Closed-loop electrical stimulation system and control method

Abstract

The invention provides a closed-loop electrical stimulation system and a control method.The closed-loop electrical stimulation system comprises an equipment main control system, a trigger and control system, an electrical stimulation system and an electrical signal collection system.The equipment main control system is used for receiving square wave trigger signals from external equipment and processing the square wave trigger signals through electrical stimulation work instructions; the electrical stimulation work instruction and the processed square wave trigger signal are transmitted to the trigger and control system; the trigger and control system is used for receiving the square wave trigger signal and the electrical stimulation work instruction, and responding to the square wave trigger signal by using a square wave generator included in the trigger and control system to generate a square wave signal; the electrical stimulation system comprises a plurality of signal channels and is used for generating a plurality of paths of electrical stimulation signal outputs; the electric signal acquisition system comprises a plurality of signal channels and is used for acquiring the current on the tested body bearing the multi-path electric stimulation signal output to obtain multi-path electric signal acquisition output, and the multi-path electric signal acquisition output is used for adjusting the parameters of the multi-path electric stimulation signal output.

Description

Technical Field

[0001] The present invention relates to the technical field of closed-loop electrical stimulation, and in particular to a closed-loop electrical stimulation system and a control method. Background Art

[0002] Transcranial Electrical Stimulation (tES) is a non-invasive and non-invasive neural stimulation technology that has little negative physical and psychological impact on people. It has become a hot topic for brain function research in recent years. According to the stimulation waveform output by transcranial electrical stimulation, it can be divided into: transcranial direct current stimulation, transcranial alternating current stimulation and transcranial random noise stimulation.

[0003] Existing transcranial electrical stimulation technologies generally use open source stimulation methods, which makes it difficult to know the patient's current state. If a closed-loop feedback is to be formed, it needs to be used in conjunction with other EEG equipment, which increases the technical and cost burden. Among them, a closed-loop feedback system refers to an automatic control system based on the feedback principle, which compares the deviation between behavior (output) and expected behavior and eliminates these deviations to achieve the expected performance. In general, a closed loop contains a signal forward path and a signal feedback path, and the feedback can be positive feedback or negative feedback.

[0004] In recent years, new transcranial electrical stimulation applications have emerged, making it difficult for the original transcranial electrical stimulation technology to adapt to new changes. For example, time-coherent electrical stimulation technology requires monitoring of coherent waveforms, and in order to achieve better focusing effects, multi-channel electrical stimulation technology is required, which poses new challenges to the real-time detection of current. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a closed-loop electrical stimulation system to eliminate or improve one or more defects existing in the prior art.

[0006] One aspect of the present invention provides a closed-loop electrical stimulation system, which includes a device main control system, a trigger and control system, an electrical stimulation system and an electrical signal acquisition system, in which: the device main control system is used to receive a square wave trigger signal and an electrical stimulation work instruction from an external device, use a trigger signal processing circuit included in the device main control system to process the square wave trigger signal, and transmit the electrical stimulation work instruction and the processed square wave trigger signal to the trigger and control system; the trigger and control system is used to receive the square wave trigger signal and the electrical stimulation work instruction, and use the square wave generator response circuit included in the trigger and control system to generate the electrical stimulation work instruction. A square wave signal is generated in response to a square wave trigger signal, and the generated square wave signal is transmitted to the electrical stimulation system; the electrical stimulation system includes multiple signal channels, which take the generated square wave signal as input and are used to generate multiple electrical stimulation signal outputs, so that the device main control system controls the electrical stimulation system according to the electrical stimulation work instructions to use the multiple electrical stimulation signal outputs to electrically stimulate the subject; the electrical signal acquisition system includes multiple signal channels, which are used to collect current on the subject who is subjected to the multiple electrical stimulation signal outputs to obtain multiple electrical signal acquisition outputs, and the multiple electrical signal acquisition outputs are used to adjust the parameters of the multiple electrical stimulation signal outputs to achieve closed-loop electrical stimulation.

[0007] In some embodiments of the present invention, the device main control system also includes a single-chip microcomputer, a first communication module, a second communication module, an operation display interface, a storage device and a data processing module; wherein the single-chip microcomputer is used to control the operation of the first communication module, the second communication module, the operation display interface, the storage device and the data processing module, and is also used to receive the square wave trigger signal processed by the trigger signal processing circuit; the first communication module is connected to an external device, and is used to receive a signal or instruction from the external device; the single-chip microcomputer is used to forward the square wave trigger signal to the second communication module, and the second communication module transmits the square wave trigger signal to the trigger and control system; the operation display interface is connected to the single-chip microcomputer, and is used to receive external input control instructions and present monitoring data of closed-loop electrical stimulation; the storage device includes variable storage and immutable storage, and is used to store parameters related to closed-loop electrical stimulation; the data processing module is connected to the single-chip microcomputer, and is controlled by the single-chip microcomputer to perform calculation processing.

[0008] In some embodiments of the present invention, the external device includes a user operation device and an external trigger device, the user operation device is used to generate a user operation instruction, and the external trigger device is used to generate a square wave trigger signal.

[0009] In some embodiments of the present invention, the trigger and control system includes a third communication module, a single-chip microcomputer and a square wave generator; wherein the third communication module establishes a communication connection with the second communication module; the single-chip microcomputer is connected to the square wave generator, and the single-chip microcomputer is used to receive a square wave trigger signal from the device main control system and control the square wave generator to generate a square wave signal; the single-chip microcomputer is also used to receive multiple electrical signal acquisition outputs from the electrical signal acquisition system.

[0010] In some embodiments of the present invention, each signal channel of the electrical stimulation system includes a signal generator, a low-pass filter, an analog-to-digital converter, a voltage amplifier, a voltage-to-current converter, a second low-pass filter, a sampling resistor and a waveform monitoring circuit; wherein the signal generator is used to generate an electrical stimulation signal based on an input square wave signal, and the signal generator is also controlled by the waveform monitoring circuit to ensure the stability of the electrical stimulation signal finally output; the low-pass filter is used to filter out high-frequency noise in the electrical stimulation signal; the analog-to-digital converter is used to convert the electrical stimulation signal in analog digital form into an electrical stimulation signal in analog signal form; the voltage amplifier is used to adjust the size of the electrical stimulation signal in analog signal form; the voltage-to-current converter is used to convert the electrical stimulation signal in voltage form into the electrical stimulation signal in current form by using a mirror current source method; the second low-pass filter is used to filter the electrical stimulation signal processed by the voltage-to-current converter; the sampling resistor includes multiple different resistance values, which is used to detect the current waveform of the electrical stimulation signal to prevent short circuit; the waveform monitoring circuit is used to perform peak monitoring, impedance monitoring and maximum output monitoring on the generated electrical stimulation signal, and the electrical stimulation signal that meets the preset requirements is output to the electrode.

