An absorbable wireless stimulating electrode for neuromodulation and neuromodulation system

Abstract

The application discloses an absorbable wireless stimulation electrode for neuromodulation, comprising an absorbable conductive coil, an absorbable capacitor structure, at least two stimulation contacts and an absorbable insulation layer. Two electrode ends of the absorbable capacitor structure are electrically connected with two ends of the absorbable conductive coil respectively, so that the two together form a passive LC resonance receiving loop, the resonance frequency of which is matched with the carrier frequency of an external wireless transmitting unit. The stimulation contacts are electrically connected with the passive LC resonance receiving loop and at least partially exposed outside the absorbable insulation layer, for outputting a stimulation electrical signal with envelope modulation parameters varying to the vicinity of the target nerve tissue. The electrode can maintain the required electrical function within a preset action period, and gradually degrade, absorb, metabolize or excrete in the body after the preset action period, thereby reducing the need for percutaneous lead connection, long-term foreign body retention and secondary surgery. The application also discloses a neuromodulation system using the wireless stimulation electrode.

Description

Technical Field

[0001] This invention belongs to the field of neuromodulation medical device technology, specifically relating to an absorbable wireless stimulation electrode for neuromodulation. Background Technology

[0002] Neuromodulation technology is an important means of improving or treating nervous system-related diseases by regulating neural activity through electrical stimulation, magnetic stimulation, etc. Among them, implantable stimulation electrodes are one of the core devices for achieving targeted stimulation output.

[0003] Currently, implantable neurostimulation electrodes commonly used in clinical and research settings can be divided into wired electrodes and wireless electrodes. Wired electrodes typically require a wire to connect to an external stimulation device or implantable pulse generator. Percutaneous leads or long-term connection structures may increase the risks of infection, lead breakage, tissue traction, and tissue adhesion. While wireless electrodes can reduce some of the problems associated with wire connections, most existing wireless electrodes are made of non-absorbable metals, silicon-based devices, or long-term retention materials, which may require long-term retention or surgical removal after implantation.

[0004] To reduce the need for prolonged foreign body placement and secondary removal surgeries, the industry has explored the use of absorbable metals, absorbable polymers, or biodegradable composite materials to fabricate neural electrodes. However, the conductivity, dielectric properties, mechanical properties, and in vivo degradation behavior of absorbable materials differ from those of traditional non-absorbable materials. Directly applying conventional wireless power supply or wireless receiver structures may not simultaneously achieve miniaturization, wireless signal reception efficiency, stimulation output stability, and the degradation and absorption requirements after a preset period. Therefore, an implantable neural stimulation electrode capable of wireless reception, stimulation output, and controlled degradation within an absorbable material system is needed. Summary of the Invention

[0005] To address the problems of existing implantable neurostimulation electrodes, such as the risks of percutaneous wire connection, long-term foreign body retention, burden of secondary removal surgery, and the difficulty of absorbable electrodes in balancing wireless signal reception and stable stimulation output, this invention provides an absorbable wireless stimulation electrode for neuromodulation.

[0006] The term "absorbable" or "degradable" as used in this invention includes situations where the material degrades, dissolves, is absorbed, metabolized, or excreted in a physiological environment; the material can maintain the structural integrity and electrical function required for neural regulation within a preset period of action, and gradually degrades or is absorbed after the preset period of action.

[0007] The objective of this invention can be achieved through the following technical solutions: An absorbable wireless stimulation electrode for neuromodulation includes an absorbable conductive coil, an absorbable capacitor structure, at least two stimulation contacts, and an absorbable insulating layer.

[0008] The absorbable conductive coil is made of absorbable or degradable conductive material and is configured to generate an induced electrical signal under the action of an alternating electromagnetic field generated by an external wireless transmitting unit.

[0009] The absorbable capacitor structure is electrically connected to the absorbable conductive coil, and together they form a passive LC resonant receiving circuit. Preferably, the absorbable capacitor structure has a first electrode and a second electrode, which are respectively electrically connected to the two ends of the absorbable conductive coil, so that the absorbable conductive coil and the absorbable capacitor structure together form a passive LC resonant receiving circuit. The resonant frequency of the passive LC resonant receiving circuit matches the carrier frequency of the external wireless transmitting unit.

