Frontal pocket flexible lead assembly and method based on brain-machine neural interface

Abstract

This invention discloses a front-end pouch-type flexible implantable electrode assembly and method based on a brain-computer interface, relating to the fields of brain-computer interface and neural electrode technology. It includes: a flexible electrode structure; a short sheath guide structure disposed within the flexible electrode structure, forming a local cavity for accommodating and limiting a top-mounted tungsten needle structure for guided propulsion; and a reinforcing pouch structure disposed within the flexible electrode structure, with the reinforcing pouch structure corresponding to one end of the short sheath guide structure. The reinforcing pouch structure has a pouch cavity further accommodating the top-mounted tungsten needle structure, thereby using its own pouch-like limiting performance to withstand the propulsion force of the tungsten needle. This invention solves the technical problems of insufficient stiffness and accuracy during the flexible electrode implantation stage in existing technologies, as well as the tendency to puncture the electrode tip with the aid of a hard needle, resulting in poor overall electrode implantation performance.

Description

Technical Field

[0001] This invention relates to the field of brain-computer interface and neural electrode technology, and more specifically, to a front-end pouch-type flexible implantable electrode assembly and method based on a brain-computer neural interface. Background Technology

[0002] Currently, fields such as brain-computer interfaces, neuromodulation, and sensory reconstruction require the placement of electrodes into or close to target neural tissue to achieve neural signal recording, neural electrical stimulation, or bidirectional interaction. Although traditional rigid electrodes have good insertion capabilities, their mechanical modulus is usually significantly higher than that of brain tissue. After long-term placement, signal quality is prone to decline due to brain tissue micromovement, inflammatory response, glial scarring, or mechanical mismatch.

[0003] To improve interaction stability, traditional rigid electrodes are designed as flexible neural electrodes. These typically use flexible materials such as polyimide, parylene, liquid crystal polymers, thermoplastic polyurethane, and silicone rubber as the base or encapsulation layer, giving them better tissue compliance during long-term placement. However, flexible materials have low axial stiffness, making them prone to bending, folding, or shifting when inserted into brain tissue, resulting in unstable insertion.

[0004] To address the issue of insufficient stiffness during the insertion of flexible electrodes, existing technologies have proposed several temporary stiffness-providing solutions, as follows: One is the front-end perforated ring traction flexible electrode, which has a perforated ring or traction hole at the front end of the electrode. The flexible electrode is pulled into the brain tissue after the implantation needle passes through or hooks the ring. This method requires high alignment accuracy between the implantation needle and the ring, and the force is concentrated at the edge of the ring. During the traction process, it is easy to tear, dislodge or deviate, which is not conducive to the placement assisted by ordinary stereotactic systems. The second type is the long sheath cavity core-assisted flexible deep electrode, which forms a long sheath cavity or core channel inside the flexible electrode. Before insertion, a metal core is inserted into the sheath cavity to provide overall rigidity. This scheme provides more continuous mechanical support and is suitable for insertion along a longer path. However, the fabrication process is complex. It requires the formation of a continuous sheath cavity over a long range of the flexible electrode and has high requirements for multilayer thin film processing, sacrificial layer release, and long-distance cavity integrity.

[0005] Thirdly, the hard needle body directly assists in the insertion. It assists the insertion of the flexible electrode by using an external hard needle, injection needle or guide cannula. If the hard needle directly pushes the front end of the flexible electrode, the local stress at the tip of the tungsten needle is too large, which can easily puncture the thin film at the front end of the electrode, causing front end rupture, interlayer separation, damage to metal traces or electrode insertion failure. Therefore, it is clear that the common contradiction among the existing solutions lies in: The flexible electrode needs to "harden" during the insertion phase, but must "soften" during the long-term retention phase; at the same time, a precise, reliable, and low-damage force transmission interface is required between the temporary rigid tool and the flexible electrode. Summary of the Invention

[0006] To address these issues, the present invention provides a front-end pouch-type flexible implantable electrode assembly and method based on a brain-computer interface, in order to solve the technical problems of insufficient rigidity and accuracy during the implantation stage of the flexible electrode in the prior art, as well as the tendency to puncture the electrode tip with the aid of a hard needle, resulting in poor overall electrode implantation effect.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface includes: Flexible electrode structure; A short sheath cavity guiding structure is disposed inside the flexible electrode structure to form a local cavity for accommodating and limiting the top tungsten needle structure to achieve guided propulsion. An enhanced pouch structure is disposed inside the flexible electrode structure, and the enhanced pouch structure is located at one end of the short sheath cavity guide structure. The enhanced pouch structure has a pouch cavity that further accommodates the top tungsten needle structure, so as to withstand the tungsten needle propulsion force by means of its own pouch limiting performance.

