Electrode interface system for spinal cord electrical stimulation and spinal cord electrical stimulation device

Abstract

The invention provides an interface system used for spinal cord electrical stimulation and a spinal cord electrical stimulation electrode device, and belongs to the technical field of medical instruments, the interface system comprises a circuit board and a flip connector, the flip connector is welded on the circuit board, the flip connector is provided with an electrode pad jack used for insertion of an electrode pad, and the flip connector is connected with the circuit board. And the flip cover can be opened and closed in a flip manner so as to fix the electrode bonding pad. The interface system for spinal cord electrical stimulation comprises a circuit board and a flip cover connector, the flip cover connector is welded on the circuit board, and the flip cover connector is provided with an electrode bonding pad jack for inserting an electrode bonding pad and a flip cover capable of being opened and closed in a flip mode to fix the electrode bonding pad. By adopting the flip connector, the electrode bonding pad can be quickly inserted and detached, the design is more reasonable, and an operator can conveniently insert and pull out the electrode bonding pad.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a wired interface system, a wireless electrode interface system and a spinal cord electrical stimulation electrode device for spinal cord electrical stimulation. Background Art

[0002] Spinal cord stimulation is a neuromodulation technology that implants electrodes into the patient's spinal cord and applies a certain current to stimulate the spinal cord. This technology has been widely used to treat spinal cord injuries, intractable pain, stroke and other diseases.

[0003] The electrode is one of the core components of the spinal cord stimulation system, and its performance directly affects the treatment effect. Traditional cylindrical electrodes have poor flexibility and large size. After implantation, they will compress the spinal cord and affect the patient's comfort. The electrode points have poor conformal contact with tissues and are easily displaced, affecting the accuracy of stimulation. With the development of medicine and materials science, the design of new spinal cord stimulation electrodes is gradually developing towards better flexibility, smaller size, higher biocompatibility, easier implantation, and more precise stimulation.

[0004] The spinal cord stimulation device includes electrodes and an electrode interface system for implantation in the human body, wherein the wired electrode interface system generally includes a circuit board, a connector, and a housing for protecting the circuit board and the connector. However, the existing wired electrode interface system is not designed reasonably, and the connector design is not user-friendly, which easily leads to technical problems such as inconvenient plugging and unplugging.

[0005] In addition, the applicant also found that the existing spinal cord electrical stimulation devices have the following disadvantages: 1) high electrode impedance, poor charge injection capability, and severe heat generation; 2) poor electrode flexibility and large size, which will compress the spinal cord after implantation, and poor conformal contact between the electrode points and tissues; 3) poor biocompatibility, and long-term use may cause biological rejection reactions; 4) high production costs. Summary of the invention

[0006] The purpose of the present application is to provide an electrode interface system for spinal cord electrical stimulation, aiming to solve the technical problems in the prior art that the electrode interface system is unreasonable in design, the connector design is not user-friendly, and it is easy to cause inconvenience in plugging and unplugging.

[0007] The purpose of the present application is also to provide a spinal cord electrical stimulation device, aiming to solve the technical problems of high electrode impedance, poor charge injection capability and severe heat generation in the prior art.

[0008] Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

[0009] According to a first aspect of the present application, there is provided an electrode interface system for spinal cord electrical stimulation, comprising a circuit board and a flip-cover connector, wherein the flip-cover connector is welded on the circuit board, the flip-cover connector is provided with an electrode pad jack for inserting an electrode pad, and a flip cover that can be flipped open and flipped closed to fix the electrode pad.

[0010] In an exemplary embodiment of the present application, it further includes:

[0011] A female header, welded on the circuit board, the female header being provided with a plurality of wire jacks for inserting a plug of an external electrical stimulation device;

[0012] A wired interface protective shell is made of biocompatible materials. The wired interface protective shell includes a wired interface protective shell body, a wired interface protective shell plug-in plate, a female connector exposure hole, a suture hole, a fixing foot, and an electrode head exposure hole. The wired interface protective shell body and the wired interface protective shell plug-in plate are connected and matched with each other through a mortise and tenon structure. The electrode head exposure hole is used for the electrode pad to be connected to the flip connector so that the electrode is exposed from the electrode head exposure hole. The suture hole is used for suturing with biological tissue. Together with the fixing foot, the position of the wired interface protective shell is relatively fixed after being implanted in a biological body. Several wire sockets of the female connector are exposed from the female connector exposure hole. The wired interface protective shell body is suitable for implantation into subcutaneous fat, and several wire sockets of the female connector are exposed to connect with the outside world.