[0011] In some embodiments of the present invention, each signal channel of the EEG signal acquisition system includes a pre-low-pass filter, a differential preamplifier, a high-pass filter, a baseline drift removal circuit, a 50Hz notch filter, a low-pass filter, a post-amplifier, a level shift circuit and an analog-to-digital converter connected in sequence. The pre-low-pass filter is connected to the electrode, and the electrical signal collected from the electrode is returned to the single-chip microcomputer via the EEG signal acquisition system, thereby obtaining an electrical signal acquisition output.

[0012] In some embodiments of the present invention, the electrical signal acquisition system and the electrical stimulation system share an electrode, namely, a multiplexed electrode, and the multiplexed electrode is controlled by a selection switch.

[0013] Correspondingly, another aspect of the present invention provides a closed-loop electrical stimulation control method, which adopts an electrical stimulation control method, and the method includes the following steps: adjusting multiple signal waveforms, signal frequencies, signal phases and signal strengths in each signal channel of the electrical stimulation system; monitoring the current output and voltage output of the output electrical stimulation signal in real time, and then monitoring the impedance changes; measuring the current intensity, peak value and impedance of the output electrical stimulation signal in real time, and forcibly interrupting the output of the electrical stimulation signal when any one of the current intensity, peak value and impedance exceeds a predetermined threshold.

[0014] On the other hand, the present invention provides a closed-loop electrical stimulation control method, which adopts an EEG acquisition control method including impedance measurement and / or common reference acquisition, and the method includes the following steps: using impedance measurement to perform closed-loop electrical stimulation control, monitoring impedance changes in real time before obtaining multi-channel electrical signal acquisition output, and adjusting the parameters of the multi-channel electrical stimulation signal output according to the monitored impedance changes; and / or using a common reference acquisition method to perform closed-loop electrical stimulation control, the signal channel of the electrical signal acquisition system and the signal channel of the electrical stimulation system share an electrode as one end, and the other end of the signal channel of the electrical signal acquisition system is connected to the reference electrode.

[0015] On the other hand, the present invention provides a closed-loop electrical stimulation control method, which adopts a trigger control method, and the trigger control method includes external trigger control and / or internal trigger control. The method includes the following steps: using an external trigger control method to perform closed-loop electrical stimulation control, an external trigger device included in an external device generates a signal input to the device main control system, causing the device main control system to interrupt, execute an interrupt program, and send instructions to the trigger and control system, and the trigger and control system controls the electrical stimulation or electrical signal acquisition system after receiving the instructions; and / or using an internal trigger control method to perform closed-loop electrical stimulation control, the internal trigger control method includes electrical stimulation triggering and acquisition signal triggering, electrical stimulation triggering refers to using the output signal of a square wave signal generator to control the opening and closing of the electrical stimulation system, and acquisition signal triggering refers to using a square wave signal generator to control the opening or stopping of the electrical signal acquisition output returned by the receiving electrical signal acquisition system.

[0016] Another aspect of the present invention provides a closed-loop electrical stimulation control method, the method adopts a threshold tracking feedback control method, and the method comprises the following steps:

[0017] The digital signal generation chip in the signal generator generates two waveforms, one is a wider square wave called polarization pulse, and the other is a narrower test pulse, which are synthesized together by the in-phase superposition circuit;

[0018] At the beginning, no polarization pulse is generated, only a test pulse is generated, and the intensity gradually increases from zero. The electrical signal acquisition system collects the electromyographic signal of the corresponding muscle. When an obvious electromyographic signal is observed, the output is stopped. This intensity is the resting threshold. The square wave generator output waveform is set, and the repetition frequency is set according to the stimulation frequency. The square wave generator sends a square wave input to the signal generator. The signal generator receives the square wave signal and outputs a pulse signal. The polarization pulse and the test pulse are output at the same time, and are synthesized by the in-phase adder. The test pulse gradually increases from zero. The square wave generator sends a square wave input to the electrical signal acquisition system. The electrical signal starts to be acquired after receiving the signal. The electrical signal acquisition system only responds to the first square wave signal. The square wave signal output is input to the single-chip microcomputer, and the single-chip microcomputer records the acquisition time of the square wave signal and transmits it to the main control system of the equipment; the main control system of the equipment segments the received electromyographic signal according to the acquisition time recorded by the single-chip microcomputer, calculates the integrated electromyographic, peak, average or median frequency of each segment, and generates an integrated electromyographic change curve, with the intensity of the test pulse as the horizontal coordinate and the calculated characteristic value as the vertical coordinate; as the test pulse increases, the change curve becomes flat, and the inflection point intensity is recorded as the maximum integrated electromyographic, and the stimulation and acquisition are stopped, and the preset percentage of the maximum integrated electromyographic is set as the threshold, and steps 3-7 are executed again. As the test pulse intensity increases, when the calculated integrated electromyographic exceeds the threshold, the test pulse intensity is reduced.

[0019] On the other hand, the present invention provides a closed-loop electrical stimulation control method, which adopts a multi-frequency time interference stimulation feedback control method. The method outputs multiple sine waves with different preset frequencies, collects the waveforms of each channel in the same time period through waveform monitoring, takes any channel as a reference, calculates the correlation function of the remaining channels and the reference channel, calculates the phase, and adjusts the phase of each channel. By calculating parameters such as event-related potential spectrum, peak intensity, peak time, average value, etc., the measured values ​​are compared with preset normal values, and the parameters of the multi-channel electrical stimulation signal output are adjusted.

[0020] The closed-loop electrical stimulation system and control method proposed in the present invention can utilize the electrical signal acquisition system to collect the size of the electrical stimulation signal applied to the subject, and adjust the parameters of the multi-channel electrical stimulation signal output to achieve closed-loop electrical stimulation by implementing the collected electrical stimulation signal size. The closed-loop electrical stimulation system proposed in the present invention can achieve closed-loop feedback of transcranial electrical stimulation without the participation of other electroencephalographic equipment. The current state of the patient can be known through closed-loop electrical stimulation. At the same time, the current formed by transcranial electrical stimulation can be detected in real time, so as to better adapt to new transcranial electrical stimulation methods.

[0021] Additional advantages, purposes, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention may be achieved and obtained by the structures specifically indicated in the specification and the accompanying drawings.

[0022] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention.