[0008] Based on the above technical solution, the present invention is further described as follows: As a further aspect of the present invention, it also includes: The top-mounted tungsten needle structure is based on the flexible electrode structure, into which the short sheath cavity guide structure and the reinforcing sac structure are sequentially inserted. The top-mounted tungsten needle structure provides axial stiffness to the flexible electrode structure and forms an auxiliary thrust to push the flexible electrode structure into the target tissue.

[0009] As a further aspect of the present invention, The top-mounted tungsten needle structure is designed to be removable based on the flexible electrode structure; Furthermore, the top-mounted tungsten needle structure provides temporary axial stiffness for the flexible electrode structure.

[0010] As a further aspect of the present invention The end of the enhanced pouch structure away from the short sheath cavity guide structure is also provided with an enhanced stop area, which further expands the force-bearing area to disperse the auxiliary thrust.

[0011] As a further aspect of the present invention, The flexible electrode structure includes a metal wiring layer; The metal wiring layer is arranged in the non-load-bearing area of ​​the reinforced pouch structure, and the metal wiring layer is far away from the thrust area formed by the pressure of the top tungsten needle structure.

[0012] As a further aspect of the present invention, The enhanced pocket structure is configured as a locally enhanced pocket and / or a soft-hard gradient enhanced pocket.

[0013] As a further aspect of the present invention, The front end stiffness of the enhanced pouch structure is higher than its rear end stiffness.

[0014] A method for flexibly retaining a front-end pouch-type flexible implantable electrode assembly using a blunt tungsten needle for assisted insertion and needle withdrawal includes the following steps: A tungsten needle with a blunt tip is inserted into the short sheath cavity guide structure of the flexible electrode and the tip of the tungsten needle enters the reinforcing bag structure to form a temporary composite structure. The temporary composite structure is placed into the target tissue along a predetermined path; Upon reaching the target tissue location, maintain the flexible electrode and withdraw the tungsten needle in the opposite direction along the short sheath guide structure; The flexible electrode body is left inside the target tissue and returns to its flexible state.

[0015] As a further aspect of the present invention, The method of inserting a blunt-tipped tungsten needle into the short sheath cavity guide structure of the flexible electrode and allowing the tip of the tungsten needle to enter the reinforcing pocket structure to form a temporary composite structure specifically includes: The blunt end of the top tungsten needle structure is advanced from the rear end of the flexible electrode structure along a preset path to the short sheath cavity guide structure. Through the constraint and guidance of the short sheath cavity guide structure, the end of the top tungsten needle structure enters the reinforcing bag structure and abuts against the reinforcing stop area. The insertion direction of the top-mounted tungsten needle structure is consistent with the axial direction of the flexible electrode structure; The step of placing the temporary composite structure into the target tissue along a predetermined path specifically includes: With the assistance of a stereotactic system, a microsurgical operating system, or a neurosurgical auxiliary positioning device, a temporary composite structure formed by combining a tungsten needle structure with a flexible electrode structure is placed into the target tissue. The process of maintaining the flexible electrode and withdrawing the tungsten needle in the reverse direction along the short sheath guide structure after reaching the target tissue location specifically includes: When the temporary composite formed by the top tungsten needle structure and the flexible electrode structure reaches the target tissue position, the flexible electrode structure is kept in position and the top tungsten needle structure is withdrawn in the opposite direction along the short sheath cavity guide structure, so that the top tungsten needle structure is detached from the reinforcing bag structure and the short sheath cavity guide structure. During needle removal, the flexible electrode structure is held in place by clamps or connecting ends to prevent it from being pulled out of the target tissue. The flexible electrode structure is left within the target tissue and restores its flexible state, specifically including: The flexible electrode structure is placed in the target tissue and restored to its flexible state. The flexible electrode structure is connected to the control device to stably realize long-term neural signal acquisition, electrical stimulation or bidirectional neural interface functions.

[0016] A neural electrode implantation system according to the aforementioned front-end pouch-type flexible implantable electrode assembly includes: The tungsten needle insertion module is used to insert a blunt-tipped tungsten needle into the short sheath cavity guide structure of the flexible electrode and allow the tip of the tungsten needle to enter the reinforcing bag structure to form a temporary composite structure. The tissue puncture module is used to insert a temporary composite structure into the target tissue along a predetermined path; The electrode positioning and needle withdrawal module is used to hold the flexible electrode after reaching the target tissue location and withdraw the tungsten needle in the opposite direction along the short sheath guide structure; The electrode flexible placement module is used to place a flexible electrode structure in the target tissue and restore its flexible state.

