A neuromorphic potential-triggered stimulation system and feedback method for tactile feedback of a prosthetic hand

Abstract

The rapid development of science and technology has greatly promoted the development of artificial prosthetic hands. However, some problems still exist in the actual application process. Solving the contradiction between the dexterity of prosthetic movement and the intuitiveness of operation control has become a key technical link that needs to be urgently solved in the current dexterous prosthetic hand system. The present invention proposes a neural potential trigger stimulation system and feedback method for prosthetic hand tactile feedback. It can select a specific neural excitation model as the trigger signal of the stimulation waveform based on the pressure information perceived by the prosthetic hand end, and use the fingertip pressure signal as the input variable of the neural excitation model to generate a stimulation waveform with different triggering morphology in both the time domain and the frequency domain, thereby realizing direct proprioception of specific sensory information such as pressure, vibration, and pain, and improving the fine operation ability of the prosthetic hand system and the energy efficiency of the equipment.

Description

Technical Field

[0001] The present invention belongs to the field of electrical stimulation tactile feedback, and in particular relates to a neuromorphic potential triggering stimulation system and a feedback method suitable for sensory information input of residual limb patients. Background Art

[0002] The rapid development of science and technology has greatly promoted the development of artificial prosthetic hands. However, some problems still exist in their actual application. This is mainly due to the fact that modern technology cannot fully simulate the functions of the human hand. In addition, the acceptance of prosthetic hands by disabled patients requires consideration of multiple aspects such as dexterity, level of anthropomorphism, and simplicity of control methods. Among them, the construction of a multi-channel sensory feedback system between amputees and prosthetic systems, which uses neural electrical stimulation to enable patients to regain tactile, position, and temperature information at the prosthetic hand end, and in conjunction with myoelectric motor channels to jointly build a complete bidirectional neural control-perception pathway, resolves the contradiction between prosthetic motor dexterity and intuitive operation control, and has become a key technical link that needs to be urgently addressed in the current dexterous prosthetic hand system.

[0003] The brachial plexus of the human upper limb is composed of the entire C5, C6, C7, and C8 segments of the spinal nerves, and smaller portions of the T1 and C4 segments. The proximal portion of the brachial plexus first divides into three peripheral nerve trunks, which then divide into three anterior and three posterior peripheral nerve branches. These branches then merge into three peripheral nerve fascicles, which further divide into terminal branches such as the ulnar, median, radial, axillary, and musculocutaneous nerves. Further research into the composition and information transmission patterns of the brachial plexus branches reveals that each nerve branch contains both efferent motor nerves and afferent sensory nerves, which transmit action potentials through axon-to-somatic or dendrite-to-somatic synapses to achieve information perception and muscle movement. This research provides technical feasibility for mimicking synaptic discharge processes to reconstruct sensory pathways in patients with residual limbs. Furthermore, based on neuroanatomical knowledge, the nerve branches corresponding to hand sensation are the terminal branches of the median, radial, and ulnar nerves, which also serve as the target interfaces for electrical stimulation devices. The median nerve primarily senses tactile information from the thumb, index, and middle finger, the radial nerve primarily senses tactile information from the ring finger and pinky finger, and the ulnar nerve primarily provides tactile feedback from the back of the hand. Given the limited number of target nerve pathways and significant individual variability in perception in patients with upper arm stumps, the present invention provides a multi-channel, bidirectional, constant-current electrical stimulation device capable of real-time adjustment of amplitude intensity, stimulation waveform morphology, and pulse width, as well as a feedback stimulation method capable of transmitting multi-dimensional sensory information through a single neural channel.

[0004] After searching, it was found that some patents related to tactile feedback and stimulators of prosthetic hand systems have been published. For example, the invention patent with authorization announcement number CN104606779A discloses a multi-channel constant current source stimulation circuit, which realizes multi-channel constant current stimulation feedback on the surface of human skin. This patent mainly realizes sensory substitution feedback by arranging multi-channel electrodes on the surface of human skin, and uses different stimulation intensities and stimulation frequency waveforms to characterize the pressure perception degree of the prosthetic fingertips. The wearer is required to translate the stimulation coding information perceived by the skin into the corresponding finger position and pressure information. The invention patent with authorization announcement number CN110946683B discloses a multi-channel low-frequency stimulation method and system, which is an electrical stimulation method and system for prosthetic fingertip pressure and joint angle feedback. The system divides the prosthetic fingertip pressure information and joint angle information into seven levels of low-frequency stimulation signals, and then outputs the stimulation signals to different channels corresponding to the finger indexes.

