CN117861073A - Stimulation position optimization system and method based on electrode array - Google Patents

Abstract

The invention discloses a stimulation position optimization system and method based on an electrode array, and relates to the field of auxiliary medical rehabilitation training. The system comprises an upper computer, a multichannel stimulator, an electrode array, an angle sensor and a power module. For a cerebral apoplexy patient with limb disorder, setting stimulation parameters according to the characteristics of different muscles through an upper computer, adjusting the number of electrodes in an electrode array and the stimulation intensity, obtaining joint transportation information generated by the maximum threshold voltage under the number of each electrode through an angle sensor, determining the optimal number of the electrodes by calculating the joint movement angle value of unit stimulation intensity, realizing automatic and sequential alternate switching of the stimulation positions through the upper computer according to the electrode combination mode of the optimal number of the electrodes, generating a test scatter diagram for the recorded electrode combination-joint angle, and further determining the optimal stimulation point of the target muscles at the affected side. The invention has simple structure and wide application range, and can automatically switch the electrode positions according to the combination mode of different electrode numbers in the array when the electrode placement is inaccurate, thereby determining the optimal stimulation position of the affected limb, acting on the target nervous system or muscle to the maximum extent, reducing side effects and enhancing the treatment effect.

Description

A stimulation position optimization system and method based on electrode array

Technical Field

The present application relates to the field of auxiliary medical rehabilitation training, and in particular to a functional electrical stimulation rehabilitation system and method based on an electrode array.

Background technique

Stroke is an acute cerebrovascular disease. Due to blockage or rupture of blood vessels in the brain, blood cannot flow into the brain, causing brain tissue damage. Limb dysfunction is one of the most common consequences of stroke. Patients will experience varying degrees of hemiplegia, dystonia, coordination disorders, muscle atrophy, etc., which seriously affect their normal life.

Functional electrical stimulation (FES) is a commonly used treatment for stroke. It uses low-frequency pulse current of a certain intensity to stimulate the nerves that control the target muscles through a pre-set program, inducing muscle contraction to replace or correct the lost function of the limbs. In theory, stimulation close to the muscle motor point can increase the muscle force output per unit stimulation intensity while reducing the patient's discomfort. Therefore, rehabilitation training at the optimal stimulation position of the muscle, such as the muscle motor point, can increase the contraction intensity and reduce the stimulation intensity, thereby producing more effective and comfortable limb movements and improving the rehabilitation effect.

Currently, commercial FES systems mainly use two pairs of large electrodes to drive two groups of muscles. However, traditional electrodes have two obvious defects. First, the attachment position is fixed, making it difficult to determine the optimal stimulation position. Second, the area is large, and the stimulation will overflow to nearby muscles, causing discomfort to the patient and not conducive to achieving functional goals.

Therefore, the appropriate electrode size and the placement of the electrode relative to the underlying skeletal muscle should be considered. Determining the optimal stimulation position during functional electrical stimulation to achieve precise movement control and achieve the best stimulation effect are issues that need to be addressed urgently.

Summary of the invention

The purpose of the present invention is to address the shortcomings of current commercial FES systems and to provide a stimulation position optimization system and method based on an electrode array, which can automatically switch the stimulation position according to the combination of different numbers of electrodes in the array during electrical stimulation, thereby determining the optimal stimulation point for the affected muscle and obtaining the maximum stimulation effect.

To achieve the above object, the present invention provides the following solutions:

A stimulation position optimization system based on an electrode array, comprising a host computer, a multi-channel electrical stimulator, an electrode array, an angle sensor, and a power module;

The host computer serves as a control center, and is used to run a control program, send a control signal to the multi-channel stimulator to apply electrical stimulation to the affected muscle, receive feedback information measured by the angle sensor during the electrical stimulation of the affected muscle, and adjust stimulation parameters and monitor muscle movement information with the user through a human-computer interaction interface; the control program includes: initial settings, maximum threshold recording, switching electrode positions, and monitoring movement information; the stimulation parameters include: sampling frequency, pulse width, waveform selection, and number of electrodes;