[0013] In an exemplary embodiment of the present application, it also includes a packaging material for filling and packaging the exposed hole of the electrode head and other gaps on the protective shell after the wired interface protective shell and the female socket are implanted into a biological body.

[0014] In an exemplary embodiment of the present application, the circuit board is provided with an induction coil, a rectifier module and a bidirectional charge balancing stimulation module, the induction module is used to receive a signal transmitted by an external energy supply module through the skin of a biological body, the rectifier module is used to modulate the signal and stimulate the bidirectional charge balancing stimulation module to generate a biphasic charge balancing electrical stimulation;

[0015] The electrode interface system also includes a wireless interface protective shell, the wireless interface protective shell includes a wireless interface protective shell body, a wireless interface protective shell plug-in plate, a suturing hole, a fixing foot and an electrode head exposure hole, the wireless interface protective shell plug-in plate and the wireless interface protective shell body can be plugged and matched, the electrode head exposure hole is used for the electrode pad to be connected with the flip cover connector so that the electrode is exposed from the electrode head exposure hole, the suturing hole is used for suturing with biological tissue, and together with the fixing foot, the position of the wireless interface protective shell is relatively fixed after being implanted in a biological body;

[0016] The circuit board is conductively connected to the electrode pad and then sealed in the wireless interface protective shell. The wireless interface protective shell and the circuit board are suitable for being completely implanted under the skin of a biological body without any interface for mechanical connection with the outside world.

[0017] According to a second aspect of the present application, a spinal cord electrical stimulation device is provided, comprising:

[0018] Planar electrode;

[0019] The electrode interface system for spinal cord electrical stimulation as described above;

[0020] The electrode pads of the planar electrodes are inserted into the electrode pad jacks of the electrode interface system to achieve mechanical and electrical connection.

[0021] In an exemplary embodiment of the present application, the planar electrode includes a flexible substrate, an electrode stimulation point, a conductive circuit, a pad and a flexible insulating layer; the electrode stimulation point is arranged on the flexible substrate, and the electrode stimulation point is connected to the pad through the conductive circuit; the flexible insulating layer at least covers the electrode area on the upper surface of the electrode except the electrode stimulation point and the pad; a modifying layer is deposited on the upper surface of the electrode stimulation point, the modifying layer forms a grass-like morphology with leaves standing in a forest, and the modifying layer is a platinum layer or a platinum-iridium alloy layer.

[0022] In an exemplary embodiment of the present application, the electrode stimulation point includes a first adhesion layer, a gold layer and a second adhesion layer from bottom to top, and the modification layer is deposited on the upper surface of the second adhesion layer.

[0023] In an exemplary embodiment of the present application, the first adhesion layer and the second adhesion layer are both titanium layers or chromium layers with a thickness ranging from 5 to 50 nm; and / or, the gold layer has a thickness ranging from 50 nm to 20 μm; and / or, the modification layer has a thickness ranging from 100 to 800 nm.

[0024] In an exemplary embodiment of the present application, the flexible insulating layer only covers the electrode area on the upper surface of the electrode except the electrode stimulation point and the pad; or, the flexible insulating layer covers the electrode area on the entire electrode surface except the electrode stimulation point and the pad.

[0025] In an exemplary embodiment of the present application, the grass-like morphology is processed by the following steps:

[0026] The electrode sample is placed below the platinum / platinum-iridium alloy evaporation source, and an angle θ exists between the surface of the electrode sample and the axis of the platinum / platinum-iridium alloy evaporation source, and the angle θ ranges from 10° to 80°;

[0027] During the deposition process of the platinum / platinum-iridium alloy layer, the platinum / platinum-iridium alloy evaporation source evaporates to form platinum / platinum-iridium alloy particles. The platinum / platinum-iridium alloy particles form random islands on the surface of the electrode sample, forming a shielding shadow effect on subsequent particles reaching the surface of the electrode sample, making the islands higher and higher until a grass-like morphology with uneven heights is formed.

[0028] The exemplary embodiments of the present application may have some or all of the following beneficial effects:

[0029] 1. The interface system for spinal cord electrical stimulation provided in the exemplary embodiment of the present application includes a circuit board and a flip connector, the flip connector is welded on the circuit board, and the flip connector is provided with an electrode pad jack for inserting the electrode pad, and a flip cover that can be flipped open and flipped closed to fix the electrode pad. The flip connector can realize the rapid insertion and removal of the electrode pad, and the design is more reasonable, which is convenient for operators to insert and remove the electrode pad.