[0005] Since the purpose of the above-mentioned electric stimulator patent is mainly to achieve alternative feedback of teaching sensations through a multi-channel electric stimulation method on the skin surface, the user is required to correctly perceive the coded stimulation signals such as the intensity, frequency, spatial position, etc. and convert them into corresponding prosthetic hand information, which is difficult to meet the natural, efficient and real-time interactive control requirements of the prosthetic hand system. Summary of the Invention

[0006] To overcome the shortcomings of the existing technology, the present invention proposes a neuromorphic electrical stimulation method and corresponding stimulation system that can directly connect to the sensory nerves of the upper arm and provide feedback on multi-dimensional tactile information. Based on the pressure information sensed by the prosthetic hand, a specific neuromorphic excitation model is selected as the trigger signal for the stimulation waveform. The fingertip pressure signal is used as the input variable of the neural excitation model to generate stimulation waveforms with different triggering morphologies in both the time and frequency domains. This enables direct proprioception of specific sensory information such as pressure, vibration, and pain, eliminating the need for the stimulation perception-information translation-effective information replacement sensory feedback process, thereby improving the prosthetic hand system's fine manipulation capabilities and equipment energy efficiency. Furthermore, the present invention specifically designs a neuromorphic potential-triggered stimulation system for prosthetic hand tactile feedback, achieving real-time square wave stimulation that follows the neuromorphic trigger waveform. At the same time, based on the mirrored Wilson constant current source hardware design, it avoids tissue burns caused by excessive local current density at the stimulation electrode, laying the hardware foundation for intuitive perceptual interactive control between the prosthetic hand system and the user. The final designed electrical stimulation device has an output pulse amplitude range of -10mA to 10mA, with an amplitude accuracy of 0.1mA; an output pulse width range of 100μs to 10ms, with a pulse width accuracy of 50μs; and can achieve hardware expansion of multiple independent stimulation channels, with a startup delay of 5ms for each channel. Specifically, it includes:

[0007] A neural potential trigger stimulation system for tactile feedback of a prosthetic hand includes a voltage-stabilized power supply module, a main control chip module, a waveform generation module, a PTC current limiting protection module and a Bluetooth / serial communication module; wherein the voltage-stabilized power supply module includes a battery, a buck module and a boost module, and the waveform generation module includes a neural waveform trigger module, a digital-to-analog conversion module, a mirror voltage-controlled constant current module and a PTC current limiting protection module; the voltage-stabilized power supply module converts the battery 10.5V voltage into a voltage-stabilized power supply to provide power supply for each module; the main control chip module provides logic control signals for each module, and the prosthetic hand device and the environmental perception device are connected and communicated with the main control chip module via the Bluetooth device / serial communication module; the neural waveform trigger module first generates a signal based on the inter-finger touch According to the intensity and type of sensory perception, one or more neural excitation waveforms are selected, and then the trigger waveform is generated in real time with the perception intensity information as the independent variable. The main control chip module sends a bidirectional square wave pulse signal to the digital-to-analog conversion module based on the trigger waveform, wherein the negative phase part of the waveform can generate a sensory transmission pulse, and the positive phase pulse part is used to neutralize the negative charge without causing neural excitation; the signal after digital-to-analog conversion is power amplified and stimulated by a constant current source through a mirror voltage-controlled constant current module, and finally enters and exits the PTC current limiting protection module to ensure the safe operation of the electrical stimulation system and the stable output of current to the external stimulation electrode interface. The PTC current limiting protection module also feeds back the stimulation current data to the main control chip module as a data reference for the main control program.