[0024] Figure 1 Schematic diagram of the structure of a closed-loop electrical stimulation system and a control method in one embodiment of the present invention.

[0025] Figure 2 Schematic diagram of the structure of the main control system of the device of the closed-loop electrical stimulation system and control method in one embodiment of the present invention.

[0026] Figure 3 It is a schematic diagram of the structure of a triggering and control system of a closed-loop electrical stimulation system and control method in one embodiment of the present invention.

[0027] Figure 4 It is a schematic diagram of the structure of an electrical stimulation system of a closed-loop electrical stimulation system and a control method in one embodiment of the present invention.

[0028] Figure 5 It is a structural schematic diagram of an electrical signal acquisition system of a closed-loop electrical stimulation system and a control method in one embodiment of the present invention.

[0029] Figure 6 Schematic diagram of the electrode connection structure of a closed-loop electrical stimulation system and control method in one embodiment of the present invention.

[0030] Figure 7 Schematic diagram of an electromyographic feedback method of a closed-loop electrical stimulation system and control method in one embodiment of the present invention.

[0031] Figure 8 Schematic diagram of phase adjustment in a neural feedback manner of a closed-loop electrical stimulation system and control method in one embodiment of the present invention.

[0032] Fig. 9 Schematic diagram of a neural feedback mode of a closed-loop electrical stimulation system and control method in one embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0034] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0035] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0036] It should also be noted that, unless otherwise specified, the term “connection” herein may refer not only to a direct connection but also to an indirect connection involving an intermediate.

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0038] The technical objectives of the present invention include: (1) Proposing a closed-loop feedback implementation scheme for transcranial electrical stimulation without combining with other EEG equipment, through which the patient's current state can be known. (2) Real-time detection of the current generated by transcranial electrical stimulation is performed to better adapt to new transcranial electrical stimulation methods.

[0039] In order to achieve the technical objectives of the present invention, the present invention proposes a closed-loop electrical stimulation system. Figure 1 The following is a schematic diagram of the structure of a closed-loop electrical stimulation system and control method in one embodiment of the present invention. The closed-loop electrical stimulation system includes a device main control system, a trigger and control system, an electrical stimulation system, and an electrical signal acquisition system. The functions of each part of the system are as follows:

[0040] (1) A main control system, which is used to receive a square wave trigger signal and an electrical stimulation work instruction from an external device, process the square wave trigger signal using a trigger signal processing circuit included in the device main control system, and transmit the electrical stimulation work instruction and the processed square wave trigger signal to a trigger and control system.

[0041] In the specific implementation process, the device main control system can include two communication modules, an operation display interface, a trigger signal processing circuit, a memory and a data processing module. The control module can realize information interaction with external devices, control the operation of the subsystem, and collect electrical signals and electrical stimulation waveform data.

[0042] (2) A trigger and control system, which is used to receive a square wave trigger signal and an electrical stimulation work instruction, and to generate a square wave signal in response to the square wave trigger signal using a square wave generator included in the trigger and control system, and the generated square wave signal is transmitted to the electrical stimulation system. The electrical signal acquisition system and the electrical stimulation system are controlled by the trigger and control system.

[0043] In the specific implementation process, the trigger and control system may include a single-chip microcomputer, a square wave generator, a communication module, etc. The trigger and control system receives instructions transmitted from the device main control system, and then controls the operation of the electrical stimulation and electrical signal acquisition subsystems, and uploads data to the device main control system.

[0044] (3) The electrical stimulation system includes multiple signal channels, which use the generated square wave signal as input to generate multiple electrical stimulation signal outputs, so that the device main control system controls the electrical stimulation system according to the electrical stimulation work instructions to use the multiple electrical stimulation signal outputs to electrically stimulate the subject.

[0045] In the specific implementation process, the electrical stimulation system may include multiple signal channels, each channel includes a signal generator, a low-pass filter, an analog-to-digital converter, a voltage amplifier, a voltage-current converter and a sampling resistor, etc., which can realize multi-channel electrical stimulation signal output.

[0046] (4) The electrical signal acquisition system includes multiple signal channels for collecting the current on the subject who is subjected to the output of multiple electrical stimulation signals to obtain multiple electrical signal acquisition outputs, and the multiple electrical signal acquisition outputs are used to adjust the parameters of the multiple electrical stimulation signal outputs to achieve closed-loop electrical stimulation. In the specific implementation process, the electrical signal acquisition system may include multiple signal channels, each channel including a low-pass filter, a differential preamplifier, a high-pass filter, a 50Hz notch filter circuit, a baseline drift removal circuit, a post-amplifier circuit, a level shift circuit and an analog-to-digital converter, etc., which can achieve multiple electrical signal acquisition outputs. The electrical signal acquisition system can achieve closed-loop electrical stimulation through the acquisition and coordination with the electrical stimulation system. Among them, closed-loop electrical stimulation is a neural regulation technology that adjusts the intensity and frequency of electrical stimulation by sensing neural signals in real time.

[0047] Based on the closed-loop electrical stimulation system proposed in the present invention, the size of the electrical stimulation signal applied to the subject can be collected by using the electrical signal acquisition system. By implementing the collected size of the electrical stimulation signal, the parameters of the multi-channel electrical stimulation signal output are adjusted to achieve closed-loop electrical stimulation. The closed-loop electrical stimulation system proposed in the present invention does not require the participation of other electroencephalographic equipment to achieve closed-loop feedback of transcranial electrical stimulation. The current state of the patient can be known through closed-loop electrical stimulation. At the same time, the current formed by transcranial electrical stimulation can be detected in real time, so as to better adapt to new transcranial electrical stimulation methods.

[0048] In one embodiment of the present invention, Figure 2 The structure diagram of the device main control system of the closed-loop electrical stimulation system and control method in one embodiment of the present invention. The device main control system also includes a single-chip microcomputer, a first communication module, a second communication module, an operation display interface, a storage device and a data processing module. The functions of each module included in the device main control system are as follows:

[0049] (1) The single chip microcomputer is used to control the operation of the first communication module, the second communication module, the operation display interface, the storage device and the data processing module, and is also used to receive the square wave trigger signal processed by the trigger signal processing circuit;

[0050] (2) The first communication module is connected to an external device and is used to receive a signal or instruction from the external device;

[0051] In the specific implementation process, the first communication module includes a serial port transceiver module, an optical module, a Bluetooth module and a WiFi module. One end of the first communication module can be connected to an external device to communicate through a serial port, an optical fiber or a short baud high frequency radio. The external device includes a user-operable device such as a personal computer, and other devices include training equipment with the above communication function. The other end of the first communication module is connected to the single-chip microcomputer, and the single-chip microcomputer controls the operation of the first communication module, receives data from the first communication module, and sends data through the first communication module.

