Modular Structure of a Fully Implantable Brain-Computer Interface System

Abstract

The present invention provides a modular structure of a fully implantable brain-computer interface system, including a power supply module, an acquisition and stimulation module, and a connection module. Among them, the power supply module is used to supply power to the devices and circuit systems within the entire brain-computer interface system; the acquisition and stimulation module is used to implement at least one of the functions of recording neural signals and stimulating nerve cells; the connection module is used to connect the power supply module and the acquisition and stimulation module. The modular structure of the present invention enables the brain-computer interface system to have the advantages of being fully implantable, percutaneous wireless power supply, multi-brain region stimulation and recording, electromagnetic compatibility, more than ten thousand channels, long battery life, scalability, etc., and can realize the long-term stable and effective service of the fully implantable brain-computer interface system in the cerebral cortex and nervous system.

Description

Technical Field

[0001] The present invention relates to the cross - technical field of electronics and biomedical engineering. Specifically, it relates to a modular structure of a fully implantable brain - machine interface system. Background Art

[0002] Implantable bioelectronics is an emerging field, which plays an important role in improving treatment effects, reducing healthcare costs, and improving quality of life, and has attracted wide attention in modern society. Considering factors such as the in - vivo temperature and humidity environment, the human immune system, as well as the system lifespan, system safety, medical monitoring limitations, and life portability after implantation, the encapsulation of implantable devices, especially fully implantable systems, plays a crucial role.

[0003] In the aspect of implantable brain - machine interface systems, the parameter indicators affecting their performance mainly include the following aspects: the number of channels of brain - machine interface devices, portability, electromagnetic compatibility, long - term stability, and functional diversification.

[0004] In terms of the number of channels of brain - machine interface devices, a higher number of channels means more neuron information and can analyze the brain mechanism more precisely. In 2017, Jun et al. published a paper titled "Fully integrated silicon probes for high - density recording of neural activity" in the international famous journal Nature, proposing a brain - machine interface device that can achieve 960 channels. In 2021, Wang et al. from Shanghai Jiao Tong University published a paper titled "Dense Packed Drivable Optrode Array for Precise Optical Stimulation and Neural Recording in Multiple - Brain Regions", achieving a 1024 - channel brain - machine interface device. In addition, in 2021, the silicon - based high - density CMOS neural probe developed by the European Microelectronics Center achieved a high - spatial - density coverage of 5120 recording channels. However, due to its high power consumption and large data volume, it can only be powered and data - transmitted in a wired manner. The 5120 - channel CMOS neural probe developed by this institution is the highest - implant - flux brain - machine interface device for in - vivo applications at the present stage. Although the goal of having tens of thousands of channels has become a widespread international pursuit, due to limitations in multiple scientific and technological fields such as the processing technology of brain - machine interface devices and signal - processing technology, a fully implantable brain - machine interface system with tens of thousands of channels has not been achieved yet.

[0005] In terms of portability, with the development of brain-computer interface technology and the improvement of people's living standards, the previous wired brain-computer interface system has brought great restrictions on the activities of patients. Therefore, the wireless brain-computer interface system has become the key development direction in the field of brain-computer interface. At present, there are two main reasons for limiting the development of wireless brain-computer interface systems: 1. System endurance; 2. System volume. For fully implanted brain-computer interface systems, batteries are required for power supply. However, the introduction of batteries will cause strong electromagnetic artifacts in the brain-computer interface system, which will not be able to achieve multi-directional and multi-parameter nuclear magnetic imaging for patients, and will greatly reduce the basic understanding of the patient's condition. In order to ensure long-term battery life, brain-computer interface systems often require larger capacity batteries. In addition, the integration of temperature and humidity sensors, signal processing chips, multi-functional brain-computer interface devices, and the increase in electrode channels and numbers will increase the volume of the entire system, which will violate the original intention of fully implanted brain-computer interfaces. In order to realize the implantable wireless system structure, Blackrock has realized a commercial wireless 96-channel electrophysiological acquisition module. Although this system structure realizes wireless functions, it still has two major disadvantages: 1. The number of channels is small and it is difficult to expand; 2. The use of a detachable semi-implantation method increases the risk of infection due to interface exposure.

[0006] In terms of electromagnetic compatibility, the research on electromagnetic compatibility solutions for brain-computer interfaces started late and developed slowly. At present, the focus is only on the material optimization of the electrode points on the surface of brain-computer interface devices, and non-magnetic materials such as carbon are mostly used to avoid electromagnetic artifacts and other problems during electromagnetic compatibility. As for the application of fully implantable systems, due to various restrictions in the fields of electronics, mechanics, biology, etc., there are currently no reports on the proposal or development of electromagnetically compatible brain-computer interface systems worldwide. Therefore, achieving electromagnetic compatibility of brain-computer interface systems will greatly accelerate the research process of brain diseases and brain science.

