Flexible electrode array and brain-computer interface device

Abstract

The utility model discloses a flexible electrode array and brain-computer interface equipment, and relates to the field of artificial intelligence. The flexible electrode array comprises a plurality of electrode assemblies arranged at intervals, each electrode assembly comprises an electrode supporting layer and a plurality of flexible electrodes arranged at intervals, and each electrode supporting layer comprises a first flexible layer and a wire layer which are arranged in sequence; the flexible electrode comprises a second flexible layer and an electrode, at least part of the electrode is exposed out of the second flexible layer, the second flexible layer is connected with the first flexible layer, and the electrode is in communication connection with the wire layer; wherein the lengths of at least two flexible electrodes in the plurality of electrodes are different. Compared with the prior art, the implant has the advantages of higher compliance matching with brain tissues, smaller trauma, smaller invasiveness, higher implantation strength, lower implantation resistance and lower implantation injury.

Description

Technical Field

[0001] The present application relates to the field of artificial intelligence technology, and in particular to a flexible electrode array brain-computer interface device. Background Art

[0002] Currently, most invasive electrode structures are rigid structures, such as the Michigan electrode and the Utah electrode. The implantation of rigid electrodes can cause damage to brain tissue, thereby increasing the foreign body rejection reaction of the brain tissue.

[0003] However, flexible electrodes usually lack sufficient implant strength and have high implant resistance, and are prone to displacement during long-term implantation, which in turn affects the accuracy of data transmission. Utility Model Content

[0004] The present application provides a flexible microelectrode array and a method for using the same, as well as a brain-computer interface device, to solve the problems of existing flexible electrodes generally having insufficient implantation strength and high implantation resistance.

[0005] In a first aspect, the present application provides a flexible electrode array for a brain-computer interface, comprising a plurality of spaced-apart electrode assemblies, wherein the electrode assemblies include:

[0006] an electrode support layer, comprising a first flexible layer and a wire layer arranged in sequence; and

[0007] a plurality of spaced-apart flexible electrodes, the flexible electrodes comprising a second flexible layer and electrodes, the electrodes at least partially exposed from the second flexible layer, the second flexible layer being connected to the first flexible layer, and the electrodes being in communication with the wire layer;

[0008] Among them, at least two flexible electrodes have different lengths.

[0009] In the present application, the flexible electrode includes a second flexible layer and an electrode, wherein the electrode is at least partially exposed in the second flexible layer, and the second flexible layer contacts the implantation site and has a low hardness, which can reduce continuous strain and repeated damage, and reduce the probability of increased local inflammation and more serious foreign body rejection reactions. The electrode can also improve the accuracy of signal transmission and reduce noise. Since the shape of the brain tissue is not a planar structure, but is composed of different curvatures, when the flexible electrode is implanted in the brain tissue, the pressure of each electrode in contact with the brain tissue is not the same. When the flexible electrode is set to have at least two flexible electrodes of different lengths, the length of the flexible electrode during implantation can be adjusted according to the curved shape of the brain tissue at the implantation site, so that when implanted, the pressure of multiple flexible electrodes in contact with the brain tissue is released in sequence, which has a higher compliance match with the brain tissue, is less traumatic and less invasive, improves the implantation strength, reduces the implantation resistance, and reduces the implantation damage.

[0010] It should be noted that at least two flexible electrodes have different lengths. In some embodiments, the electrodes may be arranged in a manner that decreases in height from left to right; in some embodiments, the flexible electrodes may be arranged in a manner that increases in height from left to right; in some embodiments, the flexible electrodes may be arranged in a manner that increases in height from the edge to the center; in some embodiments, the flexible electrodes may be arranged in a manner that decreases in height from the edge to the center. The selection can be made according to the specific usage scenario.

[0011] It should be noted that the flexible electrode is a needle-like structure, and its extension direction is in the same plane as the electrode support layer, forming a comb-like structure.

[0012] It should be noted that the electrode is at least partially exposed from the second flexible layer. In some embodiments, the electrode tip may be exposed from the second flexible layer, while the remainder is enclosed within the second flexible layer. In some embodiments, the electrode may be exposed from the second flexible layer at multiple points along its length, forming spaced electrode contacts. This exposure of the electrode contacts can improve signal acquisition sensitivity and throughput compared to exposing the electrode tip from the second flexible layer.

