Pressure regulation and control method, device and equipment based on heart rate variability and storage medium

Abstract

The invention relates to a pressure regulation and control method, device and equipment based on heart rate variability and a storage medium, and belongs to the field of pressure regulation and control. The method comprises the steps that in a control task, the blood volume change of subcutaneous capillary vessels of an operator is detected, and pulse wave signals for isolating vagus nerve electrical stimulation signal interference are collected in real time; after the collected pulse wave signals are subjected to preprocessing including amplification and filtering, the pulse wave signals are converted into a frequency domain for heart rate variability analysis, and a real-time pressure index in a control task is evaluated; establishing a pressure baseline, judging a real-time pressure level, adjusting stimulation parameters according to the pressure level to electrically stimulate the neck vagus nerve, and adjusting sympathetic-parasympathetic nerve balance to reduce pressure. The optimal physiological state of an operator is dynamically maintained on the premise that a control task is not interrupted, and safety, stability and high efficiency of high-precision operation are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of pressure regulation technology, and in particular to a pressure regulation method, device, equipment and storage medium based on heart rate variability. Background Technology

[0002] In high-precision control tasks such as flight piloting, surgical procedures, and industrial control, the operator's stress level is directly related to the operational error rate and system safety. However, existing stress management technologies suffer from serious scenario adaptation deficiencies: at the monitoring level, mainstream solutions rely on subjective scales or offline physiological monitoring that are detached from the control environment, failing to capture real-time dynamic changes in stress during the task process. While ergonomic monitoring technologies based on eye movements and electromyography can identify fatigue, they lack sufficient sensitivity to stress-induced fluctuations in cognitive load, making it difficult to accurately map their relationship to operational precision. Heart rate variability (HRV) refers to the variation in heart rate intervals, serving as an indicator of autonomic nervous system activity. HRV reflects the autonomic nervous system's regulation of stress. When facing stress, the sympathetic nervous system increases heart rate, while the parasympathetic nervous system slows it down; this balance is reflected in HRV, i.e., reduced HRV variability.

[0003] At the intervention level, traditional behavioral stress reduction techniques (such as breathing exercises) may disrupt continuous operational processes. In contrast, tVNS (tcavenos vagus nerve stimulation) bidirectionally modulates the autonomic nervous system by activating the nucleus tractus solitarius-locus coeruleus-prefrontal cortex pathway. Studies have shown that low-intensity vagus nerve stimulation can reduce heart rate variability; this intervention helps suppress sympathetic overexcitation while enhancing parasympathetic activity and improving impulsive decision-making under stress. However, traditional vagus nerve stimulation devices are open-loop controlled, requiring manual triggering and fixed parameters, making them unable to cope with the dynamic changes in stress during emergency tasks, potentially leading to inappropriate timing of stimulation or insufficient stimulation. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to disclose a stress regulation method, device, equipment, and storage medium based on heart rate variability; it achieves precise quantification of stress state through real-time heart rate variability (HRV) analysis, and dynamically maintains the operator's optimal physiological state without interrupting the control task, thereby ensuring the safety, stability, and efficiency of high-precision operation based on adaptive cervical vagus nerve stimulation.

[0005] This invention discloses a stress regulation method based on heart rate variability, comprising:

[0006] Step S1: During the operation, detect the changes in blood volume in the operator's subcutaneous capillaries and collect pulse wave signals that are isolated from interference by vagal nerve electrical stimulation signals in real time. Step S2: After preprocessing the collected pulse wave signal, including amplification and filtering, it is converted to the frequency domain for heart rate variability analysis to evaluate the real-time stress index in the control task. Step S3: Establish a pressure baseline, determine the real-time pressure level, adjust the stimulation parameters according to the pressure level to electrically stimulate the cervical vagus nerve, and regulate the sympathetic-parasympathetic nerve balance to reduce pressure. Specifically, at medium pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the amplitude of the stimulation signal while maintaining a fixed frequency; at high pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the frequency of the stimulation signal while maintaining a fixed amplitude.

