阅读说明：本技术 一种闭环控制的正中神经刺激器及其使用方法 (Closed-loop control median nerve stimulator and use method thereof ) 是由 陈永刚 郭林忠 于 2021-02-03 设计创作，主要内容包括：本发明是一种闭环控制的正中神经刺激器及其使用方法,属于医疗器械领域。现有正中神经刺激器使用开环控制缺乏反馈,无法对不同病人做适应性调节,刺激效果差。本发明提供一种闭环控制的正中神经刺激器及其使用方法,刺激器包括壳体和内置的电源、控制处理器、升压模块及高压开关,高压开关通过导线输出连接外置的电击装置,控制处理器输入端连接电压采样装置和电流采样装置,电压采样装置和电流采样装置各自包括前端采样电路和后端反馈模块,两个采样电路通过导线外接电击装置,控制处理器输入端还接肌电信号处理装置。本发明通过闭环控制实时反馈作用病人的电压、电流,同时监测病人电生理参数了解病患精神并据此调整刺激,减少病人痛苦经历。(The invention discloses a closed-loop control median nerve stimulator and a using method thereof, and belongs to the field of medical instruments. The existing median nerve stimulator lacks feedback due to open loop control, cannot perform adaptive adjustment on different patients, and has poor stimulation effect. The invention provides a closed-loop control median nerve stimulator and a use method thereof, wherein the stimulator comprises a shell, an internal power supply, a control processor, a boosting module and a high-voltage switch, the high-voltage switch is connected with an external electric shock device through a lead output, the input end of the control processor is connected with a voltage sampling device and a current sampling device, the voltage sampling device and the current sampling device respectively comprise a front-end sampling circuit and a rear-end feedback module, the two sampling circuits are externally connected with the electric shock device through leads, and the input end of the control processor is also connected with an electromyographic signal processing device. The invention feeds back the voltage and the current of the patient in real time through closed-loop control, monitors the electrophysiological parameters of the patient to know the spirit of the patient and adjusts the stimulation accordingly, thereby reducing the painful experience of the patient.)

1. A closed-loop control median nerve stimulator comprises a stimulator shell, a power supply, a control processor and a boosting module which are connected with the power supply, and a high-voltage switch and a boosting module which are connected with the output end of the control processor, wherein the stimulator shell is provided with an input key connected with the control processor, the high-voltage switch is connected with an electric shock device which is externally arranged on the stimulator shell through a lead output, the electric shock device comprises two power electrodes which are matched with each other to generate an electric stimulation signal, the closed-loop control median nerve stimulator is characterized in that the input end of the control processor is connected with a voltage sampling device and a current sampling device, the voltage sampling device comprises a front end voltage sampling circuit and a rear end voltage feedback module which are electrically connected, the current sampling device comprises a front end current sampling circuit and a rear end current feedback module which are electrically connected, and the voltage sampling device and the current sampling, the voltage sampling circuit and the current sampling circuit are externally connected with two power application electrodes through wires, the output ends of the voltage feedback module and the current feedback module are connected with a control processor, the input end of the control processor is further connected with an electromyographic signal processing device, the electromyographic signal processing device comprises three electrode patches E1, E2 and E3 which are externally arranged on a shell of the stimulator and used for collecting electromyographic signals, and an electromyographic signal processing circuit which is arranged in the shell of the stimulator and used for processing the electromyographic signals, the output end of the electromyographic signal processing circuit is connected with the control processor, the input end of the electromyographic signal processing circuit is connected with each electrode patch through wires, and the output end of the control processor is connected with a.

2. The closed-loop controlled median nerve stimulator according to claim 1, wherein the voltage sampling circuit is connected to the voltage feedback module via an isolating optocoupler output, and the current sampling circuit is connected to the current feedback module via an isolating optocoupler output.

3. The closed-loop controlled median nerve stimulator according to claim 1, wherein said high voltage switch is connected to both of said electrodes by an output of an isolation transformer, said isolation transformer being disposed in said stimulator housing and connected to both of said electrodes by a lead.