[0013] In some embodiments, among the plurality of spaced-apart flexible electrodes, the length of the center electrode is greater than the length of the electrodes on either side. During implantation, the center electrode's greater length allows the center electrode to contact brain tissue first, resulting in less resistance and easier implantation. The entire electrode array presents a tapered structure, further reducing resistance during implantation and invasiveness and wounding.

[0014] In some embodiments, among the plurality of flexible electrodes arranged at intervals:

[0015] The spacing between the flexible electrodes is 0.3 to 1 mm. Within this range, the spacing between the flexible electrodes can reduce implantation resistance and damage; and / or,

[0016] The length of the flexible electrode is 3.5 to 10 mm. Within this range, the sensitivity of brain signal acquisition can be improved while increasing the implant strength; and / or,

[0017] The number of flexible electrodes in the flexible electrode array is 1024 to 16384. Within this range, the number of flexible electrodes can increase data throughput and improve the accuracy of collected data. The number of flexible electrodes in a single electrode assembly can be 16, 32, or 64.

[0018] The flexible electrode may be rectangular or circular, with the size of the rectangle being (20-50)*(30-70) μm and the diameter of the circle being 20-100 μm.

[0019] In some embodiments, the electrode assembly further includes an internal processing chip electrically connected to the plurality of spaced-apart flexible electrodes for preprocessing brain signals collected by the plurality of spaced-apart flexible electrodes and transmitting the preprocessed signals to another processor. This enables real-time, rapid, and accurate extraction of brain signals, minimizes noise in the collected signals, and achieves stable and lossless signal transmission.

[0020] In some embodiments, the wire layer includes a plurality of wires and a plurality of first contacts, the plurality of wires are embedded in the first flexible layer, the plurality of first contacts are disposed on a surface of the first flexible layer, and the internal processing chip includes a plurality of second contacts, wherein:

[0021] One end of the plurality of wires is respectively connected to the plurality of electrodes arranged at intervals, and the other end is respectively connected to the plurality of first contacts;

[0022] The plurality of first contacts are respectively communicatively connected to the plurality of second contacts of the internal processing chips.

[0023] It should be noted that, to provide sufficient support for the electrode support layer, the electrode support layer also includes a 200-250 μm Si substrate structure to support the flexible material, enabling the electrode support layer to withstand implantation pressure during implantation. The first flexible layer connects to the flexible coating layer of the electrode outer layer, thereby securing the electrode support layer to the flexible electrode. Multiple wires are connected at one end to the plurality of spaced electrodes and at the other end to the plurality of first contacts, enabling electrode signal transmission. The first contacts communicate with the internal processing chip, transmitting brain signals collected by the electrodes to the internal processing chip. The internal processing chip can preprocess the data collected by the electrodes to reduce transmission loss and noise signals, thereby improving data transmission accuracy. This is particularly true for large electrode arrays, i.e., high-throughput electrode arrays. Directly transmitting the data collected by the electrodes to other processors is burdensome and noisy due to the enormous amount of data collected. By preprocessing the electrode-collected signals through the internal processing chip, the amount of data that needs to be transmitted to other processors after preprocessing is significantly reduced, reducing data transmission pressure and improving processing efficiency.

[0024] It should be noted that each metal wire is connected to a corresponding first contact point, so that the data collected by each electrode can be transmitted independently, thereby improving the accuracy of the data.

[0025] Typically, the internal processing chip can be a CMOS circuit chip, which is encapsulated by welding the second contact electrode of the CMOS circuit chip to the first contact on the electrode support layer through the inverted solder array, leaving only the flexible electrode exposed to contact the brain tissue.

[0026] In some embodiments, the flexible electrode array further includes an internal processor, wherein the internal processor is configured to receive the signal pre-processed by the internal processing chip and perform re-preprocessing on the pre-processed signal. 通过 Re-preprocessing the preprocessed signal can further reduce the noise signal of the collected signal and achieve stable and lossless signal transmission.