[0007] In terms of long-term stability, there are two main factors that determine the long-term stability of the fully implantable system: 1. The biocompatibility of the packaging shell; 2. The erosion of biological tissue fluid. Existing shells mostly use biocompatible titanium as a packaging material to reduce inflammatory responses. The paper "An Integrated Brain-Machine Interface Platform With Thousands of Channels" published in 2019 uses titanium as the shell material of the system. After the system is implanted in the body, biological tissue fluid will corrode the surface and interior of the system in the form of liquid, steam, etc. The research institution adopts a packaging method in which the electrode and the chip are directly connected, and the direct connection part is not protected by a sealed shell. For example, the two versions of the neural pixel probe developed by Neuropixels are easily affected by brain tissue fluid under this connection method, causing the chip to fail, and is only suitable for short-term in vivo applications.

[0008] In terms of functional diversification, the multifunctionality of the brain-computer interface system mainly includes two points here: 1. The multifunctionality of brain-computer interface devices; 2. Multiple brain regions in the brain. In terms of device multifunctionality, functions such as electricity, light, and drugs all have an irreplaceable position in brain science and medical research. Integrating more functions means a larger volume and higher power consumption, which makes it difficult to find a balanced middle point for a fully implanted brain-computer interface system. Currently, most fully implanted brain-computer interface systems use electrical stimulation and recording methods. For example, in 2016, Thomas et al. combined angiography-based coaxial catheter technology to implant a fully implanted Stentrode neural microelectrode through blood vessels for long-term signal acquisition. It has high biocompatibility, but this device cannot perform neuromodulation. Secondly, in terms of multiple brain regions in the brain, the field of brain circuit and multiple brain region collaborative research is an important part of humans' understanding of the working mechanism of the brain, which requires multi-brain region recording and stimulation. Currently, research on multiple brain regions mainly focuses on non-implantable wearable brain-computer interface systems. In implantable brain-computer interface systems, a representative one is the article titled "spelling interface using intracortical signals in a completely locked-in patient enabled via auditory neurofeedback training" published by German scientists Chaudhary et al. in the journal Nature Communication in 2022. This article implanted Utah electrodes into the supplementary motor area and primary motor area of the human brain to enable patients to spell words through auditory training. However, this system uses a semi-implanted method and does not have high channel count, electromagnetic compatibility, and portability.

[0009] In the research of existing fully implanted brain-computer interface systems, the most representative one is the fully implanted system proposed by Neuralink Corporation in the United States in 2021. This system adopts an architecture in which the brain-computer interface device and the power supply battery are placed together, and the battery, charging coil, signal acquisition chip, processing circuit, and brain electrodes are integrated in the same package and implanted into the pig brain. Combining the above aspects, this system has the following characteristics: 1. The number of channels reaches 1024 leads, which is one order of magnitude different from 10,240 leads (10,000 leads); 2. The wireless charging and fully implanted method make this system portable; 3. Due to the integrated structure of the battery and recording electrodes, this system does not have electromagnetic compatibility; 4. In terms of long-term stability, this system uses titanium as the shell and has a certain degree of biocompatibility; 5. In terms of functional diversification, this system can achieve two functions: electrical recording and electrical stimulation.

[0010] In summary, a fully implantable brain-computer interface system that is safe, reliable, and has medical and research value preferably has the following characteristics: 1. High channel count, breaking through the existing international channel bottleneck to achieve tens of thousands or even hundreds of thousands of channels; 2. Portability, enabling full implantation and effectively balancing the inhibitory relationship between multifunctionality and small size; 3. Electromagnetic compatibility, avoiding the influence of electromagnetic artifacts; 4. Long-term stability, achieving biocompatibility, reducing immune responses, and preventing erosion by biological tissue fluid; 5. Diverse functions, realizing functions other than electrical functions that have medical and research effects, such as light. Currently, except for the lack of realization of electromagnetic compatibility, certain achievements have been made unilaterally in other aspects, but they have not been combined. Therefore, there is an urgent need for a new system structure to solve the above problems, achieve organic unity, and promote the leapfrog progress of fully implantable brain-computer interface systems in the fields of life, entertainment, medicine, and scientific research. Summary of the Invention

[0011] Aiming at the defects in the prior art, the purpose of the present invention is to provide a modular structure of a fully implantable brain-computer interface system, which can enable the fully implantable brain-computer interface system to serve stably and effectively in the cerebral cortex and nervous system for a long time.

[0012] According to one aspect of the present invention, there is provided a modular structure of a fully implantable brain-computer interface system, the modular structure comprising:

[0013] A power supply module for supplying power to the devices and circuit systems within the entire brain-computer interface system;

[0014] An acquisition and stimulation module for realizing at least one of the functions of recording nerve signals and stimulating nerve cells;

[0015] A connection module for connecting the power supply module and the acquisition and stimulation module.

