Ear acupoint closed-loop ultrasonic stimulation system and method based on sleep electroencephalogram signal feedback

Abstract

The invention discloses an ear acupoint closed-loop ultrasonic stimulation system and method based on sleep electroencephalogram signal feedback, and belongs to the technical field of ultrasonic stimulation nerve regulation and control. The ear acupoint closed-loop ultrasonic stimulation system comprises an electroencephalogram acquisition module, a regulation and control module, an ultrasonic transmitting module and a dynamic association module; the electroencephalogram acquisition module is used for acquiring electroencephalogram signals within limited time specified by a user according to specified sampling frequency, amplifying and filtering the acquired signals and sending the processed signals to the regulation and control module; the regulation and control module judges the current sleep stage of the user, drives the ultrasonic transmitting module, performs variable parameter closed-loop ultrasonic stimulation on the user, and automatically adjusts stimulation parameters and duration according to the current sleep stage; and the dynamic association module sets a multi-threshold triggering mechanism based on the real-time electroencephalogram characteristic parameters and discriminates a specific physiological status. According to the invention, accurate acupoint stimulation can be realized, a real-time feedback mechanism is provided, and the accuracy and effectiveness of stimulation can be ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultrasonic stimulation nerve regulation, and specifically relates to a closed-loop ultrasonic stimulation system and method for ear acupoints based on sleep EEG signal feedback. Background Art

[0002] Sleep disorders have become a common health problem in modern society, driven by multifaceted mechanisms such as neural regulation imbalances and circadian rhythm disturbances. With technological advancements, sleep regulation solutions are evolving from traditional methods to intelligent, precise approaches. However, existing technologies still have significant limitations in terms of effectiveness, adaptability, and safety. For example, existing pharmacological interventions use chemical compounds to regulate neurotransmitters or circadian rhythms. However, while pharmacological treatments should be administered under a physician's supervision, and while effective for some patients with insomnia, they also have significant drawbacks, including drug dependence, drug resistance, side effects, drug interactions, and an inability to address the underlying causes of insomnia. Another approach is to achieve neural regulation through psychological intervention or physiological signal feedback. However, cognitive behavioral therapy requires continuous practice, and while it can improve sleep habits to some extent, its effectiveness varies from person to person. Traditional physical therapies, such as massage and hot compresses, while relatively safe, are often limited in effectiveness and fail to fundamentally address sleep problems.

[0003] In recent years, technologies such as transcranial magnetic stimulation and electrical stimulation have emerged. For example, Chinese invention patent document CN109453453B discloses a transcranial magnetic stimulation sleep-aiding system, which dynamically adjusts the frequency and intensity of the magnetic field to achieve a sleep-aiding effect. Another example is Chinese invention patent application document CN116850452A, which discloses a sleep therapy method that performs transcranial electrical stimulation during sleep detection, and provides electrical stimulation during a specific period of sleep. Neuromodulation technology has shown certain potential in improving sleep, and has brought new hope for improving sleep disorders. These technologies help restore normal sleep rhythms by regulating brain neural activity. However, these advanced technologies also have many problems, such as complex equipment, high cost, and inconvenience in use, which have limited their popularization and application.

[0004] In recent years, ultrasonic stimulation has been widely used in medicine, neuroscience, tissue engineering and other fields because it can deeply regulate the target tissue through the energy of sound waves without causing significant physical damage. For example, Chinese invention patent application document CN119280719A discloses a transcranial focused ultrasound stimulation system and method for patients with cognitive impairment, which uses ultrasonic stimulation to improve cognitive impairment. Another example is Chinese invention patent application document CN119258400A, which discloses a comprehensive control method and system based on multi-mode electromagnetic and ultrasonic stimulation, which uses ultrasonic stimulation to stimulate the target. Another example is Chinese invention patent application document CN119424198A, which discloses an ultrasonic phased array acupuncture system that simulates acupuncture techniques, which uses ultrasound to stimulate acupuncture points. As an emerging non-invasive technology, ultrasonic stimulation has become one of the hot spots for multidisciplinary cross-applications due to its advantages such as high efficiency, safety and controllability.