[0017] The present invention has the following beneficial effects: 1. This component enables the flexible electrode to achieve the expected and controllable axial propulsion stiffness during the insertion stage. At the same time, it can use the short sheath cavity guide structure to constrain the direction of the tungsten needle, and further use the front end reinforced bag structure to disperse the thrust of the tungsten needle. In this way, while ensuring the precise propulsion of the top-mounted tungsten needle structure, it can also make its thrust more evenly distributed, thereby significantly reducing the risk of direct puncture of the electrode front end by the top-mounted tungsten needle structure. As a result, the tungsten needle can be flexibly withdrawn after insertion to achieve flexible retention, improving the overall functionality and practicality.

[0018] 2. This fabrication process can effectively isolate the sheath cavity layer from the metal traces and electrode contact array through layered design, so that the metal traces and electrode contact array can be completely avoided from contact with etching solution, significantly improving the electrode fabrication yield and reliability. At the same time, the shape and size of the sheath cavity and the front end pocket are precisely controllable. Through the insertion of the sacrificial layer patterning process, the planar contour of the sacrificial layer corresponds precisely to the size and shape of the final sheath cavity and the front end pocket, thereby ensuring the precise positioning and placement of the auxiliary implantation needle. Attached Figure Description

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The structures, proportions, sizes, etc., drawn in this specification are only used to complement the content disclosed in the specification, so that those skilled in the art can understand and read them. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0020] Figure 1 This is a schematic diagram of the overall structure of the front-end pouch-type flexible implanted electrode assembly based on a brain-computer interface provided in an embodiment of the present invention, corresponding to one side.

[0021] Figure 2 This is a schematic diagram of the overall structure of the front-end pouch-type flexible implanted electrode assembly based on the brain-computer interface provided in an embodiment of the present invention, corresponding to the other side.

[0022] Figure 3 This is a diagram showing the internal structure of the top tungsten needle structure, the short sheath cavity guide structure, and the reinforcing pouch structure in the front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface provided in an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of the application state structure of the front-end pouch-type flexible implanted electrode assembly based on a brain-computer interface provided in an embodiment of the present invention.

[0024] Figure 5 This is a cross-sectional view of the front-end pouch-type flexible implanted electrode assembly based on a brain-computer interface provided in an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the thrust dispersion state of the top-mounted tungsten needle structure in the front-end pouch-type flexible implanted electrode assembly based on a brain-computer interface provided in an embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of the force component corresponding to the stop zone of the front-end pouch-type flexible implanted electrode assembly based on the brain-computer interface provided in an embodiment of the present invention.

[0027] Figure 8 This is a schematic diagram of a multi-cell structure for enhancing the cell structure in a front-end cell-cell flexible implanted electrode assembly based on a brain-computer interface, provided in an embodiment of the present invention.

[0028] Figure 9 This is a schematic diagram illustrating the array application of a front-end pouch-type flexible implanted electrode assembly based on a brain-computer interface, as provided in an embodiment of the present invention.

[0029] Figure 10 This is a schematic diagram illustrating the architectural principle of a neural electrode implantation system based on a brain-computer interface, provided in an embodiment of the present invention.

[0030] Figure 11 The fabrication process of the front-end pouch-type flexible implanted electrode assembly provided in the embodiments of the present invention corresponds to the fabrication principle of the metal trace layer.

[0031] Figure 12 The fabrication process of the front-end pouch-type flexible implanted electrode assembly provided in the embodiments of the present invention corresponds to the fabrication principle diagram of the short sheath cavity guiding structure.

[0032] The attached diagram lists the components represented by each number as follows: Flexible electrode structure 1: Flexible electrode body 11, tail end pad 12, metal trace layer 13; Electrode contact structure 2; Short sheath cavity guiding structure 3; 4. Enhance the bag structure; 41. Enhance the stop area; Top-mounted tungsten needle structure 5; Tungsten needle insertion module 10; tissue puncture module 20; electrode positioning and needle withdrawal module 30; flexible electrode placement module 40. Detailed Implementation