[0027] In some embodiments, the internal processor includes a communication module comprising a charging circuit, a data processing circuit, a wireless communication chip, a power management chip, a microstrip line connector, and a charging coil, wherein the microstrip line connector is communicatively connected to the internal processing chip. After the second contact of the CMOS circuit's flip-flop array is soldered to the first contact on the electrode support layer, the CMOS microstrip line flip-flop points, namely third contacts, are then soldered to the microstrip line to communicate with the internal processor. The data processing circuit can pre-process the data collected by the electrodes, reducing data output, removing noise, and alleviating data transmission pressure. The wireless communication chip can achieve real-time, rapid, and accurate extraction of neural signals to minimize transmission loss and noise signals. The microstrip line connector enables data transmission between the internal processor and the internal processing chip. The microstrip line connector can be connected to the third contact via a microstrip line to connect the internal processor and the internal processing chip. This application does not limit the specific location of the charging circuit, data processing circuit, wireless communication chip, power management chip, microstrip line connector, and charging coil; wiring and location arrangements can be tailored to actual needs.

[0028] It should be noted that the number of second contacts of the internal processing chip corresponds one-to-one to the number of first contacts, so the number is relatively large. The internal processing chip converts brain signals from electrical signals to digital signals, which can perform simple filtering and noise filtering, and amplify the brain signals at the same time. Therefore, the number of third contacts of the internal processing chip is greatly reduced compared to the number of second contacts.

[0029] In some embodiments, a plurality of the electrode assemblies are arranged in parallel, wherein the internal processing chip is provided with a through-hole, and a connecting rod is passed through the through-holes of two adjacent internal processing chips. Since the plurality of electrode assemblies are arranged in parallel to form a flexible electrode array, it is necessary to ensure that the entire flexible electrode array is fixed in position and does not move during implantation, so each electrode assembly needs to be fixed, that is, the single-piece electrode assembly is combined into a whole. By providing a through-hole on the internal processing chip and a connecting rod is passed through the through-holes of two adjacent internal processing chips, the plurality of electrode assemblies can be fixed by positioning the connecting rod and the through-hole, which facilitates implantation, reduces implantation pressure, and facilitates packaging of the electrode assemblies.

[0030] It should be noted that in order to further reduce the movement of the electrode assembly, after the multiple electrode assemblies are fixed through the connecting rod through-holes, a shell can be packaged on the periphery of the electrode support layer to further fix the electrode assembly and improve the reliability of the implantation.

[0031] In some embodiments, the distance between two adjacent electrode assemblies is 0.3-1 mm. The distance between two adjacent electrode assemblies within this range can reduce implantation resistance and implantation trauma; and / or,

[0032] The thickness of the first flexible layer is 25 to 50 μm. The thickness of the first flexible layer within this range can improve the coagulation firmness between the electrode support layer and the electrode, reduce the occurrence of electrode breakage, and improve implantation strength.

[0033] In a second aspect, the present application proposes a brain-computer interface device comprising the flexible electrode array of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] Figure 1 Schematic diagram of the electrode assembly structure of a flexible electrode array according to an embodiment of the present application.

[0036] Figure 2 Schematic diagram of the electrode assembly structure of a flexible electrode array according to an embodiment of the present application.

[0037] Figure 3 Schematic diagram of the electrode assembly structure of a flexible electrode array according to an embodiment of the present application.

[0038] Figure 4 Schematic diagram of the electrode assembly structure of a flexible electrode array according to an embodiment of the present application.

[0039] Figure 5 This is a cross-sectional view of an electrode assembly of a flexible electrode array according to an embodiment of the present application.

[0040] Figure 6 This is an exploded view of the structure of a flexible electrode array according to an embodiment of the present application.

[0041] Figure 7 This is a schematic diagram of the internal processing chip structure of the flexible electrode array according to one embodiment of the present application.

[0042] Description of Figure Numbers:

[0043] 100 flexible electrode array; 10 electrode assembly; 1 electrode support layer; 11 first flexible layer; 12 wire layer; 121 wire; 122 first contact; 2 flexible electrode; 21 second flexible layer; 22 electrode; 3 internal processor; 31 communication module; 311 charging circuit; 312 data processing circuit; 313 wireless communication chip; 314 power management chip; 315 microstrip line connector; 316 charging coil; 4 internal processing chip; 32 microstrip line; 41 second contact; 42 third contact; 43 through hole; 44 connecting rod; 5 outer shell. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of this application without making any creative efforts shall fall within the scope of protection of this application.

[0045] Currently, most invasive electrode structures are rigid structures, such as the Michigan electrode and the Utah electrode. The implantation of rigid electrodes can cause damage to brain tissue, thereby increasing the foreign body rejection reaction of the brain tissue.