[0008] Furthermore, the main control chip module uses the STM32F407ZGT6 chip, which is connected to the prosthetic hand system via the Bluetooth / UART serial port to obtain fingertip pressure and slip information in real time, and then adjust the neural stimulation waveform, stimulation intensity, and pulse width parameters.

[0009] Furthermore, the voltage-stabilized power supply module includes multiple voltage-boosting and voltage-buckling modules, including a 3.3V voltage-buckling module, a +5V and +15V voltage-stabilizing module, a -5V and -15V voltage-stabilizing module, and a ±50V voltage-boosting module.

[0010] Furthermore, the neural-imitation waveform trigger module simulates the changes in the membrane potential of nerve cells based on the Izhikevich model, and can generate different types of electrical stimulation waveforms in real time. The membrane potential fitting parameters and equivalent impedance parameter settings for different trigger waveforms are basically the same. The action potential waveforms of different neurons are reproduced by adjusting the discharge mode parameters, which is the pre-trigger waveform of the stimulation square wave. Among them, the perception of pressure information corresponds to the regular spike (RS) stimulation model, the perception of texture information corresponds to the chattering waveform (CH) stimulation model, and the perception of pain information corresponds to the fast spike (FS) stimulation model. The perception intensity information is used as the input variable of the neural excitation model to automatically adjust the trigger frequency of the stimulation waveform.

[0011] Furthermore, the mirror voltage-controlled constant current module linearly adjusts the output constant current source to stimulate the biphasic amplitude within the range of 10mA according to the input voltage. The relevant circuit structure is as follows: Figure 3 shown.

[0012] A stimulation method based on a neuromorphic potential triggered stimulation system, the specific control process is as follows:

[0013] 1) After the system is powered on, the clock is enabled first, and each module is initialized, maintaining the stimulation mode and stimulation waveform with original parameters.

[0014] 2) The control program polls the Bluetooth / serial port to see if it receives fingertip pressure information, makes a judgment based on the intensity and type of the pressure information, and selects and updates one or more neural excitation trigger generation models.

[0015] 3) Substitute pressure information as an independent variable into various neural excitation models to generate neural triggering waveforms that are different in both time and frequency domains.

[0016] 4) With the help of trigger waveform and mirror Wilson voltage-controlled constant current module, a biphasic square wave stimulation signal for target nerve sensory stimulation is generated. According to different sensory thresholds, the stimulation amplitude and stimulation pulse width parameters are appropriately adjusted to produce multidimensional proprioception.

[0017] 5) Use the PTC current limiting protection module to ensure the stability of the stimulation device, and collect the stimulation current back to the main control program as a basis for abnormal situation judgment.

[0018] The beneficial effects of the present invention are:

[0019] The present invention determines the corresponding neural triggering model based on the fingertip pressure signal, and then determines the electrical stimulation waveform input to the target nerve based on the neural triggering signal, thereby expanding the information dimension that a single nerve channel can perceive and enabling fine manipulation of the prosthetic system in the absence of visual feedback. In addition, the corresponding waveform generation hardware and multi-dimensional information transmission control algorithm are designed based on the neural stimulation excitation model, achieving a more natural and efficient two-way interactive control effect for the prosthetic hand system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is composed of the structure of the stimulation system of the neural model.

[0021] Figure 2 Different types of trigger waveforms based on the Izhikevich neural model.

[0022] Figure 3 It is a mirror image of the Wilson voltage-controlled constant current module schematic.

[0023] Figure 4 This is a stimulation flow chart based on the neural excitation model. DETAILED DESCRIPTION

[0024] The following describes the specific embodiments of the present invention in conjunction with the accompanying drawings so that those skilled in the art can better understand the present invention. It should be noted that the following description is only used to explain the present invention and is not intended to limit the present invention.

