Flexible closed-loop self-powered vagus nerve stimulation system for treating drug-resistant epilepsy

Abstract

The invention discloses a flexible closed-loop self-powered vagus nerve stimulation system for treating drug-resistant epilepsy. The system comprises a spiral electrode, a flexible friction nanometer generator and a flexible controller. According to the implantable vagus nerve stimulation system, the flexible material and the self-powered technology are adopted, effective stimulation on the vagus nerve is achieved, the tissue compatibility of the implantable vagus nerve stimulation system is remarkably improved, and secondary injury to a patient caused by battery replacement in an operation is avoided.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a flexible closed-loop self-powered vagus nerve stimulation system for treating drug-resistant epilepsy. Background Technology

[0002] Epilepsy is a common chronic neurological disorder, with approximately one-third of patients developing refractory (drug-resistant) epilepsy, where conventional antiepileptic drugs fail to adequately control seizures. For these patients, vagus nerve stimulation (VNS) has been widely used as a neuromodulation therapy. The VNS system uses electrical pulses to stimulate the vagus nerve in the neck, transmitting signals to the brain to inhibit seizures. It is primarily used as adjunctive therapy for drug-resistant epilepsy.

[0003] Vagus nerve stimulation (VNS) has been widely used as an adjunct therapy for epilepsy, but existing rigid VNS systems have some shortcomings. Systems represented by patents CN 206026870 U and CN 115003369 B are rigid systems, which can easily lead to tissue compression and discomfort with long-term implantation. Long-term implantation carries risks of tissue irritation and pain, and lacks self-powered capability, requiring surgical battery replacement, causing secondary injury and infection risks to patients, and increasing the economic burden. Triboelectric nanogenerators can achieve in vivo energy harvesting, but existing solutions such as CN 11499600 A still lack the characteristics of overall flexible packaging, and integrating the analysis and control module into the implant increases the size of the device. Their implantation is highly invasive, and the system's rigidity dependence remains unresolved. Therefore, developing an integrated system that combines flexible implantation, efficient self-powered operation, and intelligent closed-loop control, specifically designed for epilepsy treatment, is key to overcoming current technological bottlenecks.

[0004] To overcome the aforementioned problems, flexible electronics and self-powered technologies have begun to be applied in the field of vagus nerve stimulation in recent years. Flexible electronics uses bendable and stretchable materials to manufacture circuits and electrodes, allowing implanted devices to conform to the shape and movement of human tissue, thereby reducing tissue damage and improving wearing comfort. Meanwhile, self-powered technology uses energy harvesting devices to convert the body's own mechanical energy into electrical energy to power the implanted device, eliminating reliance on traditional batteries. These new technologies have already shown promise in related fields. Summary of the Invention

[0005] In view of this, the present invention provides a flexible closed-loop self-powered vagus nerve stimulation system for the treatment of drug-resistant epilepsy. This system, while possessing the functions of a traditional rigid vagus nerve stimulation system, improves patient comfort and safety through a flexible design, and integrates a triboelectric nanogenerator, eliminating the need for an implantable battery and thus avoiding problems such as surgical battery replacement.

[0006] The self-powered flexible vagus nerve stimulation system of the present invention includes an implantable part and a wearable part. The wearable part includes a Bluetooth module and an analysis and control module; the implantable part includes a flexible package, a flexible helical electrode, a flexible triboelectric nanogenerator power supply unit, a flexible control module, a flexible electrical stimulation generation unit, a flexible heart rate sensor, a flexible battery, and an implanted Bluetooth module. The modules of the implantable part are interconnected via flexible circuits and encapsulated in flexible materials, allowing them to move with the body tissue without damaging it. The wearable part is worn on the patient's skin and interacts with the implantable part wirelessly to analyze and process data and send control commands.

[0007] The conductivity of the heart rate sensor changes according to the strength and frequency of the heartbeat. The collected resistance change data is converted into a digital signal by an analog-to-digital converter in the flexible control module of the implanted part, obtaining real-time heart rate data. This data is wirelessly transmitted to the Bluetooth module of the wearable part via the implanted Bluetooth module, and then analyzed and processed by the analysis and control module of the wearable part. The analysis and control module can perform time-frequency analysis on the heart rate signal. When it detects characteristic waveforms related to epileptic seizures, it determines that the patient may be about to have an epileptic seizure. At this time, the analysis and control module generates a corresponding stimulation control signal, which is transmitted back to the implanted Bluetooth module via the wearable Bluetooth module. The flexible control module of the implanted part receives and analyzes the signal, and then controls the flexible electrical stimulation generation unit to generate a pulse electrical signal with specific parameters. This pulse electrical signal is applied to the vagus nerve through a flexible helical electrode to stimulate the vagus nerve. The pulse width, amplitude, and frequency parameters can be adjusted as needed to achieve the best anti-epileptic effect.