[0046] Direct electrical recording and stimulation of neural activity based on existing rigid electrodes such as silicon-based and metal microwires has made extensive contributions to basic neuroscience and therapeutic applications. However, the mismatch between the mechanical properties of these rigid electrodes and the brain is a key factor in the increased pressure at the biological-non-biological interface of brain tissue, which is particularly damaging to brain tissue for long-term implanted neural electrodes. In addition, due to periodic micro-motions of the brain caused by physiological and behavioral sources, the use of rigid electrode arrays in contact with soft brain tissue causes continuous strain and repeated damage, ultimately leading to increased local inflammation and more severe foreign body rejection reactions. The movement of fixed rigid electrodes can induce shear stress and lead to tissue scarring, thereby compromising the stability of recorded signals on timescales of weeks to months.

[0047] However, flexible electrodes usually lack sufficient implant strength and have high implant resistance, and are prone to displacement during long-term implantation, which in turn affects the accuracy of data transmission.

[0048] In view of this, the present application provides a flexible microelectrode array and a brain-computer interface device to solve the problems of existing flexible electrodes generally having insufficient implantation strength and high implantation resistance.

[0049] First, as Figures 1 to 7 As shown, the present application provides a flexible electrode array 100 for a brain-computer interface, comprising a plurality of spaced-apart electrode assemblies 10, wherein the electrode assembly 10 comprises:

[0050] The electrode support layer 1 includes a first flexible layer 11 and a wire layer 12 arranged in sequence; and

[0051] a plurality of spaced-apart flexible electrodes 2, each of the flexible electrodes 2 comprising a second flexible layer 21 and an electrode 22, wherein the electrode 22 is at least partially exposed from the second flexible layer 21, the second flexible layer 21 is connected to the first flexible layer 11, and the electrode 22 is in communication with the wire layer 12;

[0052] Therein, at least two flexible electrodes 2 have different lengths.

[0053] In the present application, the flexible electrode 2 includes a second flexible layer 21 and an electrode 22, wherein the electrode 22 is at least partially exposed in the second flexible layer 21, and the second flexible layer 21 contacts the implant site, has a low hardness, can reduce continuous strain and repeated damage, reduce the probability of increased local inflammation and more severe foreign body rejection reaction. The electrode 22 can also improve the accuracy of signal transmission and reduce noise. Since the shape of the brain tissue is not a planar structure, but is composed of different curvatures, when the flexible electrode 2 is implanted in the brain tissue, the pressure of each electrode 22 in contact with the brain tissue is not the same. When the flexible electrode 2 is set to have at least two flexible electrodes 2 of different lengths, the length of the flexible electrode 2 during implantation can be adjusted according to the curved shape of the brain tissue at the implant site, so that when implanted, the pressure of multiple flexible electrodes 2 in contact with the brain tissue is released sequentially, and the compliance with the brain tissue is higher, the trauma is less, the invasiveness is less, the implant strength is improved, the implant resistance is reduced, and the implant damage is reduced.

[0054] It should be noted that at least two flexible electrodes 2 have different lengths. In some embodiments, the flexible electrodes 2 may be arranged in a manner that decreases in height from left to right; in some embodiments, the flexible electrodes 2 may be arranged in a manner that increases in height from left to right; in some embodiments, the flexible electrodes 2 may be arranged in a manner that increases in height from the edge to the center; in some embodiments, the flexible electrodes 2 may be arranged in a manner that decreases in height from the edge to the center, and the selection can be made according to the specific usage scenario.

[0055] It should be noted that the electrode 22 is a needle-like structure, and its extension direction is in the same plane as the electrode support layer 1, forming a structure similar to a comb.

[0056] It should be noted that at least a portion of the electrode 22 is exposed from the second flexible layer 21. In some embodiments, the tip of the electrode 22 may be exposed from the second flexible layer 21, while the remainder is enclosed within the second flexible layer 21. In some embodiments, the electrode 22 may be exposed from the second flexible layer 21 at multiple points along the length of the electrode 22, forming spaced electrode contacts. This exposure of the electrode contacts can improve signal acquisition sensitivity and signal acquisition capacity compared to when the tip of the electrode 22 is exposed from the second flexible layer 21.

[0057] It should be noted that the material of the exposed portion of the electrode contact can be different from or the same as the material of the portion covered in the second flexible layer 21. The electrode portion covered in the second flexible layer 21 can serve as a conductor of the electrode contact and electrically connect to other components.