[0010] The stimulation contact is electrically connected to the passive LC resonant receiving circuit and is used to output a stimulation electrical signal to the vicinity of the target nerve tissue. The absorbable insulating layer covers at least a portion of the surface of the absorbable conductive coil and / or the absorbable capacitor structure, and exposes at least a portion of the stimulation contact.

[0011] The passive LC resonant receiving circuit is configured to receive a radio frequency pulse signal based on a carrier frequency and envelope modulated according to set neural stimulation parameters, and to form a stimulation electrical signal that varies with the envelope modulation parameters between the stimulation contacts.

[0012] Furthermore, the absorbable conductive coil has a multi-turn coil structure, with adjacent coil turns spaced apart to form an inter-turn gap to prevent short circuits between adjacent coil turns.

[0013] Furthermore, the multi-turn coil structure can be a helical coil structure, a planar helical coil structure, a multi-turn toroidal coil structure, a multi-turn elliptical coil structure, or a multi-layer coil structure. Preferably, the multi-turn coil structure is a planar helical coil structure.

[0014] Furthermore, the stimulation contact is a rounded protrusion structure, a hemispherical protrusion structure, a spherical protrusion structure, a sheet-like structure, or a surface micro / nano roughened structure.

[0015] Furthermore, when the stimulation contact is a blunt protrusion structure, a hemispherical protrusion structure, or a spherical protrusion structure, the stimulation contact protrudes outward relative to the absorbable insulating layer, and the maximum radial dimension of the stimulation contact is greater than the outer diameter of the insulating covering area adjacent to the stimulation contact, so as to facilitate the stimulation contact to preferentially contact or approach the target nerve tissue.

[0016] Furthermore, the first absorbable conductive portion and the second absorbable conductive portion are respectively layered, sheet-like, thin film-like or interdigitated conductive electrode plates, and the absorbable dielectric portion is a degradable dielectric layer disposed between the first absorbable conductive portion and the second absorbable conductive portion.

[0017] Furthermore, the absorbable capacitor structure is a multilayer capacitor structure, a thin film capacitor structure, an interdigitated capacitor structure, a wound thin film capacitor structure, or a distributed capacitor structure; the degradable dielectric layer includes one or more of magnesium oxide, zinc oxide, silicon oxide, polylactic acid, polycaprolactone, polylactic acid-glycolic acid copolymer, or composite materials thereof.

[0018] Further, the absorbable or degradable conductive material includes one or more of magnesium-based alloys, zinc-based alloys, molybdenum-based materials, or degradable conductive composite materials. The magnesium-based alloy includes one or more of magnesium-zinc alloys, magnesium-calcium alloys, or magnesium-manganese alloys; the zinc-based alloy includes one or more of zinc-magnesium alloys or zinc-calcium alloys; and the molybdenum-based material includes molybdenum films, molybdenum-based alloys, or molybdenum-based degradable conductive composite materials.

[0019] Furthermore, the absorbable insulating layer comprises one or more of polylactic acid, polyglycolic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polyanhydride, polyorthoester or biodegradable polyurethane.

[0020] Further, the carrier frequency is 1–100 MHz. In a preferred embodiment, the carrier frequency is 13.56 MHz. The capacitance value of the absorbable capacitor structure is matched according to the equivalent inductance value of the absorbable conductive coil so that the resonant frequency of the passive LC resonant receiving circuit matches the carrier frequency.

[0021] Furthermore, the envelope repetition frequency of the radio frequency pulse signal is 1–200 Hz, the envelope pulse width is 10–1000 μs, and the stimulation electrical signal formed between the stimulation contacts varies with the envelope repetition frequency and the envelope pulse width.

[0022] Furthermore, the overall maximum outer diameter of the absorbable wireless stimulation electrode is no greater than 1.0 mm, so as to be suitable for delivery to the vicinity of the target nerve tissue via an indwelling needle implantation assembly, a puncture cannula, or a catheter.