[0007] Furthermore, in step S1, using a pulse wave acquisition front-end based on a photoelectric sensor, the photoelectric sensor that records pulse waves is placed on the subject's earlobe, and the pulse wave signal is acquired by utilizing the difference in light absorption.

[0008] Further, in step S2, the preprocessing includes: 1) A high-pass analog filter with a cutoff frequency of 0.5 Hz is used for pre-processing to effectively filter out DC and extremely low frequency components introduced by respiration, body temperature changes and sensor drift, thereby suppressing baseline drift. 2) Adaptive gain amplification is applied to the signal to dynamically adjust the signal amplitude and ensure that the output signal amplitude remains stable within the set range; 3) Perform analog-to-digital conversion on the dynamically adjusted amplitude signal to obtain a digital pulse wave signal; 4) Perform a fourth-order IIR Butterworth bandpass filter on the pulse wave digital signal. The passband frequency of the bandpass filter covers the main energy distribution range of the pulse wave signal. 5) Perform 64th-order FIR filtering on the bandpass filtered pulse wave digital signal to obtain a pulse wave digital signal with optimized waveform quality.

[0009] Further, in step S2, the process of switching to the frequency domain for heart rate variability analysis and calculating the real-time stress index during the control task includes: 1) The pulse wave digital signal is divided into PPG sequences of a set length using the sliding window method; 2) Resample and detrendize the PPG sequence within the window at a set frequency; 3) The power spectral density of heart rate variability was calculated using Fast Fourier Transform (FFT); 4) Integrate the low-frequency power (0.04-0.15Hz) and high-frequency power (0.15-0.4Hz) respectively, and calculate the ratio of low-frequency power (LF) to high-frequency power (HF) as the core indicator of the pressure index.

[0010] Furthermore, step S4, the process of establishing a pressure baseline, includes: The mean resting-state pressure index was calculated based on the user's initial 5-minute resting state measurements. The first pressure baseline is set at 1.8 times the mean of the resting pressure index, and the second pressure baseline is set at 3 times the mean of the resting pressure index. When the pressure index is below the first pressure baseline, it is judged as a low pressure level; when it is between the first and second pressure baselines, it is judged as a medium pressure level; when it exceeds the second pressure baseline, it is judged as a high pressure level.

[0011] Furthermore, at a moderate pressure level, the frequency of the electrical stimulation of the cervical vagus nerve is fixed at 4Hz, and the intensity of the current stimulation is set according to the following formula: ; The base current intensity is 0.4mA. For every unit the pressure index exceeds the first pressure baseline, the current increases by 0.3mA, with a maximum of 1mA. Under high-pressure conditions, the current amplitude for electrical stimulation of the cervical vagus nerve is fixed at 1 mA, and the current stimulation frequency is set according to the following formula: ; The base frequency is 4 Hz. For every unit the pressure index exceeds the second pressure baseline, the frequency increases by 2 Hz, up to a maximum of 10 Hz.

[0012] The present invention also discloses a pressure regulation device employing the pressure regulation method based on heart rate variability as described above, comprising: a pulse acquisition front end, a processing terminal, and a vagus nerve stimulator; Among them, the pulse acquisition front end is used to detect changes in blood volume in the operator's subcutaneous capillaries using photoelectric sensors, and to acquire pulse wave signals that are isolated from interference by vagal nerve electrical stimulation signals in real time; The processing terminal is used to preprocess the acquired pulse wave signal, including amplification and filtering, and then convert it to the frequency domain for heart rate variability analysis to assess the real-time stress index in the control task; and to establish a stress baseline, determine the real-time stress level, and generate a control signal for electrical stimulation of the cervical vagus nerve based on the stress level. A vagus nerve stimulator is used to generate electrical signals to electrically stimulate the vagus nerve in the neck based on the modulation signal of electrical stimulation, thereby regulating the sympathetic-parasympathetic balance to reduce stress. Specifically, at medium pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the amplitude of the stimulation signal while maintaining a fixed frequency; at high pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the frequency of the stimulation signal while maintaining a fixed amplitude.