[0058] In conjunction with the first aspect, in some embodiments provided herein, among the plurality of spaced-apart flexible electrodes 2, the length of the middle electrode 22 is greater than the length of the electrodes 22 on either side. During implantation, the greater length of the middle electrode 22 than the electrodes 22 on either side allows the middle electrode 22 to contact brain tissue first, resulting in less resistance and easier implantation. The entire array of electrodes 22 presents a tapered structure, which reduces resistance during implantation and reduces invasiveness and wounding.

[0059] In combination with the first aspect, in some embodiments provided in the present application, among the multiple flexible electrodes 2 arranged at intervals: the spacing between the flexible electrodes 2 is 0.3 to 1 mm. The spacing between the flexible electrodes 2 is within this range, which reduces implantation resistance and reduces damage.

[0060] In combination with the first aspect, in some embodiments provided in the present application, among the multiple flexible electrodes 2 arranged at intervals, the length of the flexible electrode 2 is 3.5 to 10 mm. The length of the flexible electrode 2 is within this range, which can improve the sensitivity of brain signal acquisition and at the same time improve the implantation strength.

[0061] In conjunction with the first aspect, in some embodiments provided herein, the number of flexible electrodes 2 in the flexible electrode array 100 is 1024 to 16384. Within this range, the number of flexible electrodes 2 can increase data throughput and improve the accuracy of collected data. The number of flexible electrodes 2 in a single electrode assembly 10 can be 16, 32, or 64.

[0062] The flexible electrode 2 may be rectangular or circular, with the size of the rectangle being (20-50)*(30-70) μm and the diameter of the circle being 20-100 μm.

[0063] In conjunction with the first aspect, in some embodiments provided herein, the electrode assembly 10 further includes an internal processing chip 4, which is electrically connected to the plurality of spaced-apart flexible electrodes 2 and configured to preprocess brain signals collected by the plurality of spaced-apart flexible electrodes 2 and transmit the preprocessed signals to another processor. This enables real-time, rapid, and accurate extraction of brain signals, minimizes noise in the collected signals, and achieves stable and lossless signal transmission.

[0064] In combination with the first aspect, in some embodiments provided in the present application, the wire layer 12 includes multiple wires 121 and multiple first contacts 122, the multiple wires 121 are buried in the first flexible layer 11, and the multiple first contacts 122 are provided on the surface of the first flexible layer 11. The internal processing chip 4 includes multiple second contacts 41, wherein:

[0065] One end of the plurality of wires 121 is respectively connected to the plurality of electrodes 22 arranged at intervals, and the other end is respectively connected to the plurality of first contacts 122;

[0066] The plurality of first contacts 122 are respectively communicatively connected to the plurality of second contacts 41 of the internal processing chips 4 .

[0067] It should be noted that in order to provide sufficient support for the electrode support layer 1, the electrode support layer 1 also includes a 200-250 μm Si material substrate structure to support the first flexible layer 11, so that the electrode support layer 1 can withstand the implantation pressure during implantation. The first flexible layer 11 is connected to the second flexible layer 21 on the outer layer of the electrode 22, thereby achieving fixation of the electrode support layer 1 and the flexible electrode 2. One end of the multiple wires 121 is connected to the multiple spaced electrodes 22, and the other end is connected to the multiple first contacts 122 to achieve electrode signal transmission. The brain signals collected by the electrodes are transmitted to the internal processing chip 4 through the communication connection between the first contacts 122 and the internal processing chip 4. The internal processing chip 4 can pre-process the data collected by the electrodes 22 to reduce transmission loss and noise signals, thereby improving the accuracy of data transmission. Especially for a large number of electrode arrays, that is, high-throughput electrode arrays, since the amount of collected data is very large, directly transmitting the data collected by the electrode 22 to other processors has a high transmission pressure and a lot of noise. By preprocessing the signals collected by the electrode 22 through the internal processing chip 4, the amount of data that needs to be transmitted to other processors after preprocessing is greatly reduced, which can reduce the data transmission pressure and improve processing efficiency.

[0068] It should be noted that each metal wire 121 is correspondingly connected to the first contact 122, so that the data collected by each electrode 22 can be transmitted independently, thereby improving the accuracy of the data.

[0069] Typically, the internal processing chip 4 can be a CMOS circuit chip, which is welded to the first contact 122 on the electrode support layer 1 through the inverted solder array of the CMOS circuit chip, that is, the second contact electrode 41, thereby realizing the packaging of the electrode support layer 1, leaving only the flexible electrode 2 exposed to contact the brain tissue.