4. The closed-loop controlled median nerve stimulator of claim 1, wherein said applicator electrode is an electrode pad or electrode film that is flexibly conformable to conform over the skin.

5. The closed-loop controlled median nerve stimulator as claimed in claim 1, wherein said power source is a lithium battery connected to a DC-DC module, the output of said DC-DC module being connected to a control processor and a boost module.

6. The closed-loop controlled median nerve stimulator as claimed in claim 1, wherein said display is a led display or a liquid crystal display.

7. Use of a median nerve stimulator according to any one of claims 1 to 6, characterized in that it comprises the following steps carried out in sequence:

(1) after starting up, acquiring the reference body surface potential amplitude and the change rate of the patient: under the condition that a human body is in a calm state, with E1 as a zero potential, recording the potential difference of E3 and E1 and the potential difference of E2 and E1 as two paths of body surface potential values respectively, and processing the recorded two paths of body surface potential value data in the same calculation mode;

continuously recording the body surface potential values of each road for T1 minutes, wherein B times of body surface potential values are collected at AHz frequency every S seconds, then calculating the body surface potential amplitude and the body surface potential change rate of the position, the body surface potential amplitude is the average value of the B times of body surface potential values, the body surface potential change rate is the change rate calculated by dividing the difference value of every two adjacent body surface potential values in the B times of body surface potential values by the interval time of the two adjacent body surface potential values, and then averaging; calculating the maximum value and the minimum value of the body surface potential amplitude and the maximum value and the minimum value of the body surface potential change rate of each road from the data continuously recorded and obtained from T1 minutes, and then taking the interval range corresponding to the maximum value and the minimum value as the corresponding reference body surface potential amplitude and the reference body surface potential change rate, wherein the reference body surface potential amplitude is 0 mV-20 mV, and the reference body surface potential change rate is less than or equal to 20 mV/s;

(2) applying electrical stimulation and adjusting the electrical stimulation amplitude according to the mental state of the person:

the electrical stimulation is started from 0V, and the step pitch adjusting mode is that the step pitch is 2V/step within 0-50V, the step pitch is 5V/step within 50-100V, and the step pitch is 10V/step within 100-500V; the pulse width is 0-40us, and the step pitch is 4 us/step; the frequency is 5-100Hz, the frequency is 5-40Hz according to the step pitch 5 Hz/step, and the frequency is 40-100Hz according to the step pitch 10 Hz/step;

calculating two paths of body surface potential values in the electrical stimulation process, and comparing the two paths of body surface potential values with the reference body surface potential amplitude and the reference body surface potential change rate of the same path to judge the mental state of the person: collecting body surface potential values of the same times at the same frequency in the step (1) every T2 minutes in the process of electrical stimulation, then calculating the body surface potential amplitude and the body surface potential change rate of each path according to the method in the step (1), comparing the body surface potential amplitude and the body surface potential change rate with the same-path reference body surface potential amplitude and the reference body surface potential change rate obtained in the step (1), and judging that the person is painful when the two paths of body surface potential amplitudes are both greater than the upper limit of the respective reference body surface potential amplitudes by 0.2-0.5 mV;

on the premise of judging that the pain is caused, when the change rates of the two paths of body surface potentials are larger than the upper limit of the change rate of the same-path reference body surface potential of 130%, keeping the frequency of the stimulation voltage unchanged, and reducing the amplitude of the stimulation voltage; when the change rates of the two paths of body surface potentials are less than or equal to 70% of the lower limit of the change rate of the same-path reference body surface potential, the amplitude of the stimulation voltage is kept unchanged, the frequency of the stimulation voltage is increased, and when the frequency of the stimulation voltage is adjusted to the maximum 100Hz, the change rates of the two paths of body surface potentials are still less than or equal to 70% of the lower limit of the change rate of the same-path reference body surface potential, the pulse width is increased.