[0005] At the same time, ear acupoint stimulation, as a traditional Chinese medicine therapy, has been shown to be effective in improving sleep. Ear acupoints are closely related to the various internal organs of the human body. By stimulating specific acupoints, it is possible to regulate qi and blood, balance yin and yang, and thus improve sleep quality. However, traditional ear acupoint stimulation methods (such as acupuncture and massage) often lack precision and real-time feedback mechanisms, making it difficult to dynamically adjust stimulation parameters according to the individual's physiological state and sleep needs, which to a certain extent limits its therapeutic effect.

[0006] Therefore, there is a need for a closed-loop ultrasonic stimulation system and method for ear acupoints based on sleep EEG signal feedback that can achieve precise acupoint stimulation and has a real-time feedback mechanism. Summary of the Invention

[0007] The purpose of the present invention is to provide a closed-loop ultrasonic stimulation system and method for ear acupoints based on sleep EEG signal feedback, which can achieve precise acupoint stimulation and has a real-time feedback mechanism to ensure the accuracy and effectiveness of the stimulation.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] A closed-loop ultrasonic stimulation system for ear acupoints based on sleep EEG signal feedback includes an EEG acquisition module, a control module, an ultrasonic transmission module, and a dynamic association module; the EEG acquisition module is used to acquire EEG signals within a limited time specified by the user according to a specified sampling frequency, amplify and filter the acquired signals, and send the processed signals to the control module; the control module determines the user's current sleep stage to drive the ultrasonic transmission module, perform variable parameter closed-loop ultrasonic stimulation on the user, and automatically adjust the stimulation parameters and duration according to the current sleep stage; the dynamic association module sets a multi-threshold trigger mechanism based on real-time EEG characteristic parameters to distinguish specific physiological states.

[0010] A further improvement of the technical solution of the present invention is that the EEG acquisition module includes an electrode module, a preamplifier module, a prefilter module, a common-mode rejection filter module and an analog-to-digital conversion module, forming a complete bioelectric signal front-end acquisition path.

[0011] Further improvements to the technical solution of the present invention are: the electrode module serves as the entrance of the EEG signal, and forms a conductive path through the contact between the electrode and the user to obtain the EEG signal; the preamplifier module adopts a high-precision instrument operational amplifier to receive the EEG signal input in a differential manner, suppress common-mode noise and improve signal quality, and perform primary amplification processing on weak bioelectric signals; the prefilter module cooperates with the preamplifier module to filter out non-desirable components such as DC bias, electrode polarization voltage, myoelectric interference and high-frequency noise in the electrode input signal, and optimize the signal bandwidth and spectrum purity; the common-mode suppression filter module combines differential amplification and negative feedback mechanism, and further suppresses the common-mode signal through a secondary differential circuit, thereby improving the common-mode rejection ratio CMRR of the system and enhancing the signal-to-noise ratio of the EEG signal.

[0012] A further improvement to the technical solution of the present invention is that the analog-to-digital conversion module uses the ADS1299 highly integrated multi-channel analog front-end chip as the core to process downstream signals. The chip integrates a high-performance programmable gain amplifier PGA and a 24-bit Σ-Δ analog-to-digital converter ADC to further perform gain control and high-resolution digital conversion on the signal after pre-stage filtering and amplification. The converted digital signal is transmitted to the control module through the SPI interface for subsequent real-time analysis and feedback control.

[0013] A further improvement of the technical solution of the present invention is that the control module includes an EEG signal processing module and a driving module; after the EEG signal processing module compares the EEG signal, it determines the user's current sleep stage and sends it to the driving module for driving, and the driving module buffers the level signal and drives the ultrasonic transmitting module through the gate drive to act on the user object.

