An implantable optic nerve brain-computer interface system

Abstract

This invention proposes an implantable visual nerve brain-computer interface system, comprising: a first electrode matrix, arranged in a first region to form a first spatial layout, for acquiring a first electrical signal at a corresponding position in a preset sampling area of ​​the first region; a second electrode matrix, arranged in a second region to form a second spatial layout, for receiving a modulated signal of the first electrical signal; and a conversion module, for mapping the row and column positions of the electrodes in the first electrode matrix and the electrodes in the second electrode matrix according to the spatial layout rules of the electrode matrices, and modulating the first electrical signal so that the modulated signal of the first electrical signal is applied to the second region or a corresponding position below it via the second electrode matrix. This invention acquires a first electrical signal in a specific region through the first electrode matrix, and through reorientation and modulation by the conversion module, applies the first electrical signal as a targeted stimulation signal to the corresponding target region via the second electrode matrix to achieve effective electrical stimulation.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to an implantable optic nerve brain-computer interface system. Background Technology

[0002] The human visual system consists of three parts: the eyeball, the visual transmission pathway, and the visual center. The eyeball collects visual signals and performs preliminary processing, forming signals such as the shape, brightness, color, depth, edges, texture, and direction of motion of an image, which are then transmitted to the visual center through the visual transmission pathway. The visual transmission pathway includes the optic nerve, optic chiasm, optic tract, lateral geniculate body, and optic radiation. The visual center includes the primary visual cortex (V1 area), secondary visual cortex, and higher visual cortex, responsible for processing and interpreting visual information. External objects are visualized in the brain through the visual system; therefore, any problem with any of the three components of the visual system will affect the image quality. If there are problems with the eyeball or the visual transmission pathway, such as severe eye trauma, glaucoma, retinal disease, or optic nerve disease, the eyeball or visual transmission pathway cannot transmit image signals to the visual center. In this case, although the patient's brain's visual center functions normally, it cannot form vision because it does not receive image signals. Currently, some medical experiments have shown that applying certain electrical stimulation signals directly to the visual center of the brain, bypassing the eyeball and optic nerve, can also generate light spot images in the patient's mind, which shows the potential to restore some of the patient's visual function.

[0003] However, the process of using electrical stimulation to directly stimulate the visual nerve center of a patient to restore part of the patient's visual function has many difficulties. First, the mechanism of action between the bioelectrical signals transmitted from the optic nerve to the visual nerve center and the generated images is not clear, so it is difficult to determine the correspondence between the stimulation signal and the generated images. Second, the brain structure of each person is different, so how to overcome the differences between individuals to determine the accurate stimulation area. Summary of the Invention

[0004] To generate effective stimulation signals for the visual nerve center, this invention proposes an implantable visual nerve brain-computer interface system, comprising: a first electrode matrix arranged in a first region to form a first spatial layout, used to collect a first electrical signal at a corresponding position of a preset sampling area in the first region; a second electrode matrix arranged in a second region to form a second spatial layout, used to receive a modulation signal of the first electrical signal; and a conversion module used to map the row and column positions between the electrodes in the first electrode matrix and the electrodes in the second electrode matrix according to the spatial layout rules of the electrode matrix, and to modulate the first electrical signal so that the modulation signal of the first electrical signal is applied to the second region or a corresponding position below it via the second electrode matrix.

[0005] In one or more embodiments, the preset sampling area is located within or below the first area at a preset position.

[0006] In one or more embodiments, the implantable visual nerve brain-computer interface system of the present invention further includes a signal processing module, the signal processing module comprising: a multi-channel switching integrated circuit, used to scan the first electrode matrix at a preset scanning frequency, and in each scanning cycle, to acquire the first electrical signal on the first electrode matrix via a time-division multiplexing method through a bus, and to record the row and column numbers of the acquisition electrodes; a pre-amplification unit, used to pre-amplify the acquired first electrical signal; and an analog-to-digital conversion unit, used to perform analog-to-digital conversion on the pre-amplified first electrical signal to generate a data acquisition matrix corresponding to a plurality of electrodes.

