue reaction and inflammatory reaction and can protect the implant device from being eroded by the physiological environment. The insulating material used is C-type parylene (Parylene-C).

The beneficial effect of the invention is that the shape and anatomical characteristics of the part to be implanted into the human body are fully considered, and the flexible stimulating microelectrode array designed by the invention is especially suitable for stimulating the human nervous system. People use micro-processing technology to make high-density electrodes to obtain higher stimulation efficiency, which can provide meaningful data for clinical experiments and scientific research. The materials used to make neurostimulators have good biocompatibility and can ensure that the device is not eroded by the physiological environment in the body. The geometric dimensions of the electrodes can be controlled according to the size of the site to be stimulated, and the number, diameter and length of the stimulating electrodes attached to the supporting microelectrodes in the electrode cluster can be changed according to actual needs, so the electrode cluster can achieve precise stimulation , which is helpful for people to find the relationship between different stimulation sites and different stimulation effects.

Description of drawings

Figure 1 is a schematic diagram of wire-stimulated microelectrode clusters

Fig. 2 is a structural representation of the present invention

Figure 3 is a schematic diagram of the three-layer structure of the electrode base

Figure 4 is a schematic diagram of wiring in the middle conductive layer of the electrode base

Detailed ways

The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings: the present embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and processes are provided, but the protection scope of the present invention is not limited to the following implementations example.

As shown in Figures 1, 2, 3, and 4, this embodiment includes: metal wire stimulating microelectrode 1, metal wire supporting microelectrode 2, metal wire stimulating microelectrode cluster 3, metal wire stimulating microelectrode cluster array 4, microelectrode Substrate 5, Q metal wire microelectrodes 1 are bonded to the outer wall of the metal wire supporting microelectrodes 2 to form metal microelectrode clusters 3, the microelectrode substrate 5 has a three-layer structure, and m*n metal microelectrode clusters 3 are fixed on the microelectrodes. The metal wires composed of m*n on the electrode substrate 5 stimulate the microelectrode cluster array 4, and lead wires are drawn from the microelectrode substrate 5 to connect with external devices. The material of the wire microelectrode 1 and the wire supporting microelectrode 2 is a metal material with good biocompatibility. m represents the number of rows of the array, n represents the number of columns of the array, and Q represents the number of wire micro-stimulation electrodes on each wire micro-support electrode.

When working, the external device transmits the set electrical signal to the implanted part in the body through the wire, and the electric pulse stimulates the nervous system near the tip of the electrode through the wire to stimulate the microelectrode 1, that is, the wire stimulates the microelectrode 1 to be the implanted part in the body. Interface with human nervous tissue. Due to the different designs of the wire micro-stimulation electrodes 1 in this embodiment, nerves of different depths can be stimulated, which can make up for the defects in surgical technique precision, and the high-density stimulation sites in this embodiment improve the stimulation efficiency, which is Advantages that cannot be compared with previous technologies.

The metal material with good biocompatibility refers to one of tungsten wire, gold wire and platinum-iridium alloy wire.

The rods of the wire stimulating microelectrode 1 and the wire supporting microelectrode 2 are insulated, and the tips are exposed.

The material for insulating the wire stimulating microelectrode 1 and the wire supporting microelectrode 2 is C-type parylene.

The tip of the metal wire stimulating microelectrode 1 and the wire supporting microelectrode 2 is exposed with strong laser light.

The diameter of the metal wire stimulating microelectrode 1 is 10-20 μm.

The diameter of the tip of the wire stimulating microelectrode 1 is about 1 μm.

The diameter of the metal wire supporting the microelectrode 2 is 50-80 μm.

The length range of the metal wire stimulating microelectrode 1 is l=300-1000 μm.

The diameter of the tip of the wire stimulating microelectrode 1 is about 3 μm.

The length of the metal wire supporting the microelectrode 2 is 1.2 mm.

The total diameter of the wire stimulating microelectrode cluster 3 is 70-120 μm.

The metal wire stimulating microelectrode cluster 3 is that Q metal wire stimulating microelectrodes 1 with different lengths are adhered to the outer wall of the wire supporting microelectrode 2 according to a certain length distribution strategy.

The adhesive used for bonding the wire stimulating microelectrode 1 and the wire supporting microelectrode 2 is: cyanoacrylate adhesive.

The distribution strategy of the length of the metal wire stimulating microelectrode 1 is: set the length of the metal wire stimulating microelectrode 1 as _lp =l _l +(p-1)*Δl, and there are p total of metal wire stimulating microelectrodes The length of 1 is from l _l to l _p , and the difference between adjacent lengths is Δl.

The arrangement of the described metal wire stimulation microelectrode cluster array 4 is assuming that the array is A={m*n}, the elements l _{i and jk} of A are located in the ith row of the metal wire stimulation microelectrode array 4, and the jth column metal The length of the kth metal wire microstimulation electrode 1 in the wire microelectrode cluster 3, l _{i, j(k)} = l _l + [(i-1)*m+(j-1)]*Δl+m*n *(k-1)*Δl (i=1, 2...m, j=1, 2...n, k=1, 2...Q). l represents the length of the metal wire micro-stimulation electrode, A represents the electrode array (Array), m represents the number of rows of the array, n represents the number of columns of the array, Q represents the number of metal wire micro-stimulation electrodes on each metal wire micro-support electrode, p=m*n*Q.

The metal wire stimulating microelectrode cluster array 4 has a row spacing of 0.35-1.2mm and a column spacing of 0.35-1.2mm.