[0030] 2. The spinal cord electrical stimulation device provided in the example implementation mode of the present application, on the one hand, the planar electrode formed by the flexible substrate, the flexible insulating layer and other structures has a certain flexibility. Compared with the traditional columnar electrode, the electrode is more flexible, smaller in size, and has good conformal contact with the tissue; on the second hand, the use of a platinum layer or a platinum-iridium alloy layer as a modification layer can reduce the impedance. The grass-like morphology with leaves standing in a forest can greatly increase the contact area between the membrane layer and the tissue compared to the traditional planar morphology, and effectively reduce the impedance. The lower impedance can reduce the dissipation of current at the interface between the electrode and the biological tissue, improve the charge injection efficiency, reduce heat, and avoid thermal damage to the tissue. At the same time, the chemical reaction of the platinum-iridium alloy material during the electrical stimulation process is reversible, and will not react to produce toxic substances or cause material loss; on the third hand, a flexible insulating layer is used to insulate the electrode area outside the electrode stimulation point and the pad. The flexible insulating layer is made of polyparaxylene material. Polyparaxylene is a material with good biosafety certified by the US FDA, has better biocompatibility, and can be implanted for long-term use.

[0031] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1A schematic diagram of the circuit board structure of an interface system for spinal cord electrical stimulation in Example 1 of the present application is shown;

[0034] Figure 2 A schematic structural diagram of a wired interface protective shell of an interface system for spinal cord electrical stimulation in Example 1 of the present application is shown;

[0035] Figure 3 A schematic structural diagram of a wired interface protective shell body and a plugboard of an interface system for spinal cord electrical stimulation in Example 1 of the present application is shown;

[0036] Figure 4 A schematic diagram of a wireless interface energy transmission system of an interface system for spinal cord electrical stimulation in Example 1 of the present application is shown;

[0037] Figure 5 A schematic diagram of the structure of a wireless interface protective shell of an interface system for spinal cord electrical stimulation in Example 1 of the present application is shown;

[0038] Figure 6 A schematic structural diagram of a wireless interface protective shell body and a plugboard of an interface system for spinal cord electrical stimulation in Example 1 of the present application is shown;

[0039] Figure 7 A top view of a planar electrode in Example 2 of the present application is shown;

[0040] Figure 8 A side view of a planar electrode in Example 2 of the present application is shown;

[0041] Fig. 9 A side view showing a flexible insulating layer covering the entire electrode in Example 2 of the present application is shown;

[0042] Fig.10 A schematic diagram of material layering at the electrode stimulation point in Example 2 of the present application is shown;

[0043] Fig.11 A schematic diagram of the structure of the angle formed between the platinum / platinum-iridium alloy evaporation source and the electrode sample in Example 3 of the present application is shown.

[0044] Description of reference numerals:

[0045] 1. Flexible substrate; 2. Electrode stimulation point; 3. Surgical suture hole; 4. Conductive circuit; 5. Solder pad; 6. Reinforcement plate; 7. Flexible insulation layer; 8. Electrode pad jack; 9. Circuit board; 10. Flip-top connector; 11. Female header; 12. Wire jack; 13. Wired interface protective shell body; 14. Wired interface protective shell plug-in board; 15. Female header exposure hole; 16. Suture hole; 17. Fixed foot; 18. Electrode head exposure hole; 19. External power supply module; 20. Rectifier module; 21. Bidirectional charge balance stimulation module; 22. Wireless interface protective shell body; 23. Wireless interface protective shell plug-in board; 24. First adhesion layer; 25. Gold layer; 26. Second adhesion layer; 27. Modification layer; 28. Workbench; 29. ​​Electrode sample; 30. Evaporation source. DETAILED DESCRIPTION

[0046] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present application will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed descriptions will be omitted. In addition, the drawings are only schematic illustrations of the present application and are not necessarily drawn to scale.

[0047] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the diagram to another component, these terms are used in this specification only for convenience, such as according to the direction of the examples in the drawings. It is understood that if the device of the diagram is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0048] The terms "a", "an", "the" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first" and "second" are used merely as labels and are not intended to limit the quantity of their objects.

[0049] Example 1

[0050] This embodiment provides a specific implementation of an electrode interface system for spinal cord electrical stimulation, such as Figure 1As shown, the flip connector 10 includes a circuit board 9 and a flip connector 10, the flip connector 10 is welded on the circuit board 9, and the flip connector 10 is provided with an electrode pad jack 8 for inserting the electrode pad 5, and a flip cover that can be flipped open and flipped closed to fix the electrode pad 5. By adopting the flip connector 10, the electrode pad 5 can be quickly inserted and removed, the design is more reasonable, and it is convenient for operators to insert and remove the electrode pad 5.