[0007] In one or more embodiments, the implantable visual nerve brain-computer interface system of the present invention further includes a data communication module, the data communication module comprising: a data sending unit, which is bus-connected to the signal processing module, for converting the data acquisition matrix into serial data for transmission; and a data receiving unit, which is communicatively connected to the data sending unit and bus-connected to the conversion module, for receiving the serial data, restoring it to the data acquisition matrix, and forwarding it to the conversion module.

[0008] In one or more embodiments, the conversion module further includes a processor, the processor being configured to: partition the first spatial layout to obtain multiple first sub-space layout partitions; partition the second spatial layout to obtain multiple second sub-space layout partitions; calculate the similarity between the first sub-space layout partitions and the second sub-space layout partitions; map the electrodes in the first sub-space layout partitions with a similarity greater than a preset similarity threshold to the electrodes in the second sub-space layout partitions to form a mapping relationship lookup table; and perform row and column address transformation on the data acquisition matrix according to the mapping relationship lookup table.

[0009] In one or more embodiments, the conversion module further includes a digital-to-analog conversion unit, which is configured to: perform digital-to-analog conversion on the data acquisition matrix after row and column address transformation to obtain the first electrical signal, and use the first electrical signal as a target stimulation signal.

[0010] In one or more embodiments, the conversion module further includes a signal modulation unit, which is used to: generate two frequency-modulated signals with frequencies proportional to the signal amplitude and phase differences of 180° from the target stimulation signal by frequency modulation; and apply at least one of the frequency-modulated signals and the corresponding carrier signals to at least two stimulation electrodes in the second electrode matrix, so that the frequency-modulated signals and the corresponding carrier signals are superimposed in the target region to generate a difference frequency signal.

[0011] In one or more embodiments, the processor in the conversion module is further configured to: in response to the presence of multiple sets of electrodes corresponding to the target region, divide the preset duration of action into multiple equal parts, and use at least one set of electrodes as conducting electrodes in each equal part of the time to stimulate the target region in a time-division manner.

[0012] In one or more embodiments, the processor in the conversion module is further configured to: assign an amplification factor A to each group of electrodes according to the required stimulation intensity before applying at least one frequency-modulated signal and a corresponding carrier signal to the corresponding electrodes to form conducting electrodes; and adjust the normalized relative amplitude coefficient in each group of frequency-modulated signals. (0< <1) To adjust the relative magnitudes of the carrier component and the frequency modulation component in each group of frequency modulation signals; wherein, the amplification factors of the carrier signal and the frequency modulation signal in each group of frequency modulation signals are respectively and .

[0013] In one or more embodiments, the processor in the conversion module is further configured to: uniformly or locally adjust the amplification factor A and the normalized relative amplitude factor of the corresponding electrode. .

[0014] The beneficial effects of the present invention include: the present invention can acquire a first electrical signal in a specific area by setting a first electrode matrix at a predetermined position in the visual acquisition body, and then, through the reorientation and modulation of the conversion module, apply the first electrical signal as a targeted stimulation signal to the corresponding target area by setting a second electrode matrix at a predetermined position in the visual perception body, thereby achieving effective electrical stimulation. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the implantable visual nerve brain-computer interface system according to an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram illustrating an application scenario of the implantable visual nerve brain-computer interface system of the present invention;

[0018] Figure 3 This is a schematic diagram of the structure of the first electrode matrix or the second electrode matrix according to an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of the first electrode matrix acquiring signals at the first scanning time according to an embodiment of the present invention;

[0020] Figure 5 This is a schematic diagram of the first electrode matrix acquiring signals at the second scanning time according to an embodiment of the present invention;

[0021] Figure 6 This is a schematic diagram illustrating the mapping process between the first electrode matrix and the second electrode matrix in an embodiment of the present invention;

[0022] Figure 7 This is a schematic diagram of the signal stimulation of the second electrode matrix according to an embodiment of the present invention;