[0052] (3) The single chip microcomputer is used to forward the square wave trigger signal to the second communication module, and the second communication module transmits the square wave trigger signal to the trigger and control system.

[0053] In the specific implementation process, the second communication module includes a serial port transceiver module and an optical module. One end of the second communication module is connected to the single-chip microcomputer, the single-chip microcomputer controls the operation of the second communication module, receives data from the second communication module, and sends data through the second communication module. The other end of the second communication module is connected to the trigger and control system, and transmits the received information of the trigger and control system through the serial port and optical fiber connection.

[0054] (4) The operation display interface is connected to the single-chip microcomputer and is used to receive control commands input from the outside and present monitoring data of the closed-loop electrical stimulation.

[0055] In a specific implementation process, the operation display interface may include a liquid crystal touch screen, which is connected to the single chip microcomputer and is used to control the equipment and display monitoring data, etc.

[0056] (5) The storage device includes variable storage and immutable storage, and is used to store parameters related to closed-loop electrical stimulation.

[0057] In the specific implementation process, the variable storage and immutable storage devices include built-in read-only optical disks and solid-state hard disks. The immutable storage device contains read-only optical disk storage device information, device keys and other unchangeable information. The solid-state hard disk can be used to store changeable data. Both the variable and immutable storage devices are connected to the microcontroller and controlled by the microcontroller.

[0058] (6) The data processing module is connected to the single-chip microcomputer and performs calculation processing under the control of the single-chip microcomputer. The data processing module can include FPGA and DSP processing chips. The data processing module only retains the processing chip interface and can add chips as needed. The data processing module is connected to the single-chip microcomputer and is controlled by the single-chip microcomputer.

[0059] In addition, the system also includes a power module, which supplies power to the single-chip mainboard circuit, and the mainboard circuit supplies power to other modules.

[0060] In the specific implementation process, the trigger signal processing circuit includes a BNC interface and a signal processing circuit. The BNC interface can be connected to an external trigger device. The external trigger device includes a device with square wave output, such as an EEG acquisition device, a signal generator, etc. The signal processing circuit includes edge triggering, pulse triggering and level triggering, and the output end is connected to the interrupt interface of the single-chip microcomputer. A square wave is a non-sinusoidal waveform that usually appears during electronic signal processing. Its characteristic is that the signal value jumps between positive and negative values ​​within a fixed time interval, so it is also called a "jump wave". Edge triggering, pulse triggering and level triggering are all a type of trigger working mode.

[0061] In some embodiments of the present invention, the external device includes a user operation device and an external trigger device, the user operation device is used to generate a user operation instruction, and the external trigger device is used to generate a square wave trigger signal.

[0062] In some embodiments of the present invention, Figure 3 The structure diagram of the trigger and control system of the closed-loop electrical stimulation system and control method in one embodiment of the present invention. The trigger and control system also includes a third communication module, a single-chip microcomputer and a square wave generator. The functions of each module are as follows:

[0063] (1) The third communication module establishes a communication connection with the second communication module.

[0064] In the specific implementation process, the third communication module includes a serial port transceiver module and an optical module, which is connected to the second communication module, used for communicating with the second communication module, connected to the single-chip microcomputer, and controlled by the single-chip microcomputer.

[0065] (2) The single-chip microcomputer is connected to a square wave generator, and the single-chip microcomputer is used to receive a square wave trigger signal from the main control system of the device and control the square wave generator to generate a square wave signal. The input end of the square wave generator is connected to the single-chip microcomputer, and the single-chip microcomputer controls the signal generator to send a square wave signal. The output end of the square wave generator is connected to the electrical stimulation system to control the electrical stimulation output, and the other end of the output port is connected to the single-chip microcomputer for calibrating the time.

[0066] Specifically, the single chip microcomputer can be used to control the communication module, the square wave generator, the electrical stimulation system and the electrical signal acquisition system.

[0067] (3) The single chip microcomputer is also used to receive multiple channels of electrical signal acquisition output from the electrical signal acquisition system.

[0068] In some embodiments of the present invention, Figure 4 The schematic diagram of the structure of the electric stimulation system of the closed-loop electric stimulation system and control method in one embodiment of the present invention is shown in FIG. Each signal channel of the electric stimulation system includes a signal generator, a low-pass filter, an analog-to-digital converter, a voltage amplifier, a voltage-to-current converter, a second low-pass filter, a sampling resistor and a waveform monitoring circuit.

[0069] The functions of each module are as follows:

[0070] (1) The signal generator is used to generate an electrical stimulation signal based on an input square wave signal. The signal generator is also controlled by a waveform monitoring circuit to ensure the stability of the final output electrical stimulation signal.

[0071] In the specific implementation process, the signal generator includes a dual-channel digital signal generation chip and an in-phase superposition circuit, the input end of the signal generator is connected to the trigger and control system and is controlled by the single-chip microcomputer, the input end of the signal generator is connected to the detection circuit and is controlled by the detection circuit. The output end of the digital signal generation chip is connected to the input end of the in-phase superposition circuit, and the output end of the in-phase superposition circuit is connected to the first low-pass filter.

[0072] (2) The low-pass filter is used to filter out high-frequency noise in the electrical stimulation signal.

[0073] (3) The analog-to-digital converter is used to convert the electrical stimulation signal in analog-to-digital form into an electrical stimulation signal in analog signal form.

[0074] (4) The voltage amplifier is used to adjust the magnitude of the electrical stimulation signal in the form of an analog signal. The voltage amplifier is used to amplify the analog signal and can be used to control the magnitude of the output current.

[0075] (5) The voltage-to-current converter is used to convert the electrical stimulation signal in the form of voltage into the electrical stimulation signal in the form of current by adopting a mirror current source method, and to convert the voltage signal into the current signal.

[0076] (6) The second low-pass filter is used to filter the electrical stimulation signal after being processed by the voltage-to-current converter;

[0077] (7) The sampling resistor includes a plurality of different resistance values, which are used to detect the current waveform of the electrical stimulation signal and prevent short circuit. For example, different resistance values ​​can be set to 50 ohms, 200 ohms, 1000 ohms, and 1M ohms. The sampling resistor is used to detect the current waveform, prevent short circuit, and control safety.