[0025] A neuromorphic potential trigger stimulation system for tactile feedback of artificial hands consists of Figure 1As shown, the system primarily comprises a voltage-regulated power supply module, a main control chip module, a neural-like waveform trigger module, a PTC current-limiting protection module, and a Bluetooth / serial communication module. The waveform generation module includes a neural-like waveform trigger module, a digital-to-analog conversion module, a mirrored voltage-controlled constant current module, and a PTC current-limiting protection module. The voltage-regulated power supply module converts the portable battery's 10.5V voltage into regulated power supplies of 3.3V, ±5V, ±15V, and ±50V, respectively, to power the remaining functional modules. The main control chip module provides logic control signals for the functional modules. The prosthetic hand device and environmental sensing device communicate with the main control chip module via a Bluetooth / serial communication module. The neural-like waveform trigger module first selects one or more neural-like excitation waveforms based on the intensity and type of interdigital tactile sensation. It then generates a trigger waveform in real time using the perceived intensity information as an independent variable. Based on the trigger waveform, the main control chip module sends a bidirectional square wave pulse signal to the digital-to-analog conversion module, with a stimulation frequency ranging from 10Hz to 50Hz. The negative phase of the waveform generates sensory transmission pulses, while the positive phase pulse neutralizes negative charges without causing neural excitation, thus preventing charge accumulation and tissue damage during long-term use. Given that human tissue impedance fluctuates frequently within the range of 500Ω to 4kΩ, the generated biphasic square wave signal (±5V) requires a voltage-controlled constant current module for power amplification and constant current source stimulation. To prevent damage to human tissue caused by excessive stimulation current, the stimulation system ends with a PTC current limiting protection module, ensuring the safe operation of the electrical stimulation system and the stable output of current to the external stimulation electrodes. Simultaneously, the stimulation current data is fed back to the digital-to-analog conversion circuit of the main control module as a data reference for the main control program.

[0026] The main control chip module of this invention uses the STM32F407ZGT6 chip, which boasts a rich set of peripheral functions and ample general-purpose input / output (GPIO) interfaces. It operates at a frequency of up to 168MHz and supports a variety of functional modules, including 12 general-purpose timers, two PWM synchronization timers, three 24-bit ADCs, two 12-bit DACs, a UART interface, and an SPI interface. The main control chip connects to the prosthetic hand system via a UART serial port, acquiring real-time information about fingertip pressure and slip sensation, thereby adjusting the neurostimulation waveform, stimulation intensity, and pulse width parameters. The voltage-stabilized power supply module is mainly implemented through multiple boost / buck chip circuits. Specifically, the 3.3V buck module is implemented using TI's TPS70351 chip, the +5V and +15V voltage-stabilizing modules are implemented using TI's TPS62051 chip and LMR62014 chip respectively, the -5V and -15V voltage-stabilizing modules are implemented using Microchip Technology's inverting charge pump TC7662B chip, and the ±50V boost circuit is implemented using Linear Technology's LT8580 chip to build a SEPIC circuit.

[0027] The neural waveform triggering model, as the core functional module of the stimulation method of the present invention, simulates the changes in nerve cell membrane potential based on the Izhikevich model and can generate different electrical stimulation waveforms in real time. Compared with the classic Hodgkin–Huxley neural action potential model, the Izhikevich model simplifies the complex partial differential equations into a binary state equation containing only the membrane potential v and the refractory variable u, such as Figure 2 As shown. The Izhikevich neural discharge model can be expressed as follows:

[0028]

[0029] In the above formula, I is the input current of the synapse, which is set as the intensity signal of the integrated pressure sensor in the prosthetic hand system in this invention; A, B, C are the quadratic fitting curve constants of the rising stage of the action potential, which are usually 0.04 / Vs, 5 / s, and 140V / s respectively; R, C m — the equivalent resistance and equivalent capacitance of the neural membrane, usually taken as 1F and 1Ω; a, b, c, d — the adjustment parameters of the neural discharge pattern, representing the excitation waveforms of different types of neurons, v th ——The membrane potential threshold used to judge reset, v c ——Reset voltage of the pulse waveform.