[0023] Figure 8 This is a schematic diagram of the frequency modulation circuit according to an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0025] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0026] To generate effective stimulation signals to the visual nerve center, this invention proposes an implantable visual nerve brain-computer interface system, such as... Figure 1As shown, it includes: a first electrode matrix 100, arranged in a first region to form a first spatial layout, used to collect a first electrical signal at a position corresponding to a preset sampling area in the first region, wherein the first region and below it are bioelectrical signal conduction areas or bioelectrical signal generation areas, and the first electrical signal is an electroencephalogram (EEG) signal on the visual cortex of the brain of a person or animal with normal vision, which is the reflection of the object seen by the person on the visual cortex; a second electrode matrix 200, arranged in a second region to form a second spatial layout, used to receive the modulation signal of the first electrical signal, wherein the second region and below it are bioelectrical signal receiving areas, but essentially they are also bioelectrical signal conduction areas or bioelectrical signal generation areas; and a conversion module 300, used to map the row and column positions between the electrodes in the first electrode matrix 100 and the electrodes in the second electrode matrix 200 according to the spatial layout rules of the electrode matrix, and to modulate the first electrical signal so that the first electrical signal is applied to the second region or the corresponding position below it via the second electrode matrix. The formation of the first and second spatial layouts includes the fact that when the flexible first / second electrode matrices are attached to the corresponding regions, the relative distance and angle between the electrodes are forced to change due to the influence of the region shape. In one application, when the first and second electrode matrices are placed on the epidural surface of the brain, their spatial layout will be affected by the shape of the functional zones of the visual cortex beneath them.

[0027] The implantable visual nerve brain-computer interface system proposed in this embodiment can reproduce the electrical signals collected by the first electrode matrix 100 at a designated location using the second electrode matrix 200, thereby achieving electrical stimulation of the designated location without having to concern themselves with the interaction mechanism between the electroencephalogram (EEG) signals and the generation of visual images, and achieve a certain visual recovery effect.

[0028] In one alternative application, the first electrode matrix 100 can be positioned on the outer surface of the dura mater above the visual cortex of the pet's or user A's brain, or at other locations within the skull, such as the inner surface of the skull, thus forming a first spatial layout. The pet should be at least a mammal with a brain structure similar to that of a human, such as a cat or dog; this is because the visual formation process is similar in mammals. Figure 2As shown, light reflected from external objects enters the eyeball, forming an inverted real image on the retina. The photoreceptor cells of the retina convert the image light signal into an image electrical signal. This signal is processed by horizontal cells, amacrine cells, and bipolar cells before reaching the ganglion cells. The axons of the ganglion cells form the optic nerve, transmitting the image electrical signal to the brain. At the optic chiasm, the nasal portions of the images from both eyes are exchanged, forming the optic tract which enters the lateral geniculate body of the thalamus. From there, radial nerve fibers enter the visual cortex, which includes the primary and secondary visual cortices. The visual cortex analyzes the input image electrical signal to form vision. The second electrode matrix 200 can be positioned on the outer surface of the dura mater above the visual cortex of user B's brain, or at other locations within the skull, such as the inner surface of the skull. Figure 2 As shown, the application of the implantable visual nerve brain-computer interface system of the present invention bypasses the process by which the mammalian visual system processes light signals and converts them into electrical signals. It also eliminates the need to know the specific process by which the electrical signals transmitted to the visual nerve center ultimately form vision in the brain. Instead, it only requires extracting the electroencephalogram (EEG) signal from a designated location in brain A and applying the same electrical signal to the corresponding location in brain B. This stimulates brain B to form certain visual images, such as light spots, outlines composed of light spots, or even colors. Therefore, for patient B who is blind due to damage to the eyeball or optic nerve, if the function of the cortical portion of the visual nerve center in the brain is intact, the implantable visual nerve brain-computer interface system of the present invention, along with a pet or user A with normal visual function, can be used to restore some of the visual function of patient B.