[0014] A further improvement of the technical solution of the present invention is that the EEG signal processing module adopts a microprocessor, and through the output comparison function PWM Output Compare of the internal high-precision timer peripheral, according to the preset ultrasonic stimulation parameters, generates a PWM waveform with stable frequency and adjustable pulse width as the reference control signal of the driving module.

[0015] A further improvement to the technical solution of the present invention is that the driver module is used to drive the ultrasonic transmitter module. The module is equipped with an integrated UCC27524DR dual-channel high-speed gate driver, which synchronously controls two completely identical power amplifier channels to achieve dual-channel parallel ultrasonic output. At the same time, the TVL3501AIDR high-speed rail-to-rail buffer amplifier is introduced to perform level conversion, edge shaping and isolation drive on the control signal.

[0016] The further improvement of the technical solution of the present invention is that the ultrasonic transmitting module constructs a complete acoustic output link from signal generation to energy release through the Class E power amplifier module and the ultrasonic transducer; the Class E power amplifier module adopts the Class E high-efficiency power amplifier module, including the driving signal V in , field effect tube Q1, working power supply VDD, choke RFC, parallel capacitor C1, series resonant capacitor C r , series resonant inductor L r , phase-shift inductor L x And the standard design load R load The output end of the Class E power amplifier module is connected by an L-shaped impedance matching network, which is constructed based on resonant inductance and capacitance, so that the high input impedance of the customized ultrasonic transducer is effectively matched with the low impedance of the power amplifier output.

[0017] A further improvement of the technical solution of the present invention is that the ultrasonic transducer adopts a piezoelectric ceramic transducer, and the matched signal drives the piezoelectric ceramic transducer to operate at its mechanical resonant frequency, thereby achieving directional ultrasonic control output to the target tissue.

[0018] A closed-loop ultrasound stimulation method for ear acupoints based on sleep EEG signal feedback uses an ultrasound stimulation system for ultrasound stimulation, comprising the following steps:

[0019] Step S1: EEG signal acquisition and preprocessing: The EEG acquisition module collects the user's EEG signals within a limited time at a specified sampling frequency, forms a conductive path through the electrode module in contact with the user to obtain the signal, and then undergoes primary amplification in a differential manner through the preamplifier module. The prefilter module filters out undesirable components such as DC bias and myoelectric interference, and then suppresses power frequency interference through the secondary differential circuit of the common-mode rejection filter module to improve the common-mode rejection ratio and signal-to-noise ratio. Finally, the ADS1299 chip completes 24-bit analog-to-digital conversion and gain control. The converted digital signal is transmitted to the control module via the SPI interface;

[0020] Step S2: Sleep stage identification and stimulation parameter generation: The EEG signal processing module of the control module performs real-time comparison of the received EEG signals. By calculating the power spectrum energy and monitoring rhythm changes and other features, it determines the user's current sleep stage based on the multi-threshold trigger mechanism preset by the dynamic association module. It then generates corresponding ultrasonic stimulation parameters for different sleep stages, forming a reference control signal for driving the ultrasonic transmission module.

[0021] Step S3: Ultrasonic stimulation drive and execution: The driver module of the control module buffers the control signal generated by the EEG signal processing module, implements level conversion and drive enhancement through the UCC27524DR dual-channel high-speed gate driver and TVL3501AIDR high-speed rail-to-rail buffer amplifier, and then activates the Class E power amplifier module of the ultrasonic transmitter module to drive the piezoelectric ceramic transducer to operate at its mechanical resonant frequency, providing targeted ultrasonic stimulation to the user. The stimulation parameters are automatically adjusted according to the current sleep stage.

