Electrode and device for implantable brain-computer interface

Abstract

The utility model relates to the technical field of brain-computer interfaces, discloses an electrode for an implantable brain-computer interface and a device thereof, and aims to optimize the contact with the cerebral cortex so as to efficiently and safely capture nerve electrical activity. The electrode design comprises an elastic polymerization layer, a first coating, a metal layer and a second coating, and two morphological structures with different mechanical properties are formed. The first form provides the required mechanical strength through the combination of the metal layer and the first coating, and is suitable for stable implantation; and in the second form, through the configuration of the elastic polymerization layer and the second coating, the softness is enhanced, and the damage to brain tissues is reduced. Due to the unique bimorphic design, the signal transmission efficiency of the electrode can be ensured, meanwhile, the invasion to brain tissues can be minimized, and a new possibility is developed for the application of a brain-computer interface technology.

Description

Technical Field

[0001] The utility model belongs to the field of brain-computer interface, and in particular relates to an electrode and a device for an implantable brain-computer interface. Background Art

[0002] Implantable brain-computer interfaces using cortical electrodes have several advantages over non-invasive EEG and invasive deep electrode brain-computer interfaces, including higher spatial resolution, more stable and reliable recording, and no need for invasive surgical procedures. Implantable brain-computer interfaces based on cortical electrodes have been initially shown to have great potential for improving the lives of people with disabilities, promoting neurorehabilitation, and developing new forms of human-computer interaction.

[0003] Semi-invasive cortical electrodes currently approved for clinical use, such as foreign PMT, Ad-Tech, and domestic Huake Hengsheng electrodes, usually use stainless steel or platinum-iridium alloy as electrode contact materials, which are individually welded on discrete wires and wrapped with about 1 mm thick silicone as an insulating layer. These electrode contacts are usually 2.3 mm in diameter, 1 cm apart, and arranged as linear strip electrodes with 2 to 8 contacts or array sheet electrodes with 8-32 contacts. In clinical applications, these electrodes can be bent to cover the cortical area of ​​interest. However, the hard metal part and thick silicone result in a high effective bending stiffness. In actual applications, there will be adverse reactions such as poor contact between the electrode contacts and the cortex, movement of the contact position, insufficient spatial accuracy, and even inflammation, which limits the application of ECoG electrodes in brain-computer interfaces.

[0004] In order to solve the above problems, a common method is to use micro-nano processing technology to process electrodes on flexible polymer substrates based on polyimide and polyparaxylene C. However, due to the high Young's modulus of such flexible materials, the thickness of flexible and conformable electrodes is generally thin (several to tens of microns), and they are prone to curling after being released from the substrate. When the coverage area is large, surgical implantation is inconvenient. Elastic polymers such as silicone are also a commonly used substrate material. They have high transparency and a Young's modulus comparable to that of the brain, which can be combined with technologies such as two-photon and greatly improve biocompatibility. Since the Young's modulus of silicone is closer to that of brain tissue, it can also maintain a small bending stiffness at a thickness of 100 to 200 microns. However, due to the large thermal expansion coefficient of silicone, when used directly as a substrate material, it has poor compatibility with micro-nano processing technology. Summary of the invention

[0005] In view of this, an embodiment of the utility model provides an electrode and a device for an implantable brain-computer interface, the main purpose of which is to improve the mechanical strength and soft fitting performance of the electrode, improve the micro-nano processing compatibility of the electrode, make greater use of the high precision of the micro-nano process, improve the line density of the electrode processing, and provide higher spatial accuracy for data acquisition of the brain-computer interface.

[0006] In order to achieve the above purpose, the utility model mainly provides the following technical solutions:

[0007] On the one hand, an embodiment of the utility model provides an electrode for an implantable brain-computer interface, a portion of which is in contact with the cerebral cortex of a living being for acquiring electrical signals from the brain; the electrode comprises at least: an elastic polymer layer, a first coating, a metal layer, and a second coating; wherein the first coating and the metal layer belong to a first form, and the elastic polymer layer and the second coating belong to a second form; wherein the first form is different from the second form.