[0008] In a preferred embodiment, the implanted portion is entirely encapsulated in medical-grade polydimethylsiloxane to ensure good biocompatibility and flexibility of the system. The flexible spiral electrode is preferably made of medical conductive materials such as platinum-iridium alloy, and its surface is coated with a layer of biocompatible hydrogel to enhance the coupling between the electrode and nerve tissue. The electrode is spiral-shaped and can be wrapped around the vagus nerve to provide stable stimulation contact; the electrode spacing is designed to be approximately 2 ± 0.1 mm to ensure effective stimulation while minimizing nerve damage. The entire spiral electrode structure is encapsulated in a polydimethylsiloxane / polyimide composite film with a thickness not exceeding 0.5 mm to balance flexibility and mechanical strength.

[0009] The flexible battery is made of materials with excellent biocompatibility. Its positive electrode is preferably a lithium iron phosphate / graphene composite material, and its negative electrode is preferably a lithium titanate / carbon nanotube composite material, with a polyoxyethylene gel polymer electrolyte filling the space between them. The battery's current collector uses a gold-plated microgrid circuit on an ultrathin polyimide substrate to ensure flexibility. The entire battery is fully elastically encapsulated by a layer of medical-grade polydimethylsiloxane to prevent electrolyte leakage and improve device durability. Although the capacity of this flexible battery is not large, it can be repeatedly charged with the assistance of a self-powered unit, providing a stable operating power source for the system.

[0010] The flexible triboelectric nanogenerator (TGN) power supply unit is the core self-powered component of this system. Its structure includes a triboelectric layer, an electrode layer, and an encapsulation layer arranged sequentially. The triboelectric layer is composed of two thin films of different materials: one side is a lactic acid-lysine copolymer (P-L-polylactic acid) film, and the other side is a polydimethylsiloxane film. During human movement, these two materials undergo contact-separation relative motion, generating charge through triboelectric charging. The electrode layer, located on the back of the triboelectric layer, is made of conductive hydrogel material and is used to collect the charge generated by friction and output current. The encapsulation layer uses a thermoplastic elastomer (such as styrene-ethylene-butene-styrene) film to seal the triboelectric layer and electrode layer, preventing the intrusion of body fluids and providing some mechanical protection. The TGN power supply unit can be attached to the surface of muscles or ribs near the patient's heart, utilizing the mechanical energy generated by heartbeat, respiration, and daily movement to generate electricity. The generated electrical energy is processed by rectification and filtering circuits in the flexible control module; part of it directly supplies the system, while the other part is stored in a flexible battery for backup.

[0011] The circuitry of both the flexible control module and the flexible electrical stimulation generation unit is fabricated on a flexible PCB board to achieve bendable electronic circuitry. The flexible control module includes a microcontroller, memory, and necessary signal processing circuits (such as amplification, filtering, and rectification circuits). It coordinates the operation of each functional unit: receiving signals from the heart rate sensor and performing analog-to-digital conversion, communicating with external systems via an embedded Bluetooth module, and driving the electrical stimulation generation unit to output corresponding pulses according to received control commands. The flexible electrical stimulation generation unit includes a pulse generation circuit and a power amplification circuit, capable of generating electrical stimulation pulses with adjustable pulse width, amplitude, and frequency under the instructions of the control module. The pulses output by this unit are transmitted to helical electrodes via flexible wires, acting on the vagus nerve tissue.

[0012] The flexible heart rate sensor is made of a conductive flexible resin material, and its sensing surface has a conical micro / nano structure to increase the sensor's deformation sensitivity. When the heartbeat causes micro-strain in the surrounding tissue, the sensor's resistance changes accordingly, thereby achieving highly sensitive detection of heart rate. The sensor is connected to the signal input terminal of the control module via a flexible wire, and its output signal is amplified and converted from digital to analog before being processed by the control module.