[0030] The described neural waveform trigger module uses essentially the same membrane potential fitting parameters (A, B, C) and equivalent impedance parameters (R, Cm) for different trigger waveforms. By adjusting the discharge pattern parameters (a, b, c, d), it reproduces the action potential waveforms of different neurons, which serve as the pre-trigger waveform for the stimulation square wave. Specifically, pressure information perception corresponds to the RS (Regular Spiking) stimulation model, texture information perception corresponds to the CH (Chatting) stimulation model, and pain information perception corresponds to the FS (Fast Spiking) stimulation model. Furthermore, the perceived intensity information serves as the input variable I of the neural excitation model to automatically adjust the trigger frequency of the stimulation waveform.

[0031] The structure of the mirror voltage-controlled constant current module is as follows: Figure 3As shown, its purpose is to linearly adjust the output constant current source to stimulate the biphasic amplitude within a 10mA range based on the input voltage. The front-end DAC module generates a bidirectional control voltage with a bidirectional amplitude. The voltage output range is -5V to +5V. The DAC module uses Texas Instruments' 12-bit DAC7714 chip. The voltage-controlled constant current circuit has a mirrored structure: the upper half includes a differential amplifier U1, resistors R1, R2, R3, and transistors Q1, Q2, Q3, and Q4; the lower half includes a differential amplifier U2, resistors R4, R5, R6, and transistors Q5, Q6, Q7, and Q8. The differential amplifier uses the Analog Devices AD8054 chip.

[0032] The specific structure is as follows: in the upper part, the non-inverting input of the differential amplifier U1 is connected to the output of the DAC module, and the inverting input is grounded through resistor R1; the output of the differential amplifier U1 is connected to the base of the transistor Q1 to control the on / off of Q1 and the current flowing through resistor R1; the emitter of the transistor Q1 is grounded through resistor R1, and the collector of the transistor Q1 is connected to the collector of Q2 and the base of Q4 of the back-end Wilson constant current circuit. In the back-end mirror Wilson constant current circuit, the base of the transistor Q2 is connected to the base of Q3, and the emitters of the transistors Q2 and Q3 are connected to the positive power supply V through energy-consuming resistors R2 and R3 respectively. CC connect.

[0033] In the lower part, the non-inverting input of the differential amplifier U2 is connected to the output of the DAC module, and the inverting input is grounded through resistor R4; the output of the differential amplifier U2 is connected to the base of the transistor Q5, controlling the on / off of Q5 and the current flowing through resistor R4; the emitter of the transistor Q5 is grounded through resistor R4, and the collector of the transistor Q5 is connected to the collector of Q6 and the base of Q8 of the back-end Wilson constant current circuit. In the back-end mirror Wilson constant current circuit, the base of the transistor Q6 is connected to the base of Q7, and the emitters of the transistors Q6 and Q7 are connected to the negative power supply V through energy-dissipating resistors R5 and R6 respectively. EE connect.

[0034] In the upper and lower parts, the component network composed of transistors Q2, Q3, Q4 and energy dissipation resistors R2, R3, transistors Q6, Q7, Q8, and energy dissipation resistors R5, R6 and the load resistor R LOAD From the perspective of circuit function, the voltage-controlled constant current module can be divided into two parts: the front-end voltage-controlled current and the back-end Wilson power amplifier.

[0035] Take the positive square wave control voltage as an example ( Figure 3The positive voltage controls the transistor Q1 to conduct. According to the virtual short and virtual open relationship of the proportional amplifier circuit, the current flowing through the resistor R1 is i1 = V S / R1; if the control voltage does not change, the conduction current remains constant. In order to ensure that the stimulation waveform can still be output without distortion under different loads, the present invention connects the Wilson constant current source circuit with the front-end voltage-controlled constant current module to ensure sufficient power and output current stability. Figure 3 As shown in the upper part, the characteristics of Q2, Q3, and Q4 transistors are exactly the same (that is, the DC amplification factor β value is the same), so the output current i of the Wilson constant current source is out1 It can be expressed as:

[0036]

[0037] Correspondingly, when the control voltage V S When the voltage constant current source is negative, the current amplification factors of Q5, Q6, and Q7 in the lower part of the voltage controlled constant current module must be kept consistent. CC and V EE When the power supply is sufficient, the output current i out1 and i out2 Keeping consistent with the front-end voltage-controlled currents i1 and i2, the excess power is consumed in the two circuit structures of R2, R3, Q2, Q3 and R5, R6, Q6, Q7.