[0029] In one embodiment, the preset sampling area is located within or below a preset position within the first region. Considering safety, the implantable visual nerve brain-computer interface system of the present invention allows the second electrode matrix to be placed on the epidural surface of the brain. This requires the system of the present invention to be able to electrically stimulate the visual nerve center below the dura mater (i.e., the second region). Therefore, the present invention chooses to convert the acquired EEG signals into frequency signals, and uses the frequency signals to generate a superimposed electric field at the target location, causing the brain tissue at the target location to be excited by the electric field and generate an electrical stimulation signal. The specific method will be explained later. The advantages of implanting electrodes epidurally in this embodiment are as follows: 1. Minimal trauma: only an opening is needed in the skull, without damaging the dura mater, and without harming the brain tissue and cerebrospinal fluid within the dura mater, reducing the risk of surgical infection; 2. Compared to using an EEG cap to collect and stimulate signals outside the scalp, the collected signal strength is high, the accuracy is good, the current required for stimulation is small, the side effects are small, the spatial resolution is high, and the stimulation accuracy can be guaranteed; 3. Compared to direct stimulation on the cerebral cortex within the dura mater, there is no direct contact with cerebrospinal fluid and brain tissue, reducing the risk of surgical infection.

[0030] In one embodiment, such as Figure 1 As shown, in order to realize the acquisition and transmission of multiple signals, the implantable visual nerve brain-computer interface system of the present invention further includes a signal processing module 400. The signal processing module 400 includes: a multi-channel switching integrated circuit 410, used to scan the first electrode matrix at a preset scanning frequency, and in each scanning cycle, to acquire the first electrical signal on the first electrode matrix through a time-division multiplexing method via a bus, and record the row and column numbers of the acquisition electrodes; a pre-amplification unit 420, used to pre-amplify the acquired first electrical signal; and an analog-to-digital conversion unit 430, used to perform analog-to-digital conversion on the pre-amplified first electrical signal to generate a data acquisition matrix corresponding to several electrodes.

[0031] In one optional embodiment, the data elements in the data acquisition matrix correspond one-to-one with the electrodes in the first electrode matrix. That is, each element represents the electrical signal data acquired by each electrode when the scan arrives, including but not limited to the magnitude and direction of the electrical signal current. Within a scan cycle, due to the high scanning frequency, each data element in the data acquisition matrix can be regarded as a record of the continuous changes in the brainwave signal.

[0032] In one optional application method, such as Figure 3 As shown, the first electrode matrix 100 for acquiring EEG signals uses 32*32=1024 electrodes, each of which is an adhesive electrode. All 1024 electrodes are attached to the curved surface outside the dura mater of pet A or user A. Correspondingly, the second electrode matrix 200 for applying stimulation signals also uses 32*32=1024 electrodes, each of which is also an adhesive electrode. All 1024 electrodes are attached to the curved surface outside the dura mater corresponding to the location of the visual cortex in the occipital lobe of user B. Because the electrode array is implanted outside the dura mater or in other locations within the skull, and the processor circuitry needs to... Since the electrode needs to be implanted outside the skull, a lead wire is required to connect the two. To reduce the number of leads, a multiplexer integrated circuit 410 is provided at the output of the first array electrode. This circuit is responsible for recording multiple analog signals from 1024 electrodes in a time-division multiplexing mode and transmitting these analog signals to a processor located outside the skull via a small number of wires. This reduces the number of wires between the first electrode matrix 100 and the first processor 600. The first processor 600 controls the start / stop and operating mode of the analog-to-digital conversion unit 430 and the data transmission unit 510. In an optional embodiment, the attachment electrode provided by the present invention can be designed as a curved surface, the shape of which matches the shape of the dura mater of the brain. This ensures effective contact between the electrode and the cerebral cortex, reduces contact impedance, and the spatial distribution of the electrode matrix implies functional information of brain regions, facilitating subsequent analysis and adjustment of the mapping relationship between the first electrode matrix 100 and the second electrode matrix 200 based on the spatial distribution of the electrode matrix.