[0078] (8) The waveform monitoring circuit is used to perform peak monitoring, impedance monitoring and maximum output monitoring on the generated electrical stimulation signal. The electrical stimulation signal that meets the preset requirements is output to the electrode. In the specific implementation process, the waveform monitoring includes two differential amplifiers, a signal conditioning circuit, an analog-to-digital converter and a simple operation circuit. One of the differential amplifiers monitors the voltage across the sampling resistor and inputs the differential signal into the signal conditioning circuit. The signal conditioning circuit performs filtering and then inputs the analog-to-digital converter to convert it into a digital signal. The digital signal enters the operation circuit one way and returns to the single-chip microcomputer one way. The other analog-to-digital converter measures the voltage difference between the input and output ends. After the conditioning circuit and the analog-to-digital converter, it enters the operation circuit one way and the single-chip microcomputer one way. The operation circuit can perform the following calculations: calculate the current based on the voltage difference across the sampling resistor, calculate the impedance based on the calculated current and the voltage difference between the input and output ends. The operation circuit can compare the calculation result with the preset value. If it exceeds the preset value, the operation current returns an interrupt signal to the signal generator, and at the same time sets the sampling resistor to 1M ohm. The preset value is set to the waveform peak value, maximum impedance and maximum current.

[0079] In addition, the system may also include a square wave signal processing circuit, which includes an upper and lower edge detection circuit and a pulse width detection circuit.

[0080] In some embodiments of the present invention, Figure 5The structure diagram of the electric signal acquisition system of the closed-loop electrical stimulation system and control method in one embodiment of the present invention. Each signal channel of the EEG signal acquisition system includes a pre-low-pass filter, a differential preamplifier, a high-pass filter, a baseline drift removal circuit, a 50Hz notch filter, a low-pass filter, a post-amplifier, a level shift circuit and an analog-to-digital converter connected in sequence. The pre-low-pass filter is connected to the electrode, and the electric signal collected from the electrode is returned to the single-chip microcomputer through the EEG signal acquisition system, thereby obtaining the electric signal acquisition output. In one embodiment of the present invention, the electrode and the reference electrode must pass through the pre-low-pass filter before being input into the preamplifier, and the filtered signal is input into the differential amplifier. The differential signal is input into the baseline drift removal circuit after high-pass filtering, and then amplified again after 50Hz filtering and low-pass filtering, and input into the analog-to-digital converter after adjusting the level, and finally the processed signal is returned to the single-chip microcomputer, and the pre-low-pass filter can be controlled by a square wave signal to turn on or off signal reception.

[0081] In some embodiments of the present invention, the electrical signal acquisition system and the electrical stimulation system share one electrode, namely, a multiplexed electrode, that is, the electrical stimulation pathway and the EEG acquisition share one electrode, and the multiplexed electrode is controlled by a selection switch. Figure 6 This is a schematic diagram of the electrode connection structure of a closed-loop electrical stimulation system and control method in one embodiment of the present invention. One end of the selection switch is connected to the multiplexed electrode, and the other end is between the electrical stimulation channel and the EEG acquisition channel. The electrical stimulation channel is connected to the return electrode, and the EEG stimulation channel is connected to the reference electrode.

[0082] Based on the closed-loop electrical stimulation system provided in the above invention embodiment, the following closed-loop electrical stimulation control method can be implemented, and the control method includes: electrical stimulation control mode, EEG acquisition control mode, trigger control mode and feedback control mode.

[0083] In some embodiments of the present invention, a closed-loop electrical stimulation control method using an electrical stimulation control method is proposed, the method comprising the following steps:

[0084] (1) adjusting multiple of the signal waveform, signal frequency, signal phase and signal strength in each signal channel of the electrical stimulation system;

[0085] (2) real-time monitoring of the current output and voltage output of the output electrical stimulation signal, and then monitoring the impedance change;

[0086] (3) measuring the current intensity, peak value and impedance of the output electrical stimulation signal in real time, and forcibly interrupting the output of the electrical stimulation signal when any one of the current intensity, peak value and impedance exceeds a predetermined threshold.

[0087] In one embodiment of the present invention, the method steps for closed-loop electrical stimulation using an electrical stimulation control method include: (1) adjusting the signal waveform, signal frequency, signal phase, and signal strength of each channel, selecting the superposition mode output and setting the slow rise and slow fall function, as well as electrical stimulation monitoring and safety control. (2) The signal waveform is the output waveform of any signal generator, and the default form can be selected, that is, square wave (unidirectional or bidirectional), sine wave, triangle wave, sawtooth wave, or it can be output through a custom function. (3) The signal frequency refers to the repetition frequency of the signal (sine wave refers to the signal frequency). (4) The signal phase refers to the relative phase between the signals of each channel. (5) The signal strength refers to the output current strength of the electrode, including the root mean square value and amplitude. (6) The superposition mode means that two signal generators can be used to output signals at the same time, and the signals are combined together through a superposition circuit. (7) The slow rise and slow fall function means that when adjusting the signal strength, the signal changes linearly according to the set time period. (8) The electrical stimulation detection means that during the stimulation process, the current output and voltage output can be monitored in real time, and then the impedance change can be monitored. (9) The safety control means that during the stimulation process, the output current intensity, peak value and impedance can be measured in real time. When these three exceed the predetermined threshold value, the output can be forcibly interrupted and the sampling resistor can be adjusted to the maximum resistance value.

[0088] In some embodiments of the present invention, a closed-loop electrical stimulation control method using an EEG acquisition control method is proposed, and the EEG acquisition control method includes impedance measurement and / or common reference acquisition, and the method includes the following steps: using impedance measurement to perform closed-loop electrical stimulation control, monitoring impedance changes in real time before obtaining multi-channel electrical signal acquisition outputs, and adjusting the parameters of the multi-channel electrical stimulation signal outputs according to the monitored impedance changes; and / or, using a common reference acquisition method to perform closed-loop electrical stimulation control, the signal channel of the electrical signal acquisition system and the signal channel of the electrical stimulation system share an electrode as one end, and the other end of the signal channel of the electrical signal acquisition system is connected to the reference electrode.

[0089] In a specific embodiment of the present invention, the steps of the closed-loop electrical stimulation control method using the EEG acquisition control method include: (1) The impedance measurement refers to real-time monitoring of impedance changes before EEG signal acquisition, the device uses the output of the electrical stimulation module, the waveform uses a low-frequency, low-intensity unidirectional square wave, and the impedance is measured in real time through the impedance monitoring function of the electrical stimulation system. 92 Common reference acquisition means that one end of all EEG channels is a sampling electrode (shared with the electrical stimulation channel), and the other end is connected to the reference electrode.