8. The method of using the median nerve stimulator according to claim 7, wherein said T1 minutes is 3-5 minutes, said S seconds is 3-6 seconds, said AHz is 100 Hz-120 Hz, and said B times is 8-12 times; t2 min is 2-3 min.

Technical Field

The invention relates to the field of medical instruments, in particular to a closed-loop control median nerve stimulator and a using method thereof.

Background

The median nerve (median nerve) is a single-vessel nerve formed by the lateral and medial fascicles of the brachial plexus in the axilla. The arm is passed through the anterior orbicularis muscle, the superficial and deep flexor muscles of the middle finger of the forearm, the deep flexor muscles of the forearm, the aponeurosis of the palm, and the branch is divided into several metacarpal side nerves. Each finger-palm side nerve is divided into two finger-palm side intrinsic nerves which travel to the finger tips along the two sides of the finger. The median nerve innervates most of the muscles on the flexor side of the forearm, as well as most of the muscles in the radial half of the hand and the cutaneous sensation on the radial side of the palm. The existing research literature indicates that the function of promoting waking and stopping vomiting can be achieved by stimulating the median nerve, the electrical stimulation treatment of the median nerve adopts a low-frequency electrical stimulator to output current, an electrode is placed 2 cm above the ventral-lateral-wrist striation of the front arm, the skin of the median nerve distribution area on the inner side of the wrist of a patient is subjected to percutaneous electrical stimulation, the current stimulation intensity is only required to be slightly contracted by the fingers of the patient, and the central nervous system is stimulated through a conduction path of the median nerve-spinal nerve-cervical medulla-brainstem-thalamus-cortex functional area, so that the effects of promoting waking and stopping vomiting are achieved.

The median nerve stimulator on the market at present mainly has the following problems: the voltage stimulation only has a plurality of single fixed voltage gears, the circuit control adopts an open loop without a feedback circuit, the real treatment parameters of different patients are unknown, the change of the electrophysiological parameters of the patients cannot be sensed in time, and the automatic adjustment according to the change of the electrophysiological parameters cannot be realized to achieve the proper effect, so that the individualized adaptive adjustment cannot be carried out on different patients. In addition, the wearing mode of wrist strap is adopted to stimulator and human contact's part, leans on two stainless steel electrode slices of establishing to paste the wrist and discharge through one-way voltage stimulation, and current stainless steel electrode slice is the hard piece structure, can not conform laminating patient's skin completely, and the unstable voltage stimulation effect that also can be influenced greatly of contact.

Disclosure of Invention

The invention provides a closed-loop control median nerve stimulator, which can feed back voltage and current in real time through closed-loop control, monitor electrophysiological parameters of a patient to know the mental state of the patient, adjust the stimulation parameters accordingly, automatically adjust comfortable and effective electrical stimulation parameters and reduce the painful experience of the patient.