[0033] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The terms "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0035] like Figures 1 to 9As shown, this embodiment of the invention provides a front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface, including a flexible electrode structure 1, an electrode contact structure 2, a short sheath guide structure 3, a reinforcing pouch structure 4, and a top-mounted tungsten needle structure 5. The above structures work together to effectively achieve the desired controllable axial propulsion stiffness of the flexible electrode during the implantation stage. Simultaneously, the short sheath guide structure 3 can constrain the direction of the tungsten needle, and the front-end reinforcing pouch structure 4 can further disperse the thrust of the tungsten needle. This ensures precise propulsion of the top-mounted tungsten needle structure 5 while effectively dispersing its thrust more evenly, thus significantly reducing the risk of direct puncture of the electrode tip by the top-mounted tungsten needle structure 5. This allows for flexible placement of the tungsten needle after implantation, improving overall functionality and practicality. Specific settings are as follows: Please refer to Figure 1 The flexible electrode structure 1 includes a flexible electrode body 11, a tail-end pad 12, and a metal wiring layer 13. The flexible electrode body 11 is configured as an elongated needle-like structure, with its front end for insertion into brain or nerve tissue and its rear end for connection to external recording, stimulation, or testing equipment. The flexible electrode body 11 has a flexible insulating layer and a metal wiring layer 13 located within the flexible insulating layer. One end of the metal wiring layer 13 is electrically connected to the tail-end pad 12 located at the rear end of the flexible electrode body 11. The substrate or encapsulation material of the flexible electrode body 11 may be, but is not limited to, polyimide, parylene, liquid crystal polymer, thermoplastic polyurethane, silicone rubber, or other medical flexible insulating materials to ensure tissue compliance and insulation reliability during long-term placement.

[0036] Please continue to refer to this. Figure 1 The electrode contact structures 2 are arranged in an array, and are respectively located at the front end and / or middle section of the flexible electrode body 11 and exposed through windows in the flexible insulating layer. The array of electrode contact structures 2 is electrically connected to the metal wiring layer 13, and is used to record intracranial neural signals, stimulate neural electrical stimulation, and detect impedance along with the flexible electrode body 11. The material of the electrode contact structures 2 may be, but is not limited to, platinum, platinum-iridium alloy, iridium oxide, platinum black, platinum nanostructures, or conductive polymers to ensure electrochemical stability and charge transfer capability.

[0037] Please refer to Figure 3The short sheath cavity guide structure 3 is disposed inside the flexible electrode body 11, forming a local cavity for accommodating and limiting the top tungsten needle structure 5 to achieve guided propulsion. Specifically, the short sheath cavity guide structure 3 is disposed inside the front section of the flexible electrode body 11, and the length of the short sheath cavity guide structure 3 is set to 0.5~10 mm, preferably 1~5 mm, so as to utilize the short sheath cavity guide structure 3 to locally reduce drag and gradually constrain the propulsion direction of the top tungsten needle structure 5 with the help of its two side walls.

[0038] The short sheath cavity guiding structure 3 can be configured as, but is not limited to, an internal closed interlayer cavity based on the flexible electrode body 11, a semi-closed cavity with a rear opening, a sidewall-reinforced limiting cavity, a multi-link limiting ring structure, a partial sleeve structure, a collapsible flexible cavity, or a cavity that can be formed by the release of the sacrificial layer, to effectively limit the lateral swing of the top tungsten needle structure 5, so that the axis of the top tungsten needle structure 5 and the axis of the flexible electrode body 11 tend to be consistent within a preset error range, thereby reducing the risk of the sidewall of the flexible electrode body 11 being punctured due to eccentric pushing; the sidewall reinforcement can be, but is not limited to, a high-density setting of the same material.

[0039] Please refer to Figures 3 to 6 The reinforcing pouch structure 4 is disposed inside the flexible electrode body 11, and the reinforcing pouch structure 4 is located at the front end of the short sheath cavity guide structure 3. The reinforcing pouch structure 4 has a pouch cavity that can accommodate the front end of the top tungsten needle structure 5, so as to further receive the front end of the top tungsten needle structure 5 through the front reinforcing pouch structure 4, and withstand the propulsion force of the tungsten needle by means of its own pouch limiting performance, thereby dispersing and transmitting the local thrust of the top tungsten needle structure 5 to the side end and front end wall of the reinforcing pouch structure 4, and so that the dispersed thrust is further transmitted from the reinforcing pouch structure 4 to the flexible electrode body 11, thereby allowing the flexible electrode body 11 to enter the brain tissue in a predetermined direction.

[0040] As a preferred embodiment, please refer to Figure 7 The front end of the enhanced pouch structure 4 is also provided with an enhanced stop area 41. The enhanced stop area 41 is configured as any one or more combinations of the following: multilayer flexible insulating material stack, locally thickened polymer layer, embedded reinforcing pad, locally metal or high-strength polymer force-sharing layer, microporous interlocking structure, and gradient thickness transition structure. It is used to further expand the force-bearing area through the enhanced stop area 41 to prevent the top tungsten needle structure 5 from piercing the front end of the flexible electrode body 11.