[0008] Optionally, the elastic polymer layer, the first coating, the metal layer, and the second coating are stacked in sequence; the first coating and the metal layer are combined to form an intermediate layer; the elastic polymer layer and the second coating are combined to form a wrapping layer; the intermediate layer is arranged in the wrapping layer.

[0009] Optionally, the electrode further includes: a conductive polymer layer and a third coating layer; the conductive polymer layer is disposed above the second coating layer; and the third coating layer is disposed below the elastic polymer layer and adheres to the elastic polymer layer.

[0010] Optionally, a through hole is provided on the first surface of the second coating layer, and the conductive polymer layer is bonded to the metal layer through the through hole.

[0011] Optionally, the metal layer includes at least: an adhesive metal layer, a conductive layer, and a metal protective layer; the adhesive metal layer, the conductive layer, and the metal protective layer are stacked in sequence; the adhesive metal layer is bonded to the first coating, and the metal protective layer is bonded to the second coating.

[0012] Optionally, the edge of the first coating is in contact with the edge of the metal layer; the edge of the elastic polymer layer is in contact with the edge of the second coating; wherein the surface area of ​​the elastic polymer layer and the second coating is greater than the surface area of ​​the first coating and the metal layer.

[0013] Optionally, the electrode includes: a detection part, a transmission part and an interface part; the detection part, the transmission part and the interface part are integrally formed.

[0014] Optionally, the detection portion is rectangular, the transmission portion is in a straight line shape, and the interface portion is rectangular; wherein the detection portion is connected to the transmission portion; and the transmission portion is connected to the interface portion.

[0015] Optionally, the first form is a first shape; the second form is a second shape; wherein the first shape is different from the second shape;

[0016] On the other hand, an embodiment of the utility model provides a device for an implantable brain-computer interface, comprising: the electrode described above, which is connected to an external device; the external device comprises a signal conversion component and a data analysis component; the signal conversion component is used for data conversion between digital signals and analog signals; the data analysis component is used for analyzing and processing the brain electrical signals to obtain brain data.

[0017] An embodiment of the utility model provides an electrode and a device for an implantable brain-computer interface, wherein a portion of the electrode contacts the biological cerebral cortex and is used to obtain brain electrical signals, which are then transmitted to an external device for decoding and analysis. The electrode includes at least: an elastic polymer layer, a first coating, a metal layer, and a second coating, forming two morphological structures with different mechanical properties. The first form provides the required mechanical strength through the combination of the metal layer and the first coating, and is suitable for stable implantation; while the second form enhances softness and reduces damage to brain tissue through the configuration of the elastic polymer layer and the second coating. This unique dual-morphological design enables the electrode to minimize the intrusion on brain tissue while ensuring signal transmission efficiency, opening up new possibilities for the application of brain-computer interface technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the overall structure of an electrode provided in an embodiment of the utility model.

[0019] Figure 2 A schematic diagram of another angle of an electrode provided by an embodiment of the utility model.

[0020] Figure 3 A schematic diagram of the metal layer structure of an electrode provided in an embodiment of the utility model.

[0021] Figure 4 A schematic diagram of electrode area division provided in an embodiment of the utility model.

[0022] Explanation of reference numerals: 10, electrode; 11, third coating layer; 12, elastic polymer layer; 13, first coating layer; 14, metal layer; 15, second coating layer; 16, conductive polymer layer; 101, detection part; 102, transmission part; 103, interface part; 141, metal protective layer; 142, conductive layer; 143, adhesive metal layer DETAILED DESCRIPTION