The technical scheme adopted by the invention for solving the technical problem is as follows: a closed-loop control median nerve stimulator comprises a stimulator shell, a power supply, a control processor and a boosting module which are connected with the power supply, and a high-voltage switch and a boosting module which are connected with the output end of the control processor, wherein the stimulator shell is provided with an input key connected with the control processor, the high-voltage switch is connected with an electric shock device which is externally arranged on the stimulator shell through a lead output, the electric shock device comprises two power-applying electrodes which are matched with each other to generate an electric stimulation signal, the closed-loop control median nerve stimulator is characterized in that the input end of the control processor is connected with a voltage sampling device and a current sampling device, the voltage sampling device comprises a front end voltage sampling circuit and a rear end voltage feedback module which are electrically connected, the current sampling device comprises a front end current sampling circuit and a rear end current feedback module which are electrically connected, the voltage sampling device and the current sampling device are both arranged in the stimulator shell, and the voltage sampling circuit, the output ends of the voltage feedback module and the current feedback module are connected with a control processor, the input end of the control processor is also connected with a myoelectric signal processing device, the myoelectric signal processing device comprises three electrode patches E1, E2 and E3 which are externally arranged on a shell of the stimulator and used for collecting myoelectric signals, and a myoelectric signal processing circuit which is arranged in the shell of the stimulator and used for processing the myoelectric signals, the output end of the myoelectric signal processing circuit is connected with the control processor, the input end of the myoelectric signal processing circuit is connected with each electrode patch through a lead, and the output end of the control processor is connected with a display screen arranged on the shell of the stimulator. The invention uses closed-loop control to feed back the voltage and current actually acted on the patient by the power-applying electrode in real time, monitors the electrophysiological parameters of the patient by the electromyographic signals to know and judge the mental state of the patient, and controls the processor to adjust the stimulation parameters according to the mental state, so as to automatically adjust the stimulation parameters to comfortable and effective electrical stimulation parameters and reduce the painful experience of the patient. When the device works, the voltage sampling device and the current sampling device feed back the voltage and the current acting on the skin of a patient to the control processor, and the acquired voltage and the acquired current are displayed in real time through a display screen connected with the control processor, so that a user can know the voltage value and the current value of the patient actually acting; the electrode patch collects the electromyographic signals of a patient, the electromyographic signals are processed by the electromyographic signal processing circuit and then are sent to the control processor, the change information of the electrophysiological parameters of the patient is sent to the control processor in time, the control processor receives the electrophysiological parameters and then automatically adjusts the output voltage by combining with a pre-programmed program, the appropriate effects of waking up and stopping vomiting are achieved, and meanwhile, the pain of the patient caused by voltage stimulation is relieved. In addition, the control processor is an MCU control unit and is made of a programmable singlechip; the electrode plate with large contact area is attached to a human body to collect the myoelectric signals to judge the human body reaction, which is beneficial to reducing the contact impedance of the electrode and muscle fibers and reducing the requirement on the input impedance of the myoelectric signal processing circuit.

As a further improvement and supplement to the above technical solution, the present invention adopts the following technical measures: the voltage sampling circuit is connected with the voltage feedback module through the output of the isolation optocoupler, and the current sampling circuit is connected with the current feedback module through the output of the isolation optocoupler. The isolation optocoupler can realize 'electricity-light-electricity' conversion, current and voltage sampling signals are used as intermediate transition transmission signals through optical signals, the anti-interference capability is high, the work is stable, and the service life of the isolation optocoupler is long.

The high-voltage switch is connected with the two power-applying electrodes through the output of the isolation transformer, and the isolation transformer is arranged in the stimulator shell and connected with the two power-applying electrodes through a lead. The isolation transformer can filter the power transmission of the high-voltage switch and provide pure power supply voltage for electric equipment such as an electric shock device; meanwhile, the isolation transformer can also improve the electricity utilization safety and protect the personal safety, and the isolation transformer is in the prior art.

The application electrode is an electrode sheet or an electrode film which can be flexibly attached to cover the skin in a conformal manner. The power application electrode adopts a silica gel ultrathin electrode conductive patch or an electrode patch with similar characteristics, the thickness of the electrode patch is not more than 1mm, the conductive impedance is less than 100 omega, and the electrode patch is a 5 x 5CM self-adhesive electrode plate produced by Shenzhen Shang good life electronic technology Limited.

The power supply is formed by connecting a lithium battery and a DC-DC module, and the output of the DC-DC module is connected with the control processor and the boosting module. The DC-DC module can be directly attached to the printed circuit board to serve as a power supply device to supply power to the control processor and the boost module, and a special large-volume power supply module does not need to be arranged independently. The DC-DC module can use LINEAR LTC3533, has wide input voltage range of 1.8V-5.5V, adjustable output voltage of 1.8V-5.25V, maximum output current of 2A, and can realize voltage boosting and voltage reducing adjustment.

The display screen is an led display screen or a liquid crystal display screen. The display screen adopts the mature led display screen or liquid crystal display of prior art, prefers to use the led display screen, and the charactron shows more succinctly, is difficult for receiving the ambient light influence, even also very clear under the reflection of light condition.