[0033] In one specific embodiment, the process of acquiring electroencephalogram (EEG) signals is as follows: Figure 4 As shown, the acquisition of EEG signals requires the use of several electrodes. Furthermore, to reduce noise in the acquired signals, a differential signaling method will be used to record the EEG signals, that is, two sets of four electrodes will be used to acquire the signals separately. and With two signals, in this method, 31*31=961 signals at different locations can be recorded on the 32*32 electrodes. Then, using time-division multiplexing, the signals at these 961 different locations are recorded sequentially, including: ,in, This represents the signal at the position of the m-th row and n-th column; where the differential signal... Electrode The electrical signal acquired is relative to its two adjacent electrodes and The voltage difference of the GND signal on the electrode. In this embodiment, in order to improve the anti-interference capability of the signal acquisition electrode, electrodes are selected respectively. Two adjacent electrodes in the same row and column and Grounding ensures that there are no electrical signals in its vicinity that could interfere with it. It should be noted that... and The reference positions in the electrode matrix are the same; the difference is only to distinguish between the acquired signal and the electrode.

[0034] In one embodiment, since differential signaling requires the acquisition of both positive and negative signals, at least two acquisition electrodes are needed. To improve electrode reusability and acquire more electrical signals, this embodiment will be as follows: Figure 4 The electrode matrix shown uses two adjacent diagonal electrodes to acquire differential signals, and two other diagonal electrodes adjacent to these two are grounded. A total of four electrodes are needed to acquire one set of differential signals. When the next scan arrives, only one column needs to be moved to the right. The electrodes used for signal acquisition and grounding are then as follows: Figure 5 As shown. In this embodiment, the multi-channel switching integrated circuit 410 needs to scan two columns of electrodes simultaneously for each scan.

[0035] In another embodiment, the grounding method of the electrode matrix can also be achieved by using a reference electrode outside the electrode matrix. This means that the potential difference between any electrode in the electrode matrix and the reference electrode outside the matrix can be calculated. In this way, full-point acquisition of the electrode matrix can be achieved. For example, for a 32*32 electrode matrix, a total of 1024 channels of data can be acquired.

[0036] In one embodiment, for ease of use, the implantable visual nerve brain-computer interface system of the present invention further includes a data communication module 500. The data communication module 500 includes: a data transmitting unit 510, which is bus-connected to the signal processing module 400, for converting the data acquisition matrix into serial data for transmission; and a data receiving unit 520, which is communicatively connected to the data transmitting unit 510 and bus-connected to the conversion module 300, for receiving serial data, restoring it to the data acquisition matrix, and forwarding it to the conversion module 300. Both the data transmitting unit 510 and the data receiving unit 520 are wireless communication units, such as Bluetooth, WiFi, or Zigbee. In use, the data transmitting unit 510 and the data receiving unit 520 belong to the EEG signal acquisition subsystem containing the first electrode matrix and the electrical stimulation subsystem containing the second electrode matrix, respectively. The two subsystems are communicatively connected, and the conversion module 300 is located on one side of the electrical stimulation subsystem.

[0037] In one embodiment, the conversion module 300 further includes a processor, namely Figure 1 The second processor in the invention is configured to: partition the first spatial layout to obtain multiple first sub-spatial layout partitions; partition the second spatial layout to obtain multiple second sub-spatial layout partitions; calculate the similarity between the first and second sub-spatial layout partitions; map the electrodes in the first and second sub-spatial layout partitions with similarity greater than a preset similarity threshold to the electrodes in the second sub-spatial layout partitions using row and column indices; and perform row and column address transformation on the data acquisition matrix based on the row and column indices mapping relationship between the electrodes in the first and second sub-spatial layout partitions. It should be noted that in this embodiment, the row and column address transformation on the data acquisition matrix is ​​not a matrix transpose operation, but only to determine the starting and ending electrodes for applying electrical stimulation. Specifically, the process of establishing the mapping relationship between the first electrode matrix and the second electrode matrix in this invention is as follows: Figure 6 As shown, its function is equivalent to re-establishing the communication channel for signal acquisition from corresponding points of the first electrode matrix to corresponding points of the second electrode matrix. However, since the first and second electrode matrices are not directly connected by wires but rather communicate using a data acquisition matrix, transforming the rows and columns of the data acquisition matrix is ​​equivalent to re-establishing the communication channel between the first and second electrode matrices. It should be noted that... Figure 6 This is merely an illustrative diagram and does not represent that the mapping relationship between the first electrode matrix and the second electrode matrix in this invention can only be shown as described above. Figure 6The one-to-one mapping shown is not implemented in practice, but rather depends on the number of electrodes in the first electrode matrix and the second electrode matrix. It includes one-to-one, one-to-many, and / or many-to-one mapping relationships. For example, when calculating the similarity of electrode matrix partitions, if the size of the two subspace layout partitions or the number of electrodes in the partitions are inconsistent, one-to-one, one-to-many, and many-to-one mapping relationships will occur.