[0090] In some embodiments of the present invention, a closed-loop electrical stimulation control method using a trigger control method is proposed, wherein the trigger control method includes external trigger control and / or internal trigger control, and the method includes the following steps:

[0091] An external trigger control method is used for closed-loop electrical stimulation control, in which an external trigger device included in the external device generates a signal input to the device main control system, causing the device main control system to be interrupted, executing the interrupt program, and sending instructions to the trigger and control system. After receiving the instructions, the trigger and control system controls the electrical stimulation or electrical signal acquisition system; and / or, an internal trigger control method is used for closed-loop electrical stimulation control, and the internal trigger control method includes electrical stimulation triggering and acquisition signal triggering. Electrical stimulation triggering refers to using the output signal of a square wave signal generator to control the opening and closing of the electrical stimulation system, and acquisition signal triggering refers to using a square wave signal generator to control the opening or stopping of the electrical signal acquisition output returned by the receiving electrical signal acquisition system.

[0092] In another embodiment of the present invention, the trigger control method includes external trigger control and internal trigger control. When the external trigger device needs to be synchronized with the external device, the external trigger device signal is input to the device main control system, causing the main control system to interrupt, execute the interrupt program, and send instructions to the trigger and control system. After receiving the instructions, the trigger and control system controls the electrical stimulation or electrical signal acquisition system to work. There are two types of internal trigger control, one is electrical stimulation triggering, and the other is acquisition signal triggering. Electrical stimulation triggering means that the output signal of the square wave signal generator can control the electrical stimulation system to turn on and off; acquisition signal triggering means that the square wave signal generator can control the acquisition card to start or stop receiving the return signal of the electrical signal acquisition system or the monitoring signal of the electrical stimulation system.

[0093] In some embodiments of the present invention, a closed-loop electrical stimulation control method using a threshold tracking feedback control method is proposed. Figure 7The present invention is a schematic diagram of an electromyographic feedback method of a closed-loop electrical stimulation system and control method in one embodiment of the present invention. The method comprises the following steps: (1) the digital signal generating chip in the signal generator generates two waveforms, one is a wider square wave called a polarization pulse, and the other is a narrower test pulse, which are synthesized together through an in-phase superposition circuit; (2) at the beginning, no polarization pulse is generated, only a test pulse is generated, and the intensity gradually increases from zero. The electrical signal acquisition system collects the electromyographic signal of the corresponding muscle. When an obvious electromyographic signal is observed, the output is stopped. The intensity is the resting threshold; (3) the square wave generator output waveform is set, and the repetition frequency is set according to the stimulation frequency; (4) the square wave generator sends a square wave input to the signal generator. The signal generator receives the square wave signal and outputs a pulse signal. The polarization pulse and the test pulse are output simultaneously. After being synthesized by the in-phase superposition device, the test pulse gradually increases from zero; (5) the square wave generator sends a square wave input to the electrical signal acquisition system. The electrical signal acquisition system starts to collect the signal after receiving it, and the electrical signal acquisition system only responds to the first square wave signal; (6) The square wave signal emitted by the square wave generator is input to the single-chip microcomputer, and the single-chip microcomputer records the collection time of the square wave signal and transmits it to the main control system of the equipment; (7) The main control system of the equipment divides the received electromyographic signal into segments according to the collection time recorded by the single-chip microcomputer, calculates the integrated electromyographic signal, peak value, average value or median frequency of each segment, and generates an integrated electromyographic change curve, with the intensity of the test pulse as the horizontal axis and the calculated characteristic value as the vertical axis; (8) As the test pulse increases, the change curve becomes flat, and the inflection point intensity is recorded as the maximum integrated electromyographic signal, and the stimulation and collection are stopped, and the preset percentage of the maximum integrated electromyographic signal is set as the threshold, and steps 3-7 are executed again. As the test pulse intensity increases, when the calculated integrated electromyographic signal exceeds the threshold, the test pulse intensity is reduced.

[0094] In another embodiment of the present invention, the steps of the closed-loop electrical stimulation control method using the threshold tracking feedback control method specifically include:

[0095] (1) The digital signal generation chip in the signal generator generates two waveforms, one is a wider square wave called polarization pulse, and the other is a narrower test pulse, which are synthesized together through the in-phase superposition circuit. The intensity of the polarization pulse is generally 10% of the resting threshold (can be a negative value), and the pulse width can be set to 40ms. The test pulse intensity is adjustable, the pulse width is set to 2ms, and the phase is set to 20ms after the polarization pulse occurs.

[0096] (2) At the beginning, no polarization pulse is generated, only the test pulse is generated, and the intensity gradually increases from zero. The electrical signal acquisition system collects the electromyographic signal of the corresponding muscle (for example, the stimulation electrode is arranged on the ulnar nerve of the forearm, and the acquisition electrode is arranged on the hypothenar muscle). When a clear electromyographic signal is observed, the output is stopped, and this intensity is the resting threshold.

[0097] (3) Set the square wave generator output waveform, set the repetition frequency according to the stimulation frequency (set to 10 Hz), and set the duty cycle to 10%.

[0098] (4) The square wave generator sends a square wave input to the signal generator. The signal generator receives the square wave signal and outputs a pulse signal. The polarization pulse and the test pulse are output simultaneously and synthesized by the in-phase adder. The test pulse is gradually increased from zero.

[0099] (5) The square wave generator sends a square wave input to the electrical signal acquisition system. The electrical signal acquisition system starts collecting signals after receiving the signals. The electrical signal acquisition system only responds to the first square wave signal.

[0100] (6) The square wave signal emitted by the square wave generator is input into the single-chip microcomputer, which records the rising edge moment (acquisition time) of the square wave signal and transmits it to the main control system.

[0101] (7) The main control system divides the received EMG signal into segments according to the acquisition time recorded by the single-chip microcomputer, calculates the integrated EMG, peak value, average value, median frequency or other custom features of each segment, and generates an integrated EMG change curve (the horizontal axis is the intensity of the test pulse, and the vertical axis is the calculated characteristic value).

[0102] (8) As the test pulse increases, the curve becomes flatter, the inflection point intensity is recorded as the maximum integrated electromyographic signal, and stimulation and acquisition are stopped.

[0103] (9) Set 40% of the maximum integrated electromyography as the threshold, and execute steps (3)-(7) again. As the test pulse intensity increases, when the calculated integrated electromyography exceeds the threshold, reduce the test pulse intensity by the following amount: (integrated electromyography-threshold) / threshold*pulse intensity=reduced intensity.