The invention feeds back the voltage and current actually acting on the patient in real time through closed-loop control, and learns the mental state of the patient by taking the electrophysiological parameters of the patient monitored by the electromyographic signals as the standard, thereby adjusting the output stimulation parameters, automatically adjusting to comfortable and effective electrical stimulation parameters and reducing the painful experience of the patient.

A method of using a median nerve stimulator, the method of use comprising the steps of, in order:

(1) after starting up, acquiring the reference body surface potential amplitude and the change rate of the patient: under the condition that a human body is in a calm state, with E1 as a zero potential, recording the potential difference of E3 and E1 and the potential difference of E2 and E1 as two paths of body surface potential values respectively, and processing the recorded two paths of body surface potential value data in the same calculation mode;

continuously recording the body surface potential values of each road for T1 minutes, wherein B times of body surface potential values are collected at AHz frequency every S seconds, then calculating the body surface potential amplitude and the body surface potential change rate of the position, the body surface potential amplitude is the average value of the B times of body surface potential values, the body surface potential change rate is the change rate calculated by dividing the difference value of every two adjacent body surface potential values in the B times of body surface potential values by the interval time of the two adjacent body surface potential values, and then averaging; calculating the maximum value and the minimum value of the body surface potential amplitude and the maximum value and the minimum value of the body surface potential change rate of each road from the data continuously recorded and obtained from T1 minutes, and then taking the interval range corresponding to the maximum value and the minimum value as the corresponding reference body surface potential amplitude and the reference body surface potential change rate, wherein the reference body surface potential amplitude is 0 mV-20 mV, and the reference body surface potential change rate is less than or equal to 20 mV/s;

(2) applying electrical stimulation and adjusting the electrical stimulation amplitude according to the mental state of the person:

the electrical stimulation starts from 0V, and the step pitch (gear) adjusting mode is that the step pitch is 2V/step within 0-50V, the step pitch is 5V/step within 50-100V, and the step pitch is 10V/step within 100-500V; the pulse width is 0-40us, and the step pitch is 4 us/step; the frequency is 5-100Hz, the frequency is 5-40Hz according to the step pitch 5 Hz/step, and the frequency is 40-100Hz according to the step pitch 10 Hz/step;

calculating two paths of body surface potential values in the electrical stimulation process, and comparing the two paths of body surface potential values with the reference body surface potential amplitude and the reference body surface potential change rate of the same path to judge the mental state of the person: collecting body surface potential values of the same times at the same frequency in the step (1) every T2 minutes in the process of electrical stimulation, then calculating the body surface potential amplitude and the body surface potential change rate of each path according to the method in the step (1), comparing the body surface potential amplitude and the body surface potential change rate with the same-path reference body surface potential amplitude and the reference body surface potential change rate obtained in the step (1), and judging that the person is painful when the two paths of body surface potential amplitudes are both greater than the upper limit of the respective reference body surface potential amplitudes by 0.2-0.5 mV;

on the premise of judging that the pain is caused, when the change rates of the two paths of body surface potentials are larger than the upper limit of the change rate of the same-path reference body surface potential of 130%, keeping the frequency of the stimulation voltage unchanged, and reducing the amplitude of the stimulation voltage; when the change rates of the two paths of body surface potentials are less than or equal to 70% of the lower limit of the change rate of the same-path reference body surface potential, the amplitude of the stimulation voltage is kept unchanged, the frequency of the stimulation voltage is increased, and when the frequency of the stimulation voltage is adjusted to the maximum 100Hz, the change rates of the two paths of body surface potentials are still less than or equal to 70% of the lower limit of the change rate of the same-path reference body surface potential, the pulse width is increased.