[0041] More preferably, a microporous interlocking structure and / or a micropillar interlocking structure are provided between the front outer wall of the reinforcing pouch structure 4 and the reinforcing stop area 41 to effectively increase the interlayer bonding area and mechanical locking force and prevent interlayer peeling during the advancement process; and the inner diameter of the reinforcing pouch structure 4 is slightly larger than the outer diameter of the top tungsten needle structure 5 to facilitate the smooth insertion or removal of the top tungsten needle structure 5.

[0042] As another preferred embodiment, please refer to Figure 8 The enhanced pouch structure 4 is configured as a multi-pouch structure, which forms multiple levels of barriers to withstand the propulsion force of the tungsten needle through the multi-pouch structure. This enables the subsequent pouches to continue to maintain the predetermined propulsion force dispersion after at least one set of pouches has ruptured. At the same time, the spacer layer between two adjacent sets of pouches can be used to stabilize the pressure and maintain the propulsion direction of the tungsten needle after rupture.

[0043] As another preferred embodiment, the metal wiring layer 13 avoids the load-bearing area of ​​the end of the top tungsten needle structure 5 corresponding to the reinforcing pouch structure 4, and the metal wiring layer 13 adopts serpentine wiring, arc wiring, widened wiring or stress relief structure in the area close to the reinforcing pouch structure 4, so as to effectively reduce the risk of wiring breakage or electrical failure caused by the thrust of the top tungsten needle structure 5.

[0044] More preferably, the electrode contact structure 2 is disposed in the region behind the flexible electrode body 11 corresponding to the reinforcing pouch structure 4, so as to significantly reduce the direct impact of the tungsten needle thrust on the electrode contact.

[0045] As another preferred embodiment, the stiffness of the flexible electrode body 11 and / or the reinforcing pouch structure 4 varies with a soft-hard gradient from the front end to the rear end. Specifically, the overall front end stiffness is higher than the rear end stiffness, so as to effectively coordinate and balance the front end insertion stiffness and the rear end long-term retention compliance.

[0046] Please continue to refer to this. Figure 3 and Figure 6 The top-mounted tungsten needle structure 5 is configured as a tungsten needle with a blunt front end. Specifically, it can be configured, but is not limited to, a blunt front end, a spherical head, a hemispherical head, a flat blunt head, or a structure with a passivation cap. The top-mounted tungsten needle structure 5 can be made of tungsten, tungsten alloy, nickel-titanium alloy, titanium alloy, or other high-rigidity biocompatible metal materials to provide temporary axial stiffness for the flexible electrode body 11 during the electrode placement stage, and to use the blunt end to assist in dispersing the thrust to push the flexible electrode body 11 into the target tissue.

[0047] Please refer to Figure 4 and Figure 9The present invention also provides a method for flexibly retaining a front-end pouch-type flexible implantable electrode assembly by using a blunt tungsten needle for assisted insertion and needle removal, specifically including the following steps: S1: Insert a blunt-tipped tungsten needle into the short sheath cavity guide structure 3 of the flexible electrode and make the tip of the tungsten needle enter the reinforcing bag structure 4 to form a temporary composite structure. The specific process is as follows: The blunt end of the top tungsten needle structure 5 is pushed from the rear end of the flexible electrode body 11 along a preset path to the short sheath cavity guide structure 3. Through the constraint and guidance of the short sheath cavity guide structure 3, the end of the top tungsten needle structure 5 enters the reinforcing bag structure 4 and abuts against the reinforcing stop area 41. The insertion direction of the top-mounted tungsten needle structure 5 is consistent with the axial direction of the flexible electrode body 11; S2: With the assistance of a positioning and importing device, the temporary composite structure is placed into the target tissue along a predetermined path; The specific process is as follows: With the assistance of a stereotactic system, a micro-operating system, or a neurosurgical auxiliary positioning device, a temporary composite formed by combining the top tungsten needle structure 5 and the flexible electrode body 11 is placed into the target tissue. S3: After reaching the target tissue location, maintain the flexible electrode and withdraw the tungsten needle in the opposite direction along the short sheath guide structure 3; The specific process is as follows: When the temporary composite formed by the top tungsten needle structure 5 and the flexible electrode body 11 reaches the target tissue position, the position of the flexible electrode body 11 is maintained and the top tungsten needle structure 5 is withdrawn in the opposite direction along the short sheath cavity guide structure 3, so that the top tungsten needle structure 5 is detached from the reinforcing bag structure 4 and the short sheath cavity guide structure 3. During needle withdrawal, the flexible electrode body 11 is held in position by clamps or connecting ends to prevent the flexible electrode body 11 from being pulled out of the target tissue. S4: The flexible electrode body 11 is placed in the target tissue and returns to its flexible state; The specific process is as follows: The flexible electrode body 11 is left in the target tissue and restored to its flexible state. The flexible electrode body 11 is connected to a neural recording, electrical stimulation, impedance detection or closed-loop control device to stably achieve long-term neural signal acquisition, electrical stimulation or bidirectional neural interface function.