[0022] Step S4: EEG feedback and closed-loop control: After ultrasonic stimulation is implemented, the user's EEG signal changes, and the EEG signal processing module re-identifies the changed EEG signal to determine the new EEG sleep stage and whether ultrasonic stimulation needs to continue; if ultrasonic stimulation is still needed, the stimulation effect is changed according to the current user's EEG sleep stage, and an instruction is sent to the lower computer through the threshold trigger mechanism of the dynamic association module to specify a new set of ultrasonic stimulation parameters and pass them to the ultrasonic transmission module, thereby forming an individualized variable parameter closed-loop ultrasonic stimulation based on EEG feedback.

[0023] Due to the adoption of the above technical solution, the technical advancements achieved by the present invention are:

[0024] The present invention provides a closed-loop ultrasonic acupoint stimulation system and method based on sleep EEG signal feedback, which can achieve precise acupoint stimulation and ensure the accuracy and effectiveness of the stimulation. It also has a real-time feedback mechanism and can dynamically adjust the stimulation parameters according to the individual's EEG signals and sleep status.

[0025] The present invention designs a multi-threshold discrimination mechanism based on power spectrum analysis and EEG rhythm monitoring, which can identify the dynamic changes of the user's sleep stages in real time; establishes a mapping relationship between EEG characteristics and stimulation parameters through a dynamic association module, realizes intelligent matching and stage-by-stage adaptation of stimulation parameters; improves the response ability to nonlinear sleep state transitions, making the stimulation plan more personalized and timely.

[0026] The present invention uses high-speed devices such as UCC27524DR and TVL3501AIDR to achieve low-latency, high-speed level conversion and buffered drive from control signals to power amplification. It uses a Class E power amplifier circuit combined with a piezoelectric ceramic transducer to operate at the mechanical resonant frequency point, effectively improving the system's energy efficiency and stimulation output intensity. By adaptively adjusting the drive parameters according to different sleep stages, the stimulation frequency, duty cycle and duration are optimized, enhancing the system's physiological compatibility and safety.

[0027] The present invention can realize a stimulation response regulation mechanism based on real-time EEG feedback, and can adjust the stimulation parameters according to the changes in EEG state after ultrasonic stimulation; it constructs a closed-loop feedback loop with variable parameters to realize the dynamic iteration and individualized evolution of the stimulation strategy; this closed-loop design is significantly superior to the traditional open-loop stimulation method, and can achieve more accurate, continuous and effective sleep regulation intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural block diagram of the ear acupoint closed-loop ultrasonic stimulation system based on sleep EEG signal feedback of the present invention;

[0029] Figure 2 This is a closed-loop flow chart of EEG signal feedback in the present invention;

[0030] Figure 3 This is a schematic diagram of the ultrasonic transmitting module of the present invention;

[0031] Figure 4 This is a basic principle diagram of the Class E power amplifier module in the present invention. DETAILED DESCRIPTION

[0032] The present invention is described in further detail below in conjunction with the embodiments:

[0033] Example 1

[0034] like Figure 1 As shown, this embodiment provides a closed-loop ultrasonic stimulation system for ear acupoints based on sleep EEG signal feedback, comprising an EEG acquisition module, a control module, an ultrasonic transmission module, and a dynamic association module. The EEG acquisition module is used to collect EEG signals within a limited time specified by the user according to a specified sampling frequency, amplify and filter the collected signals, and send the processed signals to the control module. The control module determines the user's current sleep stage and drives the ultrasonic transmission module to perform variable-parameter closed-loop ultrasonic stimulation on the user, automatically adjusting the stimulation parameters and duration based on the current sleep stage.

[0035] Furthermore, the EEG acquisition module includes an electrode module, a preamplifier module, a prefilter module, a common-mode rejection filter module, and an analog-to-digital conversion module, forming a complete bioelectric signal front-end acquisition path, achieving high-precision signal amplification, filtering, and high resolution to improve the hardware design.