[0023] Furthermore, the present invention also provides a neuromodulation system, including an external wireless transmitting unit and the above-mentioned absorbable wireless stimulation electrode for neuromodulation; the external wireless transmitting unit is configured to output a radio frequency pulse signal based on a carrier frequency and envelope modulated according to set neurostimulation parameters, and the absorbable wireless stimulation electrode is configured to receive the radio frequency pulse signal and form a stimulation electrical signal that varies with the envelope modulation parameters between the stimulation contacts.

[0024] The beneficial effects of this invention are as follows: 1. This invention forms a passive LC resonant receiving circuit by combining an absorbable conductive coil and an absorbable capacitor structure, enabling the implanted electrode to receive radio frequency pulse signals output by an external wireless transmitting unit and form a stimulation electrical signal for neuromodulation between stimulation contacts, thereby reducing the risks of infection, breakage and tissue traction caused by percutaneous wire connection.

[0025] 2. By setting an absorbable insulating layer and exposing at least part of the stimulation contacts, the present invention enables the stimulation electrical signal to act mainly on the vicinity of the target nerve tissue, which helps to reduce stimulation of non-target tissues and energy dispersion, and improves the targeting of stimulation output.

[0026] 3. This invention uses absorbable or degradable conductive materials, absorbable dielectric materials and absorbable polymer materials to prepare conductive coils, capacitor structures and insulating layers, so that the electrodes maintain the required electrical function within a preset working period, and gradually degrade, absorb, metabolize or excrete after the preset working period, thereby reducing the need for long-term foreign body retention and secondary removal surgery.

[0027] 4. This invention can adjust the wireless receiving characteristics, electrical stability time and degradation process of the electrodes by adjusting the coil structure, capacitor structure, material composition, dielectric layer parameters and insulating layer thickness, so as to meet the needs of short-term or medium-term neuromodulation applications.

[0028] 5. The absorbable wireless stimulation electrode of the present invention is small in size and can be delivered to the vicinity of the target nerve tissue via an indwelling needle implantation component, a puncture cannula or catheter, which helps to reduce open implantation trauma and improve the convenience of implantation operation. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art are briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0031] Figure 2 This is a schematic diagram of the equivalent circuit of the passive LC resonant receiving circuit in this invention.

[0032] Figure 3 This is a schematic diagram of the layered structure of the absorbable capacitor structure in this invention.

[0033] Figure 4 This is a partial structural diagram of the stimulation contact point in this invention.

[0034] Explanation of reference numerals in the attached figures: 100, absorbable conductive coil; 101, stimulation contact; 200, absorbable capacitor structure; 300, absorbable insulating layer. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0036] like Figure 1 As shown, the present invention provides an absorbable wireless stimulation electrode for neural modulation, comprising an absorbable conductive coil 100, an absorbable capacitor structure 200, a stimulation contact 101, and an absorbable insulating layer 300.

[0037] The absorbable conductive coil 100 is made of an absorbable or degradable conductive material and is configured to receive the alternating electromagnetic field generated by the external wireless transmitting unit and generate an induced electrical signal. The absorbable capacitor structure 200 is electrically connected to the absorbable conductive coil 100 and together they form a passive LC resonant receiving circuit. The resonant frequency of the passive LC resonant receiving circuit is matched with the carrier frequency of the external wireless transmitting unit to improve the reception efficiency of the target radio frequency signal.

[0038] like Figure 2 As shown, the absorbable conductive coil 100 can serve as an equivalent inductor L, and the absorbable capacitor structure 200 can serve as an equivalent capacitor C. Together, they constitute a passive LC resonant receiving circuit. The stimulation contact 101 is electrically connected to the tissue load near the target nerve tissue, thereby generating a stimulation electrical signal acting on the vicinity of the target nerve tissue after receiving the radio frequency pulse signal.

[0039] like Figure 3 As shown, the absorbable capacitor structure 200 may include a first absorbable conductive portion, a second absorbable conductive portion, and an absorbable dielectric portion disposed between the two. The first absorbable conductive portion and the second absorbable conductive portion may respectively form a first electrode and a second electrode, and are respectively electrically connected to the two ends of the absorbable conductive coil 100.