The multi-channel stimulator is connected to the host computer wirelessly via Bluetooth; the multi-channel stimulator includes: a power interface, a boost module, a Bluetooth communication module, a controller, a multi-channel signal generating module, a multi-channel output interface and a safety detection and protection module; the power interface is connected to the power module, and is used to provide the required low-voltage power supply to the controller, and provide the multi-channel signal generating module with a high-voltage power supply through the boost module; the controller is used to receive a control signal through the Bluetooth communication module, and control the multi-channel signal generating module to generate a stimulation signal with a specific frequency and pulse width; the multi-channel output interface is connected to the electrode array through a cable, so that the stimulation signal of each channel is transmitted to the corresponding position; the safety detection and protection module is used to monitor the working status of the system, ensure that the stimulation parameters are within a safe range, and take necessary measures to protect the safety of patients and equipment;

The electrode array is connected to the multi-channel electrical stimulator via a cable; the electrode array includes independent electrodes and reference electrodes forming a two-dimensional distribution, which is used to be attached to the target muscle, and the stimulation position of the affected muscle is changed by the electrode position switching program of the host computer;

The angle sensor is fixed to the patient's affected limb joint, and is used to measure the movement angle of the affected limb joint under the stimulation of each electrode combination in the array, monitor the movement state of the affected limb joint in real time, and feed back the measured movement information to the host computer in order to adjust the stimulation parameters and determine the optimal stimulation position;

The power supply module is used to provide a stable power supply for the multi-channel electrical stimulator to ensure the normal operation of the entire system.

Optionally, the control program run by the host computer includes initial setting, maximum threshold recording, switching electrode positions, and monitoring motion information executed by MATLAB;

The initial setup program is used by the user to initialize stimulation parameters, including sampling frequency, pulse width, waveform selection, number of electrodes and affected side position;

The maximum threshold recording program is used to record and store the maximum threshold voltage and joint movement angle corresponding to different numbers of electrodes, and determine the optimal number of electrodes by calculating the joint movement angle per unit stimulation intensity, thereby determining the electrode combination method;

Further, the maximum threshold voltage is defined as the PWM wave output by the host computer, which automatically and gradually increases the duty cycle, and stops outputting when the patient feels uncomfortable, and the last output amplitude is recorded as the maximum threshold voltage;

Furthermore, the joint movement angle per unit stimulation intensity = joint movement angle value/maximum threshold voltage;

Furthermore, there are three modes of electrode combination, including: single electrode mode, double electrode mode and four electrode mode:

Among them, the single electrode mode is to use one electrode in the array to apply electrical stimulation, and take the electrode to form a group of single electrode combination mode;

Among them, the two-electrode mode is to use two electrodes in the array to apply electrical stimulation, and take one electrode and the electrode adjacent to its right side to form a set of two-electrode combination;

Among them, the four-electrode mode is to use four electrodes in the array to apply electrical stimulation, and take two electrodes adjacent to each other in the horizontal direction and the two electrodes below them to form a group of four electrodes;

The switching electrode position program is used to input the optimal number of electrodes, switch the stimulation position according to the determined electrode combination mode, and display the applied electrodes and coordinates at each switch;

Furthermore, the switching method is that, for the two-dimensional electrode array, each electrode combination starts from the upper left corner of the array and moves one electrode unit to the right in turn. When reaching the end of the row, it moves to the starting position of the next row and continues to move to the right. This process continues until reaching the lower right corner of the array, thereby achieving a systematic traversal of it;

The program for monitoring movement information is used to record and display in real time the movement of the joint of the affected limb each time the stimulation position is switched and electrical stimulation is applied, with the horizontal axis being the sampling time and the vertical axis being the angle value.

Optionally, the controller uses an Arduino microcontroller.

Optionally, the multi-channel signal generator includes a multi-channel voltage source module and a multi-channel voltage amplifier;

The multi-channel voltage source module is used to generate specific frequency and pulse width according to the control signal, and each channel can be set separately;

The multi-channel voltage amplifier is used to amplify the voltage signal generated by the voltage source to ensure that the intensity and shape of the voltage meet specific stimulation requirements.

Optionally, the electrode array is made of a bendable and foldable flexible printed circuit (FPC), including 4*4 independent electrodes and 1 reference electrode.