[0013] Furthermore, the pulse acquisition front end is an ear clip-on PPG sensor, which is clipped onto the subject's earlobe so that the pulse wave recording electrode using the sensor is placed on the subject's earlobe.

[0014] The present invention also discloses an electronic device, the electronic device including a memory and a processor, the memory being used to store at least one instruction, and the processor being used to execute the at least one instruction to implement the stress regulation method based on heart rate variability as described above.

[0015] The present invention also discloses a computer-readable storage medium storing at least one instruction that, when executed by a processor, implements the stress regulation method based on heart rate variability as described above.

[0016] This invention can achieve one of the following beneficial effects: This invention discloses a stress regulation method, device, equipment, and storage medium based on heart rate variability (HRV). By acquiring pulse wave signals isolated from interference from vagal nerve electrical stimulation signals in real time and performing heart rate variability (HRV) analysis, the stress state of the operator can be accurately quantified. The parameters of cervical vagal nerve stimulation are adaptively adjusted according to the real-time stress state. At medium stress levels, a fixed frequency and modulation amplitude are used to gently stimulate the vagus nerve; at high stress levels, a fixed amplitude and modulation frequency are used to rapidly regulate the sympathetic-parasympathetic balance. This adaptive regulation mechanism can dynamically adjust stimulation parameters according to the specific needs of the operator, ensuring optimal stimulation effects.

[0017] By using real-time HRV analysis to accurately quantify stress levels and by using adaptive vagus nerve stimulation in the neck, "on-the-job control" is achieved without interrupting the operation task. This ensures that the operator's physiological and psychological state remains at its best during high-pressure tasks where task interruption is not allowed, thereby guaranteeing the safety, stability, and efficiency of high-precision operation. Attached Figure Description

[0018] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Figure 1 This is a flowchart of the stress regulation method based on heart rate variability in an embodiment of the present invention; Figure 2 This is a schematic diagram showing the connection of the pressure regulation device in an embodiment of the present invention; Figure 3 This is a schematic diagram of the ear clip-on PPG sensor and its wearing method in an embodiment of the present invention; Figure 4 This is a schematic diagram of the vagus nerve electrical stimulator system in an embodiment of the present invention; Figure 5 This is an example diagram of the gel patch electrode structure in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of an electronic device in an embodiment of the present invention. Detailed Implementation

[0019] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0020] Example 1 One embodiment of the present invention discloses a stress regulation method based on heart rate variability, such as... Figure 1 As shown, it includes: Step S1: During the operation, detect the changes in blood volume in the operator's subcutaneous capillaries and collect pulse wave signals that are isolated from interference by vagal nerve electrical stimulation signals in real time. Step S2: After preprocessing the collected pulse wave signal, including amplification and filtering, it is converted to the frequency domain for heart rate variability analysis to evaluate the real-time stress index in the control task. Step S3: Establish a pressure baseline, determine the real-time pressure level, adjust the stimulation parameters according to the pressure level to electrically stimulate the cervical vagus nerve, and regulate the sympathetic-parasympathetic nerve balance to reduce pressure. Specifically, at medium pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the amplitude of the stimulation signal while maintaining a fixed frequency; at high pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the frequency of the stimulation signal while maintaining a fixed amplitude.

[0021] Specifically, in step S1, the pulse wave acquisition front end based on a photoelectric sensor is used to place the photoelectric sensor that records the pulse wave on the subject's earlobe, and the pulse wave PPG signal is acquired by utilizing the difference in light absorption.

[0022] In the real-time pulse wave monitoring of this step, the problem of traditional ECG modal data being easily interfered with by electrical signals is overcome. A photoelectric sensor (LED + photodiode) detects changes in blood volume in the operator's subcutaneous capillaries, and pulse wave signals are acquired using differences in light absorption. Since vagal nerve stimulation produces an electrical signal, it has no effect on light absorption. Therefore, it is possible to record a complete pulse wave signal under vagal nerve electrical stimulation, effectively recording the user's heart rate information online.