[0040] At least two stimulation contacts 101 are provided and electrically connected to the passive LC resonant receiving circuit for outputting stimulation electrical signals to the vicinity of the target nerve tissue. The absorbable insulating layer 300 covers at least a portion of the surface of the absorbable conductive coil 100 and / or the absorbable capacitor structure 200, and exposes at least a portion of the stimulation contacts 101 so that the stimulation electrical signals mainly act on the vicinity of the target nerve tissue. The passive LC resonant receiving circuit is configured to receive radio frequency pulse signals based on the carrier frequency and envelope modulated according to set nerve stimulation parameters, and to form stimulation electrical signals that vary with the envelope modulation parameters between the stimulation contacts 101; the absorbable conductive coil 100, the absorbable capacitor structure 200, and the absorbable insulating layer 300 are configured to maintain the electrical functions required for nerve modulation within a preset action period, and to be gradually degraded, absorbed, metabolized, or excreted in the body after the preset action period.

[0041] like Figure 4 As shown, in embodiments where the stimulation contact 101 is a hemispherical protrusion, a blunt protrusion, or a spherical protrusion, the stimulation contact 101 protrudes outward relative to the absorbable insulating layer 300, thereby facilitating the stimulation contact 101 to preferentially contact or approach the target nerve tissue.

[0042] In use, the external wireless transmitting unit outputs a radio frequency pulse signal based on a preset carrier frequency and envelope-modulated according to set neural stimulation parameters. After receiving the radio frequency pulse signal, the passive LC resonant receiving circuit generates a stimulation electrical signal that varies with the envelope modulation parameters between the stimulation contacts 101; this stimulation electrical signal acts on the vicinity of the target nerve tissue, thereby achieving neural modulation.

[0043] The resonant frequency of the passive LC resonant receiving circuit can be determined according to... The design is carried out, where L is the equivalent inductance of the absorbable conductive coil 100 and C is the equivalent capacitance of the absorbable capacitor structure 200. In actual fabrication, the capacitor area, dielectric layer thickness, and dielectric layer material can be adjusted to match the coil size, number of turns, material resistance, tissue load environment, and carrier frequency of the external transmitting unit. The equivalent inductance of the absorbable conductive coil 100 and the resonant frequency of the passive LC resonant receiving circuit can be determined using an impedance analyzer or network analyzer. By adjusting the capacitor plate area, dielectric layer thickness, or dielectric constant of the dielectric material, the resonant frequency of the passive LC resonant receiving circuit can be matched with the carrier frequency of the external wireless transmitting unit.

[0044] Within a preset period of action, the absorbable conductive coil 100, absorbable capacitor structure 200, and absorbable insulating layer 300 maintain the structural integrity and electrical function required for neural regulation. After the preset period of action, the above structures can be gradually degraded, absorbed, metabolized, or excreted in the body fluid environment, thereby reducing the need for long-term foreign body retention and secondary removal surgery.

[0045] Furthermore, the absorbable conductive coil 100 has a multi-turn coil structure with inter-turn gaps between adjacent coil turns. The multi-turn structure can improve the coil's ability to induce external electromagnetic fields, and the inter-turn gaps can reduce the risk of short circuits between adjacent turns and provide a channel for body fluid infiltration and subsequent degradation.

[0046] The multi-turn coil structure can be a helical coil structure, a planar helical coil structure, a multi-turn ring coil structure, a multi-turn elliptical coil structure, or a multi-layer coil structure. Preferably, the multi-turn coil structure is a planar helical coil structure to reduce the overall thickness of the electrode, making it easier to attach to or near the target nerve tissue.

[0047] As an optional implementation, the outer diameter of the absorbable conductive coil 100 can be 0.2–1.0 mm, the number of turns can be 3–20, the wire diameter or wire width can be 0.005–0.05 mm, and the gap between adjacent coil turns can be 0.005–0.08 mm. The overall maximum outer diameter of the absorbable wireless stimulation electrode can be no greater than 1.0 mm, to be suitable for delivery to the vicinity of the target nerve tissue via an indwelling needle implantation assembly, a puncture cannula, or a catheter.

[0048] Furthermore, the stimulation contact 101 may be a rounded protrusion structure, a hemispherical protrusion structure, a spherical protrusion structure, a sheet-like structure, or a surface micro / nano-roughened structure. Preferably, the stimulation contact 101 is a hemispherical protrusion structure to reduce the mechanical stimulation of nerve tissue caused by sharp edges and improve the contact stability between the contact and the target tissue.