Optionally, the angle sensor is a wireless electronic joint angle measurement system of Biometrics Ltd, comprising an angle sensor and a wireless receiver;

The angle sensor is fixed to the joint of the affected limb;

The wireless receiver is connected to the host computer.

A stimulation position optimization method based on an electrode array is applied to the stimulation position optimization system based on an electrode array; the stimulation position optimization method based on an electrode array comprises:

For patients with limb movement disorders caused by stroke, the electrode array is attached to the corresponding muscles on the affected side in a relaxed state, connected to a multi-channel electrical stimulator, and the angle sensor is fixed to the corresponding joint position of the affected limb, and the joint angle in the relaxed state is set to zero;

Run the initial setup program in the host computer, input the sampling frequency and pulse width, select one of the square wave, triangle wave and trapezoidal wave according to the muscle characteristics of the affected side, and select the left and right position of the affected side and the number of electrodes in the array to be used;

The threshold voltage test is performed on the patient using 1, 2, and 4 electrodes in the array respectively. The host computer automatically increases the pulse width step by step according to the selected stimulation parameters, and applies electrical stimulation to the patient through the multi-channel electrical stimulator. When the patient feels uncomfortable, the stimulation signal is stopped, and the output amplitude at the last sampling time is recorded as the threshold voltage of the selected number of electrodes. During the stimulation process, the angle sensor measures and records in real time the movement angle of the affected limb joint when the threshold voltage is reached using different numbers of electrodes.

By calculation, the number of electrodes corresponding to the maximum value of the joint movement angle per unit stimulation intensity is defined as the optimal number of electrodes for the affected limb. The host computer switches the electrode positions through the arrangement and combination of the determined optimal number of electrodes and outputs the corresponding threshold voltage. At the same time, the angle sensor measures and records the angle information generated by the joint of the affected limb at each switch in real time.

The movement angle of the joint of the affected limb when electrical stimulation is applied to each recorded electrode combination is used to generate a test scatter plot, with the horizontal axis being the combination number and the vertical axis being the joint angle corresponding to the threshold voltage. By comparison, the position of the electrode combination with the largest joint angle is determined as the optimal stimulation position for the affected limb.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

1. The present invention can automatically switch the electrode position according to the combination of different numbers of electrodes in the array when the electrode placement is inaccurate, thereby determining the optimal stimulation point of the affected limb, maximizing the effect on the target nervous system or muscle, reducing side effects and enhancing the treatment effect.

2. The stimulation position optimization method proposed in the present invention has a wide range of applications. Different stimulation parameters and different electrode combination modes can be selected for different patients and different affected-side muscles, which can effectively determine the optimal stimulation position and help formulate individualized treatment plans.

3. The stimulation position optimization system proposed in the present invention has a simple structure and low cost, and can be used to implement functional rehabilitation training of affected limbs in a more portable and effective manner, thereby reducing the required electrical stimulation intensity and time, thereby improving the economic efficiency of treatment.

4. The present invention can communicate with the host computer, can display and store stimulation data in real time, and facilitate medical staff to adjust the rehabilitation plan in real time.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic structural diagram of a stimulation position optimization system based on an electrode array according to the present invention.

FIG. 2 is a schematic diagram of the functional modules of the host computer of the present invention.

FIG. 3 is a flow chart of a threshold voltage test of the present invention.

FIG. 4 is a schematic diagram of different electrode combinations of the present invention.

FIG. 5 is a schematic diagram of the functional modules of the multi-channel stimulator of the present invention.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The purpose of the present invention is to address the shortcomings of current commercial FES systems and to provide a stimulation position optimization system and method based on an electrode array, which can automatically switch the stimulation position according to the combination of different numbers of electrodes in the array during electrical stimulation, thereby determining the optimal stimulation point for the affected muscle and obtaining the maximum stimulation effect.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG1 , a stimulation position optimization system based on an electrode array provided by the present invention includes: a host computer, a multi-channel electrical stimulator, an electrode array, an angle sensor and a power module.