[0016] Furthermore, the power supply module includes a first housing unit and a power supply unit disposed within the first housing unit; the first housing unit includes a first housing for protecting the internal unit, a first expandable interface is provided on the first housing, and a first fixing hole for fixing the power supply module to the skull, the first expandable interface is used for connecting the acquisition and stimulation module and expanding the number of the power supply modules; the power supply mode of the power supply unit adopts at least one of an internal battery and a wireless power supply mode.

[0017] Further, a first data processing unit and a first sensor unit, both connected to the energy supply unit, are also provided inside the first housing unit; the first sensor unit is used to monitor the environmental state of the energy supply module, and the first sensor unit includes at least one of a temperature sensor, a humidity sensor, a gas sensor, a pressure sensor, an accelerometer, and a gyroscope; the first data processing unit is used to perform at least one of processing the recorded signals of the acquisition and stimulation module, controlling the stimulation instructions of the acquisition and stimulation module, processing the data collected by the first sensor unit, and processing the wireless energy supply data.

[0018] Further, the acquisition and stimulation module includes a second housing unit and a brain-computer interface device disposed inside the second housing unit; the second housing unit includes a second housing for protecting the internal unit, a second expandable interface is provided on the second housing, and a second fixing hole for fixing the acquisition and stimulation module to the skull, and the second expandable interface is used to connect the acquisition and stimulation module and expand the number of the energy supply modules; the brain-computer interface device has at least one of an acquisition function and a stimulation function, wherein the acquisition function includes acquiring electroencephalogram signals and intracerebral chemical signals, and the stimulation function includes at least one of light stimulation, electrical stimulation, drug stimulation, and acoustic stimulation.

[0019] Further, a second data processing unit and a second sensor unit are also provided inside the second housing unit; the second sensor unit includes at least one of a temperature sensor, a humidity sensor, a gas sensor, a pressure sensor, an accelerometer, and a gyroscope; the second data processing unit is used to perform at least one of processing the recorded signals of the acquisition and stimulation module, controlling the stimulation instructions of the acquisition and stimulation module, processing the data collected by the second sensor unit, and processing the wireless energy supply data.

[0020] Further, a connection method of three-dimensional through-hole substrate matching with feedthrough is adopted between the brain-computer interface device and the second data processing unit; the tail end of the brain-computer interface device is connected to the second data processing unit through a three-dimensional through-hole substrate and a feedthrough substrate in sequence.

[0021] Further, a biopassivation layer is provided on the surfaces of the first housing unit, the energy supply unit, the first data processing unit, the first sensor unit, the second housing unit, the brain-computer interface device, the second data processing unit, and the second sensor unit, and the biopassivation layer has corrosion resistance.

[0022] Furthermore, the housing materials of the first housing unit and the second housing unit are made of at least one of biocompatible metals, ceramics, and biocompatible polymers; the top covers of the first housing unit and the second housing unit are formed of ceramic materials, the bases of the first housing unit and the second housing unit are formed of biocompatible metals, and the top cover and the base are fixedly connected by means of ceramic metallization welding.

[0023] Furthermore, the connection module is used for power supply and signal connection between the power supply module and the acquisition and stimulation module, and the connection module is respectively connected to the power supply module and the acquisition and stimulation module in a pluggable manner; the connection module is formed of a biocompatible material, or the surface of the connection module has a biocompatible coating.

[0024] Furthermore, the acquisition and stimulation module, the power supply module, and the connection module are all implanted under the scalp, and the acquisition and stimulation module and the power supply module are fixed under the scalp by means of embedding in the skull or directly placing on the skull.

[0025] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0026] 1. Through the modular structure design of dividing the entire system package into an acquisition and stimulation module, a power supply module, and a connection module, the present invention can achieve breakthrough effects: ① Since the acquisition and stimulation electrodes are far from the battery, electromagnetic artifacts generated by the battery can be avoided, thereby achieving electromagnetic compatibility, such as being compatible with functional magnetic resonance imaging (fMRI), etc.; ② Realize multi-brain region acquisition and stimulation, which is beneficial to the research and treatment of multi-brain coordination and neural circuits.

[0027] 2. Through the expandable manner of each module, the present invention can achieve beneficial effects: ① Under the comprehensive bottleneck of the development technologies in the existing fields of electronics, machinery, biology, etc., find a reasonable breakthrough point, and through the expandable manner, achieve recording and stimulation of ten thousand leads or even tens of thousands of leads or higher density; ② The multi-module and expandable design can realize the multi-function of the brain-computer interface device in the fully implanted brain-computer interface system. The expandable module can effectively share the burdens of signals, power consumption, volume, etc. brought by multi-functions such as electricity, light, medicine, sound, and heat, and realize the multi-function of the fully implanted brain-computer interface system; ③ Long battery life. The expandability of the power supply module can flexibly solve the problem of high energy consumption brought by the multi-function and multi-channel of the fully implanted brain-computer interface system, and also greatly improve the living convenience of users.