[0070] In conjunction with the first aspect, in some embodiments provided herein, the flexible electrode array 100 further includes an internal processor 3, wherein the internal processor 3 is configured to receive the signal preprocessed by the internal processing chip 4 and further preprocess the preprocessed signal. By further preprocessing the preprocessed signal, noise in the collected signal can be further reduced, thereby achieving stable and lossless signal transmission.

[0071] In conjunction with the first aspect, the internal processor 3 includes a communication module 31, which includes a charging circuit 311, a data processing circuit 312, a wireless communication chip 313, a power management chip 314, a microstrip line connector 315, and a charging coil 316, wherein the microstrip line connector 315 is communicatively connected to the internal processing chip 4. After the CMOS circuit's inverted solder array, i.e., the second contact 41, is soldered to the first contact 122 on the electrode support layer 1, it is then in communication with the internal processor 3 via the CMOS microstrip line inverted solder points, i.e., the third contact 42, which is inverted soldered to the microstrip line 32. The data processing circuit 312 can pre-process the data collected by the electrodes 22, reducing the data output, removing noise data, and alleviating data transmission pressure. The wireless communication chip 313 can achieve real-time, rapid, and accurate derivation of neural signals to minimize transmission loss and noise signals. The microstrip line connector 315 can realize data transmission between the internal processor 3 and the internal processing chip 4. The microstrip line connector 315 can be connected to the third contact 42 via the microstrip line 32 to realize the connection between the internal processor 3 and the internal processing chip 4. The specific locations of the charging circuit 311, data processing circuit 312, wireless communication chip 313, power management chip 314, microstrip line connector 315, and charging coil 316 are not limited in this application, and the wiring and position arrangement can be carried out according to actual conditions.

[0072] It should be noted that the number of second contacts 41 of the internal processing chip 4 corresponds one-to-one to the number of first contacts 122, so the number of second contacts 41 is relatively large. The internal processing chip 4 converts brain signals from electrical signals into digital signals, and simple filtering and noise filtering can be performed, while the brain signals are amplified. Therefore, the number of third contacts 42 of the internal processing chip 4 is greatly reduced compared to the number of second contacts 41.

[0073] In combination with the first aspect, in some embodiments provided in the present application, a plurality of electrode assemblies 10 are arranged in parallel, wherein a through-hole 43 is provided on the internal processing chip 4, and a connecting rod 44 is passed through the through-holes 43 of two adjacent electrode assemblies 10. Since the plurality of electrode assemblies 10 are arranged in parallel to form a flexible electrode array 100, it is necessary to ensure that the entire flexible electrode array 100 is fixed in position and does not move during implantation. Therefore, each electrode assembly 10 needs to be fixed, that is, the single-piece electrode assembly 10 is combined into a whole. By providing a through-hole 43 on the internal processing chip 4 and passing a connecting rod 44 through the through-hole 43 of two adjacent electrode assemblies 10, the plurality of electrode assemblies 10 can be fixed by positioning the connecting rod 44 and the through-hole 43, which facilitates implantation, reduces implantation pressure, and facilitates packaging of the electrode assembly 10. Usually, the position of the through-hole 43 on the internal processing chip 4 needs to avoid the position of the second contact 41 and the third contact 42 to reduce interference with the circuit.

[0074] It should be noted that in order to further reduce the movement of the electrode assembly 10, after the multiple electrode assemblies 10 are fixed through the connecting rod through-holes, the outer shell 5 can be encapsulated on the periphery of the electrode support layer 1 to further fix the electrode assembly 10 and improve the reliability of implantation.

[0075] In combination with the first aspect, in some embodiments provided in the present application, the spacing between two adjacent electrode assemblies 10 is 0.3 to 1 mm. The spacing between two adjacent electrode assemblies 10 is within this range, which can reduce implantation resistance and implantation trauma.

[0076] In combination with the first aspect, in some embodiments provided in the present application, the thickness of the first flexible layer 11 is 25 to 50 μm. The thickness of the first flexible layer 11 within this range can improve the coagulation firmness between the electrode support layer 1 and the electrode 22, reduce the occurrence of electrode 22 breakage, and improve implantation strength.

[0077] The material of the first flexible layer 11 includes at least one of PI (polyimide), PDMS (polydimethylsiloxane) and silicone resin. The use of the above materials can improve the biocompatibility of the flexible array, reduce rejection reactions after implantation, and reduce damage to brain tissue.