[0013] The implanted Bluetooth module and the wearable Bluetooth module constitute the system's wireless communication link for bidirectional data and control signal transmission. The implanted Bluetooth module is integrated into the flexible control module of the implanted part and communicates with the outside world through a flexible antenna; the wearable Bluetooth module is integrated into the wearable part and communicates with the user's smart terminal or the doctor's programmer. Low-power Bluetooth technology is preferably used to reduce power consumption and ensure communication reliability. Communication content includes uploading physiological data such as heart rate, and issuing stimulation parameters and control commands.

[0014] In practice, the implanted portion is preferably implanted subcutaneously in the patient's left chest, while the flexible helical electrode is carefully wound surgically around the vagus nerve on the left side of the patient's neck. This implantation location is similar to that of traditional vagus nerve stimulation systems, facilitating the use of the neural pathway between the left vagus nerve and the brain. The wearable portion can be worn on the patient's wrist (e.g., in the form of a smartwatch) or left upper arm, facilitating communication with the implanted portion and monitoring motion data. The implanted and wearable portions maintain a real-time connection via Bluetooth. During the patient's daily activities, the triboelectric nanogenerator continuously captures energy from body movement and charges the flexible battery. When no signs of a seizure are detected, the system maintains a low-intensity background stimulation mode to modulate neural activity and prevent seizures. Once the analysis and control module detects characteristics of a seizure through signals such as heart rate, it immediately switches to a high-intensity stimulation mode, applying a strong electrical pulse to the vagus nerve via the helical electrode to quickly terminate or alleviate the seizure. Due to the flexible battery as energy storage, even when vigorous exercise causes instability in the output of the triboelectric nanogenerator, the system can still release the stored energy to ensure sufficient stimulation intensity, thereby improving the reliability of the treatment.

[0015] Compared with existing technologies, the advantages of this invention are as follows: the implantation part of this system uses flexible materials and structures, which can bend with the movement of human tissue without generating rigid pressure. The flexible spiral electrode fits closely to the nerve without damaging it, and the flexible encapsulation avoids the stimulation of surrounding tissues by traditional rigid shells, making long-term implantation safer and more comfortable.

[0016] The integrated triboelectric nanogenerator can power the device using the patient's own heartbeat, respiration, and movement energy. Combined with a flexible energy storage battery, the system can operate continuously without a large-capacity battery, fundamentally avoiding the inconvenience and risks of periodic battery replacements. This not only reduces the patient's medical burden but also improves the device's lifespan and reliability.

[0017] The system monitors the patient's physiological state in real time using a heart rate sensor and automatically adjusts the stimulation strategy when signs of an epileptic seizure are detected. Compared to traditional open-loop stimulation with fixed parameters, closed-loop control can provide stronger intervention when needed and reduce stimulation intensity when not needed, thereby improving treatment efficacy and reducing unnecessary stimulation side effects. This intelligent response makes treatment more targeted and personalized. Furthermore, placing the analysis and control module on a wearable device and communicating with the implanted component via Bluetooth significantly reduces the system complexity of the implanted component compared to devices that implant the analysis and control module directly in the body.

[0018] In summary, the flexible closed-loop self-powered vagus nerve stimulation system for treating drug-resistant epilepsy of the present invention functionally encompasses the stimulation and therapeutic effects of traditional vagus nerve stimulation systems. At the same time, through the introduction of flexible electronics and self-powered technology, it significantly improves the tissue compatibility and ease of use of implantable devices, providing a more comfortable, longer-lasting, and intelligent new treatment option for patients with drug-resistant epilepsy. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the constituent modules of a self-powered flexible vagus nerve stimulation system according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the implanted portion in one embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the wearable part structure in one embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of the layered structure of the flexible triboelectric nanogenerator power supply unit in one embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of a flexible heart rate sensor in one embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the workflow of a flexible vagus nerve stimulation system for treating epilepsy according to the present invention.

[0026] The labels in the diagram represent the following: 100 - Implantable part, 101 - Flexible encapsulation, 102 - Flexible battery, 103 - Flexible spiral electrode, 104 - Flexible electrical stimulation generating unit, 105 - Implantable Bluetooth module, 106 - Flexible control module, 107 - Flexible heart rate sensor, 108 - Flexible triboelectric nanogenerator power supply unit, 200 - Wearable part, 201 - Wearable Bluetooth module, 202 - Analysis and control module. Detailed Implementation