[0023] Specifically, the preprocessing in step S2 includes: 1) A high-pass analog filter with a cutoff frequency of 0.5 Hz is used for pre-processing to effectively filter out DC and extremely low frequency components introduced by breathing, body temperature changes and sensor drift, thereby suppressing baseline drift and improving signal quality; 2) Adaptive gain amplification is applied to the signal to dynamically adjust the signal amplitude and ensure that the output signal amplitude remains stable within the set range; During dynamic amplitude adjustment, the amplification factor is adjusted in real time according to the strength of the input signal to ensure that the output signal amplitude is stable within the range of 0.8–1.2 Vpp, so as to meet the optimal input dynamic range for subsequent analog-to-digital conversion and avoid signal saturation or signal-to-noise ratio degradation.

[0024] 3) Perform analog-to-digital conversion on the dynamically adjusted amplitude signal to obtain a digital pulse wave signal; 4) Perform a fourth-order IIR Butterworth bandpass filter on the pulse wave digital signal. The passband frequency of the bandpass filter covers the main energy distribution range of the pulse wave signal. The passband frequency of the bandpass filter is set to 0.01–4 Hz to cover the main energy distribution range of the pulse wave signal. The filter has a flat passband response and good stopband attenuation characteristics, which can effectively eliminate high-frequency noise (such as electromyographic interference and power frequency noise) and ultra-low frequency interference, while preserving the morphological characteristics of the pulse wave.

[0025] 5) Perform 64th-order FIR filtering on the bandpass filtered pulse wave digital signal to obtain a pulse wave digital signal with optimized waveform quality; Using a 64th-order FIR filter can balance phase linearity and computational efficiency, further optimize waveform quality, and ensure the accuracy and reliability of subsequent heart rate variability (HRV) analysis.

[0026] In step S2, the process of switching to the frequency domain for heart rate variability analysis and calculating the real-time stress index during the control task includes: 1) The pulse wave digital signal is divided into PPG sequences of a set length using the sliding window method; Specifically, in the sliding window method, the window is set to a length of 5 minutes, and the sliding step is 2 seconds; 2) Resample and detrendize the PPG sequence within the window at a set frequency; Specifically, the resampling frequency was set to 4Hz, and a smoothing prior method was used for detrending processing.

[0027] 3) The power spectral density (PSD) of heart rate variability was calculated using Fast Fourier Transform (FFT); 4) Integrate the low-frequency power (0.04-0.15Hz) and high-frequency power (0.15-0.4Hz) respectively, and calculate the ratio of low-frequency power (LF) to high-frequency power (HF) (LF / HF) as the core indicator of the pressure index. .

[0028] Specifically, in step S4, the process of establishing a pressure baseline includes: The mean resting-state pressure index was calculated based on the user's initial 5-minute resting state measurements. The first pressure baseline is set at 1.8 times the mean of the resting pressure index, and the second pressure baseline is set at 3 times the mean of the resting pressure index. When the pressure index is below the first pressure baseline, it is judged as a low pressure level; when it is between the first and second pressure baselines, it is judged as a medium pressure level; when it exceeds the second pressure baseline, it is judged as a high pressure level.

[0029] Specifically, in step S4, during the adjustment of stimulation parameters, the modulation mode of the stimulation waveform is adjusted in real time using the pressure index to adapt to different pressure states: under low to medium pressure conditions, the stimulation parameters are adjusted using an amplitude modulation strategy to adjust the amplitude of the waveform to more gently match the stimulation needs of the vagus nerve; under high pressure levels, the stimulation output is adjusted using frequency modulation to quickly adjust the sympathetic-parasympathetic balance.