The host computer sends a control signal to the multi-channel electrical stimulator, which controls the electrode array to generate a specific stimulation signal to act on the patient's affected side muscles. During the stimulation process, the angle sensor fixed on the joint of the affected limb measures the movement angle information of the joint in real time, which is transmitted to the host computer as a feedback signal to adjust the stimulation parameters.

Among them, the stimulation objects are patients whose limb movement dysfunction is caused by neuromuscular damage caused by cerebral stroke. Normal healthy people can also simulate patients as stimulation objects when their limb movements are not voluntary during the stimulation process.

The host computer can use a portable laptop computer installed with MATLAB and Biometrics Ltd analysis software to run the control program, send control signals to the multi-channel stimulator to apply electrical stimulation to the affected muscle, receive feedback information measured by the angle sensor during the electrical stimulation of the affected muscle, and adjust the stimulation parameters and monitor the muscle movement information with the user through the human-computer interaction interface.

Specifically, the control program is shown in FIG2 , and is run by MATLAB, including initial settings, maximum threshold recording, switching electrode positions, and monitoring motion information.

Among them, the initial setting program is a human-computer interaction interface, and the user can set the initialization stimulation parameters, including sampling frequency, pulse width, waveform selection, number of electrodes and affected side position. Generally, when stimulating the biceps brachii, the sampling frequency is set to 40Hz, the initial value of the pulse width is set to 0, and the number of selected electrodes provides three options of 1, 2 and 4. According to the electrical stimulation characteristics of different muscles, the user can choose three waveforms: square wave, triangle wave and trapezoidal wave. Taking into account that the selected angle sensor has positive and negative values in different bending directions, the user needs to select the left or right position of the affected side.

Among them, the maximum threshold recording program is used to record and store the maximum threshold voltage and joint motion angle corresponding to different numbers of electrodes. See Figure 3 for the maximum threshold voltage test flow chart. Select different numbers of electrodes to run the program. The host computer outputs a PWM wave that automatically and gradually increases the duty cycle. When the patient feels uncomfortable, it stops running. At this time, the interface displays the output amplitude at the last sampling moment as the maximum threshold voltage of the selected number of electrodes. The optimal number of electrodes is determined by calculating the joint motion angle of the unit stimulation intensity.

Among them, the switching electrode position program is used to automatically switch the stimulation position in turn according to the optimal number of electrodes and the corresponding electrode combination method. The upper computer realizes automatic switching of the stimulation position according to the determined combination method, and displays the applied electrode position at each switch, that is, the program draws a schematic diagram of the electrode array. When the electrode combination in the array is used to apply electrical stimulation, the electrodes used are highlighted.

Among them, the motion information monitoring program is used to record and display in real time the movement process of the joint of the affected limb when the stimulation position is switched each time the electrical stimulation is applied. When a certain electrode combination is used to apply electrical stimulation to the affected limb, the joint of the affected limb will produce a certain movement angle due to muscle contraction. The angle sensor measures the movement angle of the joint of the affected limb and displays it in real time on the program interface. The horizontal axis is the sampling time and the vertical axis is the angle value.

As shown in FIG4 , the electrode combination has three modes, including: a single electrode mode, a double electrode mode and a four-electrode mode: the single electrode mode is to use one electrode in the array to apply electrical stimulation, and the electrode is taken to form a single electrode combination mode, which is used to directly stimulate a specific nerve or muscle area; the double electrode mode is to use two electrodes in the array to apply electrical stimulation, and one electrode and the electrode adjacent to its right side are taken to form a double electrode combination mode, which is used to expand the stimulation range while maintaining a relatively simple configuration; the four-electrode mode is to use four electrodes in the array to apply electrical stimulation, and two electrodes adjacent to each other in the horizontal direction and the two electrodes corresponding to the lower side are taken to form a four-electrode combination mode, which is used to more comprehensively cover the target area and improve the accuracy and effect of stimulation. By flexibly using these configuration modes, the requirements of personalized treatment of patients can be better met to ensure the best effect of electrical stimulation.

The switching method is that, for a two-dimensional electrode array, each group of electrode combinations moves one electrode unit to the right in turn starting from the upper left corner of the array. When reaching the end of a row, it moves to the starting position of the next row and continues to move to the right. This process continues until reaching the lower right corner of the array, thereby achieving a systematic traversal of it.