[0023] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the utility model, the specific implementation, structure, characteristics and effects of the electrodes of the implantable brain-computer interface proposed by the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0024] like Figure 1 , 2 As shown, an embodiment of the utility model proposes an electrode 10 for an implantable brain-computer interface, the electrode 10 at least comprising: an elastic polymer layer 12, a first coating 13, a metal layer 14, a second coating 15, and a conductive polymer layer 16; wherein the elastic polymer layer 12 is arranged at the bottom layer of the electrode 10, and the conductive polymer layer 16 is arranged at the top layer of the electrode 10, and at the same time, the conductive polymer layer 16 is in contact with the cerebral cortex of the organism, so that the electrode 10 acquires electrical signals from the cerebral cortex of the organism; that is, a part of the electrode 10 is in contact with the brain of the organism, which means that the conductive polymer layer 16 is in contact with the cerebral cortex of the organism, specifically, the detection part 101 of the conductive polymer layer 12 is in contact with the cerebral cortex of the organism, and at the same time, the conductive polymer layer 16 only blocks part of the structure of the second coating 15, so the partial area of ​​the second coating 15 not blocked by the conductive polymer layer 16 is also in contact with the cerebral cortex of the organism, that is, the structural surfaces of the detection part 101 and the transmission part 102 of the second coating 15 are in contact with the cerebral cortex of the organism. The first coating 13 is arranged above the elastic polymer layer 12 for bonding, so that the elastic polymer layer 12 is combined with the metal layer 14; the metal layer 14 is arranged above the first coating 13 for acquiring and transmitting biological brain electrical signals; the second coating 15 is arranged above the metal layer 14, on the one hand for bonding, so that the metal layer 14 is bonded to other structures, and on the other hand for sealing, that is, to combine the elastic polymer layer 12 with the second coating 15.

[0025] The first coating layer 13 and the metal layer 14 belong to the first form, and the elastic polymer layer 12 and the second coating layer 15 belong to the second form; the first form is different from the second form. Among them, the first form can be defined as the first coating layer 13 and the metal layer 14: having the same shape but not the same size; it can also be a structure having the same shape and the same size; it can also be a structure having a size within a certain range and having the same shape; it can also be a structure having a size within a certain range and not having the same shape. The second form can be positioned as the elastic polymer layer 12 and the second coating layer 15: having the same shape but not the same size; it can also be a structure having the same shape and the same size; it can also be a structure having a size within a certain range and having the same shape; it can also be a structure having a size within a certain range and not having the same shape.

[0026] Secondly, the first form and the second form may be different in that one of the structural parameters is different, all of the parameters are different, or the parameters are the same but the structures are different; that is, the first form and the second form may be considered different if there is a difference in shape or structural parameters.

[0027] Specifically, the first coating 13 and the metal layer 14 can be within a first size range and have the same first shape, and the second coating 15 and the elastic polymer layer 12 can be within a second size range and have the same first shape, that is, the length range of the first size is different from the length range of the second size, and the size here includes thickness; for example: the length of the first coating 13 and the metal layer 14 is 10-200 mm, the width is 1-200 mm, the thickness of the first coating 13 and the metal layer 14 is 10 nanometers-100 microns, and the first coating 13 and the metal layer 14 are both rectangular; the length of the second coating 15 and the elastic polymer layer 12 is 10-200 mm, the width is 1-200 mm, the thickness is 10 nanometers-100 microns, and the second coating 15 and the elastic polymer layer 12 are both rectangular.

[0028] The first coating layer 13 and the metal layer 14 can also have a first size and the same first shape, and the second coating layer and the elastic polymer layer 12 have a second size and the same first shape; for example: the dimensions of the first coating layer 13 and the metal layer 14 are 60 mm long, 5 mm wide, the first coating layer has a thickness of 3 microns, the metal layer has a thickness of 100 nanometers, and the first coating layer 13 and the metal layer 14 are both square, the second coating layer 15 and the elastic polymer layer 12 are 65 mm long, 6 mm wide, and 3 microns thick, and the second coating layer 15 and the elastic polymer layer 12 are both square.

[0029] The first coating layer 13 and the metal layer 14 can be within the first size range and have the same first shape, and the second coating layer and the elastic polymer layer 12 can be within the first size range and have the same second shape, that is, the first shape is different from the second shape; for example: the first coating layer 13 and the metal layer 14 have a length of 10-100 mm, a width of 1-20 mm, a thickness of 1-10 microns, and a thickness of 50-500 nanometers, and both the first coating layer 13 and the metal layer 14 are elliptical; the second coating layer 15 and the elastic polymer layer 12 have a size of 10-100 mm, a width of 1-20 mm, and a thickness of 1-10 microns, and both the second coating layer 15 and the elastic polymer layer 12 are rectangular. The first form and the second form optimize the contact efficiency between the electrode and the cerebral cortex and the ability to reduce brain tissue damage through the difference in their shapes.

