CN-121489509-B - Noninvasive bioelectric signal detection method based on flexible sensing technology

Abstract

The invention relates to the technical field of noninvasive bioelectricity detection, in particular to a noninvasive bioelectricity signal detection method based on a flexible sensing technology, which comprises the steps of collecting myoelectric original signals of a target area through a flexible electrode, and synchronously acquiring skin micro-deformation amplitude parameters captured by a high-frequency micro-strain sensor, interface impedance change rate parameters generated by dynamic scanning of an alternating-current impedance spectrum and electrode contact pressure attenuation parameters quantized by a distributed film pressure sensor array; three types of parameters are input into a dynamic coupling analysis model, a real-time contact pressure compensation instruction is generated through a pressure compensation algorithm, a signal amplification gain adjustment instruction is generated through a gain self-adaptive algorithm, a periodic pressure maintenance instruction is generated through a pressure attenuation suppression algorithm, a miniature pressure actuator and a programmable amplifier are driven according to the instruction, the adjustment is completed before the electromyographic signal peak period, the electromyographic signal with optimized signal-to-noise ratio is output, and the detection accuracy and wearing comfort are considered.

Inventors

• CAI JINGYAO
• ZHANG JIAQI
• BAI YUEHUA

Assignees

• 华北理工大学

Dates

Publication Date

20260508

Application Date

20251230

Claims (10)