[0049] Furthermore, when the stimulation contact 101 is a blunt protrusion structure, a hemispherical protrusion structure, or a spherical protrusion structure, the stimulation contact 101 protrudes outward relative to the absorbable insulating layer 300, and the maximum radial dimension of the stimulation contact 101 is greater than the outer diameter of the insulating covering area adjacent to the stimulation contact 101, thereby facilitating the stimulation contact 101 to preferentially contact or approach the target nerve tissue.

[0050] As an optional implementation, the diameter of the stimulation contact 101 can be 0.05–0.15 mm, the protrusion height can be 0.01–0.08 mm, and the distance between two stimulation contacts 101 can be 0.1–0.5 mm. The surface of the stimulation contact 101 can be electrochemically polished or micro / nano roughened to improve interfacial contact performance.

[0051] Furthermore, the absorbable capacitor structure 200 may be a multilayer capacitor structure, a thin-film capacitor structure, an interdigitated capacitor structure, a wound thin-film capacitor structure, or a distributed capacitor structure. The degradable dielectric layer may include one or more of magnesium oxide, zinc oxide, silicon oxide, polylactic acid, polycaprolactone, polylactic acid-glycolic acid copolymer, or composite materials thereof.

[0052] Further, the absorbable or degradable conductive material includes one or more of magnesium-based alloys, zinc-based alloys, molybdenum-based materials, or degradable conductive composite materials. Preferably, the magnesium-based alloy includes one or more of magnesium-zinc alloys, magnesium-calcium alloys, or magnesium-manganese alloys; the zinc-based alloy includes one or more of zinc-magnesium alloys or zinc-calcium alloys; and the molybdenum-based material includes molybdenum films, molybdenum-based alloys, or molybdenum-based degradable conductive composite materials.

[0053] Further, the absorbable insulating layer 300 comprises one or more of polylactic acid, polyglycolic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polyanhydride, polyorthoester, or biodegradable polyurethane. The absorbable insulating layer 300 can be formed on the surface of the absorbable conductive coil 100 and / or the absorbable capacitor structure 200 by dip coating, spraying, spin coating, lamination, or overmolding.

[0054] Furthermore, the carrier frequency can be 1–100 MHz. In a preferred embodiment, the carrier frequency is 13.56 MHz. The envelope repetition frequency of the radio frequency pulse signal can be 1–200 Hz, and the envelope pulse width can be 10–1000 μs. Example 1

[0055] This embodiment provides a magnesium-zinc alloy absorbable wireless stimulation electrode suitable for short- to medium-term neuromodulation applications.

[0056] An absorbable conductive coil 100 is made of a magnesium-zinc alloy, wherein the magnesium content is 90%–97% and the zinc content is 3%–10%. The magnesium-zinc alloy is machined into a planar spiral multi-turn coil structure with an outer diameter of 0.8 mm, 8 turns, a wire diameter of 0.02 mm, a gap of 0.03 mm between adjacent turns, an overall electrode length of 3 mm, and a maximum overall outer diameter not exceeding 1.0 mm. The surface of the absorbable conductive coil 100 is electrochemically polished to reduce surface burrs and improve conductive contact stability.

[0057] The absorbable capacitor structure 200 employs a multilayer capacitor structure or a thin-film capacitor structure. The absorbable capacitor structure 200 includes a first biodegradable conductive electrode plate, a second biodegradable conductive electrode plate, and a biodegradable dielectric layer disposed between the two. The first and second biodegradable conductive electrode plates are made of magnesium-zinc alloy thin film or molybdenum thin film, and the biodegradable dielectric layer is made of magnesium oxide, zinc oxide, or polylactic acid-glycolic acid copolymer. The capacitance value of the absorbable capacitor structure 200 is matched according to the equivalent inductance value of the absorbable conductive coil 100, and the passive LC resonant receiving circuit is matched to the 13.56 MHz carrier frequency by adjusting the area of ​​the conductive electrode plate, the thickness of the dielectric layer, and the dielectric layer material.