[0051] In this embodiment, the electrode interface system also includes a female connector 11 and a wired interface protective shell, such as Figure 2 and Figure 3 As shown, the female connector 11 is welded on the circuit board 9, and the female connector 11 is provided with a plurality of wire jacks 12 for inserting the plug of the external electrical stimulation device. The wired interface protection shell is made of biocompatible materials. The wired interface protection shell includes a wired interface protection shell body 13, a wired interface protection shell plug-in plate 14, a female connector exposure hole 15, a suture hole 16, a fixing foot 17, and an electrode head exposure hole 18. The wired interface protection shell body 13 and the wired interface protection shell plug-in plate 14 are connected and matched by a mortise and tenon structure, so that the wired interface protection shell plug-in plate 14 can be slidably set on the wired interface protection shell On the protective shell body 13, the wired interface protective shell plug-in plate 14 can be pushed and pulled and installed on the wired protective shell body; the electrode head exposure hole 18 is used for the electrode pad 5 to be connected to the flip connector 10, and the electrode is exposed from the electrode head exposure hole 18, and the suture hole 16 is used for suturing with biological tissue, and together with the fixing foot 17, the position of the wired interface protective shell is relatively fixed after being implanted into the biological body, and several wire jacks 12 of the mother socket 11 are exposed from the mother socket exposure hole 15, and the wired interface protective shell can be implanted into subcutaneous fat, exposing several wire jacks 12 of the mother socket 11 to connect with the outside world.

[0052] Furthermore, at the connection point between the wired interface protective shell body 13 and the wired interface protective shell plug-in plate 14, the wired interface protective shell body 13 is recessed, and the wired interface protective shell plug-in plate 14 is protruding on both sides. The protruding size of the wired interface protective shell plug-in plate 14 is 0.1-0.2mm smaller than the recessed size of the wired interface protective shell body 13, so as to facilitate the pushing and pulling of the wired interface protective shell plug-in plate 14.

[0053] In this embodiment, before the wired interface protective shell and the female connector 11 are implanted into the body, the electrode head exposure hole 18 and other gaps on the protective shell are filled with packaging materials to prevent tissue fluid from penetrating into the protective shell after the electrode is implanted into the body, causing corrosion and short circuit of the circuit board 9.

[0054] In this embodiment, during the implantation operation, the suture holes 16 located on the front, left and right sides of the wired interface protective shell body 13 are sutured with biological tissues through medical sutures to ensure that the position of the wired interface protective shell is relatively fixed after implantation in the biological body to avoid displacement and misalignment. The main body of the protective shell is implanted into the subcutaneous fat, exposing the wire jack 12 of the female connector 11 to connect to the outside world.

[0055] In some other embodiments, the circuit board 9 is provided with an induction coil, a rectifier module 20 and a bidirectional charge balance stimulation module 21, such as Figure 4 , Figure 5 and Figure 6 As shown, the sensing module is used to receive the signal transmitted through the skin of the organism by the external energy supply module 19, and the rectifying module 20 is used to modulate the signal and stimulate the bidirectional charge balance stimulation module 21 to generate bidirectional charge balance electrical stimulation; the electrode interface system includes a wireless interface protective shell, and the wireless interface protective shell includes a wireless interface protective shell body 22, a wireless interface protective shell plug-in plate 23, a suture hole 16, a fixing foot 17 and an electrode head exposure hole 18, the wireless interface protective shell plug-in plate 23 and the wireless interface protective shell body 22 can be plugged and matched, the electrode head exposure hole 18 is used for the electrode pad 5 to be connected to the flip connector 10, and the electrode is exposed from the electrode head exposure hole 18, the suture hole 16 is used for suturing biological tissue, and together with the fixing foot 17, the position of the wired interface protective shell is relatively fixed after being implanted in the organism; further, the circuit board 9 is conductively connected to the electrode pad 5 and then sealed in the wireless interface protective shell, the wireless interface protective shell and the circuit board 9 can be implanted under the skin of the organism, and there is no interface with any mechanical connection to the outside world, so as to realize wireless transmission of signals.

[0056] Furthermore, the circuit board 9 equipped with the rectifier module 20 and the bidirectional charge balance electrical stimulation module is conductively connected to the pad 5 and then sealed in the wireless interface protective shell, and receives energy provided by the external energy supply module 19 through the wireless energy transmission method of magnetic coupling resonance. When the wireless interface is implemented, the electrode, the circuit board 9 and the protective shell are completely implanted subcutaneously without any interface for mechanical connection with the outside world, thereby reducing the risk of infection.

[0057] In this embodiment, the wired interface protection shell body 13 and the wireless interface protection shell body 22 are both made of biocompatible resin and are manufactured by 3D printing or injection molding.