1. 1. A noninvasive bioelectric signal detection method based on a flexible sensing technology is characterized by comprising the following steps of: S1, acquiring myoelectricity original signals of a target area through a flexible electrode, and synchronously initializing skin micro-deformation amplitude parameters, interface impedance change rate parameters and electrode contact pressure attenuation parameters, wherein the skin micro-deformation amplitude parameters are captured by a high-frequency micro-strain sensor, the interface impedance change rate parameters are generated through dynamic scanning of alternating current impedance spectrum, and the electrode contact pressure attenuation parameters are quantitatively acquired by a distributed film pressure sensor array; S2, inputting the three parameters of the skin micro deformation amplitude parameter, the interface impedance change rate parameter and the electrode contact pressure attenuation parameter into a dynamic coupling analysis model, and executing the following processing, wherein the processing specifically comprises the following steps of: a. based on the proportional relation between the skin micro deformation amplitude parameter and a preset deformation amplitude threshold, generating a real-time contact pressure compensation instruction through a pressure compensation algorithm, wherein the pressure compensation algorithm establishes nonlinear mapping of micro deformation unit increment and pressure compensation quantity, so that the contact pressure synchronously increases when the micro deformation is increased; b. Generating a signal amplification gain adjustment instruction through a gain self-adaptive algorithm based on the deviation value of the interface impedance change rate parameter and a preset impedance threshold value, wherein the gain self-adaptive algorithm establishes a positive feedback mechanism of an impedance unit increment and a gain up-regulation quantity; c. based on the derivative relation between the electrode contact pressure attenuation parameter and the time attenuation function, generating a periodic pressure maintaining instruction through a pressure attenuation suppression algorithm, and blocking the coupling negative cycle of the skin micro-deformation amplitude parameter, the interface impedance change rate parameter and the electrode contact pressure attenuation parameter; And S3, driving a miniature pressure actuator according to the real-time contact pressure compensation instruction, controlling a programmable amplifier according to the signal amplification gain adjustment instruction, and outputting an electromyographic signal with optimized signal-to-noise ratio.
2. 2. The method for detecting the noninvasive bioelectric signal based on the flexible sensing technology of claim 1, wherein the generating the real-time contact pressure compensation command by the pressure compensation algorithm comprises the following steps: The method comprises the steps of constructing a nonlinear converter taking a skin micro-deformation amplitude parameter as an input and taking a pressure compensation quantity as an output, triggering a dynamic compensation mechanism based on deformation and a pressure coupling factor when the real-time skin micro-deformation amplitude parameter captured by a micro-strain sensor exceeds a preset deformation amplitude threshold, and converting an instantaneous increment of the real-time skin micro-deformation amplitude parameter into an air cavity volume adjustment instruction of a miniature pressure actuator through a feedback channel of an embedded processor by the dynamic compensation mechanism so that the pressure compensation quantity is in nonlinear increment along with the deformation amplitude.
3. 3. The method for detecting the noninvasive bioelectric signal based on the flexible sensing technology of claim 2, wherein the pressure compensation algorithm establishes a nonlinear mapping of the micro-deformation unit increment and the pressure compensation amount, and the method specifically comprises the following steps: the method comprises the steps of presetting a deformation pressure conversion matrix in an embedded processor, wherein the deformation pressure conversion matrix is generated through machine learning training, a row vector of the deformation pressure conversion matrix corresponds to a discretization interval of a micro deformation unit increment, a column vector of the deformation pressure conversion matrix is mapped to a nonlinear incremental gradient of a pressure compensation quantity, and conversion weight of each discretization interval is dynamically corrected by a cooperative change rate of a skin micro deformation amplitude parameter and a contact pressure attenuation parameter.
4. 4. The method for detecting the noninvasive bioelectric signal based on the flexible sensing technology of claim 3, wherein the step of synchronously increasing the contact pressure when the micro-deformation is increased is characterized by comprising the following steps: When the deformation pressure conversion matrix detects micro deformation unit increment span transition, a gradient jump module of pressure compensation quantity is activated, the gradient jump module overlaps the current air cavity volume adjustment instruction with the differential value of the preamble instruction through a multi-stage pneumatic valve controller of the micro pressure actuator to form step compensation of contact pressure, and meanwhile, the step amplitude is calibrated in a closed loop by utilizing real-time feedback data of the distributed film pressure sensor array.
5. 5. The method for detecting a noninvasive bioelectric signal based on a flexible sensing technology according to claim 1, wherein the generating a signal amplification gain adjustment instruction by a gain adaptive algorithm based on a deviation value between an interfacial impedance change rate parameter and a predetermined impedance threshold specifically comprises: and establishing an impedance deviation gain tuning function, wherein the impedance deviation gain tuning function takes algebraic difference between an interface impedance change rate parameter generated by alternating current impedance spectrum scanning and a preset impedance threshold as an independent variable, and the output end of the impedance deviation gain tuning function is connected with a gain control register of the programmable amplifier, wherein when the impedance deviation value exceeds a linear response interval, a piecewise saturation mechanism of a gain self-adaptive algorithm is triggered, so that the gain up-regulation quantity is switched from linear increase to logarithmic increase when the impedance deviation value is increased.
6. 6. The method for detecting the noninvasive bioelectric signal based on the flexible sensing technology of claim 5, wherein the derivative of the sweat volatilization rate parameter is introduced as a correction coefficient of an impedance deviation gain tuning function, the time second derivative of the sweat volatilization rate parameter is calculated through the skin surface curvature change rate parameter synchronously captured by the high-frequency microstrain sensor, and the time second derivative and the impedance deviation value are subjected to convolution operation to generate a gain-tuned dynamic damping factor, so that gain oscillation caused by sweat volatilization mutation is inhibited.
7. 7. The method for detecting the noninvasive bioelectric signal based on the flexible sensing technology of claim 6, wherein the gain adaptive algorithm establishes a positive feedback mechanism of the impedance unit increment and the gain up-adjustment, and the method specifically comprises the following steps: The gain impedance coupler is integrated in the programmable amplifier, the gain impedance coupler disassembles the impedance unit increment into a fundamental frequency component and a harmonic component, wherein the fundamental frequency component is directly input into the gain control register to realize linear up-regulation, and the harmonic component is injected into a reference voltage end of the impedance detection circuit through the positive feedback loop to form self-enhancement circulation of the impedance unit increment and the gain up-regulation quantity.
8. 8. The method for detecting a noninvasive bioelectric signal based on a flexible sensing technology according to claim 1, wherein the generating a periodic pressure maintenance instruction by a pressure decay suppression algorithm specifically comprises: And constructing a pressure maintenance function taking the first derivative of the electrode contact pressure attenuation parameter with respect to time as an input, wherein the output end of the pressure maintenance function is connected with a pulse trigger module of the miniature pressure actuator, and when the derivative value of the pressure attenuation parameter exceeds the attenuation rate threshold value of the time attenuation function, a pulse sequence generator based on pressure attenuation phase compensation is started to generate a periodic pressure maintenance instruction with an exponential attenuation envelope.
9. 9. The method for detecting the noninvasive bioelectric signal based on the flexible sensing technology according to claim 8, wherein the spectral characteristics of the skin micro-deformation amplitude parameter and the fluctuation variance of the interface impedance change rate parameter are synchronously collected in the execution period of the pressure maintenance instruction, the spectral characteristics and the fluctuation variance are input into a recursive filter of a pressure attenuation suppression algorithm through a reverse feedback channel of a dynamic coupling analysis model to generate a negative circulation blocking coefficient, and the negative circulation blocking coefficient adjusts the envelope attenuation slope of a pulse sequence generator so that the output energy of the periodic pressure maintenance instruction is inversely proportional to the intensity of coupled negative circulation.
10. 10. The method for detecting the noninvasive bioelectric signal based on the flexible sensing technology of claim 8, wherein the real-time contact pressure compensation instruction is encoded into a duty ratio control signal of the pneumatic valve, the duty ratio control signal is converted into a step change of the volume of the air cavity through a piezoelectric ceramic driver of the miniature pressure actuator, meanwhile, the signal amplification gain adjustment instruction is encoded into a gain control word and is loaded into a digital-analog converter of the programmable amplifier, wherein the loading time sequence of the gain control word and the volume change of the air cavity are strictly aligned through a clock synchronization module of a dynamic coupling analysis model, and the completion of pressure compensation and gain adjustment is ensured before the action potential peak period of the electromyographic signal.