[0027] Figure 1 This is a schematic diagram of the constituent modules of a self-powered flexible vagus nerve stimulation system according to an embodiment of the present invention. The self-powered flexible vagus nerve stimulation system for treating epilepsy according to the present invention consists of two main parts: an implantable part 100 and a wearable part 200, which are connected wirelessly. The implantable part 100 includes components such as 100-implantation part, 101-flexible encapsulation, 102-flexible battery, 103-flexible spiral electrode, 104-flexible electrical stimulation generating unit, 105-implanted Bluetooth module, 106-flexible control module, 107-flexible heart rate sensor, and 108-flexible triboelectric nanogenerator power supply unit. Each component is manufactured using flexible materials and integrated on a flexible circuit board, and the entire system is encapsulated by the flexible encapsulation 101, forming a bendable and stretchable implantable device.

[0028] Figure 2This is a schematic diagram of the implantation portion in one embodiment of the present invention. The flexible encapsulation 101 preferably uses medical-grade polydimethylsiloxane material to seal all electronic components and circuits of the implantation portion. Polydimethylsiloxane has good bioinertness and flexibility, with a Young's modulus of approximately 0.5–5 MPa, close to the mechanical properties of soft tissue, thus ensuring that the implanted device will not damage surrounding tissues during movement within the body. The thickness of the encapsulation layer is designed as needed, typically on the order of several hundred micrometers, to provide sufficient insulation and protection. The flexible helical electrode 103 is used to directly contact and stimulate the vagus nerve. In this embodiment, the electrode is made of platinum-iridium alloy wire wound into a helical spring shape, which can be looped around the vagus nerve. Platinum-iridium alloy is a commonly used medical electrode material with good conductivity and corrosion resistance. A thin hydrogel coating is applied to the electrode surface to enhance the interfacial coupling between the electrode and nerve tissue and reduce polarization. A spacing of approximately 2 mm is maintained between adjacent turns of the helical electrode to ensure that each turn can independently apply an electric field to the nerve, while avoiding short circuits between turns or excessive compression of the nerve. The entire spiral electrode structure is embedded in a composite film approximately 0.5 mm thick, which is composed of polydimethylsiloxane and polyimide, possessing both the flexibility of polydimethylsiloxane and the mechanical strength of polyimide. The electrode is connected to the internal flexible electrical stimulation generating unit 104 via flexible wires, which are also encapsulated in the film and can be bent and extended.

[0029] Figure 4This is a schematic diagram of the layered structure of a flexible triboelectric nanogenerator power supply unit in one embodiment of the present invention. The flexible triboelectric nanogenerator power supply unit 108 is the energy source of this system. It includes a friction layer 108a, an electrode layer 108b, and an encapsulation layer 108c stacked sequentially. The friction layer 108a is composed of two different polymer films; in this embodiment, poly(L-lactic acid) film and polydimethylsiloxane film are selected as the friction materials. These two materials generate charges due to friction when they come into contact and separate: poly(L-lactic acid) is positively charged, and polydimethylsiloxane is negatively charged. The electrode layer 108b is located on the back of the friction layer and is made of conductive hydrogel, covering the surface of the friction layer in a thin film form. The conductive hydrogel has good conductivity and flexibility, and can collect and conduct the charges generated by friction. Two flexible leads are led out from the electrode layer and connected to the power input interface of the control module 104 for outputting electrical energy. The encapsulation layer 101c uses a styrene-ethylene-butene-styrene elastomer film to seal the friction layer and the electrode layer inside. Styrene-ethylene-butene-styrene material possesses similar flexibility and biocompatibility to polydimethylsiloxane, and exhibits good aging resistance, protecting the internal structure of the triboelectric nanogenerator from bodily fluid erosion and mechanical wear. The size of the triboelectric nanogenerator power supply unit 108 can be designed according to the required power, typically a few square centimeters in size and about 1 mm thick. It can be attached to the surface of the muscles of the left chest wall or near the pericardium, fully utilizing the mechanical energy of heartbeats and respiratory movements to generate electricity.

[0030] The flexible control module 106 is a control module responsible for signal processing and device control. It is made of a flexible PCB and integrates a microcontroller chip, a memory chip, and necessary analog circuitry. The analog circuitry includes signal amplification and filtering circuitry (for heart rate sensor signal conditioning), and rectification and voltage regulation circuitry (for converting the AC output from the triboelectric nanogenerator into stable DC power). The microcontroller runs an embedded program to acquire heart rate data, process Bluetooth communication protocols, and control the electrical stimulation generation unit. The flexible control module 106 is connected via flexible wires to the heart rate sensor 107, the electrical stimulation generation unit 104, the triboelectric nanogenerator power supply unit 108, the flexible battery 102, and the implanted Bluetooth module 105 to coordinate the operation of each component. To ensure reliable operation within the body, all circuit components of the control module are medical-grade low-power devices, and the entire module is sealed within a flexible package, completely isolated from body fluids.