[0038] Furthermore, in order to facilitate the control of the electrical stimulation position, the present invention binds the electrode positions in the second electrode matrix with the element positions in the data acquisition matrix. For example, the data element at the first row and first column position in the data acquisition matrix will be applied to the corresponding electrode at the first row and first column position in the second electrode matrix after being converted into an analog signal.

[0039] Furthermore, since the function of the brain is closely related to the distribution of its surface sulci and gyri, and the distribution of sulci and gyri will affect the shape of the dura mater, and thus affect the spatial distribution of the electrode matrix, the purpose of this embodiment is to indirectly determine the characteristics of the brain functional areas below by analyzing the characteristics of the spatial layout, thereby indirectly realizing the correspondence of brain functional areas.

[0040] In one optional application, after the first and second electrode matrices are deployed, the present invention can obtain a first spatial layout image of the first electrode matrix and a second spatial layout image of the second electrode matrix by taking X-rays or color Doppler ultrasound. Then, the images are partitioned, and the similarity of the electrode layout in each partition of the first and second spatial layout images is determined by image analysis to generate a mapping relationship reference table between the partitioned electrodes. In another optional embodiment, the spatial layout of the first electrode matrix and the spatial layout of the second electrode matrix can also be partitioned according to the correspondence between the brain functional partitions of brain A and stimulated brain B, and a mapping relationship reference table between the partitioned electrodes can be generated.

[0041] In one embodiment, the conversion module 300 is further configured to: perform digital-to-analog conversion on the data acquisition matrix after row and column address transformation to obtain a first electrical signal, and use the first electrical signal as a target stimulation signal.

[0042] In one embodiment, the conversion module is further configured to: generate two frequency-modulated signals from the targeted stimulation signal using frequency modulation, wherein the frequency is proportional to the signal amplitude and the phase difference is 180°, such as... Figure 7 As shown, or There are two frequency modulation signals, and the corresponding carrier signals for the two frequency modulation signals are... or At least one frequency-modulated signal and at least one corresponding carrier signal are applied to at least one pair of stimulating electrodes, such that the electric fields generated by the frequency-modulated signal and the corresponding carrier signal are superimposed in the target region to generate a difference frequency signal. The difference frequency signal This is the targeted stimulation signal, also known as the first electrical signal. Preferably, two frequency-modulated signals with a 180° phase difference and two corresponding carrier signals (also with a 180° phase difference) are simultaneously applied to the four electrodes, thereby creating differential signals between the two frequency-modulated signals and between the two carrier signals, and causing the four signals to superimpose in the target region to generate a difference frequency signal. The method of applying electrical stimulation using two sets of difference frequency signals can avoid the formation of a DC component in the target area, thereby avoiding the problem of electrical neutrality caused by DC bias.

[0043] Specifically, the conversion module also includes a digital-to-analog converter unit 310 and a frequency modulation circuit 320. The digital-to-analog converter unit 310 is used to convert the data acquisition matrix after row and column address transformation into a digital-to-analog signal to obtain the first electrical signal. The structure of the frequency modulation circuit 320 is as follows: Figure 8 As shown, it includes: a carrier generation unit 321 for generating a carrier at a specified frequency, such as a carrier of 20~200kHz; a signal modulation unit 322 for loading a first electrical signal into the carrier signal; and a frequency modulation signal amplifier 323 for amplifying the frequency modulation signal, with an amplification factor of [missing value]. ,in, This represents the normalized relative amplitude coefficient in the m-th row and n-th column, ranging from 0 to 1. The smaller the value, the smaller the carrier component is relative to the frequency modulation component; The larger the value, the larger the carrier component is relative to the frequency modulation component; and the carrier amplifier 324 is used to amplify the carrier signal to maintain consistency with the carrier component in the amplified frequency modulation signal, and its amplification factor is [missing value]. Optionally, both the FM signal amplifier 323 and the carrier amplifier 324 are gain-adjustable amplifiers.