[0078] The material of the wire 121 includes at least one of gold, platinum, iridium, tungsten, magnesium, molybdenum, platinum-iridium alloy, titanium alloy, graphite, and carbon nanotubes. The use of the above materials for the wire 121 can improve the accuracy of data transmission.

[0079] The material of the second flexible layer 21 includes at least one of PI, PDMS and silicone resin. The use of the above materials can improve the biocompatibility of the second flexible layer 21, reduce rejection reactions after implantation, and reduce damage to brain tissue.

[0080] The material of the electrode 22 includes at least one of gold, platinum, iridium, tungsten, magnesium, molybdenum, platinum-iridium alloy, titanium alloy, graphite, and carbon nanotubes. Using the above-mentioned electrode 22 materials can improve the sensitivity of the electrode 22 in collecting data and improve the accuracy of the data.

[0081] The flexible electrode array can be prepared by the following preparation method:

[0082] Prepare an oxide layer on the surface of the silicon wafer as a dielectric layer;

[0083] Prepare a first flexible layer material on the surface of the silicon wafer with a thickness of 30 μm to ensure implantation strength;

[0084] Depositing metal on the surface of the first flexible layer and patterning the deposited metal into metal conductors;

[0085] A first flexible layer material is prepared on the metal surface to encapsulate the metal wire, and then a coating process is performed, followed by photolithography, development, and etching to prepare a cavity.

[0086] Depositing electrode material at the cavity mouth and obtaining contact electrodes by lift-off;

[0087] Depositing indium metal in the cavity of the electrode support layer to form a plurality of first contact electrodes;

[0088] Release the electrode assembly from the silicon substrate. The release process can be mechanical, physical or chemical, wherein the silicon wafer behind the electrode support layer is not peeled off, only the electrode is peeled off;

[0089] The electrode assembly is welded to the CMOS circuit through the first contact electrode, and multiple electrode assemblies are connected and fixed by connecting rods through through holes etched or laser cut on the electrode support layer, and then packaged in a packaging shell to form a flexible electrode array.

[0090] The method for using the flexible electrode array in this application may include the following steps:

[0091] Multiple flexible electrodes of the flexible electrode array are soaked in liquid nitrogen and then implanted into the target area of ​​the brain.

[0092] Because the flexible electrodes of the flexible electrode array are made of flexible materials that come into contact with brain tissue, insufficient implantation pressure can easily lead to large wounds. To improve the implant strength of the flexible electrodes, they are treated with liquid nitrogen before implantation to increase their hardness during implantation. After implantation, the flexible electrodes return to their flexible state based on the thermal effect, reducing the damage caused to brain tissue by rigid electrodes during implantation. Liquid nitrogen implantation also offers higher implantation efficiency, simplifies the surgical process, reduces reliance on auxiliary equipment such as surgical robots, and reduces surgical complexity and cost. Designing easy-to-use implantation tools and methods allows doctors to quickly and accurately implant electrodes into the target area.

[0093] It should be noted that before the flexible electrode is immersed in liquid nitrogen, it can also be immersed in physiological saline to reduce impurity contamination.

[0094] After the plurality of flexible electrodes of the flexible electrode array are soaked in liquid nitrogen and then implanted into the target area, the method further comprises:

[0095] Collect raw data of brain nerves;

[0096] The raw data of brain nerves is processed by the internal processor to obtain pre-processed data;

[0097] The pre-processed data is wirelessly transmitted to other processors for processing.

[0098] By processing raw brain nerve data through an internal processor to obtain preprocessed data, and then wirelessly transmitting this preprocessed data to other processors for processing, the data collected by the electrodes can be preprocessed to reduce transmission loss and noise signals, thereby improving the accuracy of data transmission. This is especially true for large electrode arrays, namely high-throughput electrode arrays. Due to the huge amount of data collected, directly transmitting the data collected by the electrodes to other processors is stressful and noisy. By preprocessing the electrode-collected signals through the internal processor, the amount of data that needs to be transmitted to other processors after preprocessing is greatly reduced, which can reduce data transmission pressure and improve processing efficiency.

[0099] In a second aspect, the present application provides a brain-computer interface device comprising the flexible electrode array of the first aspect. The brain-computer interface device incorporates all the technical solutions of the flexible electrode array and thus possesses all the beneficial effects of the flexible electrode array, which will not be detailed further herein.