[0048] Please refer to Figure 10 The present invention also provides a neural electrode implantation system including a flexible electrode and a tungsten needle, comprising: The tungsten needle insertion module 10 is used to insert a tungsten needle with a blunt tip into the short sheath cavity guide structure 3 of the flexible electrode and to allow the tip of the tungsten needle to enter the reinforcing bag structure 4 to form a temporary composite structure. Tissue puncture module 20 is used to insert a temporary composite structure into the target tissue along a predetermined path with the assistance of a positioning and import device; The electrode positioning and needle withdrawal module 30 is used to hold the flexible electrode after reaching the target tissue position and withdraw the tungsten needle in the opposite direction along the short sheath guide structure 3. The electrode flexible placement module 40 is used to place the flexible electrode body 11 in the target tissue and restore its flexible state.

[0049] Please refer to Figures 11 to 12 The present invention also provides a fabrication process for the above-mentioned front-end pouch-type flexible implanted electrode assembly, which specifically includes the following steps: S1: Construct a detachable processing carrier platform; The specific process is as follows: Select a glass or silicon wafer with a surface cleanliness and flatness that meets the photolithography requirements as a temporary processing substrate a, and perform surface moisture and organic contaminant removal treatment on the temporary processing substrate a. After cleaning, a release layer is spin-coated or vapor-deposited onto the surface of the temporary processing substrate a. The release layer is made of a soluble polymer, a water-soluble sacrificial layer material, or a heat-release adhesive film. After all the preparation processes are completed, the flexible electrode body 11 formed by several layers of flexible insulating layers can be peeled off from the surface of the temporary processing substrate a by means of immersion dissolution, heat treatment, or chemical corrosion, and the peeling process does not damage the structural integrity of the flexible electrode body 11. More specifically, the thickness of the release layer can be set to 200 nm to 5 μm. After coating, it is cured and uniformly covers the surface of the temporary processing substrate a, and forms sufficient adhesion strength between it and the temporary processing substrate a, so that the flexible electrode body 11 remains stable. At the same time, the adhesion force between the release layer and the flexible electrode body 11 is lower than the interlayer bonding strength of the flexible electrode body 11 itself, so as to achieve subsequent selective separation. S2: A flexible substrate layer b is formed based on the processing carrier platform; The specific process is as follows: The release layer of the processing carrier platform is subjected to surface activation treatment, and the first layer of polyimide (PI) material is coated and cured by spin coating process. The spin coating speed and coating time are adjusted to make the wet film thickness uniform. The dry film thickness range after curing is set to 2μm~20μm, and the film thickness uniformity deviation does not exceed 5%, so as to prepare a stable flexible base layer b corresponding to the release layer, which serves as the lower wall of the sheath cavity layer. That is, the aforementioned flexible substrate layer b effectively serves as the bottom support foundation of the flexible electrode body 11, and at the same time constitutes the lower wall of the subsequent short sheath cavity guiding structure 3 and the reinforcing bag structure 4. S3: Precisely patterned deposition of sacrificial layer material for flexible substrate layer b according to preset sheath cavity and sac morphology; The specific process is as follows: based on the required length and diameter of the sheath layer and the shape of the anterior capsule, the planar shape and thickness of the sacrificial layer are pre-designed so that the overall shape of the sacrificial layer is consistent with the final sheath and capsule. The sacrificial layer material can be selected from, but is not limited to, metal sacrificial layers such as titanium, aluminum, copper or chromium, polymer sacrificial layers, soluble materials, photoresist, wax, biodegradable temporary materials or other materials that can be subsequently removed. For example, when using a metal sacrificial layer, the sacrificial layer can be patterned and removed by O2 plasma etching or wet etching to remove its existing occupants and form a precise sheath cavity and sac outline. S4: Prepare a flexible barrier layer c, and form a sandwich cavity d that can locate the sacrificial layer by corresponding to the flexible base layer b; The specific process is as follows: Based on the flexible substrate layer b and the patterned sacrificial layer, the second layer of polyimide (PI) material is coated and cured by spin coating process. The spin coating speed and coating time are adjusted to make the wet film thickness uniform. At this time, the second layer of polyimide (PI) material coating liquid covers the upper surface and side of the sacrificial layer, and directly contacts and adheres to the surface of the flexible substrate layer b in the outer area of ​​the sacrificial layer. After curing is completed according to the stepped heating procedure, a flexible barrier layer c is formed. A sandwich cavity d that can locate the sacrificial layer is formed between the flexible barrier layer c and the flexible base layer b, which is the subsequent sheath cavity and bag cavity. Specifically, a direct chemical bond is formed between the flexible barrier layer c on the outer side of the sandwich cavity d and the flexible base layer b to achieve interlayer sealing and bonding. The interlayer sealing and bonding method can be, but is not limited to, using hot-press bonding or local application of polymer adhesive for auxiliary sealing. This can prevent the etching solution from leaking to the outside of the cavity in the subsequent etching process, thereby ensuring the controllability of the subsequent etching steps. As a preferred embodiment, an enhanced stop area is formed corresponding to the front end direction of the interlayer cavity d; specifically, the enhanced stop area may be formed by, but is not limited to, multilayer coating and / or local thickening coating of polyimide (PI) material, micropore interlocking between the flexible barrier layer c and the flexible base layer b, and / or local reinforcement sheet embedding. S5: Construct a patterned metal trace and electrode contact