[0028] 3. Through the method of bio-coating inside and outside the housing, the present invention uses the dual protection of the housing material and the bio-coating to improve the biocompatibility of the brain-computer interface system.

[0029] 4. The present invention combines in-situ three-dimensional through-hole substrate chip flow with feedthrough connection, greatly improving the airtightness of the brain-computer interface system and preventing biological tissue fluid from entering the system interior through liquid or vapor and causing erosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other features, objects, and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0031] Figure 1 Schematic diagram of the modular structure of a fully implantable brain-computer interface system according to an embodiment of the present invention;

[0032] Figure 2 Schematic diagram of the power supply module according to an embodiment of the present invention;

[0033] Figure 3 Schematic diagram of the acquisition and stimulation module according to an embodiment of the present invention.

[0034] In the figure: 1 is the power supply module, 11 is the first housing unit, 111 is the first expandable interface, 112 is the first fixing hole, 12 is the power supply unit, 13 is the first data processing unit, 2 is the acquisition and stimulation module, 21 is the second housing unit, 211 is the second expandable interface, 212 is the second fixing hole, 22 is the second sensor unit, 23 is the second data processing unit, 24 is the feedthrough substrate, 25 is the three-dimensional through-hole substrate, 26 is the brain-computer interface device, 261 is the tail end of the brain-computer interface device, 262 is the front end of the brain-computer interface device, and 3 is the connection module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those of ordinary skill in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention. In the description of the embodiments of the present invention, it should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the orientation and positional relationships indicated by terms such as "upper", "lower", etc. are based on the orientation and positional relationships shown in the drawings, and are only used to facilitate the description of the present invention and the embodiments, and do not indicate that the parts involved must have the specific orientation and positional combination, and thus cannot be understood as a limitation of the present invention.

[0036] Refer toFigure 1 , which is a schematic structural diagram of the modular structure of a fully implanted brain-computer interface system provided by an embodiment of the present invention. The modular structure includes: an energy supply module 1, an acquisition and stimulation module 2, and a connection module 3. Among them, the energy supply module 1 is used to supply energy to the devices and circuit systems within the entire brain-computer interface system; the acquisition and stimulation module 2 is used to implement at least one of the functions of recording neural signals and stimulating nerve cells; the connection module 3 is used to connect the energy supply module 1 and the acquisition and stimulation module 2. The energy supply module 1 and the acquisition and stimulation module 2 are respectively fixed to the skull, and the acquisition and stimulation module 2 is separated from the energy supply module 1. Since the acquisition and stimulation module 2 is far from the energy supply module 1, it can avoid the interference caused by the built-in battery and wireless functional unit to the acquisition and stimulation, as well as the problems of nuclear magnetic artifacts or electromagnetic artifacts, thereby achieving electromagnetic compatibility, such as being compatible with functional magnetic resonance imaging (fMRI), etc.; in addition, multi-brain region acquisition and stimulation can also be realized, which is beneficial to the research and treatment of multi-brain coordination and neural circuits. The modular structure of the fully implanted brain-computer interface system, by separating the two brain-computer interface modules of the energy supply module 1 and the acquisition and stimulation module 2, enables the brain-computer interface system to have the advantages of full implantation, percutaneous wireless power supply, multi-brain region stimulation and recording, electromagnetic compatibility, channel expandability, etc., providing a highly feasible solution for the long-term stability in vivo and implant portability of the brain-computer interface system.

[0037] To achieve the all-time power supply of the brain-computer interface system, referring to Figure 2 , in some specific embodiments, the energy supply module 1 includes a first housing unit 11 and an energy supply unit 12 provided in the first housing unit 11; the first housing unit 11 includes a first housing for protecting the internal unit, and a first expandable interface 111 and a first fixing hole 112 for fixing the energy supply module 1 to the skull are provided on the first housing. The first expandable interface 111 is used to connect the acquisition and stimulation module 2 and expand the number of the energy supply module 1 and the acquisition and stimulation module 2; the power supply method of the energy supply unit 12 adopts at least one of the built-in battery such as the built-in disposable battery and the wireless power supply method to achieve long-term in-vivo measurement. Specifically, the energy supply unit 12 includes a battery for energy storage and related circuits matched with the battery; when adopting wireless power supply, that is, the wireless charging method, it also includes related components for wireless power supply.

[0038] In some preferred embodiments, a first data processing unit 13 and a first sensor unit, which are respectively connected to the energy supply unit 12, are further provided inside the first housing unit 11. The energy supply unit 12 is used to supply power to the first data processing unit 13 and the first sensor unit. The first sensor unit is used to monitor the environmental state of the energy supply module 1, and the first sensor unit includes at least one of a temperature sensor, a humidity sensor, a gas sensor, a pressure sensor, an accelerometer, and a gyroscope. The first data processing unit 13 is used to implement at least one of processing the recorded signals of the acquisition and stimulation module 2, controlling the stimulation instructions of the acquisition and stimulation module 2, processing the data collected by the first sensor unit, and processing the wireless energy supply data.