Description

Noninvasive bioelectric signal detection method based on flexible sensing technology Technical Field The invention relates to the technical field of noninvasive bioelectric detection, in particular to a noninvasive bioelectric signal detection method based on a flexible sensing technology. Background The noninvasive bioelectricity detection is an important technology, is particularly applied to the daily monitoring link of the noninvasive myoelectric signals of the wrist, and is characterized in that the dual optimization of the signal-to-noise ratio and wearing comfort is realized by cooperatively processing the multi-factor coupling influence under the dynamic scene, the core requirements of the daily office scene on the accuracy and comfort of the myoelectric monitoring are adapted, in the daily monitoring of the noninvasive myoelectric signals of the wrist, the human body breathing can drive the wrist skin to generate periodical micro-deformation, the sweat volatilization can change the impedance of the skin and the electrode interface, the flexible electrode can generate contact pressure attenuation along with wearing time, and as the three parts can form dynamic coupling, the micro deformation leads to the instantaneous disconnection of the electrode and skin contact, so that interface impedance is increased to amplify low-frequency noise, and the pressure attenuation can aggravate contact instability to form vicious circle, so that the signal-to-noise ratio of the electromyographic signal is reduced in a dynamic scene. Disclosure of Invention The invention aims to provide a noninvasive bioelectric signal detection method based on a flexible sensing technology, which aims to solve the problems in the background technology. In order to achieve the above object, one of the objects of the present invention is to provide a method for detecting a noninvasive bioelectric signal based on a flexible sensing technology, comprising the steps of: s1, acquiring myoelectricity original signals of a target area through a flexible electrode, and synchronously initializing skin micro-deformation amplitude parameters, interface impedance change rate parameters and electrode contact pressure attenuation parameters; s2, capturing the skin micro-deformation amplitude parameter by a high-frequency micro-strain sensor, generating the interface impedance change rate parameter by alternating current impedance spectrum dynamic scanning, and quantitatively acquiring the electrode contact pressure attenuation parameter by a distributed film pressure sensor array; S3, inputting the skin micro deformation amplitude parameter, the interface impedance change rate parameter and the electrode contact pressure attenuation parameter into a dynamic coupling analysis model, and executing the following processing, wherein the processing specifically comprises the following steps of: a. based on the proportional relation between the skin micro deformation amplitude parameter and a preset deformation amplitude threshold, generating a real-time contact pressure compensation instruction through a pressure compensation algorithm, wherein the pressure compensation algorithm establishes nonlinear mapping of micro deformation unit increment and pressure compensation quantity, so that the contact pressure synchronously increases when the micro deformation is increased; b. Generating a signal amplification gain adjustment instruction through a gain self-adaptive algorithm based on the deviation value of the interface impedance change rate parameter and a preset impedance threshold value, wherein the gain self-adaptive algorithm establishes a positive feedback mechanism of an impedance unit increment and a gain up-regulation quantity; c. based on the derivative relation between the electrode contact pressure attenuation parameter and the time attenuation function, generating a periodic pressure maintaining instruction through a pressure attenuation suppression algorithm, and blocking the coupling negative cycle of the skin micro-deformation amplitude parameter, the interface impedance change rate parameter and the electrode contact pressure attenuation parameter; And S4, driving a miniature pressure actuator according to the real-time contact pressure compensation instruction, controlling a programmable amplifier according to the signal amplification gain adjustment instruction, and outputting an electromyographic signal with optimized signal-to-noise ratio. Compared with the prior art, the invention has the beneficial effects that: According to the invention, three parameters including skin micro deformation amplitude, interface impedance change rate and electrode contact pressure attenuation are synchronously captured through the flexible electrode, the three parameters are cooperatively processed through the dynamic coupling analysis model, the coupling negative circulation of the three parameters is effectively blocked, the pressure compensation