array based on a flexible barrier layer c; The specific process is as follows: A metal seed layer is deposited at a predetermined layout position on the flexible barrier layer c by means of magnetron sputtering, evaporation, electroplating, photolithography, etching, laser patterning or printing. The material of the metal traces and electrode contact array can be at least one of platinum, platinum-iridium alloy, gold, titanium-gold composite layer or chromium-gold composite layer. After deposition, photoresist is spin-coated, and a photoresist mask with a wiring pattern is formed by UV exposure and development. Then, the metal areas not protected by the mask are removed by wet etching or ion beam etching. Finally, the photoresist is removed to form a precise patterned metal wiring and electrode contact array. In the wiring layout design, the metal wiring and electrode contact array are located on one end face of the flexible barrier layer c facing away from the flexible substrate layer b, and the metal wiring and electrode contact array preferentially avoid the sacrificial layer and the sheath cavity bag area; at the same time, the wiring segments near the front sacrificial layer and the sheath cavity bag area can be further preferably set as serpentine wiring or arc wiring structure to increase adaptive flexibility and reduce the risk of metal fracture caused by stress concentration; By setting the above flexible barrier layer c, a physical isolation layer can be formed to effectively block the sacrificial layer area from the metal traces and electrode contact array area. This layered design can ensure that the etching solution cannot contact the metal traces in the subsequent etching steps, and at the same time significantly improve the overall architecture functional stability in subsequent applications. S6: Prepare a flexible sealing layer according to the metal traces and electrode contact array corresponding to the flexible barrier layer c; The specific process is as follows: Based on the flexible barrier layer c and the metal traces and electrode contact array, the third layer of polyimide (PI) material is coated and cured by spin coating process. The spin coating speed and coating time are adjusted to make the wet film thickness uniform so as to form an overall encapsulation insulation layer of the flexible electrode body 11 after curing. The aforementioned metal traces and electrode contact array are wrapped between the flexible barrier layer c and the flexible sealing layer to improve the stability of the metal circuit. After curing, windowing is performed at the electrode contact array position of the metal trace electrical connection and the tail pad 12 position: Specifically, photoresist is spin-coated corresponding to the flexible cover layer, and a windowing area mask is formed by exposure and development. Then, the polyimide (PI) material in the pre-windowed area is removed by reactive ion etching (RIE) or laser windowing to expose the internal electrode contact array and tail pad 12. S7: For the flexible substrate layer b, an etching channel e is opened to connect the sacrificial layer, and the sacrificial layer is removed; The specific process is as follows: The device that has completed the above steps is flipped so that the flexible substrate layer b is on top and the flexible capping layer is on the bottom. Then, several sets of etching channels e are opened on the flexible substrate layer b corresponding to the sacrificial layer position using laser micromachining or focused ion beam method to accelerate the entry speed of the etching solution and improve the removal efficiency of the sacrificial layer. After the channel is opened, the sacrificial layer material is removed by O2 plasma etching or wet etching to form a hollow sheath cavity and front end pocket structure. For example, by using wet etching, the etching solution corresponding to the sacrificial layer material is introduced into the interlayer cavity d of the sacrificial layer through the etching channel e. If the sacrificial layer is aluminum, a sodium hydroxide solution or a mixture of phosphoric acid, acetic acid and nitric acid is used; if the sacrificial layer is titanium, a hydrofluoric acid solution is used; if the sacrificial layer is soluble photoresist, an organic solvent such as N-methylpyrrolidone is used. The etching solution can only enter the interlayer cavity d through the etching channel e, and diffuses in the transverse direction in the interlayer cavity d, gradually dissolving all the sacrificial layer material, and finally forming a completely hollow sheath cavity and front end pocket structure between the flexible base layer b and the flexible barrier layer c. During the etching process, the flexible barrier layer c acts as a layer to prevent the metal traces and electrode contact array from coming into contact with the etching solution throughout the etching process, thereby preventing etching damage to electrical wires. S8: Release and separate the flexible electrode body from the self-processing carrier platform; The specific process is as follows: The flexible electrode body, which has completed the above steps and has a processing carrier platform, is then introduced into a dissolving solution corresponding to the release layer material, so that the release layer is fully dissolved or softened by the dissolving solution. The flexible electrode body is then separated from the processing carrier platform of the release layer. The entire separation process avoids applying shear force or local concentrated force to prevent the flexible electrode body from folding, tearing or delamination, thereby obtaining a flexible insertable electrode with a short sheath cavity and a front-end reinforcing sac. S9: Inserting tungsten needles into a flexible electrode body and performing assembly verification; The specific process is as follows: The blunt tungsten needle tip is inserted into the sheath cavity and reinforcing bag from the electrode tail end and abuts against the reinforcing stop area. Then, the insertion and removal smoothness, microstructure integrity, channel impedance, insulation and front end bag load-bearing capacity are tested. S10: Complete the cleaning, sterilization, and packaging of the entire validated flexible electrode; The specific process is as follows: The validated flexible electrode body and the top-mounted tungsten needle structure 5 are cleaned, sterilized, and packaged. Before subsequent use, the flexible electrode body and the top tungsten needle structure 5 are tested, including but not limited to channel connectivity, impedance, insulation resistance, bag integrity, tungsten needle insertion and removal smoothness and appearance defect inspection.