The using method of the invention obtains the electrophysiological parameters of the patient through the three electrode patches, compares the electrophysiological parameters before and after electrical stimulation, specifically compares the calculated electrophysiological parameters after receiving the electrical stimulation with the calculated reference values before electrical stimulation, judges the current state of the patient's mental grasping, then adjusts the output electrical stimulation according to different comparison results only when judging that the patient is painful, fully utilizes the feedback data after electrical stimulation to adjust the electrical stimulation, further reduces the pain experienced by the patient in the process of electrical stimulation, and improves the treatment experience; the judgment is based on that the electrophysiological parameters of the patient before the electrical stimulation are taken as the reference, so that the electrical stimulation can be adaptively adjusted according to the self conditions of different patients, and the pertinence to different patients is better. Here, E1 is used as a reference zero potential, the body surface potentials, i.e. potential differences, are all relative to the reference zero potential, theoretically, the body surface potentials on the body surface relative to a certain reference point change with the change of the human emotion, and meanwhile, the magnitude change speed (i.e. change rate) also differs, and the magnitude change is shown in fig. 11. The reference body surface potential amplitude and the change rate also fluctuate within a certain time, the fluctuation range has a maximum value and a minimum value, and the average value is adopted to be beneficial to reducing the adverse effect caused by fluctuation. When the device works, before electrical stimulation is applied to a patient, the two paths of body surface potential values are measured and respectively calculated to obtain the reference body surface potential amplitude values and the reference body surface potential change rate of the two paths of the patient, because the body surface potential values and the body surface potential change rate can fluctuate along with the change of mental states, the fluctuation range can have the maximum value and the minimum value, the body surface potential amplitude values and the body surface potential change rate measured after the patient receives the electrical stimulation are calculated, and then the body surface potential amplitude values and the body surface potential change rate are compared with the reference body surface potential amplitude values and the body surface potential change rate of the patient, whether the emotion of the patient becomes painful or not is judged in the whole process, and the emotion change is judged to be painful only when the; and then comparing the body surface potential change rate with the reference body surface potential change rate, and respectively adjusting the stimulation voltage amplitude or the stimulation voltage frequency according to different comparison results, wherein the adjustment is performed when the two paths of comparison are met, and the current electrical stimulation parameters are still kept unchanged when only one path of comparison is met.

The time T1 is 3-5 minutes, the time S is 3-6 seconds, the time AHz is 100-120 Hz, and the time B is 8-12; t2 min is 2-3 min. The limited time length, the sampling frequency and the sampling times can meet the use requirement of the median nerve stimulator, effectively judge the mental state of a person and make adjustment, and reduce the pain in the stimulation process.

According to the using method, the electrical signals of the special parts of the arms of the human body are collected, then the mental state of the human body is detected according to the electrical signals, the mental state signal feedback of the human body is used as evaluation to adjust the electrical stimulation, the stimulation signal acting on the median nerve is further changed, the experience feeling acting on the human body is better, and the pain experienced by the human body in the whole stimulation process is effectively reduced.

Drawings

FIG. 1: the invention has a schematic structure.

FIG. 2: the invention is a working principle block diagram.

FIG. 3: the circuit diagram of the invention.

FIG. 4: the DC-DC block is enlarged in fig. 3.

FIG. 5: the boost module and the high voltage switch and the isolation transformer are enlarged in fig. 3.

FIG. 6: in fig. 3, two power applying electrodes, a butt joint voltage sampling circuit and a current sampling circuit are enlarged.

FIG. 7: in fig. 3, two isolated optocouplers are butted with a current feedback module and a voltage feedback module in an enlarged manner.

FIG. 8: the control processor is enlarged in fig. 3.

FIG. 9: the invention relates to an electromyographic signal processing circuit (with three electrode patches).

FIG. 10: the invention relates to a front-end power supply of an isolation optocoupler.

FIG. 11: the change of the body surface potential amplitude is shown schematically.

In the figure: 1, led display screen, 2, stimulator housing.

Detailed Description

The invention is further described with reference to the following description and embodiments in conjunction with the accompanying drawings.