[0058] The stimulation contacts 101 are configured as a pair and electrically connected to the passive LC resonant receiving circuit. Each stimulation contact 101 has a hemispherical protrusion structure with a diameter of 0.08 mm and a protrusion height of 0.03 mm. The distance between the two stimulation contacts 101 is 0.2 mm. The surface of each stimulation contact 101 is polished to improve its contact stability with the target nerve tissue.

[0059] The absorbable insulating layer 300 is made of polylactic acid-glycolic acid copolymer material with a thickness of 0.02 mm, and covers the surface of the absorbable conductive coil 100 and the absorbable capacitor structure 200 except for the stimulation contact 101, so that the stimulation contact 101 is at least partially exposed outside the absorbable insulating layer 300.

[0060] In use, an indwelling needle cannula with an inner diameter not smaller than the overall maximum outer diameter of the absorbable wireless stimulation electrode can be selected; for example, an indwelling needle cannula with an inner diameter of 0.8–1.2 mm and a length of 15 mm can be used for delivery. After delivery to the vicinity of the target nerve tissue via puncture, it is withdrawn so that the stimulation contact 101 is close to or in contact with the target nerve tissue. The external wireless transmitting unit outputs a radio frequency pulse signal with a carrier frequency of 13.56 MHz and an envelope modulation frequency of 10 Hz, with an envelope pulse width of 100 μs. After receiving the radio frequency pulse signal, the passive LC resonant receiving circuit forms a corresponding stimulation electrical signal between the stimulation contacts 101, thereby realizing neural modulation.

[0061] In this embodiment, by adjusting the magnesium-zinc alloy composition, coil wire diameter, absorbable insulating layer 300 thickness, and surface treatment method, the electrical stability time and subsequent degradation process of the electrode within a preset working period can be controlled. Example 2

[0062] This embodiment provides a zinc-magnesium alloy absorbable wireless stimulation electrode, suitable for medium-term neuromodulation applications requiring a relatively long period of electrical stability.

[0063] Unlike Example 1, the absorbable conductive coil 100 in this example is made of zinc-magnesium alloy, with a zinc content of 95%–99% and a magnesium content of 1%–5%. The zinc-magnesium alloy is processed into a planar spiral multi-turn coil structure, with an outer diameter of 0.6–1.0 mm, 6–12 turns, a wire diameter of 0.015–0.03 mm, a gap between adjacent coil turns of 0.02–0.06 mm, and an overall maximum outer diameter of the electrode of no more than 1.0 mm.

[0064] The absorbable capacitor structure 200 employs a thin-film capacitor structure or an interdigitated capacitor structure. The first and second biodegradable conductive electrode plates of the absorbable capacitor structure 200 are made of zinc-magnesium alloy thin film or molybdenum thin film, and the biodegradable dielectric layer is made of zinc oxide, magnesium oxide, polycaprolactone, or polylactic-co-glycolic acid copolymer. The capacitance value of the absorbable capacitor structure 200 is matched according to the measured equivalent inductance value of the absorbable conductive coil 100 to match the carrier frequency of the passive LC resonant receiving circuit with that of the external wireless transmitting unit.

[0065] The stimulation contacts 101 are a pair of hemispherical protrusions with a diameter of 0.05–0.1 mm and a height of 0.02–0.05 mm. The distance between the two stimulation contacts 101 is 0.2–0.3 mm. The absorbable insulating layer 300 is made of polycaprolactone, polylactic acid, or polylactic acid-glycolic acid copolymer, with a thickness of 0.02–0.05 mm, and covers the non-stimulated areas of the absorbable conductive coil 100 and the absorbable capacitor structure 200.

[0066] In this embodiment, the carrier frequency of the external wireless transmitting unit is 13.56 MHz, the envelope repetition frequency is 20–50 Hz, and the envelope pulse width is 100–300 μs. The passive LC resonant receiving circuit is matched with the carrier frequency of the external wireless transmitting unit to enhance the reception efficiency of the radio frequency pulse signal and to form a stimulation electrical signal for neuromodulation between the stimulation contacts 101.