The multi-channel electrical stimulator shown in FIG5 includes: a power supply interface, a boost module, a Bluetooth communication module, a controller, a multi-channel signal generation module, a multi-channel output interface and a safety detection and protection module, and these modules are integrated in a PCB board.

Specifically, the power interface adopts a standard USB interface, which is connected to the power module, passes through the EMI and RFI filtering units to prevent the stimulator from being interfered by external power supply, and is used to provide the required 5V low-voltage power supply for the controller, and provide a 100V high-voltage power supply for the multi-channel signal generating module through the boost module. The boost module uses the HRB05200D power chip to realize the DC-DC boost circuit of 5V to 100V. The controller uses the Arduino Uno single-chip microcomputer, and connects the HC-05 Bluetooth module through serial communication, so that Arduino can transmit and communicate data with the host computer through Bluetooth, and is used to control the multi-channel signal generating module to generate a stimulation signal with a specific frequency and pulse width. The multi-channel signal sending module includes a 16-channel voltage source module and a voltage amplifier, each channel can be controlled separately, and when applying electrical stimulation, the host computer sends a control signal to open the voltage source module corresponding to the applied electrode, then the 5V power supply voltage outputs a 100V voltage through the boost module, and the voltage amplifier corresponding to the channel outputs a stimulation voltage with a specific frequency, pulse width and shape. The multi-channel output interface has 17 channels, connecting a 16-channel voltage amplifier with an electrode array, and another channel is used to connect a reference electrode, so that the stimulation signal of each channel is transmitted to the corresponding position. The safety detection and protection module is used to monitor the working status of the system, use a voltage sensor to detect the input and output voltage of the circuit, use a current sensor to detect the circuit condition of the circuit, ensure that the stimulation parameters are within a safe range, and use a protection switch to cut off the circuit when the system fails to protect the safety of patients and equipment.

The electrode array is made of a bendable and foldable flexible circuit board (FPC), including 4*4 independent electrodes and 1 reference electrode to form a two-dimensional arrangement, which is connected to the multi-channel stimulator through a cable. The overall size of the electrode array is 150mm*80mm, and the bendability of the FPC can cover the entire belly of the biceps. The inputs of the 16 independent electrodes are respectively connected to the outputs of the 16-channel voltage amplifier, and the size of each independent electrode is 25mm*15mm. The reference electrode is connected to the ground of the multi-channel electrical stimulator, and the size is 40mm*20mm. During use, a layer of electrode gel is covered on each electrode sheet to reduce the contact resistance between the electrode and the skin surface, reduce stimulation, and improve the user's comfort. The stimulation position of the affected muscle is changed by switching the electrode position program of the host computer.

The angle sensor uses the wireless electronic joint angle measurement system of Biometrics Ltd, including an angle sensor and a wireless receiver. The angle sensor is fixed on the joint of the affected limb, and the wireless receiver is connected to the host computer to measure the movement angle of the joint of the affected limb under the stimulation of each electrode combination in the array. The measurement data is transmitted to the Biometrics Ltd analysis software of the host computer through the wireless receiver, and the data is integrated using MATLAB.

The power module provides a 5V stable power supply for powering the multi-channel electrical stimulator to ensure the normal operation of the entire system.

The best mode for carrying out the present invention is described in further detail below.

Recruit a number of subjects required for the experiment, and obtain written consent from all subjects before the experiment. Before participating in the experiment, there was no history of upper body joint problems and neurological diseases, and no pain in the biceps brachii of the upper arm was reported. Within 24 hours before the start of the experiment, the biceps brachii of the subjects were in a relaxed state and did not experience long-term contraction fatigue.

Set up the serial port to connect the host computer and the multi-channel stimulator, connect the power module to put the multi-channel stimulator in working state, use the flat cable to connect the multi-channel stimulator and the electrode array, attach the electrode array to the skin surface of the left biceps brachii of the experimental subject A with medical tape, fix the angle sensor at the elbow joint of the left arm, and place the forearm of the experimental subject A on the table. Open the Biometrics Ltd analysis software, and set the elbow joint angle measured by the angle sensor of the experimental subject A in the natural relaxation state to zero.