[0030] Specifically, the electrode 10 of the implantable brain-computer interface of the present solution can be an ECoG electrode (traditionally called a semi-implantable neural electrode), a probe electrode (traditionally called a fully implantable neural electrode), or some other implantable electrode. The organism in the present solution can be: a human, a pig, a monkey, a mouse or other organisms. The elastic polymer layer 12 in the present solution can be: silicone, polydimethylsiloxane (PDMS), polyurethane (PU), silicone rubber, etc. The elastic polymer layer is formed by spin coating, spray coating, injection molding, molding, etc., and cured by heating. For example: if the organism is a human, and the elastic polymer layer 12 is silicone, the surface of the silicone is attached to the human cerebral cortex, and the patient's brain electrical signal is obtained through the metal layer 14, and then the brain electrical signal is transmitted to an external analysis device, and the brain electrical signal is analyzed by the external analysis device. In the present solution, the first coating 13 and the second coating 15 can be: polyimide (PI), parylene, polyurethane (PU), etc. The first coating 13 and the second coating 15 are made by physical vapor deposition (PVD).

[0031] Furthermore, the first coating layer 13 and the metal layer 14 are combined to form an intermediate layer; the elastic polymer layer 12 and the second coating layer 15 are combined to form a wrapping layer, and the intermediate layer is arranged in the wrapping layer. In other words, the first coating layer 13 and the metal layer 14 are sealed and wrapped by the elastic polymer layer 12 and the second coating layer 15 to prevent the metal layer 14 and the first coating layer 13 from being soaked by cerebrospinal fluid, which affects the detection and transmission functions of the metal layer 14.

[0032] Since the wrapping layer wraps the middle layer, the overall area of ​​the wrapping layer is not less than the overall surface area of ​​the middle layer; that is, the surface area of ​​the elastic polymer layer 12 and the second coating 15 is larger than the surface area of ​​the first coating 13 and the metal layer 14, and at the same time, the edge of the first coating 13 is in contact with the edge of the metal layer 14, and the edge of the elastic polymer layer 12 is in contact with the edge of the second coating 15.

[0033] Furthermore, a conductive polymer layer 16 is provided on the second coating layer 15, and a through hole is provided on the first surface of the second coating layer 15. The conductive polymer layer 16 passes through the first surface of the second coating layer 15 and adheres to the metal layer 14. The conductive polymer layer 16 can be electroplated with a conductive polymer or a metal, and the purpose of reducing the electrode impedance is achieved in this way. The electroplated metal can be selected as gold or Pt, and the electroplated conductive polymer can be selected from one or more of polyaniline, polythiophene, polypyrrole, etc. Preferably, the electroplated conductive polymer is polyethylene dioxythiophene, and the electroplating parameters are fine-tuned according to the size of the electrode site.

[0034] A third coating 11 is also provided below the elastic polymer layer 12 and is bonded to the elastic polymer layer 12; the third coating 11 may be: polyimide (PI), parylene (Parylene), polyurethane (PU), etc. The metal layer is made by vacuum evaporation or magnetron sputtering, and the metal layer material is one or more of gold, silver, copper, platinum, etc. Preferably, the metal layer material is one or more of gold and platinum. The third coating 11 can make the electrode 10 have a better sealing and moisture-proof effect. At the same time, when the electrode 10 is placed under the dura mater, the third coating 11 can reduce the friction between the electrode 10 and the dura mater and reduce the immune response.

[0035] Further, if Figure 3 As shown, the metal layer 14 at least includes: an adhesive metal layer 143, a conductive layer 142, and a metal protective layer 141, which are stacked in sequence. The adhesive metal layer 143 is used to perform adhesion between the second coating layer 15 and the conductive layer 142, the conductive layer 142 is used to obtain and transmit brain electrical signals, and the metal protective layer 141 is used to protect and buffer the metal layer 14.