As shown in fig. 1 to 9, a closed-loop controlled median nerve stimulator includes a stimulator housing 2, in which a power supply, a control processor and a voltage boosting module connected to the power supply, and a high voltage switch and a voltage boosting module connected to an output end of the control processor are disposed, the power supply of this embodiment is formed by connecting a lithium battery (not shown) and a DC-DC module (see fig. 4), an output of the DC-DC module is connected to the control processor and the voltage boosting module, the stimulator housing is provided with three input keys K1, K2, and K3 connected to the control processor, the high voltage switch is connected to an electric shock device externally disposed on the stimulator housing through a lead output, the electric shock device includes two electrodes matched with each other to generate an electrical stimulation signal, the two electrodes for applying voltage in this embodiment are E4 and E5 (which may be replaced by electrode films) capable of being flexibly attached to form a shape to cover the skin, as shown in fig. 1, two electrode plates are stuck on the wrist position of the palm side, the output of the high-voltage switch is connected with an isolation transformer, and the isolation transformer is arranged in the stimulator shell and is connected with the two electrode plates E4 and E5 through leads; the input end of the control processor is also connected with a voltage sampling device and a current sampling device, wherein the voltage sampling device comprises a front-end voltage sampling circuit and a rear-end voltage feedback module which are electrically connected, the current sampling device comprises a front-end current sampling circuit and a rear-end current feedback module which are electrically connected, the voltage sampling device and the current sampling device are both arranged in a stimulator shell, the input ends of the voltage sampling circuit and the current sampling circuit are externally connected with electrode plates E4 and E5 through wires, the output ends of the voltage sampling circuit and the current sampling circuit are connected with the corresponding voltage feedback module and the corresponding current feedback module through isolated optical coupler outputs, and the output ends of the voltage feedback module and the current feedback module are connected with the control processor; the input end of the control processor is also connected with a myoelectric signal processing device, the myoelectric signal processing device comprises three electrode patches (E1, E2 and E3 in the figure) which are externally arranged on the shell of the stimulator and used for collecting myoelectric signals and a myoelectric signal processing circuit which is arranged in the shell of the stimulator and used for processing the myoelectric signals, the output end of the myoelectric signal processing circuit is connected with the control processor, the input end of the myoelectric signal processing circuit is connected with the three electrode patches E1, E2 and E3 through leads, and the output end of the control processor is connected with the led display screen 1 arranged on the shell of the stimulator. In the circuit diagram of fig. 8, the LCD interface is used to simplify the illustration of the led display screen that can be connected to the control processor, which is the prior art; the control processor in this embodiment employs an 8-bit micro-control processor PIC16F1788-I/SS (see FIG. 8). In the boost module in fig. 5, for a simplified voltage regulation circuit, an input low voltage is first regulated to an accurate voltage required by the boost circuit, and then a push-pull circuit is used to boost a low voltage at an input end of a high-voltage power supply to a required high voltage through a boost transformer; the push-pull circuit can enable the input end of the transformer to adopt bidirectional excitation, improves the use efficiency of the transformer and reduces energy loss.

In order to reduce the interference of a high-voltage sampling electric signal to a low-voltage electric signal in use, power supplies used in front of and behind the isolation optocoupler need to be isolated, wherein a front-end power supply of the isolation optocoupler is a 3V isolation power supply in a figure 10, a rear-end power supply of the isolation optocoupler is connected with an output power supply of the DC-DC module, and the front power supply and the rear power supply are isolated and used more safely.

In addition, when the median nerve stimulator works, the stimulator can be operated by three keys, and is selected to be in an automatic adjusting mode or a manual adjusting mode, and the automatic adjusting mode can automatically adjust the strength of the nerve stimulation signal according to the mental state of a human body, so that the proper strength is achieved; the manual regulation mode is divided into a voltage stimulation mode and a current stimulation mode, and the intensity of the output stimulation signal is manually regulated according to the manual judgment and the requirement of a user.