[0044] In one embodiment, the processor 340 in the conversion module 300 is further configured to: in response to the presence of multiple sets of electrodes corresponding to the target region, divide the preset duration of action into multiple equal parts, and use each set of electrodes as conducting electrodes in each equal part of time to stimulate the target region in a time-division manner.

[0045] In one embodiment, the presence of multiple sets of electrodes corresponding to the target region means that multiple electrodes can act on the target region, and the multiple sets of electrodes may include a common electrode, for example, attached. Figure 5 In , , , All four electrodes can act on the same target area, and the resulting multiple sets of electrodes can include: and , and , and , and , and as well as and A separate, newly added embodiment will be described.

[0046] In one embodiment, the processor 340 in the conversion module 300 is further configured to: before applying each frequency modulation signal and its corresponding carrier signal to the corresponding electrode to form a conducting electrode, assign an amplification factor A to each group of electrodes according to the required stimulation intensity, i.e., the amplification factor of the frequency modulation signal amplifier 323 or the carrier amplifier 324; and adjust the normalized relative amplitude coefficient in each group of frequency modulation signals. This is to adjust the relative magnitudes of the carrier component and the frequency modulation component in each group of frequency modulation signals; wherein, the final amplification factor of each group of frequency modulation signals (carrier signal and corresponding frequency modulation signal) is respectively... and .

[0047] In one embodiment, the processor 340 in the conversion module 300 is further configured to: uniformly or partially adjust the amplification factor A and the normalized relative amplitude factor of the corresponding electrode. .

[0048] In one embodiment, such as Figure 1 As shown, the implantable visual nerve brain-computer interface system of the present invention consists of two parts: a signal acquisition subsystem and an electrical stimulation subsystem. The two subsystems are connected wirelessly, requiring corresponding power supply modules 700 and 800 for each. Each power supply module consists of a wireless power transmitter, a wireless power receiver, and a power management unit. The power management unit can be a function program preset in the first processor 600 or the second processor 340.

[0049] The implantable visual nerve brain-computer interface system of the present invention has the following characteristics:

[0050] 1. The curved electrode is attached to the dura mater in the cerebral cortex to ensure that the electrode can make full contact with the cerebral cortex and effectively reduce contact resistance;

[0051] 2. The electrodes are attached to the outside of the dura mater, and the stimulation precision can be controlled within the millimeter level through spatiotemporal interference stimulation.

[0052] 3. A 32*32=1024 electrode array was used to record the electroencephalogram (EEG) signals of the visual cortex. This 32*32=1024 electrode array stimulated the visual cortex. The signal recorded by each electrode was then address-transformed to stimulate the visual cortex of the brain.

[0053] 4. High-frequency current (20kHz) can penetrate the dura mater and superficial tissues, and converge and overlap in deep brain regions;

[0054] 5. By employing the time-interference stimulation method, the position of the low-frequency signal formed by the time interference can be adjusted by regulating the normalized relative amplitude coefficient;

[0055] 6. Employ time-division multiplexing to perform intermittent EEG signal recording and intermittent deep brain stimulation, reducing the number of wires between electrodes and the processor;

[0056] 7. A multiplexer integrated circuit is set on the first electrode matrix to record 961 differential analog signals from 1024 electrode sites in a time-division manner, or 1024 analog signals recorded relative to a common reference electrode, and transmit these analog signals to the processor circuit located outside the skull through a few wires, thereby reducing system complexity.

[0057] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. The embodiment numbers disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0058] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. An implantable visual nerve brain-computer interface system, characterized in that, include: A first electrode matrix is ​​arranged in a first region to form a first spatial layout, and is used to collect a first electrical signal at a corresponding position of a preset sampling area in the first region. The second electrode matrix is ​​arranged in the second region to form a second spatial layout, and is used to receive the modulation signal of the first electrical signal; The conversion module is used to map the row and column positions between the electrodes in the first electrode matrix and the electrodes in the second electrode matrix according to the spatial layout rules of the electrode matrix, and to modulate the first electrical signal so that the modulated signal of the first electrical signal is applied to the second region or the corresponding position below it via the second electrode matrix.