[0031] The flexible electrical stimulation generating unit 104 is responsible for generating electrical pulse signals that meet the treatment requirements. It is also fabricated on a flexible PCB and includes circuitry such as a pulse generator and a power amplifier. Under the command of the control module 104, the pulse generator generates electrical pulse waveforms of a specific frequency and width. The power amplifier then amplifies this waveform to the required current / voltage amplitude to drive the spiral electrodes to stimulate the nerve. In this embodiment, the electrical stimulation unit can output biphasic pulses with adjustable pulse width (0.1–1 ms), adjustable frequency (1–50 Hz), and adjustable amplitude (0–5 V) to meet the stimulation needs of different patients and different seizure situations. The output of the electrical stimulation unit is connected to the two ends of the spiral electrode 102 via flexible wires. When a pulse is output, current is applied to the vagus nerve through the electrodes, causing depolarization of the nerve fibers, thereby modulating the nerve signal.

[0032] Figure 5 This is a schematic diagram of a flexible heart rate sensor in one embodiment of the present invention. The flexible heart rate sensor 107 is used to sense changes in a patient's heart rate and rhythm. This embodiment uses a resistance strain gauge flexible sensor, whose sensitive material is a flexible polymer resin doped with conductive particles. The sensing surface of the sensor is micro-nano-processed to form a dense conical protrusion structure to improve its resistance change rate (i.e., sensitivity) under strain. The sensor can be attached to the inner side of the chest wall near the left ventricle of the heart or the surface of the aortic arch. When the heart contracts and relaxes, causing local tissue deformation, the resistance of the sensor changes periodically. This resistance signal is connected to the signal input channel of the flexible control module 106 through two flexible leads. After being excited and amplified by a constant current source, it is converted into a digital signal by an analog-to-digital converter for processing by the microcontroller. The microcontroller calculates the heart rate by analyzing the frequency of resistance changes and can further analyze parameters such as heart rate variability for the detection of epileptic seizures.

[0033] The flexible battery 102 is used to store energy and provide a stable power supply when needed. In this embodiment, the flexible battery employs a thin-film stacked structure. The positive electrode is a thin film composed of lithium iron phosphate and graphene, the negative electrode is a thin film composed of lithium titanate and carbon nanotubes, and the electrolyte is a gel-state polyethylene oxide polymer. This material combination offers high safety and cycle life, and has no toxic side effects on biological tissues. The positive and negative electrode current collectors of the battery consist of a microgrid of gold deposited on an ultrathin polyimide film, ensuring both conductivity and flexibility. The battery is encapsulated within a polydimethylsiloxane elastic film, forming a bendable flat battery unit. The battery capacity in this embodiment is designed to be tens of milliampere-hours, sufficient to support short-term operation of the system when the triboelectric nanogenerator's energy is insufficient. The flexible battery is connected to the triboelectric nanogenerator power supply unit and control module via a charging management circuit: when the electrical energy generated by the triboelectric nanogenerator exceeds the system's immediate consumption, the excess energy is rectified and used to charge the battery; when the triboelectric nanogenerator's output is insufficient or requires a large current stimulus, the battery discharges to supplement the power supply. This design ensures the continuity and stability of the system's power supply.

[0034] The implanted Bluetooth module 105 serves as the interface for communication between the implanted part and the outside world. Its hardware circuitry is integrated on the flexible PCB of the flexible control module 106 and connected to a flexible antenna (which can be printed on an encapsulation film) for wireless signal transmission and reception. The Bluetooth module follows the Bluetooth Low Energy protocol and can establish a secure wireless connection with the Bluetooth module 201 of the wearable part within a range of several meters. The implanted Bluetooth module is primarily responsible for packaging and sending data such as heart rate to the wearable device, and receiving control commands and parameter configuration information sent by the wearable device. In this embodiment, Bluetooth communication uses encrypted transmission to protect patient privacy and data security. When the implanted part's battery is too low or an abnormality is detected, the Bluetooth module can also send an alarm signal to the wearable device to alert the user.