[0058] Example 2

[0059] This embodiment provides a specific implementation of a spinal cord electrical stimulation device, including a planar electrode and the electrode interface system for spinal cord electrical stimulation in Example 1, wherein the electrode pad 5 of the planar electrode is inserted into the electrode pad jack 8 of the electrode interface system to achieve mechanical and electrical connection.

[0060] In this embodiment, Figure 7 , Figure 8 and Fig. 9 As shown, the planar electrode includes a flexible substrate 1, an electrode stimulation point 2, a conductive line 4, a pad 5 and a flexible insulating layer 7. The electrode stimulation point 2 is arranged on the flexible substrate 1, and the electrode stimulation point 2 is connected to the pad 5 through a conductive line; the flexible insulating layer 7 at least covers the electrode area on the upper surface of the electrode except the electrode stimulation point 2 and the pad 5, and a modification layer 27 is deposited on the upper surface of the electrode stimulation point 2, and the modification layer 27 forms a grass-like morphology with leaves standing in a forest, and the modification layer 27 is a platinum layer or a platinum-iridium alloy layer. On the one hand, the planar electrode formed by the flexible substrate 1, the flexible insulating layer 7 and other structures has a certain flexibility. Compared with the traditional columnar electrode, the electrode is more flexible, smaller in size, and has good contact with the tissue. On the other hand, the use of a platinum layer or a platinum-iridium alloy layer as the modification layer 27 can reduce the impedance. The grass-like morphology with leaves standing in a forest can greatly increase the contact area between the membrane layer and the tissue compared to the traditional planar morphology, effectively reducing the impedance. The lower impedance can reduce the dissipation of current at the interface between the electrode and the biological tissue, improve the charge injection efficiency, reduce heat, and avoid thermal damage to the tissue. At the same time, the chemical reaction of the platinum-iridium alloy material during electrical stimulation is reversible, and will not react to produce toxic substances or cause material loss.

[0061] Furthermore, if Fig.10 As shown, the electrode stimulation point 2 includes a first adhesion layer 24, a gold layer 25 and a second adhesion layer 26 from bottom to top, and a modification layer 27 is deposited on the upper surface of the second adhesion layer 26. Specifically, the first adhesion layer 24 and the second adhesion layer 26 are titanium layers or chromium layers with a thickness range of 5-50nm, the thickness range of the gold layer 25 is 50nm-20μm, and the thickness range of the modification layer 27 is 100-800nm.

[0062] Furthermore, the thickness of the modification layer 27 is 100-800 nm. In this embodiment, the thickness of the modification layer 27 is preferably 300 nm.

[0063] In this embodiment, the flexible insulating layer 7 only covers the electrode area on the upper surface of the electrode except the electrode stimulation point 2 and the pad 5. The flexible insulating layer 7 insulates the conductive circuit 4 to prevent the conductive circuit 4 from directly contacting the biological tissue and preventing the conductive circuit 4 from stimulating the biological tissue by discharge during electrical stimulation. The flexible insulating layer 7 only covers the upper surface of the electrode to minimize the number of material layers and reduce the overall thickness of the electrode, thereby reducing the bending stiffness of the electrode and improving the flexibility of the electrode.

[0064] In some other embodiments, the flexible insulating layer 7 covers the entire electrode surface except the electrode stimulation point 2 and the pad 5. The flexible insulating layer 7 completely covers the entire electrode surface except the electrode stimulation point 2 and the pad 5, so that the electrode does not separate from the layers when it is immersed in tissue fluid for a long time, thereby ensuring the structural stability of the electrode during long-term implantation.

[0065] Furthermore, the material of the flexible insulating layer 7 is polyparaxylene, which is a long-term implantable biosafety material certified by the US FDA. The thickness of the flexible insulating layer 7 is in the range of 1-20 μm.

[0066] In this embodiment, the electrode stimulation point 2 is the discharge area when electrical stimulation is applied. The electrode stimulation point 2 is circular in shape and smoothly connected to the conductive circuit 4 without sharp corners to avoid local tissue damage caused by tip discharge during electrical stimulation.

[0067] In this embodiment, the grass-like morphology of the modified layer 27 is processed by the following steps: the electrode sample 29 is placed above the platinum / platinum-iridium alloy evaporation source 30, and there is an angle θ between the surface of the electrode sample 29 and the axis of the platinum / platinum-iridium alloy evaporation source 30; during the deposition of the platinum / platinum-iridium alloy layer, the platinum / platinum-iridium alloy evaporation source 30 evaporates to form platinum / platinum-iridium alloy particles, and the platinum / platinum-iridium alloy particles form random islands on the surface of the electrode sample 29, forming a shielding shadow effect on the subsequent particles reaching the surface of the electrode sample 29, so that the islands become higher and higher until a grass-like morphology with uneven heights is formed.