[0038] The flowchart of the neuromorphic potential triggering stimulation of the present invention is as follows Figure 4 As shown, the specific control process is as follows:

[0039] 1) After the system is powered on, the clock is enabled and each module is initialized, maintaining the stimulation mode and stimulation waveform with the original parameters (no waveform is output for the first time);

[0040] 2) The control program polls the Bluetooth / serial port to see if it receives fingertip pressure information, determines the intensity and type of the pressure information, and selects and updates one or more neural excitation trigger generation models;

[0041] 3) Substituting pressure information as an independent variable into various neural excitation models to generate neural triggering waveforms that are different in both time and frequency domains;

[0042] 4) Using the trigger waveform and the mirrored Wilson voltage-controlled constant current module, a biphasic square wave stimulation signal is generated for target nerve sensory stimulation. According to the sensory threshold of different subjects, the stimulation amplitude and pulse width and other parameters are appropriately adjusted to produce multi-dimensional proprioception;

[0043] 5) The PTC current limiting protection module is used to ensure the stability of the stimulation device, and the stimulation current is collected back to the main control program through the ADC module as a basis for abnormal situation judgment.

[0044] The above content has provided a detailed introduction to the present invention, but the description of the specific implementation methods is only used to explain the method of the present invention and its core ideas, so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation methods. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concepts of the present invention are protected.

Claims

1. A neuromorphic potential-triggered stimulation system for tactile feedback of a prosthetic hand, characterized by: It includes a voltage-stabilized power supply module, a main control chip module, a waveform generation module and a Bluetooth / serial communication module; wherein the voltage-stabilized power supply module includes a battery, a buck module and a boost module, and the waveform generation module includes a neural waveform trigger module, a digital-to-analog conversion module, a mirror voltage-controlled constant current module and a PTC current limiting protection module; the voltage-stabilized power supply module converts the battery 10.5V voltage into a voltage-stabilized power supply to provide power supply for each module; the main control chip module provides logic control signals for each module, and the artificial hand device and the environmental perception device are connected and communicated with the main control chip module through the Bluetooth / serial communication module; the neural waveform trigger module first selects a certain level according to the intensity and type of tactile sensation between the fingers. One or more neural excitation-simulating waveforms are generated, and then a trigger waveform is generated in real time using the perception intensity information as an independent variable. The main control chip module sends a biphasic square wave pulse signal to the digital-to-analog conversion module based on the trigger waveform, wherein the negative phase part of the waveform can generate a sensory transmission pulse, and the positive phase pulse part is used to neutralize the negative charge without causing neural excitation; the signal after digital-to-analog conversion is power amplified and stimulated by a constant current source through a mirror voltage-controlled constant current module, and finally enters the PTC current limiting protection module to ensure the safe operation of the electrical stimulation system and the stable output of the current to the external stimulation electrode interface. At the same time, the PTC current limiting protection module feeds back the stimulation current data to the main control chip module as a data reference for the main control program; The front end of the mirror voltage-controlled constant current module generates a bidirectional control voltage with a bidirectional amplitude by a DAC module, and the voltage output range is -5V~+5V. The circuit connection structure is divided into an upper and lower mirror structure. The upper part includes a differential amplifier U1, resistors R1, R2, R3, transistors Q1, Q2, Q3, Q4, and the lower part includes a differential amplifier U2, resistors R4, R5, R6, transistors Q5, Q6, Q7, Q8; in the upper part, the non-inverting input end of the differential amplifier U1 is connected to the output end of the DAC module, and the inverting input end is connected to the output end of the DAC module. The phase input terminal is grounded through resistor R1; the output terminal of the differential amplifier U1 is connected to the base of the transistor Q1 to control the on / off of Q1 and the current flowing through the resistor R1; the emitter of the transistor Q1 is grounded through resistor R1, and the collector of the transistor Q1 is connected to the collector of Q2 and the base of Q4 of the back-end Wilson constant current circuit; in the back-end Wilson constant current circuit, the base of the transistor Q2 is connected to the base of Q3, and the emitters of the transistors Q2 and Q3 are connected to the positive phase power supply V through energy dissipation resistors R2 and R3 respectively. CC connection; in the lower part, the non-inverting input of the differential amplifier U2 is connected to the output of the DAC module, and the inverting input is grounded through the resistor R4; the output of the differential amplifier U2 is connected to the base of the transistor Q5 to control the on and off of Q5 and the current flowing through the resistor R4; the emitter of the transistor Q5 is grounded through the resistor R4, and the collector of the transistor Q5 is connected to the collector of Q6 and the base of Q8 of the back-end Wilson constant current circuit; in the back-end Wilson constant current circuit, the base of the transistor Q6 is connected to the base of Q7, and the emitters of the transistors Q6 and Q7 are connected to the negative power supply V through the energy dissipation resistors R5 and R6 respectively. EE connect; In the upper and lower parts, the component network composed of transistors Q2, Q3, Q4 and energy dissipation resistors R2, R3, transistors Q6, Q7, Q8, and energy dissipation resistors R5, R6 and the load resistor R LOAD Connect to deliver a constant biphasic stimulation current.