[0030] Specifically, at low pressure levels, no electrical stimulation was applied to the cervical vagus nerve; after a 60-second delay, the pressure index was measured again. At moderate pressure levels, the frequency of electrical stimulation of the cervical vagus nerve is fixed at 4Hz, and the intensity of the current stimulation is set according to the following formula: ; The base current intensity is 0.4mA. For every unit the pressure index exceeds the first pressure baseline, the current increases by 0.3mA, with a maximum of 1mA. Under high-pressure conditions, the current amplitude for electrical stimulation of the cervical vagus nerve is fixed at 1 mA, and the current stimulation frequency is set according to the following formula: ; The base frequency is 4 Hz. For every unit the pressure index exceeds the second pressure baseline, the frequency increases by 2 Hz, up to a maximum of 10 Hz.

[0031] Furthermore, the electrical stimulation waveform is a square pulse with a fixed pulse width of 200 μS. Each stimulation lasts for 60 seconds. After the stimulation ends, the stress index is reassessed. If it is still at a medium to high stress level, a new round of regulation is triggered.

[0032] In summary, the stress regulation method based on heart rate variability disclosed in this invention can accurately quantify the operator's stress state by real-time acquisition of pulse wave signals isolated from vagal nerve electrical stimulation signal interference and performing heart rate variability (HRV) analysis. Based on the real-time stress state, the parameters of cervical vagal nerve stimulation are adaptively adjusted. Under medium stress levels, a fixed frequency and modulation amplitude are used to gently stimulate the vagus nerve; under high stress levels, a fixed amplitude and modulation frequency are used to rapidly regulate the sympathetic-parasympathetic balance. This adaptive regulation mechanism can dynamically adjust stimulation parameters according to the operator's specific needs, ensuring optimal stimulation effects.

[0033] By using real-time HRV analysis to accurately quantify stress levels and by using adaptive vagus nerve stimulation in the neck, "on-the-job control" is achieved without interrupting the operation task. This ensures that the operator's physiological and psychological state remains at its best during high-pressure tasks where task interruption is not allowed, thereby guaranteeing the safety, stability, and efficiency of high-precision operation.

[0034] Example 2 This invention discloses a pressure regulation device employing the heart rate variability-based pressure regulation method as described in Embodiment 1. Figure 2 As shown, it includes: a pulse acquisition front-end, a processing terminal, and a vagus nerve stimulator; wherein, The pulse acquisition front end is used to detect changes in blood volume in the operator's subcutaneous capillaries during operation tasks and to acquire pulse wave signals that are isolated from interference by vagal nerve electrical stimulation signals in real time. The processing terminal is used to preprocess the acquired pulse wave signal, including amplification and filtering, and then convert it to the frequency domain for heart rate variability analysis to assess the real-time stress index in the control task; and to establish a stress baseline, determine the real-time stress level, and generate a control signal for electrical stimulation of the cervical vagus nerve based on the stress level. A vagus nerve stimulator is used to generate electrical signals to electrically stimulate the vagus nerve in the neck based on the modulation signal of electrical stimulation, thereby regulating the sympathetic-parasympathetic balance to reduce stress. Specifically, at medium pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the amplitude of the stimulation signal while maintaining a fixed frequency; at high pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the frequency of the stimulation signal while maintaining a fixed amplitude.

[0035] Specifically, the pulse acquisition front end is an ear clip-on PPG sensor, which is clipped onto the subject's earlobe so that the pulse wave recording electrode of the sensor is located on the subject's earlobe. For example... Figure 3 The image shows an ear clip-on PPG sensor and its wearing method.

[0036] More specifically, considering the design requirements of this embodiment, a reflective integrated PPG sensor module was selected. This module, manufactured by Maxim Integrated, integrates a pulse oximeter and heart rate monitor biosensor, and includes a 660nm red LED, an 880nm infrared LED, a photodetector, and an ambient light suppression circuit. This approach saves costs and facilitates system integration, with the PPG recording electrode located on the subject's earlobe.