[0068] In this embodiment, a flexible substrate layer is first prepared, and a photoresist structure having a pattern of an electrode stimulation point 2, a conductive circuit 4, and a pad 5 is processed on the flexible substrate layer. Electrode stimulation points 2 are deposited at the pattern positions of the electrode stimulation points 2. When no modification layer 27 is deposited on the electrode stimulation points 2, the electrode samples 29 are obtained.

[0069] Furthermore, the photoresist structure forming electrode sample 29 is set on the rotating workbench 28, and the platinum / platinum-iridium alloy evaporation source 30 is set below the photoresist structure forming electrode sample 29.

[0070] In this embodiment, the electrode stimulation point 2 and the pad 5 are electrically connected through the conductive line 4. The material of the conductive line 4 is a metal material with stable chemical properties and good conductivity, such as gold, platinum, etc. The thickness of the conductive line 4 ranges from 50nm-20μm, and the line width ranges from 1-100μm. Further, the pad 5 is the position on the electrical stimulation electrode connected to the rear-end circuit board. The pad 5 can be electrically connected to the rear-end circuit board by welding, mechanical clamping, anisotropic conductive adhesive bonding, etc. The material of the pad 5 is a metal material with good conductivity, such as copper, gold, platinum, etc., the thickness ranges from 50nm-20μm, and the line width ranges from 50-500μm.

[0071] In this embodiment, surgical suture holes 3 are provided on both sides of the flexible substrate 1 of the planar electrode. During the implantation operation, the surgical suture holes 3 are sutured with the biological tissue using medical sutures to ensure that the position of the electrode is relatively fixed after implantation into the biological body, thereby avoiding displacement or misalignment of the electrode.

[0072] In this embodiment, a reinforcement plate 6 is provided at the tail of the planar electrode, and the reinforcement plate 6 can enhance the mechanical strength of the pad 5 at the tail of the electrode, so as to facilitate reliable fixation and connection between the pad 5 and the rear circuit board. Further, the reinforcement plate 6 has the same width as the tail of the electrode, a thickness range of 200 μm-1 mm, and has sufficient mechanical strength and rigidity. Specifically, the material of the reinforcement plate 6 is polyimide or stainless steel, and the reinforcement plate 6 is bonded to the flexible substrate 1 by an adhesive, the reinforcement plate 6 is bonded to the bottom layer of the flexible substrate 1, and the pad 5 is located on the top layer of the flexible substrate 1.

[0073] Example 3

[0074] The present embodiment provides a specific implementation method of a method for preparing a planar electrode for a spinal cord electrical stimulation electrode, including the spinal cord electrical stimulation device in Example 2, and also includes the following steps of preparing the planar electrode: preparing a flexible substrate layer; processing a photoresist structure having a pattern of electrode stimulation points 2, conductive lines 4, and pads 5 on the flexible substrate layer; depositing electrode stimulation points 2 at the pattern positions of the electrode stimulation points 2, and depositing a modification layer 27 on the upper surface of the electrode stimulation points 2, and making the modification layer 27 form a grass-like morphology with leaves standing in a forest.

[0075] In this embodiment, the step of forming the modified layer 27 into a grass-like morphology with a forest of leaves includes: setting a photoresist structure above a platinum / platinum-iridium alloy evaporation source 30, and there is an angle θ between the surface of the photoresist structure and the axis of the platinum / platinum-iridium alloy evaporation source 30; the platinum / platinum-iridium alloy evaporation source 30 evaporates to form platinum / platinum-iridium alloy particles, and the platinum / platinum-iridium alloy particles are deposited on the surface of the electrode stimulation point 2 pattern position of the photoresist structure, and the platinum / platinum-iridium alloy particles form random islands on the surface of the electrode stimulation point 2 pattern position, forming a shielding shadow effect on the particles that subsequently arrive at the surface of the electrode stimulation point 2 pattern position, so that the islands become higher and higher until a grass-like morphology with uneven heights is formed.

[0076] Furthermore, the angle θ ranges from 10° to 80°.

[0077] Specifically, Figure 5 As shown, a photoresist structure forming electrode sample 29 is set on the surface of a rotating workbench 28 , and a platinum / platinum-iridium alloy evaporation source 30 is placed under the rotating workbench 28 .