The application method of the median nerve stimulator comprises the following steps:

a method of using a median nerve stimulator, the method of use comprising the steps of, in order:

(1) after starting up, acquiring the reference body surface potential amplitude and the change rate of the patient: under the condition that a human body is in a calm state, with E1 as a zero potential, recording the potential difference of E3 and E1 and the potential difference of E2 and E1 as two paths of body surface potential values respectively, and processing the recorded two paths of body surface potential value data in the same calculation mode;

continuously recording the body surface potential values of each path for 5 minutes, wherein 10 times of body surface potential values are acquired every 5 seconds at a frequency of 100Hz, and then calculating the body surface potential amplitude and the body surface potential change rate of the position, the body surface potential amplitude is the average value of the 10 times of body surface potential values, the body surface potential change rate is the change rate calculated by dividing the difference value of every two adjacent body surface potential values in the 10 times of body surface potential values by the interval time of the two adjacent body surface potential values and then averaging; calculating the maximum value and the minimum value of the body surface potential amplitude and the maximum value and the minimum value of the body surface potential change rate of each road from the data continuously recorded and obtained in 5 minutes, and then taking the interval range corresponding to the maximum value and the minimum value as the corresponding reference body surface potential amplitude and the reference body surface potential change rate, wherein the amplitude of the reference body surface potential is 0 mV-20 mV, and the change rate of the reference body surface potential is less than or equal to 20 mV/s;

(2) applying electrical stimulation and adjusting the electrical stimulation amplitude according to the mental state of the person:

the electrical stimulation starts from 0V, and the step pitch (gear) adjusting mode is that the step pitch is 2V/step within 0-50V, the step pitch is 5V/step within 50-100V, and the step pitch is 10V/step within 100-500V; the pulse width is 0-40us, and the step pitch is 4 us/step; the frequency is 5-100Hz, the frequency is 5-40Hz according to the step pitch 5 Hz/step, and the frequency is 40-100Hz according to the step pitch 10 Hz/step;

calculating two paths of body surface potential values in the electrical stimulation process, and comparing the two paths of body surface potential values with the reference body surface potential amplitude and the reference body surface potential change rate of the same path to judge the mental state of the person: collecting the same 10 times of body surface potential values at the same 100Hz frequency in the step (1) every 2 minutes in the electrical stimulation process, then calculating the body surface potential amplitude and the body surface potential change rate of each path according to the method in the step (1), respectively comparing the body surface potential amplitude and the body surface potential change rate with the same path reference obtained in the step (1), and judging that the person is painful when the two paths of body surface potential amplitudes are both greater than the upper limit of the respective reference body surface potential amplitude by 0.2-0.5 mV;

on the premise of judging that the pain is caused, when the change rates of the two paths of body surface potentials are larger than the upper limit of the change rate of the same-path reference body surface potential of 130%, keeping the frequency of the stimulation voltage unchanged, and reducing the amplitude of the stimulation voltage; when the change rates of the two paths of body surface potentials are less than or equal to 70% of the lower limit of the change rate of the same-path reference body surface potential, the amplitude of the stimulation voltage is kept unchanged, the frequency of the stimulation voltage is increased, and when the frequency of the stimulation voltage is adjusted to the maximum 100Hz, the change rates of the two paths of body surface potentials are still less than or equal to 70% of the lower limit of the change rate of the same-path reference body surface potential, the pulse width is increased.

The starting-up default condition is an automatic adjustment mode and a voltage stimulation mode, and due to the existence of human body difference, sometimes under the condition that the automatic adjustment mode and the voltage stimulation mode are not ideal, the combination of keys K1 and K3 is used for switching to a manual adjustment mode; because the safe voltage level of most people can be considered under the voltage stimulation mode, the voltage amplitude is limited below 100V, but when some human skin is dry in contact and seriously aged, the conductivity is reduced, the passing current is too small to achieve the ideal stimulation effect, the current stimulation mode needs to be changed at the moment, the stimulation is performed in the constant current mode, the effect is better than that of the voltage mode, the safety of the voltage and the current level is integrated, and the possible voltage limit value can be larger than 100V. The invention uses pulse voltage stimulation, has low average voltage and is in a safe range.