[0037] The chip consists of two parts: analog and digital circuits. The former mainly acquires signals, converting the light signals reflected from the human body into analog electrical signals, and finally converting them into digital signals through an ADC. The latter digitally filters the raw data and stores it in a buffer. The processor reads and writes the corresponding data in the chip's internal registers via an I2C interface. Because this module integrates complete circuitry, the design of the peripheral circuitry is relatively simple, requiring only proper power conversion and decoupling. Since the chip's internal LEDs require 3.3V-5V power, while the logic levels require 1.8V, which is incompatible with conventional MCU levels, an LDO is needed for voltage reduction. The INT pin is left floating and uses internal interrupt triggering. This module uses IIC communication, with the SCL and SDA pins connected to the microcontroller. A TVS diode is added to the electrode at the earlobe end for electrostatic discharge protection.

[0038] Specifically, a vagus nerve stimulator is a microprocessor-controlled current / voltage source that can generate high-precision current / voltage signals. Early nerve stimulation devices mostly used voltage stimulation, which has advantages such as simple circuitry and low cost. However, the actual current flowing into the body is greatly affected by contact resistance, resulting in significant differences in stimulation effects under different impedances. Currently, almost all nerve stimulation devices use current stimulation, employing current feedback technology to ensure a constant current flowing into the body under different contact resistances. This has led to the gradual phasing out of voltage stimulation. Currently, many companies in the domestic and international markets produce nerve stimulation devices with maximum output voltages ranging from ±9V to ±40V and output currents from ±500μA to ±4500μA. Internally, it is a constant current source, capable of outputting one or more current waveforms within the maximum output voltage range. During stimulation, the current flows from the anode through the body tissue to the cathode. This process stimulates the skin, producing sensations of stinging and itching; high-intensity stimulation can even burn the skin. Therefore, status monitoring is crucial. When excessively high impedance is detected, the system immediately cuts off the output to ensure safety.

[0039] The vagus nerve electrical stimulator consists of three parts: a signal generation circuit, a voltage-to-current conversion circuit, and a status monitoring circuit. The system structure is as follows: Figure 4As shown, the waveform output by the DAC is a voltage signal, which is then converted from voltage to current and output to the human body. This design scheme features simple structure, low noise, and high precision. The system output achieves a bandwidth of 20kHz while maintaining high DC accuracy, requiring operational amplifiers with exceptional DC precision and placing high demands on critical components and wiring.

[0040] The system output current range is within 20mA. To drive sufficiently high impedances, the system output voltage range is set to ±27V. The TI OPA454 high-voltage operational amplifier is well-suited for operation at this voltage and has sufficient current drive capability. The OPA454 is a high-voltage operational amplifier with a very wide supply range of ±5V to ±50V and can output up to ±50mA of current.

[0041] This project utilizes a bare-metal program developed based on the STM32F103 microcontroller to achieve precise pulse waveform generation (10μs-level timing control). It supports real-time parameter adjustment, power-down memory, power monitoring, and a TTL external control interface. A dual protection mechanism of hardware watchdog and overcurrent detection ensures medical-grade safety standards (response latency <20μs). The main control chip is primarily responsible for the data reception, transmission, and control functions of the digital-to-analog converter, button module, and OLED switch. The analog-to-digital converter utilizes an internal DAC module. The OLED and main control chip communicate via the IIC protocol, and information input is achieved through buttons.

[0042] The functional modules include stimulation parameter settings, battery monitoring, and a synchronization interface. Stimulation parameter settings are adjustable from 10-50Hz in frequency, 0.1-1ms in pulse width, and 1-5 minutes in duration. Parameters are stored in flash memory and have a power-off recovery function, eliminating the need for users to reset parameters each time they power on. The device also features battery monitoring, recording real-time battery level information. Additionally, a TTL interface is provided for triggering and control via external devices.