[0078] In this embodiment, the step of preparing a flexible substrate layer 1 includes preparing a layer of polyimide on a silicon-based substrate; the step of processing a photoresist structure having a pattern of electrode stimulation points 2, conductive circuits 4, and pads 5 on the flexible substrate layer 1 includes spin coating photoresist on the polyimide, and performing photolithography and development in sequence to process a positive photoresist structure having a pattern of electrode stimulation points 2, conductive circuits 4, and pads 5.

[0079] In this embodiment, it also includes using an electron beam evaporation thin film deposition method to deposit a titanium layer, a gold layer 25, a titanium layer, and a platinum / platinum-iridium alloy layer on the electrode stimulation point 2 in sequence, and using acetone to dissolve and peel off the photoresist after the deposition is completed to obtain a conductive pattern on the polyimide layer, the conductive pattern including the electrode stimulation point 2, the conductive circuit 4 and the pad 5 whose upper surface is modified with a platinum / platinum-iridium alloy layer; cutting the electrode contour to cut out the electrode shape; using an electrolytic silicon method to release the electrode semi-finished product on the silicon-based substrate from the silicon-based substrate; using a chemical vapor deposition method to deposit polyparaxylene on the upper surface of the electrode semi-finished product, and pre-wrapping the pad 5 with tape before deposition; using a hollow stainless steel mask to cover the electrode, the hollow area corresponds to the size, shape and position of the electrical stimulation point, and using a reactive ion etching method to etch and remove the polyparaxylene below the hollow area of ​​the stainless steel mask to expose the conductive platinum / platinum-iridium alloy; assembling the prepared electrode with an adapter plate and an interface protective shell, and using polydimethylsiloxane to fill and encapsulate the gap on the protective shell to prepare a planar electrode for spinal cord electrical stimulation.

[0080] The above-mentioned electrode processing technology is a micro-nano processing technology with low processing cost. The electrode materials all have a micrometer or nanometer thickness, which saves materials.

[0081] The following is an explanation of the above method through a specific case:

[0082] A 10 μm thick polyimide layer was prepared by spin coating on a silicon wafer;

[0083] Spin-coat photoresist on the polyimide layer, and then perform photolithography and development processes in sequence to produce a positive photoresist structure having patterns of electrode stimulation points 2, conductive circuits 4, and pads 5;

[0084] Using an electron beam evaporation thin film deposition method, 10 nm titanium, 100 nm gold, 10 nm titanium, and 300 nm platinum / platinum-iridium alloy are sequentially deposited, and the platinum / platinum-iridium alloy layer forms a grass-like morphology with uneven heights. After the deposition is completed, the photoresist is dissolved and stripped using acetone to obtain a conductive pattern on the polyimide layer;

[0085] Cut the electrode contour using laser cutting to cut out the electrode shape and surgical suture hole 3;

[0086] By electrolyzing silicon, the electrode semi-finished product on the silicon wafer is released from the silicon wafer;

[0087] Adhere a reinforcing plate 6 to the tail of the semi-finished electrode;

[0088] Deposit polyparaxylene with a thickness of 2 μm using a chemical vapor deposition method. Before deposition, wrap the pad 5 with a tape to prevent the deposited polyparaxylene from insulating the pad 5. After the deposition is completed, tear off the tape wrapping the pad 5.

[0089] A hollow stainless steel mask plate is used to cover the electrode. The hollow area of ​​the stainless steel mask plate corresponds to the size, shape and position of the electrode stimulation point 2. The polyparaxylene under the hollow area of ​​the stainless steel mask plate is etched away using a reactive ion etching method to expose a conductive platinum / platinum-iridium alloy layer to obtain a planar electrode for spinal cord electrical stimulation.

[0090] Those skilled in the art will easily think of other embodiments of the present application after considering the specification and practicing the embodiments of the present application. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that the present application does not apply for. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present application are pointed out by the appended claims.

Claims

1. An electrode interface system for spinal cord electrical stimulation, characterized in that: The invention comprises a circuit board and a flip cover connector, wherein the flip cover connector is welded on the circuit board, the flip cover connector is provided with an electrode pad jack for inserting an electrode pad, and a flip cover which can be flipped open and flipped closed to fix the electrode pad.

2. The electrode interface system for spinal cord electrical stimulation according to claim 1, characterized in that: Also includes: A female header, welded on the circuit board, the female header being provided with a plurality of wire jacks for inserting a plug of an external electrical stimulation device; A wired interface protective shell is made of biocompatible materials. The wired interface protective shell includes a wired interface protective shell body, a wired interface protective shell plug-in plate, a female connector exposure hole, a suture hole, a fixing foot, and an electrode head exposure hole. The wired interface protective shell body and the wired interface protective shell plug-in plate are connected and matched with each other through a mortise and tenon structure. The electrode head exposure hole is used for the electrode pad to be connected to the flip connector so that the electrode is exposed from the electrode head exposure hole. The suture hole is used for suturing with biological tissue. Together with the fixing foot, the position of the wired interface protective shell is relatively fixed after being implanted in a biological body. Several wire sockets of the female connector are exposed from the female connector exposure hole. The wired interface protective shell body is suitable for implantation into subcutaneous fat, and several wire sockets of the female connector are exposed to connect with the outside world.