[0036] The electrode module serves as the entrance to the EEG signal, forming a conductive path through the contact between the electrodes and the user to obtain the EEG signal. The preamplifier module uses a high-precision instrumentation operational amplifier, such as the INA series, to receive the EEG signal input in a differential manner, suppress common-mode noise, improve signal quality, and perform primary amplification processing on weak bioelectric signals. The prefilter module cooperates with the preamplifier module to filter out undesirable components such as DC bias, electrode polarization voltage, myoelectric interference, and high-frequency noise in the electrode input signal, thereby optimizing the signal bandwidth and spectral purity. The common-mode suppression filter module combines differential amplification with a negative feedback mechanism, and further suppresses common-mode signals such as 50 / 60Hz power frequency interference and other physiological common-mode noise through a secondary differential circuit, thereby improving the system's common-mode rejection ratio (CMRR) while enhancing the signal-to-noise ratio of the EEG signal, further improving the system's anti-interference performance. The analog-to-digital conversion module uses the ADS1299 highly integrated multi-channel analog front-end chip as its core to process downstream signals. The chip integrates a high-performance programmable gain amplifier (PGA) and a 24-bit Σ-Δ analog-to-digital converter (ADC). It performs further gain control and high-resolution digital conversion on the signal after pre-stage filtering and amplification. The converted digital signal is transmitted to the control module via the SPI interface for subsequent real-time analysis and feedback control, realizing the closed-loop control function of the system.

[0037] The control module includes an EEG signal processing module and a driver module. The EEG signal processing module compares the EEG signals, determines the user's current sleep stage, and sends them to the driver module for activation. The driver module buffers the level signal and drives the ultrasonic transmitter module through gate drive, which acts on the user.

[0038] Specifically, the EEG signal processing module utilizes a microprocessor, such as an embedded STM32 microcontroller. Using the PWM Output Compare function of its internal high-precision timer peripheral, it generates a frequency-stable, pulse-width-adjustable PWM waveform based on preset ultrasound stimulation parameters, such as frequency, duty cycle, pulse period, and duration. This waveform serves as the reference control signal for the driver module. The driver module, which drives the ultrasound transmitter module, integrates the UCC27524DR dual-channel, high-speed gate driver, which boasts high current drive capability (up to 5A peak current) and low propagation delay. It synchronously controls two identical power amplifier channels, enabling dual-channel parallel ultrasound output, suitable for advanced control scenarios such as bilateral stimulation or spatial interferometric modulation. To ensure sufficient drive capability and signal integrity at the driver input, the TVL3501AIDR high-speed rail-to-rail buffer amplifier is incorporated to perform level conversion, edge shaping, and isolated driving of the control signal. This improves the system's control stability and response speed at high frequencies (e.g., 500kHz) and enhances drive matching with the power amplifier stage.

[0039] like Figure 3 As shown in FIG, the ultrasonic transmitting module constructs a complete acoustic output link from signal generation to energy release through the Class E power amplifier module and the ultrasonic transducer.

[0040] Among them, such as Figure 4 As shown, the Class E power amplifier module uses a Class E high efficiency power amplifier module, including the drive signal V in , field effect tube Q1, working power supply VDD, choke RFC, parallel capacitor C1, series resonant capacitor C r , series resonant inductor L r , phase-shift inductor L x And the standard design load R load , adopting a Class E high-efficiency power amplifier topology, whose core is an N-channel power MOSFET, such as the IRFP240PBF. By driving the module's high-speed switching, it achieves near-ideal zero-voltage switching (ZVS) operation, significantly reducing switching losses and device heating, and improving the system's energy efficiency and long-term stability. The output end of the Class E power amplifier module is connected by an L-shaped impedance matching network, constructed based on resonant inductors and capacitors. This effectively matches the high input impedance of the customized ultrasonic transducer with the low impedance of the power amplifier output, maximizing energy transmission efficiency and reducing signal reflections. The ultrasonic transducer uses a piezoelectric ceramic transducer. The matched signal drives the piezoelectric ceramic transducer to operate at its mechanical resonant frequency (500kHz), achieving directional ultrasonic control output to the target tissue, providing a physical intervention method for the EEG closed-loop control system.