[0100] In summary, the flexible electrode includes a second flexible layer and an electrode, wherein the electrode is at least partially exposed in the second flexible layer, and the second flexible layer contacts the implant site, has low hardness, can reduce continuous strain and repeated damage, and reduce the probability of increased local inflammation and more serious foreign body rejection reactions. The electrode can also improve the accuracy of signal transmission and reduce noise. Since the shape of the brain tissue is not a planar structure, but is composed of different curvatures, when the flexible electrode is implanted in the brain tissue, the pressure of each electrode in contact with the brain tissue is not the same. When the electrode is set to have at least two electrodes of different lengths, the length of the flexible electrode during implantation can be adjusted according to the curved shape of the brain tissue at the implant site, so that when implanted, the pressure of multiple flexible electrodes in contact with the brain tissue is released in sequence, which has a higher compliance match with the brain tissue, is less traumatic and less invasive, improves the implant strength, reduces the implant resistance, and reduces the implant damage.

[0101] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments / methods or examples. In addition, those skilled in the art may combine and combine different embodiments / methods or examples described in this specification and the features of different embodiments / methods or examples, unless they are contradictory.

[0102] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0103] It should be noted that, in the present application, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment comprising a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or equipment comprising the elements. In the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly specified.

[0104] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A flexible electrode array for a brain-computer interface, characterized in that: The invention comprises a plurality of electrode assemblies arranged at intervals, wherein the electrode assembly comprises: an electrode support layer, comprising a first flexible layer and a wire layer arranged in sequence; and a plurality of spaced-apart flexible electrodes, the flexible electrodes comprising a second flexible layer and electrodes, the electrodes at least partially exposed from the second flexible layer, the second flexible layer being connected to the first flexible layer, and the electrodes being in communication with the wire layer; Among them, at least two flexible electrodes have different lengths.

2. The flexible electrode array for brain-computer interface according to claim 1, wherein: Among the plurality of flexible electrodes arranged at intervals, the length of the electrode at the middle position is greater than the length of the electrodes at both sides.

3. The flexible electrode array for brain-computer interface according to claim 1, wherein: The spacing between the flexible electrodes is 0.3 to 1 mm; and / or, The length of the flexible electrode is 3.5 to 10 mm; and / or, The number of flexible electrodes in the flexible electrode array is 1024 to 16384.

4. The flexible electrode array for brain-computer interface according to claim 1, wherein: The electrode assembly also includes an internal processing chip, which is electrically connected to the multiple flexible electrodes arranged at intervals, and is used to preprocess brain signals collected by the multiple flexible electrodes arranged at intervals, and transmit the preprocessed signals to other processors.

5. The flexible electrode array for brain-computer interface according to claim 4, characterized in that: The wire layer includes a plurality of wires and a plurality of first contacts, the plurality of wires are embedded in the first flexible layer, the plurality of first contacts are provided on the surface of the first flexible layer, and the internal processing chip includes a plurality of second contacts, wherein: One end of the plurality of wires is respectively connected to the plurality of electrodes arranged at intervals, and the other end is respectively connected to the plurality of first contacts; The plurality of first contacts are respectively communicatively connected to the plurality of second contacts of the internal processing chips.

6. The flexible electrode array for brain-computer interface according to claim 5, characterized in that: The flexible electrode array further includes an internal processor, wherein the internal processor is configured to receive the signal pre-processed by the internal processing chip and perform re-preprocessing on the pre-processed signal.

7. The flexible electrode array for brain-computer interface according to claim 6, characterized in that: The internal processor includes a communication module, which includes a charging circuit, a data processing circuit, a wireless communication chip, a power management chip, a microstrip line connector and a charging coil that are communicatively connected, wherein the microstrip line connector is communicatively connected to the internal processing chip.

8. The flexible electrode array for brain-computer interface according to claim 4, characterized in that: A plurality of the electrode assemblies are arranged in parallel, wherein the internal processing chip is provided with a through hole, and a connecting rod is passed through the through holes of two adjacent internal processing chips.

9. The flexible electrode array for brain-computer interface according to claim 1, wherein: The distance between two adjacent electrode assemblies is 0.3 to 1 mm; and / or, The thickness of the first flexible layer is 25-50 μm.

10. A brain-computer interface device, characterized in that: Comprising the flexible electrode array according to any one of claims 1 to 9.

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