3. The electrode interface system for spinal cord electrical stimulation according to claim 2, characterized in that: It also includes a packaging material for filling and packaging the exposed hole of the electrode head and the gaps on other protective shells after the wired interface protective shell and the female socket are implanted into a biological body.

4. The electrode interface system for spinal cord electrical stimulation according to claim 1, characterized in that: The circuit board is provided with an induction coil, a rectifier module and a bidirectional charge balancing stimulation module, wherein the induction module is used to receive the signal transmitted by the external energy supply module through the skin of the biological body, and the rectifier module is used to modulate the signal and stimulate the bidirectional charge balancing stimulation module to generate a biphase charge balancing electrical stimulation; The electrode interface system also includes a wireless interface protective shell, the wireless interface protective shell includes a wireless interface protective shell body, a wireless interface protective shell plug-in plate, a suturing hole, a fixing foot and an electrode head exposure hole, the wireless interface protective shell plug-in plate and the wireless interface protective shell body can be plugged and matched, the electrode head exposure hole is used for the electrode pad to be connected with the flip cover connector so that the electrode is exposed from the electrode head exposure hole, the suturing hole is used for suturing with biological tissue, and together with the fixing foot, the position of the wireless interface protective shell is relatively fixed after being implanted in a biological body; The circuit board is conductively connected to the electrode pad and then sealed in the wireless interface protective shell. The wireless interface protective shell and the circuit board are suitable for being completely implanted under the skin of a biological body without any interface for mechanical connection with the outside world.

5. A spinal cord electrical stimulation device, characterized in that: include: Planar electrode; An electrode interface system for spinal cord electrical stimulation according to any one of claims 1 to 4; The electrode pads of the planar electrodes are inserted into the electrode pad jacks of the electrode interface system to achieve mechanical and electrical connection.

6. The spinal cord electrical stimulation device according to claim 5, characterized in that: The planar electrode includes a flexible substrate, an electrode stimulation point, a conductive circuit, a pad and a flexible insulating layer; the electrode stimulation point is arranged on the flexible substrate, and the electrode stimulation point is connected to the pad through the conductive circuit; the flexible insulating layer at least covers the electrode area on the upper surface of the electrode except the electrode stimulation point and the pad; a modification layer is deposited on the upper surface of the electrode stimulation point, and the modification layer forms a grass-like morphology with leaves standing in a forest, and the modification layer is a platinum layer or a platinum-iridium alloy layer.

7. The spinal cord electrical stimulation device according to claim 6, characterized in that: The electrode stimulation point comprises, from bottom to top, a first adhesion layer, a gold layer, and a second adhesion layer, and the modification layer is deposited on the upper surface of the second adhesion layer.

8. The spinal cord electrical stimulation device according to claim 7, characterized in that: The first adhesion layer and the second adhesion layer are both titanium layers or chromium layers with a thickness ranging from 5 to 50 nm; and / or, the gold layer has a thickness ranging from 50 nm to 20 μm; and / or, the modification layer has a thickness ranging from 100 to 800 nm.

9. The spinal cord electrical stimulation device according to any one of claims 6 to 8, characterized in that: The flexible insulating layer only covers the electrode area on the upper surface of the electrode except the electrode stimulation point and the pad; or, the flexible insulating layer covers the electrode area on the entire electrode surface except the electrode stimulation point and the pad.

10. The spinal cord electrical stimulation device according to any one of claims 6 to 8, characterized in that: The grass-like morphology is processed by the following steps: The electrode sample is placed above the platinum / platinum-iridium alloy evaporation source, and an angle θ exists between the surface of the electrode sample and the axis of the platinum / platinum-iridium alloy evaporation source, and the angle θ ranges from 10° to 80°; During the deposition process of the platinum / platinum-iridium alloy layer, the platinum / platinum-iridium alloy evaporation source evaporates to form platinum / platinum-iridium alloy particles. The platinum / platinum-iridium alloy particles form random islands on the surface of the electrode sample, forming a shielding shadow effect on subsequent particles reaching the surface of the electrode sample, making the islands higher and higher until a grass-like morphology with uneven heights is formed.

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