[0039] In some specific embodiments, the acquisition and stimulation module 2 includes a second housing unit 21 and a brain-computer interface device 26 disposed inside the second housing unit 21. The second housing unit 21 includes a second housing for protecting the internal unit. A second expandable interface 211 and a second fixing hole 212 for fixing the acquisition and stimulation module 2 to the skull are provided on the second housing. The second expandable interface 211 is used to connect to the energy supply module 1 and expand the number of the energy supply module 1 and the acquisition and stimulation module 2. The connection module 3 is used for the power supply line of the energy supply module 1 to multiple acquisition and stimulation modules 2. The energy supply module 1 and the acquisition and stimulation module 2 are connected through the first expandable interface 111 and the second expandable interface 211, and are used for the energy supply module 1 to supply energy to multiple acquisition and stimulation modules 2. The brain-computer interface device 26 has at least one of an acquisition function and a stimulation function. Among them, the acquisition function includes acquiring electroencephalogram signals and intracerebral chemical signals, and the stimulation function includes at least one of optical stimulation, electrical stimulation, drug stimulation, and acoustic stimulation.

[0040] In some preferred embodiments, a second data processing unit 23 and a second sensor unit 22 are further provided inside the second housing unit 21. The second sensor unit 22 includes at least one of a temperature sensor, a humidity sensor, a gas sensor, a pressure sensor, an accelerometer, and a gyroscope. The second data processing unit 23 is used to implement at least one of processing the recorded signals of the acquisition and stimulation module 2, controlling the stimulation instructions of the acquisition and stimulation module 2, processing the data collected by the second sensor unit 22, and processing the wireless energy supply data. Compared with the first data processing unit 13, the second data processing unit 23 can further process the nerve signals recorded by the brain-computer interface device 26, and can receive the wireless control signals transmitted by the host computer outside the brain, and wirelessly transmit the nerve signals recorded by the brain-computer interface device 26 to the host computer outside the brain. Specifically, the second data processing unit 23 is used to perform processing such as filtering, amplifying, compressing, and transmitting the recorded nerve cell signals, controlling the stimulation mode of the brain-computer interface device, and recording, transmitting, and processing the test data of the second sensor unit 22.

[0041] In the embodiment of the present invention, the modular packaging method adopts an expandable interface. Expandable interfaces are provided on both the acquisition and stimulation module 2 and the power supply module 1 for expanding the number and functions of the modules. There is no limit to the number of the acquisition and stimulation module 2 and the power supply module 1 and they can be expanded, and there is no limit to the length of the connecting line. Through the expandable method of each module, the embodiment of the present invention finds a reasonable breakthrough point under the comprehensive bottleneck restricted by the existing technologies in the fields of electronics, machinery, biology, etc., and realizes recording and stimulation with ten thousand leads or even tens of thousands of leads or higher density through the expandable method. Secondly, the design of multiple modules and expandability can realize the multi-function of the brain-computer interface device in the fully implantable brain-computer interface system. The expandable module can effectively share the burdens of signals, power consumption, volume, etc. brought by multi-functions such as electricity, light, medicine, sound, and heat, and realize the multi-function of the fully implantable brain-computer interface system. In addition, for long-term battery life, the expandability of the power supply module 1 can flexibly solve the problem of high energy consumption brought by the multi-function and multi-channel of the fully implantable brain-computer interface system, and also greatly improve the life convenience of users.

[0042] The brain-computer interface device 26 includes a brain-computer interface device tail end 261 and a brain-computer interface device front end 262. The brain-computer interface device front end 262 is located outside the second housing unit 21 and is used to implant into the brain tissue to record nerve signals and stimulate nerve cells. Inside the second housing unit 21, from top to bottom, there are a second sensor unit 22, a second data processing unit 23, a feedthrough substrate 24, a three-dimensional through-hole substrate 25, and the brain-computer interface device tail end 261. In some specific embodiments, a connection method of three-dimensional through-hole substrate embedded feedthrough is adopted between the brain-computer interface device 26 and the second data processing unit 23; specifically, the tail end of the brain-computer interface device 26 is connected to the second data processing unit 23 through the three-dimensional through-hole substrate 25 and the feedthrough substrate 24 in sequence.