[0104] In some embodiments of the present invention, a closed-loop electrical stimulation control method using a multi-frequency time interference stimulation feedback control method is proposed. Figure 8 Schematic diagram of phase adjustment in a neural feedback manner of a closed-loop electrical stimulation system and control method in one embodiment of the present invention. Fig. 9 The figure is a schematic diagram of a neural feedback method of a closed-loop electrical stimulation system and control method in another embodiment of the present invention. The method outputs a plurality of sine waves of different preset frequencies, collects the waveforms of each channel in the same time period through waveform monitoring, takes any channel as a reference, calculates the correlation function of the remaining channels and the reference channel, calculates the phase, and adjusts the phase of each channel, calculates the event-related potential spectrum, peak intensity, peak time, average value and other parameters, compares the measured values ​​with the preset normal values, and adjusts the parameters of the multi-channel electrical stimulation signal output.

[0105] In one embodiment of the present invention, the closed-loop electrical stimulation control method using a multi-frequency time interference stimulation feedback control method specifically comprises the following steps:

[0106] (1) The control system sends a command to the electrical stimulation device to start multi-channel electrical stimulation output (taking three channels as an example, outputting 1000 Hz, 1010 Hz, and 1020 Hz sine waves respectively).

[0107] (2) The waveforms of each channel in the same time period are collected through waveform monitoring. Taking any channel as the reference, the correlation function between the remaining channels and the reference channel is calculated, the phase is calculated (select a zero crossing point of the reference channel and the zero crossing point of another channel), and the phase of each channel is adjusted.

[0108] (3) The square wave generator generates a square wave signal (10 Hz, 50% duty cycle). The waveform monitor starts collecting when it detects the rising edge and stops collecting when it detects the falling edge. The collected data is transmitted to the main control system, which calculates the superimposed waveform of each channel and displays it.

[0109] (4) According to the displayed superimposed waveform, adjust the square wave phase so that the main peak of the superimposed waveform is displayed on the display screen included in the main control system of the equipment.

[0110] (5) Maintain square wave output, stop acquisition triggering, and the microcontroller records the time when the rising and falling edges of the square wave occur. The electrical signal acquisition system starts measuring the signal.

[0111] (6) The main control system divides the collected electrical signal according to the rising edge and falling edge time recorded by the single-chip microcomputer, and continuously superimposes the divided signals to obtain the electrical stimulation event-related potential.

[0112] (7) Calculate event-related potential spectrum, peak intensity, peak time, average value and other parameters, compare the measured values ​​with those of normal people, and adjust the corresponding electrical stimulation parameters.

[0113] The closed-loop electrical stimulation system and control method proposed in the present invention can utilize the electrical signal acquisition system to collect the size of the electrical stimulation signal applied to the subject, and adjust the parameters of the multi-channel electrical stimulation signal output to achieve closed-loop electrical stimulation by implementing the collected electrical stimulation signal size. The closed-loop electrical stimulation system proposed in the present invention can achieve closed-loop feedback of transcranial electrical stimulation without the participation of other electroencephalographic equipment. The current state of the patient can be known through closed-loop electrical stimulation. At the same time, the current formed by transcranial electrical stimulation can be detected in real time, so as to better adapt to new transcranial electrical stimulation methods.

[0114] It should be understood by those skilled in the art that the exemplary components, systems and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software or a combination of the two. Whether it is performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link via a data signal carried in a carrier.

[0115] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0116] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A closed-loop electrical stimulation system, characterized in that: The closed-loop electrical stimulation system includes a device main control system, a trigger and control system, an electrical stimulation system and an electrical signal acquisition system, in which: The device main control system is used to receive the square wave trigger signal and the electrical stimulation work instruction from the external device, process the square wave trigger signal by using the trigger signal processing circuit included in the device main control system, and transmit the electrical stimulation work instruction and the processed square wave trigger signal to the trigger and control system; A trigger and control system, which is used to receive a square wave trigger signal and an electrical stimulation work instruction, and to generate a square wave signal in response to the square wave trigger signal using a square wave generator included in the trigger and control system, and the generated square wave signal is transmitted to the electrical stimulation system; The electrical stimulation system comprises a plurality of signal channels, which take the generated square wave signal as input and are used to generate a plurality of electrical stimulation signal outputs, so that the main control system of the device controls the electrical stimulation system according to the electrical stimulation work instruction to perform electrical stimulation on the subject by using the plurality of electrical stimulation signal outputs; The electrical signal acquisition system includes multiple signal channels for collecting the current on the subject who is subjected to multiple electrical stimulation signal outputs to obtain multiple electrical signal acquisition outputs, which are used to adjust the parameters of the multiple electrical stimulation signal outputs to achieve closed-loop electrical stimulation.

2. A closed-loop electrical stimulation system according to claim 1, characterized in that: The device main control system also includes a single chip microcomputer, a first communication module, a second communication module, an operation display interface, a storage device and a data processing module; wherein, The single chip microcomputer is used to control the operation of the first communication module, the second communication module, the operation display interface, the storage device and the data processing module, and is also used to receive the square wave trigger signal processed by the trigger signal processing circuit; The first communication module is connected to an external device and is used to receive a signal or instruction from the external device; The single chip microcomputer is used to forward the square wave trigger signal to the second communication module, and the second communication module transmits the square wave trigger signal to the trigger and control system; The operation display interface is connected to the single-chip microcomputer and is used to receive control instructions input from the outside and present monitoring data of the closed-loop electrical stimulation; The storage device comprises a variable storage and an immutable storage, and is used for storing parameters related to the closed-loop electrical stimulation; The data processing module is connected to the single chip microcomputer and performs calculation processing under the control of the single chip microcomputer.

3. A closed-loop electrical stimulation system according to claim 1, characterized in that: The external device includes a user operation device and an external trigger device. The user operation device is used to generate a user operation instruction, and the external trigger device is used to generate a square wave trigger signal.

4. A closed-loop electrical stimulation system according to claim 2, characterized in that: The trigger and control system comprises a third communication module, a single chip microcomputer and a square wave generator; wherein, The third communication module establishes a communication connection with the second communication module; The single-chip microcomputer is connected to the square wave generator, and the single-chip microcomputer is used to receive a square wave trigger signal from the device main control system and control the square wave generator to generate a square wave signal; The single chip microcomputer is also used to receive multi-channel electrical signal acquisition outputs from the electrical signal acquisition system.