Open the MATLAB control program in the host computer, and in the initial setting of the program human-computer interaction interface, set the sampling frequency to 40 Hz and the pulse width to zero according to the characteristics of the human biceps. Since the trapezoidal wave waveform is relatively smooth and more suitable for simulating the activation state of the biceps than the triangular wave and square wave, the trapezoidal wave is selected as the waveform, and the affected side is selected as the left.

Select the number of electrodes as 1, open 1 electrode channel in the MATLAB electrical stimulation program, run the threshold voltage test program, record the maximum threshold voltage that the left arm biceps brachii of subject A can withstand when 1 electrode number is selected, and record the elbow joint movement angle measured by the angle sensor under the stimulation of 1 electrode threshold voltage. Rest for 1 minute, select the number of electrodes as 2, open 2 electrode channels in the MATLAB electrical stimulation program, including the electrode selected in the previous step and the electrode adjacent to the right, run the threshold voltage test program, record the maximum threshold voltage that the left arm biceps brachii of subject A can withstand when 2 electrodes are selected, and record the elbow joint movement angle measured by the angle sensor under the stimulation of 2 electrode threshold voltages. Rest for 1 minute, select the number of electrodes as 4, open 4 electrode channels in the MATLAB electrical stimulation program, including the 2 electrodes selected in the previous step and the 2 electrodes adjacent to the lower side, run the threshold voltage test program, record the maximum threshold voltage that the left arm biceps brachii of subject A can withstand when 4 electrodes are selected, and record the elbow joint movement angle measured by the angle sensor under the stimulation of 4 electrode threshold voltages. By calculating the joint angles for three unit stimulation intensities, that is, the joint movement angle value/maximum threshold voltage, the results showed that for the left biceps brachii of subject A, the joint angle value for unit stimulation intensity was the largest when four electrodes were used. Therefore, the optimal number of electrodes for the left biceps brachii of subject A was defined as four.

See Figure 4. There are nine combinations of 4 electrodes. Run the electrode position switching program and enter the optimal number of electrodes 4. The host computer automatically controls the multi-channel electrical stimulator to output 9 times the maximum threshold voltage corresponding to the 4 electrodes in turn according to the combination of Figure 5. The program interface highlights the electrode position used, and each stimulation interval is 1 minute. At the same time, the angle sensor measures the movement angle of the elbow joint during each stimulation in real time. The collected data is sent to the Biometrics Ltd analysis software through a wireless receiver. The motion information monitoring program obtains the data in the analysis software in real time and displays and stores it in the interface.

After the nine combinations were tested, a test scatter plot was generated for the recorded electrode combination-joint angle, with the horizontal axis being the sequence number of the nine different electrode combinations and the vertical axis being the elbow joint angle corresponding to the threshold voltage when the number of electrodes was 4. By comparison, the position of the electrode combination with the largest joint angle was defined as the optimal stimulation position for the left biceps brachii of subject A.

As another specific embodiment, a stimulation position optimization method based on an electrode array is also provided in the system corresponding to the above embodiment, including:

S1, for patients with limb movement disorders caused by stroke, the electrode array is attached to the corresponding muscles on the affected side in a relaxed state, connected to a multi-channel electrical stimulator, and the angle sensor is fixed at the corresponding joint position of the affected limb, and the joint angle in the relaxed state is set to zero;

S2, running the initial setting program in the host computer, inputting the sampling frequency and pulse width, selecting one of the square wave, triangle wave and trapezoidal wave according to the muscle characteristics of the affected side, and selecting the left and right positions of the affected side and the number of electrodes in the array to be used;

S3, respectively use 1, 2, and 4 electrodes in the array to test the threshold voltage of the patient. The host computer automatically increases the pulse width according to the selected stimulation parameters, applies electrical stimulation to the patient through the multi-channel electrical stimulator, stops outputting the stimulation signal when the patient feels uncomfortable, and records the output amplitude at the last sampling moment as the threshold voltage of the selected number of electrodes. During the stimulation process, the angle sensor measures and records in real time the movement angle of the affected limb joint when the threshold voltage is reached using different numbers of electrodes;