[0043] In some specific embodiments, the three-dimensional through-hole substrate 25 is fabricated by any one of through-silicon via (TSV) technology, through-glass via (TGV) technology, and through-ceramic via (TCV) technology. The material of the three-dimensional through-hole substrate 25 can be selected from any one of silicon, glass, and ceramic. The connections between the components of the feedthrough substrate 24, the three-dimensional through-hole substrate 25, and the second data processing unit 23 are made using any one of ball grid array (BGA) packaging technology, thin small outline package (TSOP) technology, and anisotropic conductive adhesive technology. Preferably, the brain-computer interface device 26 is connected to the second data processing unit 23 through the three-dimensional through-hole substrate 25 and the feedthrough substrate 24. The acquisition and stimulation electrodes in the acquisition and stimulation module 2 establish connections with the inside of the module through feedthrough technology, preventing the internal circuits, devices, etc. of the module from being eroded by the in-vivo environment for a long time, which is beneficial to improving long-term stability. Specifically, the three-dimensional through-hole substrate 25 and the brain-computer interface device 26 are simultaneously fabricated in-situ by micro-nano processing technology, and then the three-dimensional through-hole substrate 25 and the feedthrough substrate 24 are electrically connected using BGA ball soldering technology. By combining in-situ three-dimensional through-hole substrate chip flow and feedthrough connection, the airtightness of the brain-computer interface system is greatly improved in the embodiments of the present invention, preventing biological tissue fluid from entering the system internally in the form of liquid or vapor and causing erosion.

[0044] To improve the biocompatibility of the brain-computer interface system, in some specific embodiments, a biopassivation layer with corrosion resistance is provided on the surfaces of the first housing unit 11, the power supply unit 12, the first data processing unit 13, the first sensor unit, the second housing unit 21, the brain-computer interface device 26, the second data processing unit 23, and the second sensor unit 22. Preferably, at least one of polyimide, parylene, polymethyl methacrylate, polydimethylsiloxane, silicon dioxide, and silicon carbide is deposited on the outside of the housing unit, the surface of the sensor unit, the surface of the data processing unit, and the surface of the brain-computer interface device 26.

[0045] To further improve the biocompatibility of the brain-computer interface system, in some preferred embodiments, the housing materials of the first housing unit 11 and the second housing unit 21 are made of at least one of biocompatible metals, ceramics, and biocompatible polymers; for facilitating the penetration of wireless energy, the top covers of the first housing unit 11 and the second housing unit 21 are formed of ceramic materials, and the bases of the first housing unit 11 and the second housing unit 21 are formed of biocompatible metals such as titanium alloy, etc., which can ensure the strength of the power supply module 1 and the acquisition and stimulation module 2. The top cover and the base are fixedly connected by means of ceramic metallization welding. By using the ceramic metallization process and realizing the welding of ceramics and metals with lead-free solder, the reliability of the connection can be ensured. In the embodiments of the present invention, through the method of the biological coating inside and outside the housing, with the dual protection of the housing material and the biological coating, the biocompatibility of the brain-computer interface system can be effectively improved.

[0046] In some specific embodiments, the connection module 3 is used for power supply and signal connection between the power supply module 1 and the acquisition and stimulation module 2. For the convenience of the expandable functions of the power supply module 1 and the acquisition and stimulation module 2, preferably, the connection module 3 is connected to the power supply module 1 and the acquisition and stimulation module 2 respectively in a pluggable manner; the connection module 3 is formed of biocompatible materials, or the surface of the connection module 3 has a biocompatible coating.

[0047] In the embodiments of the present invention, the modular packaging method can achieve the maximum integration and is beneficial to the subcutaneous full implantation. In some specific embodiments, the acquisition and stimulation module 2, the power supply module 1, and the connection module 3 are all implanted under the scalp. The acquisition and stimulation module 2 and the power supply module 1 are fixed under the scalp by means of embedding in the skull or directly placing on the skull. Preferably, for increasing the portability and aesthetics, the method of embedding in the skull is used for implantation under the scalp.

[0048] In the embodiment of the present invention, the working principle of the energy supply module 1 is as follows: After receiving energy through wireless energy supply, the battery in the energy supply unit 12 is charged by the energy supply unit 12 containing an impedance matching circuit, an energy recovery circuit, and a post-stage circuit. Similarly, the first housing unit 11 of the entire energy supply module 1 is encapsulated with a packaging material having good heat dissipation performance, and is encapsulated by welding with "ceramic-metal" dissimilar materials. The top cover of the energy supply module 1 is made of ceramic material to facilitate the penetration of wireless energy. The base of the energy supply module 1 is made of biocompatible materials such as titanium alloy, and the strength of the energy supply module 1 is ensured to a certain extent. At the ceramic-metal connection, a ceramic metallization process is adopted, and lead-free solder is used to realize the welding of ceramic and metal. When selecting a rechargeable implantable battery, it is necessary to meet high safety and reliability, and at the same time, factors including energy density, power density, self-discharge, discharge curve, charge and discharge capacitance, etc. should be considered to achieve the best balance in terms of battery size and system power supply time / charging time requirements. At least one of polyimide, parylene, polymethyl methacrylate, polydimethylsiloxane, silicon dioxide, and silicon carbide is deposited on the outside of the first housing unit 11, the surface of the energy supply unit 12, and the surface of the first data processing unit 13 to improve the biocompatibility of the brain-computer interface system.