The diameters of the wire micro-stimulation electrodes 1 in the wire micro-stimulation electrode clusters 3 on the wire stimulation micro-electrode cluster array 4 are the same, but the lengths are different; the diameters and lengths of the wire support micro-electrodes 2 are the same.

The composition of the three-layer electrode substrate 5 is: a silicon rubber layer 6 on the surface, a conductive layer 7 in the middle, and a silicon rubber layer 8 on the bottom layer.

The silicon rubber layer 6 of the surface layer has a thickness of 0.5-1 mm.

The thickness of the middle conductive layer 7 is 0.5-1mm.

The silicon rubber layer 8 of the bottom layer has a thickness of 1-2mm.

Claims (10)

1. one kind implantable bunch shape optic nerve stimulating micro electrode array, it is characterized in that, comprise: tinsel stimulating micro electrode (1), wire support microelectrode (2) and microelectrode substrate (5), wherein: Q different tinsel stimulating micro electrode (1) of length is bonded on the outer wall of wire support microelectrode (2) forms tinsel stimulating micro electrode bunch (3), microelectrode substrate (5) is a three-decker, m*n tinsel microelectrode bunch (3) is fixed in microelectrode substrate (5) and goes up the tinsel stimulating micro electrode cluster array (4) of forming m*n, drawing lead-in wire from microelectrode substrate (5) links to each other with external equipment, the material of the little support microelectrode of tinsel stimulating micro electrode (1) and tinsel (2) is the metal material of good biocompatibility, and it is C type Parylene that tinsel stimulating micro electrode (1) and wire support microelectrode (2) are carried out insulating material;

Described m represents the line number of array, and n represents the columns of array, and Q represents the number of tinsel microstimulation electrode on the little support electrode of each tinsel.

2. neural bunch of shape stimulating micro electrode array of human implantable according to claim 1 is characterized in that the metal material of described good biocompatibility is meant the wherein a kind of of tungsten filament, spun gold and platinumiridio silk; The bar portion of described tinsel stimulating micro electrode (1) and wire support microelectrode (2) is through insulation processing and most advanced and sophisticated light laser exposed electrodes.

3. neural bunch of shape stimulating micro electrode array of human implantable according to claim 1 and 2 is characterized in that, the length range of described tinsel stimulating micro electrode (1) is 1=300-1000 μ m, and diameter is 10-20 μ m, and tip diameter is 1-3 μ m.

4. neural bunch of shape stimulating micro electrode array of human implantable according to claim 1 and 2 is characterized in that the length of described wire support microelectrode (2) is 1.2mm, and diameter is 50-80 μ m, and tip diameter is 1-3 μ m.

5. neural bunch of shape stimulating micro electrode array of human implantable according to claim 1 is characterized in that described tinsel stimulating micro electrode (1) is bonded in wire support microelectrode (2), specifically is to carry out bonding with cyanoacrylate adhesive; The overall diameter of described tinsel stimulating micro electrode bunch (3) is 70-120 μ m.

6. neural bunch of shape stimulating micro electrode array of human implantable according to claim 1, it is characterized in that, the number Q of the tinsel stimulating micro electrode (1) that each tinsel stimulating micro electrode bunch (3) is comprised is 4 or 6 or 8 or 10, and the length difference of each tinsel stimulating micro electrode (1), the length of tinsel stimulating micro electrode (1) is made as l _p=l ₁+ (p-1) * Δ l, p altogether, promptly the length of tinsel stimulating micro electrode (1) is from l ₁To l _p, the adjacent lengths difference is Δ l, and l represents the length of tinsel microstimulation electrode, and A represents electrod-array, and m represents the line number of array, and n represents the columns of array, and Q represents the number of tinsel microstimulation electrode on the little support electrode of each tinsel, p=m*n*Q.

7. neural bunch of shape stimulating micro electrode array of human implantable according to claim 1, it is characterized in that, being arranged as of described tinsel stimulating micro electrode cluster array (4): establishing array is A={m*n}, the ranks of tinsel stimulating micro electrode cluster array (4) are several to be adjusted according to needs, be that array A is m*n, m, n=1,2,3,4 ..., the element l of A _{I, j (k)}Be that to be positioned at the i of tinsel stimulating micro electrode array (4) capable, the length l of k tinsel microstimulation electrode 1 in the j row tinsel microelectrode bunches 3 _{I, j (k)}=l ₁+ [(i-1) * m+ (j-1)] * Δ l+m*n* (k-1) * Δ l, i=1,2...m, j=1,2 ... n, k=1,2 ... Q.

8. according to claim 1 or neural bunch of shape stimulating micro electrode array of 7 described human implantables, it is characterized in that, the diameter that described tinsel stimulating micro electrode cluster array (4) is gone up the tinsel microstimulation electrode (1) in the tinsel microstimulation electrode bunch (3) is identical, but length has nothing in common with each other; The diameter of described wire support microelectrode (2) is identical with length.

9. according to claim 1 or neural bunch of shape stimulating micro electrode array of 7 described human implantables, it is characterized in that the line space of described tinsel stimulating micro electrode cluster array (4) is 0.35-1.2mm, column pitch is 0.35-1.2mm.

10. neural bunch of shape stimulating micro electrode array of human implantable according to claim 1, it is characterized in that, described microelectrode substrate (5) is a three-decker, specifically comprise: the silastic-layer (8) of the silastic-layer on top layer (6), intermediary conductive layer (7) and bottom, wherein: the thickness of the silastic-layer on top layer (6) is 0.5-1mm, the thickness of intermediary conductive layer (7) is 0.5-1mm, and the thickness of the silastic-layer of bottom (8) is 1-2mm.

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