S4, through calculation, the number of electrodes corresponding to the maximum value of the joint motion angle per unit stimulation intensity is defined as the optimal number of electrodes for the affected limb, the upper computer switches the electrode position through the arrangement and combination of the determined optimal number of electrodes, and outputs the corresponding threshold voltage, and at the same time, the angle sensor measures and records the angle information generated by the joint of the affected limb at each switch in real time;

S5, generates a test scatter plot of the movement angle of the joint of the affected limb when electrical stimulation is applied to each recorded electrode combination, with the horizontal axis being the combination number and the vertical axis being the joint angle corresponding to the threshold voltage. By comparison, the position of the electrode combination with the largest joint angle is determined as the optimal stimulation position for the affected limb.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims (11)

1. A stimulation position optimization system based on an electrode array, characterized in that it comprises: a host computer, a multi-channel electrical stimulator, an electrode array, an angle sensor and a power module; The host computer serves as a control center, and is used to run a control program, send a control signal to the multi-channel stimulator to apply electrical stimulation to the affected muscle, receive feedback information of the affected muscle measured by the angle sensor during the electrical stimulation process, and adjust stimulation parameters and monitor muscle movement information with the user through a human-computer interaction interface; The multi-channel stimulator includes: a power interface, a boost module, a Bluetooth communication module, a controller, a multi-channel signal generating module, a multi-channel output interface and a safety detection and protection module; the power interface is connected to the power module, and is used to provide the required low-voltage power supply to the controller, and provide the multi-channel signal generating module with a high-voltage power supply through the boost module; the controller is used to receive a control signal through the Bluetooth communication module, and control the multi-channel signal generating module to generate a stimulation signal with a specific frequency and pulse width; the multi-channel output interface is connected to the electrode array through a cable, so that the stimulation signal of each channel is transmitted to the corresponding position; the safety detection and protection module is used to monitor the working state of the system, ensure that the stimulation parameters are within a safe range, and take necessary measures to protect the safety of patients and equipment; The electrode array is connected to the multi-channel electrical stimulator via a cable; the electrode array includes independent electrodes and reference electrodes forming a two-dimensional distribution, which is used to be attached to the target muscle, and the stimulation position of the affected muscle is changed by the electrode position switching program of the host computer; The angle sensor is fixed to the patient's affected limb joint, and is used to measure the movement angle of the affected limb joint under the stimulation of each electrode combination in the array, monitor the movement state of the affected limb joint in real time, and feed back the measured movement information to the host computer in order to adjust the stimulation parameters and determine the optimal stimulation position; The power supply module is used to provide a stable power supply for the multi-channel electrical stimulator to ensure the normal operation of the entire system. 2. A stimulation position optimization system based on an electrode array according to claim 1, characterized in that the host computer control program includes: initial setting, maximum threshold recording, switching electrode positions and monitoring movement information; The initial setup program is used by the user to initialize stimulation parameters, including sampling frequency, pulse width, waveform selection, number of electrodes and affected side position; The maximum threshold recording program is used to record and store the maximum threshold voltage and joint movement angle corresponding to different numbers of electrodes, and determine the optimal number of electrodes by calculating the joint movement angle per unit stimulation intensity, thereby determining the electrode combination method; The switching electrode position program is used to input the optimal number of electrodes, switch the stimulation position according to the determined electrode combination mode, and display the applied electrodes and coordinates at each switch; The program for monitoring movement information is used to record and display in real time the movement of the joint of the affected limb each time the stimulation position is switched and electrical stimulation is applied, with the horizontal axis being the sampling time and the vertical axis being the angle value. 3. A stimulation position optimization system based on an electrode array according to claim 1, characterized in that the maximum threshold voltage is defined as a PWM wave output by the host computer, which automatically and gradually increases the duty cycle. When the patient feels uncomfortable, the output is stopped, and the last output amplitude is recorded as the maximum threshold voltage. 