[0036] Further, if Figure 4As shown, the electrode 10 at least includes: a detection part 101, a transmission part 102 and an interface part 103, wherein the detection part is mainly used to obtain brain electrical signals, the transmission part 102 is used to transmit brain electrical signals to the outside of the brain, and the interface part is used to connect external devices. That is to say, each layer of the third coating 11, the elastic polymer layer 12, the first coating 13, the metal layer 14, the second coating 15, and the conductive polymer layer 16 includes a detection part 101, a transmission part 102, and an interface part 103. The detection part 101, the transmission part 102 and the interface part 103 can be integrally formed or detachably installed. Integral molding can improve efficiency in production and use. Among them, the detection part 101 is connected to the transmission part 102, and the transmission part 102 is connected to the interface part 103 to form a transmission path of the electrode 10. The detection part 101 can be rectangular, the transmission part 102 can be in a straight line shape, and the interface part 103 can be rectangular; the detection part 101 can also be square or circular, the transmission part 102 can be in a straight line shape, and the interface part 103 can be rectangular or circular.

[0037] An embodiment of the utility model proposes a device for an implantable brain-computer interface, wherein an electrode 10 is connected to an external device, and the external device itself may include a signal conversion component and a data analysis component. The external device may also be two separate devices, namely a signal conversion device and a data analysis device, but the functions are signal conversion and electrical signal analysis and processing respectively.

[0038] Specifically, the signal conversion may be a conversion between a digital signal and an analog signal, or a conversion between other types of signals. The data analysis device may analyze brain electrical signals to obtain brain data.

[0039] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An electrode for an implantable brain-computer interface, characterized in that: A portion of the electrode is in contact with the cerebral cortex of the organism to obtain brain electrical signals; The electrode at least comprises: an elastic polymer layer, a first coating layer, a metal layer, and a second coating layer; Wherein, the first coating layer and the metal layer belong to a first form, and the elastic polymer layer and the second coating layer belong to a second form; The first form is different from the second form.

2. The electrode according to claim 1, characterized in that The elastic polymer layer, the first coating, the metal layer, and the second coating are stacked in sequence; The first coating layer and the metal layer are combined with each other to form an intermediate layer; The elastic polymer layer and the second coating layer are combined with each other to form a wrapping layer; The intermediate layer is arranged in the wrapping layer.

3. The electrode according to claim 2, characterized in that The electrode further comprises: a conductive polymer layer and a third coating; The conductive polymer layer is disposed above the second coating layer; The third coating layer is disposed below the elastic polymer layer and is in contact with the elastic polymer layer.

4. The electrode according to claim 3, characterized in that A through hole is provided on the first surface of the second coating layer, and the conductive polymer layer is bonded to the metal layer through the through hole.

5. The electrode according to claim 1, characterized in that The metal layer at least includes: an adhesive metal layer, a conductive layer, and a metal protective layer; The adhesive metal layer, the conductive layer, and the metal protection layer are stacked in sequence; The adhesive metal layer is in contact with the first coating layer, and the metal protective layer is in contact with the second coating layer.

6. The electrode according to claim 2, characterized in that The edge of the first coating layer is in contact with the edge of the metal layer; The edge of the elastic polymer layer is aligned with the edge of the second coating layer; The surface areas of the elastic polymer layer and the second coating layer are greater than the surface areas of the first coating layer and the metal layer.

7. The electrode according to claim 1, characterized in that The electrode comprises: a detection part, a transmission part and an interface part; The detection part, the transmission part and the interface part are integrally formed.

8. The electrode according to claim 7, characterized in that The detection part is rectangular, the transmission part is in a straight line, and the interface part is rectangular; Wherein, the detection unit is connected to the transmission unit; The transmission part is connected to the interface part.

9. The electrode according to claim 1, characterized in that The first form is a first shape; The second form is a second shape; The first shape is different from the second shape.

10. A device for an implantable brain-computer interface, characterized in that: include: The electrode according to any one of claims 1 to 9, wherein the electrode is connected to an external device; The external device includes a signal conversion component and a data analysis component; The signal conversion component is used for data conversion between digital signals and analog signals; The data analysis component is used to analyze and process the brain electrical signals to obtain brain data.

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