[0049] In the embodiment of the present invention, the working principle of the acquisition and stimulation module 2 is as follows: The second housing unit 21 adopts the same design scheme as the first housing unit 11. After drilling a hole in the skull and removing the meninges, the front end 262 of the brain-computer interface device is implanted into the brain tissue to record nerve signals and stimulate nerve cells; the tail end 261 of the brain-computer interface device is sequentially connected to the three-dimensional through-hole substrate 25 and the feedthrough substrate 24; the recorded nerve signals are transmitted to the second data processing unit 23 for signal processing. After processing such as low-noise signal amplification, high-precision low-power analog-to-digital conversion, and high-efficiency lossless data compression, they are transmitted to the host computer through wireless transmission; the implantable wireless data transmission methods that can be used include any one of Bluetooth, WiFi, infrared wireless, and low-power wireless transmission (such as ISM band Zigbee, Medical Body Area Network), etc. Similarly, the stimulation control and recording process for nerve cells is exactly the opposite. The stimulation command is transmitted to the second data processing unit 23 through wireless transmission, and stimulation is performed by a programmable multi-mode high-precision electrical stimulator with charge balance in the second data processing unit 23; the stimulation current control in the electrical stimulator can adopt high-precision bipolar analog-to-digital conversion technology to ensure that the net charge passing through the electrode is zero and avoid damage caused by charge accumulation. The second sensor unit 22 includes a temperature sensor and a humidity sensor to monitor the states of the energy supply module 1 and the acquisition and stimulation module 2.

[0050] Limited by the current MEMS process processing accuracy level, the effective acquisition size of neurons, the impedance requirements of the brain-computer interface interface, and the material substrate, etc., the number of channels of the current brain-computer interface cannot reach ten thousand leads. Through modular design, the embodiments of the present invention can greatly reduce the technical difficulty required for a single brain-computer interface device in terms of a high number of channels, and achieve a total number of channels reaching ten thousand leads or even tens of thousands of leads.

[0051] In addition, a higher number of channels leads to higher power consumption. To ensure battery life, it is necessary to increase the volume of the brain-computer interface system. Therefore, a high number of channels and portability have a mutually inhibitory effect in combination. In the embodiments of the present invention, the modular structure can separate the power supply from the acquisition channels, reduce the volume of the integrated single-module system to achieve portability. In addition, the modular structure can modularize the power supply, and the introduction of multiple batteries can greatly improve the battery life of the system and solve the problem of the system's battery life.

[0052] In terms of electromagnetic compatibility, most metals will bring the problem of electromagnetic artifacts. In a fully implantable brain-computer interface system, the most restrictive problem brought by the battery is electromagnetic artifacts. However, to achieve full implantation, it is necessary to introduce a battery for power supply. Based on the existing brain-computer interface technology, there are many studies on integrated brain-computer interface systems, aiming to integrate the brain-computer interface and the battery into the same package housing. The advantage of this is that the surgery is more convenient and only one position needs to be implanted. However, the highest number of channels that can be achieved by this structure is one thousand channels. To achieve full implantation, some device functions and system performance must be sacrificed within a limited volume; moreover, this integrated structure directly places the battery above the device, maximizing the influence of the battery and unable to achieve electromagnetic compatibility. The embodiments of the present invention provide a modular structure that can separate the device from the battery, move the battery away from the lesion or the research point, minimize the influence of electromagnetic artifacts on the brain-computer interface device, and achieve electromagnetic compatibility.

[0053] In terms of biocompatibility, the embodiments of the present invention provide a solution of three-dimensional through-hole substrate chip flow and feedthrough connection, which can effectively block the erosion of biological tissue fluid on the inside of the system and improve the long-term stability of the system. The embodiments of the present invention provide a method of depositing a biological passivation layer on the outer surface of the housing and the internal circuit, which can secondarily protect the internal circuit and reduce the immune response of the brain tissue to the system.

[0054] In terms of the combination of diverse functions, high channel count, long battery life, and fully implantable portability, the multifunctionality of brain-computer interface devices also leads to an increase in system volume occupancy and power consumption. The integrated structure cannot provide sufficient space for stimulation methods such as drugs, sound, and light, as well as the introduced multi-processing chips. Moreover, the high energy consumption introduced by this method will significantly reduce the battery life of the system. The reduction in battery life not only decreases the actual application ability of the system but also leads to an inability to collect sufficient data volume, affecting clinical diagnosis and scientific research. The embodiments of the present invention provide a modular structure that can effectively share the pressure brought by the multifunctionality of the device to the system by expanding the acquisition and stimulation module and the power supply module, decomposing the difficulty of combining diverse functions, high channel count, long battery life, and portability into the difficulty of single functions and low channels. Additionally, the modular structure can also cover the required brain regions with brain-computer interface devices through the connection module, meeting the research requirements of neural circuits and multi-brain region coordination, which is also impossible for the integrated structure to achieve.