2. The neuromorphic potential-triggered stimulation system for tactile feedback of a prosthetic hand according to claim 1, characterized in that: The main control chip module uses the STM32F407ZGT6 chip, which is connected to the prosthetic hand system through the Bluetooth / UART serial port to obtain fingertip pressure and slip information in real time, and then adjust the neural stimulation waveform, stimulation intensity, and pulse width parameters.

3. The neuromorphic potential-triggered stimulation system for tactile feedback of a prosthetic hand according to claim 1, characterized in that: The voltage-stabilized power supply module includes multiple voltage-boosting and voltage-buckling modules, including a 3.3V voltage-buckling module, a +5V and +15V voltage-stabilizing module, a -5V and -15V voltage-stabilizing module, and a ±50V voltage-boosting module.

4. The neuromorphic potential-triggered stimulation system for tactile feedback of a prosthetic hand according to claim 1, characterized in that: The neural-imitation waveform trigger module simulates the changes in the membrane potential of nerve cells based on the Izhikevich model and can generate different types of electrical stimulation waveforms in real time. The membrane potential fitting parameters and equivalent impedance parameter settings for different trigger waveforms are basically the same. The action potential waveforms of different neurons are reproduced by adjusting the discharge pattern parameters, which is the pre-trigger waveform of the stimulation square wave. Among them, the perception of pressure information corresponds to a regular spike stimulation model, the perception of texture information corresponds to a jitter waveform stimulation model, and the perception of pain information corresponds to a fast spike stimulation model. The perception intensity information is used as the input variable of the neural excitation model to automatically adjust the trigger frequency of the stimulation waveform.

5. The neuromorphic potential-triggered stimulation system for tactile feedback of a prosthetic hand according to claim 1, characterized in that: The mirror voltage-controlled constant current module linearly adjusts the output constant current source to stimulate the biphasic amplitude within a range of 10mA according to the input voltage.

6. A stimulation method for the neuromorphic potential-triggered stimulation system for tactile feedback of a prosthetic hand according to claim 1, characterized in that: The specific control process is as follows: 1) After the system is powered on, the clock is enabled and each module is initialized, maintaining the stimulation mode and stimulation waveform with the original parameters; 2) The control program polls the Bluetooth / serial port to see if it receives fingertip pressure information, determines the intensity and type of the pressure information, and selects and updates one or more neural excitation trigger generation models; 3) Substituting pressure information as an independent variable into various neural excitation models to generate neural triggering waveforms that are different in both time and frequency domains; 4) Using the trigger waveform and the mirror voltage-controlled constant current module, a biphasic square wave pulse signal is generated for target nerve sensory stimulation. According to different sensory thresholds, the stimulation amplitude and stimulation pulse width parameters are appropriately adjusted to produce multi-dimensional proprioception; 5) Use the PTC current limiting protection module to ensure the stability of the stimulation device, and collect the stimulation current back to the main control program as a basis for abnormal situation judgment.

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