4. A stimulation position optimization system based on an electrode array according to claim 1, characterized in that the joint movement angle per unit stimulation intensity = joint movement angle value/maximum threshold voltage. 5. A stimulation position optimization system based on an electrode array according to claim 1, characterized in that the electrode combination has three modes, including: a single electrode mode, a double electrode mode and a four-electrode mode; The single electrode mode is to use one electrode in the array to apply electrical stimulation, and the electrode is taken to form a group of single electrode combinations; The dual-electrode mode is to use two electrodes in the array to apply electrical stimulation, and take one electrode and the electrode adjacent to its right side to form a dual-electrode combination; The four-electrode mode is to use four electrodes in the array to apply electrical stimulation, and two electrodes adjacent to each other in the horizontal direction and two electrodes corresponding to the lower sides thereof form a group of four-electrode combination. 6. A stimulation position optimization system based on an electrode array according to claim 1, characterized in that the switching method is that, for a two-dimensional electrode array, starting from the upper left corner of the array, each group of electrode combinations moves one electrode unit to the right in turn, and when reaching the end of the row, it moves to the starting position of the next row and continues to move to the right. This process continues until it reaches the lower right corner of the array, thereby achieving a systematic traversal of it. 7. A stimulation position optimization system based on an electrode array according to claim 1, characterized in that the controller uses an Arduino single-chip microcomputer. 8. The stimulation position optimization system based on electrode array according to claim 1, characterized in that the multi-channel signal generator comprises a multi-channel voltage source module and a multi-channel voltage amplifier; The multi-channel voltage source module is used to generate a specific frequency and pulse width according to the control signal, and each channel can be set separately; The multi-channel voltage amplifier is used to amplify the voltage signal generated by the voltage source to ensure that the intensity and shape of the voltage meet specific stimulation requirements. 9. A stimulation position optimization system based on an electrode array according to claim 1, characterized in that the electrode array is made of a bendable and foldable flexible printed circuit (FPC), including 4*4 independent electrodes and 1 reference electrode. 10. A stimulation position optimization system based on an electrode array according to claim 1, characterized in that the angle sensor is a wireless electronic joint angle measurement system of Biometrics Ltd, comprising an angle sensor and a wireless receiver; The angle sensor is fixed to the joint of the affected limb; The wireless receiver is connected to the host computer. 11. A stimulation position optimization method based on an electrode array, characterized in that it is applied to a stimulation position optimization system based on an electrode array according to any one of claims 1 to 10; the stimulation position optimization method based on an electrode array comprises: For patients with limb movement disorders caused by stroke, the electrode array is attached to the corresponding muscles on the affected side in a relaxed state, connected to a multi-channel electrical stimulator, and the angle sensor is fixed to the corresponding joint position of the affected limb, and the joint angle in the relaxed state is set to zero; Run the initial setup program in the host computer, input the sampling frequency and pulse width, select one of the square wave, triangle wave and trapezoidal wave according to the muscle characteristics of the affected side, and select the left and right position of the affected side and the number of electrodes in the array to be used; The threshold voltage test is performed on the patient using 1, 2, and 4 electrodes in the array respectively. The host computer automatically increases the pulse width step by step according to the selected stimulation parameters, and applies electrical stimulation to the patient through the multi-channel electrical stimulator. When the patient feels uncomfortable, the stimulation signal is stopped, and the output amplitude at the last sampling time is recorded as the threshold voltage of the selected number of electrodes. During the stimulation process, the angle sensor measures and records in real time the movement angle of the affected limb joint when the threshold voltage is reached using different numbers of electrodes. By calculation, the number of electrodes corresponding to the maximum value of the joint movement angle per unit stimulation intensity is defined as the optimal number of electrodes for the affected limb. The host computer switches the electrode positions through the arrangement and combination of the determined optimal number of electrodes and outputs the corresponding threshold voltage. At the same time, the angle sensor measures and records the angle information generated by the joint of the affected limb at each switch in real time. The movement angle of the joint of the affected limb when electrical stimulation is applied to each recorded electrode combination is used to generate a test scatter plot, with the horizontal axis being the combination number and the vertical axis being the joint angle corresponding to the threshold voltage. By comparison, the position of the electrode combination with the largest joint angle is determined as the optimal stimulation position for the affected limb.