[0050] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface, characterized in that, include: Flexible electrode structure; A short sheath cavity guiding structure is disposed inside the flexible electrode structure to form a local cavity for accommodating and limiting the top tungsten needle structure to achieve guided propulsion. An enhanced pouch structure is disposed inside the flexible electrode structure, and the enhanced pouch structure is correspondingly connected to one end of the short sheath cavity guide structure. The enhanced pouch structure has a pouch cavity that further accommodates the top tungsten needle structure, so as to withstand the tungsten needle propulsion force by means of its own pouch limiting performance.

2. The front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface according to claim 1, characterized in that, Also includes: The top-mounted tungsten needle structure is based on the flexible electrode structure, into which the short sheath cavity guide structure and the reinforcing sac structure are sequentially inserted. The top-mounted tungsten needle structure provides axial stiffness to the flexible electrode structure and forms an auxiliary thrust to push the flexible electrode structure into the target tissue.

3. The front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface according to claim 2, characterized in that, The top-mounted tungsten needle structure is designed to be removable based on the flexible electrode structure; Furthermore, the top-mounted tungsten needle structure provides temporary axial stiffness for the flexible electrode structure.

4. The front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface according to claim 1, 2, or 3, characterized in that, The end of the enhanced pouch structure away from the short sheath cavity guide structure is also provided with an enhanced stop area, which further expands the force-bearing area to disperse the auxiliary thrust.

5. The front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface according to claim 2, characterized in that, The flexible electrode structure includes a metal wiring layer; The metal wiring layer is arranged in the non-load-bearing area of ​​the reinforced pouch structure, and the metal wiring layer is far away from the thrust area formed by the pressure of the top tungsten needle structure.

6. The front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface according to claim 1, characterized in that, The enhanced pocket structure is configured as a locally enhanced pocket and / or a soft-hard gradient enhanced pocket.

7. The front-end pouch-type flexible implantable electrode assembly based on a brain-computer interface according to claim 1 or 6, characterized in that, The front end stiffness of the enhanced pouch structure is higher than its rear end stiffness.

8. A neural electrode implantation system according to any one of claims 1-7, characterized in that, The system includes: The tungsten needle insertion module is used to insert a blunt-tipped tungsten needle into the short sheath cavity guide structure of the flexible electrode and allow the tip of the tungsten needle to enter the reinforcing bag structure to form a temporary composite structure. The tissue puncture module is used to insert a temporary composite structure into the target tissue along a predetermined path; The electrode positioning and needle withdrawal module is used to hold the flexible electrode after reaching the target tissue location and withdraw the tungsten needle in the opposite direction along the short sheath guide structure; The electrode flexible placement module is used to place a flexible electrode structure in the target tissue and restore its flexible state.

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