[0055] Those skilled in the art can understand that the modular structure of the fully implantable brain-computer interface system in the embodiments of the present invention may include other circuit units according to actual situations in addition to the above-mentioned housing unit, data processing unit, connection unit between the data processing unit and the brain-computer interface device, brain-computer interface device, sensor unit, and power supply unit. It should be noted that any design concept that separates the acquisition and stimulation functions from the power supply function falls within the protection scope of the present invention.

[0056] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various deformations or modifications within the scope of the claims, which do not affect the essence of the present invention. The above preferred features can be combined arbitrarily without conflict.

Claims

1. A modular structure of a fully implanted brain-computer interface system, characterized in that, Including: A power supply module for supplying power to devices and circuit systems within the entire brain-computer interface system; An acquisition and stimulation module for implementing at least one of the functions of recording neural signals and stimulating nerve cells; A connection module for connecting the power supply module and the acquisition and stimulation module; The power supply module includes a first housing unit and a power supply unit disposed within the first housing unit; The first housing unit includes a first housing for protecting internal units. A first expandable interface and a first fixing hole for fixing the power supply module to the skull are provided on the first housing. The first expandable interface is used for connecting the acquisition and stimulation module and expanding the number of the power supply modules; The acquisition and stimulation module includes a second housing unit and brain-computer interface devices disposed within the second housing unit; The second housing unit includes a second housing for protecting internal units. A second expandable interface and a second fixing hole for fixing the acquisition and stimulation module to the skull are provided on the second housing. The second expandable interface is used for connecting the acquisition and stimulation module and expanding the number of the power supply modules; The housing materials of the first housing unit and the second housing unit are made of biocompatible metal or biocompatible polymer; the bases of the first housing unit and the second housing unit are formed of biocompatible metal; A first sensor unit connected to the power supply unit is further disposed inside the first housing unit, and a second data processing unit and a second sensor unit are further disposed inside the second housing unit; A connection method of three-dimensional via substrate matching feedthrough is adopted between the brain-computer interface device and the second data processing unit; The power supply method of the power supply unit adopts a wireless power supply method; The connection module is used for power supply and signal connection between the power supply module and the acquisition and stimulation module, and the connection module is respectively connected to the power supply module and the acquisition and stimulation module in a pluggable manner.

2. The modular structure of the fully implanted brain-computer interface system according to claim 1, characterized in that, A first data processing unit connected to the power supply unit is further disposed inside the first housing unit; The first sensor unit is used for monitoring the environmental state of the power supply module, and the first sensor unit includes at least one of a temperature sensor, a humidity sensor, a gas sensor, a pressure sensor, an accelerometer and a gyroscope; The first data processing unit is used for implementing at least one of processing the recording signals of the acquisition and stimulation module, controlling the stimulation instructions of the acquisition and stimulation module, processing the data collected by the first sensor unit and processing the wireless power supply data.

3. The modular structure of the fully implanted brain-computer interface system according to claim 2, characterized in that, The brain-computer interface device has at least one of an acquisition function and a stimulation function. Among them, the acquisition function includes acquiring electroencephalogram signals and intracranial chemical signals, and the stimulation function includes at least one of optical stimulation, electrical stimulation, drug stimulation and acoustic stimulation.

4. The modular structure of the fully implanted brain-computer interface system according to claim 3, characterized in that, The second sensor unit includes at least one of a temperature sensor, a humidity sensor, a gas sensor, a pressure sensor, an accelerometer and a gyroscope; The second data processing unit is configured to implement at least one of processing the recording signals of the acquisition and stimulation module, controlling the stimulation instructions of the acquisition and stimulation module, processing the data acquired by the second sensor unit, and processing the wireless power supply data.

5. The modular structure of the fully implanted brain-computer interface system according to claim 4, characterized in that, The tail end of the brain-computer interface device is sequentially connected to the second data processing unit through a three-dimensional through-hole substrate and a feedthrough substrate.

6. The modular structure of the fully implanted brain-computer interface system according to claim 4, characterized in that, Bio-passivation layers are provided on the surfaces of the first housing unit, the power supply unit, the first data processing unit, the first sensor unit, the second housing unit, the brain-computer interface device, the second data processing unit, and the second sensor unit, and the bio-passivation layers have corrosion resistance.

7. The modular structure of the fully implanted brain-computer interface system according to claim 3, characterized in that, The top covers of the first housing unit and the second housing unit are formed of ceramic materials, and the top covers and the bases are fixedly connected by ceramic metallization welding.

8. The modular structure of the fully implanted brain-computer interface system according to any one of claims 1-7, characterized in that, The connection module is formed of a biocompatible material, or the surface of the connection module has a biocompatible coating.

9. The modular structure of the fully implanted brain-computer interface system according to any one of claims 1-7, characterized in that, The acquisition and stimulation module, the power supply module, and the connection module are all implanted under the scalp, and the acquisition and stimulation module and the power supply module are fixed under the scalp by embedding the skull or directly placing it on the skull.

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