[0035] The wearable component 200 is worn outside the patient's body and maintains real-time communication with the implanted component 100 via Bluetooth. In this embodiment, the wearable component is designed as a wearable device similar to a smartwatch, including a wearable Bluetooth module 201, an analysis and control module 202, and power management and user interface components (not shown in detail in the figure). The wearable Bluetooth module 201 pairs with the implanted Bluetooth module 108 to receive data uploaded by the implanted component and send instructions to the implanted component. The analysis and control module 202 is the core of the wearable device, typically consisting of a microprocessor or embedded processor, running epilepsy detection algorithms and control logic. After obtaining real-time heart rate data from the Bluetooth module, this module calls a preset analysis algorithm to process the heart rate signal. When the analysis and control module determines that the patient may be about to have an epileptic seizure, it immediately generates a corresponding stimulation control signal, such as increasing the stimulation intensity or triggering an additional stimulation. This control signal is sent to the implanted component through the wearable Bluetooth module 201, and the implanted component executes the specific stimulation action. When no seizure is detected, the analysis and control module maintains the normal stimulation parameters according to the preset plan, or adjusts the stimulation strategy according to the patient's activity.

[0036] Figure 6 This is a schematic diagram of the workflow of a flexible vagus nerve stimulation system for treating epilepsy according to the present invention. The workflow of the system of the present invention can be summarized as "energy supply - signal acquisition - analysis and decision-making - stimulation execution - data communication", and each link is closely connected to form a closed loop.

Claims

1. A flexible closed-loop self-powered vagus nerve stimulation system for treating drug-resistant epilepsy, comprising an implanted portion and a wearable portion.

2. The system according to claim 1, wherein the wearable part includes a Bluetooth module and an analysis and control module; and the implanted part includes a flexible package, a flexible helical electrode, a flexible triboelectric nanogenerator power supply unit, a flexible control module, a flexible electrical stimulation generation unit, a flexible heart rate sensor, a flexible battery, and an implanted Bluetooth module.

3. The system according to claim 2, characterized in that, The flexible heart rate sensor uses a resistive flexible pressure sensor. The collected resistance data is used as heart rate data and transmitted to the wearable Bluetooth module via the implanted Bluetooth module. After analysis and processing by the analysis and control circuit, the stimulation signal is transmitted back to the implanted Bluetooth module. Through analysis and processing by the flexible control module, the flexible electrical stimulation unit pulse electrical signal is controlled and applied to the vagus nerve through the flexible spiral electrode.

4. The system according to claim 2, characterized in that, The implanted portion is entirely encapsulated with preferred medical-grade polydimethylsiloxane to ensure good biocompatibility of the system.

5. The system according to claim 2, characterized in that, The flexible spiral electrode is made of platinum-iridium alloy and coated with a biocompatible hydrogel layer. The electrode spacing is 2±0.1 mm, and the whole is encapsulated in a polydimethylsiloxane / polyimide composite film with a thickness of ≤0.5 mm.

6. The system according to claim 2, characterized in that, The flexible battery consists of a biocompatible lithium iron phosphate / graphene composite cathode and a lithium titanate / carbon nanotube composite anode, with a polyethylene oxide gel polymer electrolyte filling the space between them. The current collector uses a gold-plated microgrid circuit on an ultrathin polyimide substrate; the entire battery is omnidirectionally and elastically encapsulated by a layer of medical-grade polydimethylsiloxane.

7. The system according to claim 2, characterized in that, The flexible triboelectric nanogenerator power supply unit comprises three layers: a friction layer, an electrode layer, and an encapsulation layer. The friction layer is composed of a thin film of polylactic acid (PLA) and polydimethylsiloxane (PDMS), and generates an electric current through contact-separation motion caused by human heartbeats and movement, resulting in friction between the particles. The electrode layer uses a conductive hydrogel material. The encapsulation layer uses a styrene-ethylene-butene-styrene film.

8. The system according to claim 2, characterized in that, The analysis and control module performs time-frequency analysis on the heart rate signal. When a characteristic waveform of epilepsy is detected, a high-intensity stimulation mode is activated; otherwise, a low-intensity control mode is maintained.

9. The system according to claim 2, characterized in that, The circuit systems of the implantable flexible control module and the flexible electrical stimulation generating unit are both made of flexible PCB board.

10. The system according to claim 2, characterized in that, Flexible resistive sensors are made of conductive flexible resin materials and have a conical micro / nano structure for greater sensitivity.

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