5. A closed-loop electrical stimulation system according to claim 1, characterized in that: Each signal channel of the electrical stimulation system includes a signal generator, a low-pass filter, an analog-to-digital converter, a voltage amplifier, a voltage-to-current converter, a second low-pass filter, a sampling resistor and a waveform monitoring circuit; wherein, The signal generator is used to generate an electrical stimulation signal based on an input square wave signal, and the signal generator is also controlled by a waveform monitoring circuit to ensure the stability of the final output electrical stimulation signal; The low-pass filter is used to filter out high-frequency noise in the electrical stimulation signal; The analog-to-digital converter is used to convert the electrical stimulation signal in analog-to-digital form into the electrical stimulation signal in analog signal form; The voltage amplifier is used to adjust the magnitude of the electrical stimulation signal in the form of an analog signal; The voltage-to-current converter is used to convert the electrical stimulation signal in the form of voltage into the electrical stimulation signal in the form of current by using a mirror current source method; The second low-pass filter is used to filter the electrical stimulation signal after being processed by the voltage-to-current converter; The sampling resistor includes a plurality of different resistance values, and is used to detect the current waveform of the electrical stimulation signal to prevent short circuit; The waveform monitoring circuit is used to perform peak monitoring, impedance monitoring and maximum output monitoring on the generated electrical stimulation signal, and the electrical stimulation signal that meets the preset requirements is output to the electrode.

6. A closed-loop electrical stimulation system according to claim 1, characterized in that: Each signal channel of the EEG signal acquisition system includes a pre-low-pass filter, a differential preamplifier, a high-pass filter, a baseline drift removal circuit, a 50Hz notch filter, a low-pass filter, a post-amplifier, a level shift circuit and an analog-to-digital converter connected in sequence. The pre-low-pass filter is connected to the electrode, and the electrical signal collected from the electrode is returned to the single-chip microcomputer via the EEG signal acquisition system, thereby obtaining an electrical signal acquisition output.

7. A closed-loop electrical stimulation system according to claim 6, characterized in that: The electrical signal acquisition system and the electrical stimulation system share one electrode, namely, a multiplexed electrode, and the multiplexed electrode is controlled by a selection switch.

8. A closed-loop electrical stimulation control method, characterized in that: The method adopts an electrical stimulation control mode, and the method comprises the following steps: adjusting multiple of a signal waveform, a signal frequency, a signal phase, and a signal strength within each signal channel of the electrical stimulation system; Real-time monitoring of the current output and voltage output of the output electrical stimulation signal, and then monitoring the impedance change; The current intensity, peak value and impedance of the output electrical stimulation signal are measured in real time. When any one of the current intensity, peak value and impedance exceeds a predetermined threshold, the output of the electrical stimulation signal is forcibly interrupted.

9. A closed-loop electrical stimulation control method, characterized in that: The method adopts an EEG acquisition control mode including impedance measurement and / or common reference acquisition, and the method includes the following steps: Using impedance measurement to perform closed-loop electrical stimulation control, real-time monitoring of impedance changes before obtaining multi-channel electrical signal acquisition outputs, and adjusting the parameters of the multi-channel electrical stimulation signal outputs according to the monitored impedance changes; and / or A common reference acquisition method is adopted for closed-loop electrical stimulation control, wherein a signal channel of the electrical signal acquisition system and a signal channel of the electrical stimulation system share a common electrode as one end, and the other end of the signal channel of the electrical signal acquisition system is connected to a reference electrode.

10. A closed-loop electrical stimulation control method, characterized in that: The method adopts a trigger control mode, which includes external trigger control and / or internal trigger control. The method includes the following steps: An external trigger control method is used for closed-loop electrical stimulation control. The external trigger device contained in the external device generates a signal input to the device main control system, causing the device main control system to interrupt, execute the interrupt program, and send instructions to the trigger and control system. After receiving the instructions, the trigger and control system controls the electrical stimulation or electrical signal acquisition system to work; and / or An internal trigger control method is used for closed-loop electrical stimulation control, and the internal trigger control method includes electrical stimulation triggering and acquisition signal triggering. Electrical stimulation triggering refers to using the output signal of a square wave signal generator to control the opening and closing of the electrical stimulation system, and acquisition signal triggering refers to using a square wave signal generator to control the opening or stopping of the electrical signal acquisition output returned by the receiving electrical signal acquisition system.

11. A closed-loop electrical stimulation control method, characterized in that: The method adopts a threshold tracking feedback control method, and the method comprises the following steps: The digital signal generation chip in the signal generator generates two waveforms, one is a wider square wave called polarization pulse, and the other is a narrower test pulse, which are synthesized together by the in-phase superposition circuit; At the beginning, no polarization pulse is generated, only the test pulse is generated, and the intensity gradually increases from zero. The electrical signal acquisition system collects the electromyographic signal of the corresponding muscle. When obvious electromyographic signal is observed, the output is stopped. This intensity is the resting state threshold. Set the square wave generator output waveform and set the repetition frequency according to the stimulation frequency; The square wave generator sends a square wave input to the signal generator. The signal generator receives the square wave signal and outputs a pulse signal. The polarization pulse and the test pulse are output at the same time and synthesized by the in-phase adder. The test pulse is gradually enhanced from zero. The square wave generator sends a square wave to the electrical signal acquisition system, and the electrical signal acquisition system starts collecting signals after receiving them. The electrical signal acquisition system only responds to the first square wave signal; The square wave signal emitted by the square wave generator is input into the single chip microcomputer, which records the acquisition time of the square wave signal and transmits it to the main control system of the equipment; The main control system of the equipment divides the received electromyographic signal into segments according to the acquisition time recorded by the single-chip microcomputer, calculates the integrated electromyographic, peak, average or median frequency of each segment, and generates an integrated electromyographic change curve, with the intensity of the test pulse as the horizontal axis and the calculated characteristic value as the vertical axis; As the test pulse increases, the curve becomes flatter, and the inflection point intensity is recorded as the maximum integrated EMG. Stimulation and acquisition are stopped, and the preset percentage of the maximum integrated EMG is set as the threshold. Steps 3-7 are performed again. As the test pulse intensity increases, when the calculated integrated EMG exceeds the threshold, the test pulse intensity is reduced.

12. A closed-loop electrical stimulation control method, characterized in that: The method adopts a multi-frequency time interference stimulation feedback control method. The method outputs multiple sine waves with different preset frequencies, collects the waveforms of each channel in the same time period through waveform monitoring, takes any channel as a reference, calculates the correlation function of the remaining channels and the reference channel, calculates the phase, and adjusts the phase of each channel. By calculating parameters such as event-related potential spectrum, peak intensity, peak time, average value, etc., the measured values ​​are compared with preset normal values, and the parameters of the multi-channel electrical stimulation signal output are adjusted.

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