[0043] Choose biocompatible gel patch electrodes, such as Figure 5 As shown, it is composed of conductive material that contacts the skin surface and connects to the stimulator through a 2mm diameter metal plug, transmitting the pulsed electrical stimulation output from the stimulator to the human body. The upper limit of the pulsed stimulation voltage is increased within a safe range. This patch electrode has high tolerance and good contact, ensuring prolonged stimulation during use without contact detachment or impedance abnormalities. Before use, the neck should be cleaned to remove any oil from the skin. The current line uses flexible twisted-pair cable transmission to reduce environmental electromagnetic interference and incorporates an overvoltage / overcurrent protection module to ensure human safety.

[0044] Example 3 Based on the same technical concept, one embodiment of the present invention also provides an electronic device. (See also...) Figure 6 The diagram shows the structure of the computer device 400 provided in this embodiment, including a processor 601, a memory 602, and a bus 603. The memory 602 stores execution instructions and includes a main memory 6021 and an external memory 6022. The main memory 6021, also called internal memory, is used to temporarily store computational data in the processor 601 and data exchanged with external memory such as a hard disk 6022. The processor 601 exchanges data with the external memory 6022 through the main memory 6021. When the computer device 600 is running, the processor 601 and the memory 602 communicate through the bus 603, causing the processor 601 to execute a stress regulation method based on heart rate variability as described in Embodiment 1. The specific processing flow of the processor 601 can be referred to the description in Embodiment 1, and will not be repeated here.

[0045] This disclosure also provides a computer-readable storage medium storing a computer program that, when executed by a processor, performs the steps of the heart rate variability-based stress regulation method described in the above-described method embodiments. The storage medium can be volatile or non-volatile computer-readable storage.

[0046] The computer program product of the stress regulation method based on heart rate variability provided in this disclosure includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the steps of the stress regulation method based on heart rate variability described in the above method embodiments. For details, please refer to the above method embodiments, which will not be repeated here.

[0047] This disclosure also provides a computer program that, when executed by a processor, implements any of the methods described in the foregoing embodiments. The computer program product can be implemented specifically through hardware, software, or a combination thereof. In one optional embodiment, the computer program product is specifically embodied in a computer storage medium; in another optional embodiment, the computer program product is specifically embodied in a software product, such as a software development kit, etc.

[0048] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here. In the several embodiments provided in this disclosure, it should be understood that the disclosed device and method can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection may be through some communication interfaces; the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0049] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0050] In addition, the functional units in the various embodiments of this disclosure can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0051] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this disclosure, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0052] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A stress regulation method based on heart rate variability, characterized in that, include: Step S1: During the operation, detect the changes in blood volume in the operator's subcutaneous capillaries and collect pulse wave signals that are isolated from interference by vagal nerve electrical stimulation signals in real time. Step S2: After preprocessing the collected pulse wave signal, including amplification and filtering, it is converted to the frequency domain for heart rate variability analysis to evaluate the real-time stress index in the control task. Step S3: Establish a pressure baseline, determine the real-time pressure level, adjust the stimulation parameters according to the pressure level to electrically stimulate the cervical vagus nerve, and regulate the sympathetic-parasympathetic nerve balance to reduce pressure. Specifically, at medium pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the amplitude of the stimulation signal while maintaining a fixed frequency; at high pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the frequency of the stimulation signal while maintaining a fixed amplitude.

2. The stress regulation method based on heart rate variability according to claim 1, characterized in that, In step S1, the pulse wave acquisition front end based on a photoelectric sensor is used to place the photoelectric sensor that records the pulse wave on the subject's earlobe, and the pulse wave signal is acquired by utilizing the difference in light absorption.

3. The stress regulation method based on heart rate variability according to claim 1, characterized in that, In step S2, the preprocessing includes: 1) A high-pass analog filter with a cutoff frequency of 0.5 Hz is used for pre-processing to effectively filter out DC and extremely low frequency components introduced by respiration, body temperature changes and sensor drift, thereby suppressing baseline drift. 2) Adaptive gain amplification is applied to the signal to dynamically adjust the signal amplitude and ensure that the output signal amplitude remains stable within the set range; 3) Perform analog-to-digital conversion on the dynamically adjusted amplitude signal to obtain a digital pulse wave signal; 4) Perform a fourth-order IIR Butterworth bandpass filter on the pulse wave digital signal. The passband frequency of the bandpass filter covers the main energy distribution range of the pulse wave signal. 5) Perform 64th-order FIR filtering on the bandpass filtered pulse wave digital signal to obtain a pulse wave digital signal with optimized waveform quality.