[0067] Compared to magnesium-zinc alloy electrodes, the zinc-magnesium alloy in this embodiment exhibits a relatively mild degradation process in bodily fluids, which is beneficial for maintaining the stability of the electrode structure and electrical properties over a longer preset action period. This embodiment can be used for mid-term neuromodulation scenarios such as rehabilitation stimulation after spinal cord injury, auxiliary stimulation for motor function rehabilitation after stroke, stimulation during the repair period of peripheral nerve injury, and staged pain control. Example 3

[0068] This embodiment provides a molybdenum thin-film composite absorbable wireless stimulation electrode, which is suitable for miniaturized thin-film electrodes, animal experiments, and short-term neuromodulation research.

[0069] The absorbable wireless stimulation electrode includes a flexible absorbable substrate, a molybdenum thin-film conductive coil, an absorbable capacitor structure 200, stimulation contacts 101, and an absorbable insulating layer 300. The flexible absorbable substrate is made of polylactic acid-glycolic acid copolymer, polycaprolactone, or polylactic acid.

[0070] A planar helical coil of molybdenum thin film is formed on the surface of the flexible absorbable substrate, serving as an absorbable conductive coil 100. The molybdenum thin film can be formed by thin film deposition, photolithography, laser etching, or micro / nano fabrication processes. The molybdenum thin film has a thickness of 0.1–5 μm, a linewidth of 5–50 μm, an outer diameter of 0.2–1.0 mm, and 5–20 turns.

[0071] The absorbable capacitor structure 200 employs a thin-film laminated structure. The absorbable capacitor structure 200 includes a first biodegradable conductive electrode plate, a second biodegradable conductive electrode plate, and a biodegradable dielectric layer. Both the first and second biodegradable conductive electrode plates are made of molybdenum thin film, and the biodegradable dielectric layer is made of silicon oxide, magnesium oxide, zinc oxide, polylactic acid-glycolic acid copolymer, or polycaprolactone. The capacitance value of the absorbable capacitor structure 200 is matched to the equivalent inductance value of the molybdenum thin-film planar spiral coil to form a passive LC resonant receiving circuit that matches the external carrier frequency.

[0072] The stimulation contact 101 is formed using a thickened area of ​​molybdenum thin film, a molybdenum-based composite conductive layer, or magnesium-zinc alloy micro-bumps, and is at least partially exposed outside the absorbable insulating layer 300. Optionally, the surface of the stimulation contact 101 is provided with a micro-nano roughened structure to increase the effective contact area and improve the interfacial contact stability.

[0073] The absorbable insulating layer 300 is made of polylactic acid-glycolic acid copolymer, polycaprolactone, or polylactic acid, and covers the non-stimulating areas of the molybdenum thin-film conductive coil and the absorbable capacitor structure 200. The absorbable insulating layer 300 can be formed by spin coating, spraying, dip coating, or thin-film lamination.

[0074] In use, the external wireless transmitting unit outputs a radio frequency pulse signal with a carrier frequency of 13.56 MHz and envelope modulation according to the set nerve stimulation parameters. After the passive LC resonant receiving circuit formed by the molybdenum thin film planar spiral coil and the absorbable capacitor structure 200 receives the radio frequency pulse signal, a stimulation electrical signal is formed between the stimulation contacts 101, thereby acting on the vicinity of the target nerve tissue.

[0075] In this embodiment, the thin-film composite structure facilitates the miniaturization and flexible attachment of electrodes, and can be used for superficial peripheral nerve stimulation, short-term neuromodulation studies in animal experiments, and local nerve stimulation scenarios requiring small implantation volumes.

[0076] In the description of this specification, references to terms such as "an embodiment," "example," and "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0077] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The descriptions in the foregoing embodiments and specifications are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. An absorbable wireless stimulation electrode for neural modulation, characterized in that, include: An absorbable conductive coil (100) is made of absorbable or degradable conductive material and includes a first coil end and a second coil end, and is configured to generate an induced electrical signal under the action of an alternating electromagnetic field generated by an external wireless transmitting unit. An absorbable capacitor structure (200) includes a first absorbable conductive part, a second absorbable conductive part and an absorbable dielectric part located between the first absorbable conductive part and the second absorbable conductive part, which are mutually insulated from each other, and form a first electrode and a second electrode. The first electrode is electrically connected to the first coil end, and the second electrode is electrically connected to the second coil end, so that the absorbable conductive coil (100) and the absorbable capacitor structure (200) together form a passive LC resonant receiving circuit, and the resonant frequency of the passive LC resonant receiving circuit matches the carrier frequency of the external wireless transmitting unit. At least two stimulation contacts (101) are electrically connected to the passive LC resonant receiving circuit and are used to output stimulation electrical signals to the vicinity of the target nerve tissue; An absorbable insulating layer (300) covers at least a portion of the surface of the absorbable conductive coil (100) and / or the absorbable capacitor structure (200) and exposes at least a portion of the stimulation contact (101).