2. The implantable visual nerve brain-computer interface system according to claim 1, characterized in that, The preset sampling area is located within the first area or at a preset position below it.

3. The implantable visual nerve brain-computer interface system according to claim 1, characterized in that, It also includes a signal processing module, which comprises: A multi-channel switching integrated circuit is used to scan the first electrode matrix at a preset scanning frequency, and in each scanning cycle, to acquire the first electrical signal on the first electrode matrix through a time-division multiplexing method via a bus, and to record the row and column numbers of the acquisition electrodes. A pre-amplification unit is used to pre-amplify the acquired first electrical signal; and The analog-to-digital conversion unit is used to perform analog-to-digital conversion on the first electrical signal after the prevention of large-scale transmission to generate a data acquisition matrix corresponding to several electrodes.

4. The implantable visual nerve brain-computer interface system according to claim 3, characterized in that, It also includes a data communication module, which comprises: A data transmission unit, which is connected to the signal processing module bus, is used to convert the data acquisition matrix into serial data for transmission. A data receiving unit, which is communicatively connected to the data sending unit and bus-connected to the conversion module, is used to receive the serial data, restore it to the data acquisition matrix, and forward it to the conversion module.

5. The implantable visual nerve brain-computer interface system according to claim 3, characterized in that, The conversion module further includes a processor, the processor being used for: The first spatial layout is partitioned to obtain multiple first sub-space layout partitions; The second spatial layout is partitioned to obtain multiple second sub-space layout partitions; Calculate the similarity between the first subspace layout partition and the second subspace layout partition; A mapping table is formed by mapping the row and column numbers of the electrodes in the first subspace layout partition with the electrodes in the second subspace layout partition, where the similarity is greater than the preset similarity threshold. The data acquisition matrix is ​​transformed in terms of row and column addresses according to the mapping relationship lookup table.

6. The implantable visual nerve brain-computer interface system according to claim 5, characterized in that, The conversion module further includes a digital-to-analog conversion unit, which is used for: The data acquisition matrix after row and column address transformation is converted from digital to analog to obtain the first electrical signal, and the first electrical signal is used as the target stimulation signal.

7. The implantable visual nerve brain-computer interface system according to claim 6, characterized in that, The conversion module further includes a signal modulation unit, which is used for: The targeted stimulation signal is modulated to generate two frequency-modulated signals whose frequency is proportional to the signal amplitude and whose phase difference is 180°. At least one of the frequency-modulated signals and the corresponding carrier signals are respectively applied to at least two stimulation electrodes in the second electrode matrix, so that the frequency-modulated signals and the corresponding carrier signals are superimposed in the target region to generate a difference frequency signal.

8. The implantable visual nerve brain-computer interface system according to claim 7, characterized in that, The processor in the conversion module is also used for: In response to the presence of multiple sets of electrodes in the target area, the preset duration of action is divided into multiple equal parts, and at least one set of electrodes serves as the conducting electrode in each equal part of the time to stimulate the target area in a time-division manner.

9. The implantable visual nerve brain-computer interface system according to claim 8, characterized in that, The processor in the conversion module is also used for: Before applying at least one frequency modulation signal and the corresponding carrier signal to the corresponding electrode to form a conducting electrode, an amplification factor A is assigned to each group of electrodes according to the required stimulation intensity. Adjust the normalized relative amplitude coefficient in each group of FM signals (0 < < 1) To adjust the relative magnitudes of the carrier component and the frequency modulation component in each group of frequency modulation signals; In each group of FM signals, the amplification factors of the carrier signal and the FM signal are respectively... and .

10. The implantable visual nerve brain-computer interface system according to claim 9, characterized in that, The processor in the conversion module is also used for: Adjust the amplification factor A and normalized relative amplitude factor of the corresponding electrodes uniformly or locally. .

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