4. The stress regulation method based on heart rate variability according to claim 1, characterized in that, In step S2, the process of switching to the frequency domain for heart rate variability analysis and calculating the real-time stress index during the control task includes: 1) The pulse wave digital signal is divided into PPG sequences of a set length using the sliding window method; 2) Resample and detrendize the PPG sequence within the window at a set frequency; 3) The power spectral density of heart rate variability was calculated using Fast Fourier Transform (FFT); 4) Integrate the low-frequency power (0.04-0.15Hz) and high-frequency power (0.15-0.4Hz) respectively, and calculate the ratio of low-frequency power (LF) to high-frequency power (HF) as the core indicator of the pressure index.

5. The stress regulation method based on heart rate variability according to claim 4, characterized in that, Step S4, the process of establishing a pressure baseline includes: The mean resting-state pressure index was calculated based on the user's initial 5-minute resting state measurements. The first pressure baseline is set at 1.8 times the mean of the resting pressure index, and the second pressure baseline is set at 3 times the mean of the resting pressure index. When the pressure index is below the first pressure baseline, it is judged as a low pressure level; when it is between the first and second pressure baselines, it is judged as a medium pressure level; when it exceeds the second pressure baseline, it is judged as a high pressure level.

6. The stress regulation method based on heart rate variability according to claim 5, characterized in that, At moderate pressure levels, the frequency of electrical stimulation of the cervical vagus nerve is fixed at 4Hz, and the intensity of the current stimulation is set according to the following formula: ； The base current intensity is 0.4mA. For every unit the pressure index exceeds the first pressure baseline, the current increases by 0.3mA, with a maximum of 1mA. Under high-pressure conditions, the current amplitude for electrical stimulation of the cervical vagus nerve is fixed at 1 mA, and the current stimulation frequency is set according to the following formula: ； The base frequency is 4 Hz. For every unit the pressure index exceeds the second pressure baseline, the frequency increases by 2 Hz, up to a maximum of 10 Hz.

7. A pressure regulation device employing the pressure regulation method based on heart rate variability as described in any one of claims 1-6. Its features are, Includes: pulse acquisition front end, processing terminal and vagus nerve stimulator; Among them, the pulse acquisition front end is used to detect changes in blood volume in the operator's subcutaneous capillaries using photoelectric sensors, and to acquire pulse wave signals that are isolated from interference by vagal nerve electrical stimulation signals in real time; The processing terminal is used to preprocess the acquired pulse wave signal, including amplification and filtering, and then convert it to the frequency domain for heart rate variability analysis to assess the real-time stress index in the control task; and to establish a stress baseline, determine the real-time stress level, and generate a control signal for electrical stimulation of the cervical vagus nerve based on the stress level. A vagus nerve stimulator is used to generate electrical signals to electrically stimulate the vagus nerve in the neck based on the modulation signal of electrical stimulation, thereby regulating the sympathetic-parasympathetic balance to reduce stress. Specifically, at medium pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the amplitude of the stimulation signal while maintaining a fixed frequency; at high pressure levels, the vagus nerve in the vagus neck is stimulated by modulating the frequency of the stimulation signal while maintaining a fixed amplitude.

8. The pressure regulating device according to claim 7, characterized in that, The pulse acquisition front end is an ear clip-on PPG sensor. The PPG sensor is clipped on the subject's earlobe, so that the pulse wave recording electrode of the sensor is placed on the subject's earlobe.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory being used to store at least one instruction, and the processor being used to execute the at least one instruction to implement the stress regulation method based on heart rate variability as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one instruction, which, when executed by a processor, implements the stress regulation method based on heart rate variability as described in any one of claims 1 to 7.

Images