2. The absorbable wireless stimulation electrode for neuromodulation according to claim 1, characterized in that, The absorbable conductive coil (100) is a multi-turn coil structure, with adjacent coil turns spaced apart to form an inter-turn gap to prevent short circuits between adjacent coil turns; the multi-turn coil structure is a spiral coil structure, a planar spiral coil structure, a multi-turn ring coil structure, a multi-turn elliptical coil structure, or a multi-layer coil structure.

3. The absorbable wireless stimulation electrode for neuromodulation according to claim 1, characterized in that, The stimulation contact (101) is a rounded protrusion structure, a hemispherical protrusion structure, a spherical protrusion structure, a sheet structure, or a surface micro / nano roughened structure.

4. The absorbable wireless stimulation electrode for neuromodulation according to claim 3, characterized in that, When the stimulation contact (101) is a blunt protrusion structure, a hemispherical protrusion structure or a spherical protrusion structure, the stimulation contact (101) protrudes outward relative to the absorbable insulating layer (300), and the maximum radial dimension of the stimulation contact (101) is greater than the outer diameter of the insulating covering area adjacent to the stimulation contact (101).

5. The absorbable wireless stimulation electrode for neuromodulation according to claim 1, characterized in that, The first absorbable conductive part and the second absorbable conductive part are layered, sheet-like, thin film-like or interdigitated conductive electrode plates, and the absorbable dielectric part is a degradable dielectric layer disposed between the first absorbable conductive part and the second absorbable conductive part.

6. The absorbable wireless stimulation electrode for neuromodulation according to claim 5, characterized in that, The absorbable capacitor structure (200) is a multilayer capacitor structure, a thin film capacitor structure, an interdigitated capacitor structure, a wound thin film capacitor structure, or a distributed capacitor structure; the degradable dielectric layer includes one or more of magnesium oxide, zinc oxide, silicon oxide, polylactic acid, polycaprolactone, polylactic acid-glycolic acid copolymer, or composite materials thereof.

7. The absorbable wireless stimulation electrode for neuromodulation according to claim 1, characterized in that, The absorbable or degradable conductive material includes one or more of magnesium-based alloys, zinc-based alloys, molybdenum-based materials, or degradable conductive composite materials; wherein, the magnesium-based alloy includes one or more of magnesium-zinc alloys, magnesium-calcium alloys, or magnesium-manganese alloys, the zinc-based alloy includes one or more of zinc-magnesium alloys or zinc-calcium alloys, and the molybdenum-based material includes molybdenum film, molybdenum-based alloy, or molybdenum-based degradable conductive composite material.

8. The absorbable wireless stimulation electrode for neuromodulation according to claim 1, characterized in that, The absorbable insulating layer (300) includes one or more of polylactic acid, polyglycolic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polyanhydride, polyorthoester or biodegradable polyurethane.

9. The absorbable wireless stimulation electrode for neuromodulation according to claim 1, characterized in that, The carrier frequency is 1–100 MHz; the capacitance value of the absorbable capacitor structure (200) is matched according to the equivalent inductance value of the absorbable conductive coil (100) so that the resonant frequency of the passive LC resonant receiving circuit matches the carrier frequency.

10. A neural modulation system, characterized in that, The device includes an external wireless transmitting unit and an absorbable wireless stimulation electrode for neuromodulation as described in any one of claims 1 to 9; the external wireless transmitting unit is configured to output a radio frequency pulse signal based on a carrier frequency and envelope-modulated according to set neurostimulation parameters, and the absorbable wireless stimulation electrode is configured to receive the radio frequency pulse signal and form a stimulation electrical signal that varies with the envelope modulation parameters between the stimulation contacts (101).

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