[0041] The dynamic association module sets a multi-threshold trigger mechanism based on real-time EEG characteristic parameters, such as power spectrum energy, event-related potentials or rhythm changes, to achieve the discrimination of specific physiological states (such as falling asleep, waking up, and abnormal brain rhythms). When the signal characteristics meet the preset trigger conditions, a control instruction is automatically sent to the lower computer, and the microprocessor starts the drive module to complete the precise drive and control of the ultrasonic transmission module, thereby realizing closed-loop ultrasonic stimulation intervention based on EEG feedback. The present invention not only has good scalability and modularity, but also provides strong support for the automated execution and precise control of the device.

[0042] Example 2

[0043] like Figure 2 As shown, this embodiment provides a closed-loop ultrasonic stimulation method for ear acupoints based on sleep EEG signal feedback, using the ultrasonic stimulation system in Example 1 to perform ultrasonic stimulation, including the following steps:

[0044] Step S1: EEG signal acquisition and preprocessing: The EEG acquisition module collects the user's EEG signals within a limited time at a specified sampling frequency, forms a conductive path through the electrode module in contact with the user to obtain the signal, and then undergoes primary amplification in a differential manner through the preamplifier module. The prefilter module filters out undesirable components such as DC bias and myoelectric interference, and then suppresses power frequency interference through the secondary differential circuit of the common-mode rejection filter module to improve the common-mode rejection ratio and signal-to-noise ratio. Finally, the ADS1299 chip completes 24-bit analog-to-digital conversion and gain control. The converted digital signal is transmitted to the control module via the SPI interface;

[0045] Step S2: Sleep stage identification and stimulation parameter generation: The EEG signal processing module of the control module performs real-time comparison of the received EEG signals. By calculating the power spectrum energy and monitoring rhythm changes and other features, it determines the user's current sleep stage based on the multi-threshold trigger mechanism preset by the dynamic association module. It then generates corresponding ultrasonic stimulation parameters for different sleep stages, forming a reference control signal for driving the ultrasonic transmission module.

[0046] Step S3: Ultrasonic stimulation drive and execution: The driver module of the control module buffers the control signal generated by the EEG signal processing module, implements level conversion and drive enhancement through the UCC27524DR dual-channel high-speed gate driver and TVL3501AIDR high-speed rail-to-rail buffer amplifier, and then activates the Class E power amplifier module of the ultrasonic transmitter module to drive the piezoelectric ceramic transducer to operate at its mechanical resonant frequency, providing targeted ultrasonic stimulation to the user. The stimulation parameters are automatically adjusted according to the current sleep stage.

[0047] Step S4: EEG feedback and closed-loop control: After ultrasonic stimulation is implemented, the user's EEG signal changes, and the EEG signal processing module re-identifies the changed EEG signal to determine the new EEG sleep stage and whether ultrasonic stimulation needs to continue; if ultrasonic stimulation is still needed, the stimulation effect is changed according to the current user's EEG sleep stage, and an instruction is sent to the lower computer through the threshold trigger mechanism of the dynamic association module to specify a new set of ultrasonic stimulation parameters and pass them to the ultrasonic transmission module, thereby forming an individualized variable parameter closed-loop ultrasonic stimulation based on EEG feedback.

[0048] The present invention is verified below with reference to examples:

[0049] The ultrasonic stimulation system in Example 1 is combined with the user's ear acupuncture points to improve sleep, and has good practical effects. The specific steps are as follows:

[0050] Step S1: Select the corresponding ear acupoint and ultrasonic stimulation parameters according to user needs, taking the ear Shenmen acupoint as an example;

[0051] Step S2: Wearing the ultrasonic acupoint stimulation component on the user's ear, ensuring that the ultrasonic transducer is aligned with the selected acupoint;

[0052] Step S3: Start the system, monitor the user's EEG activity in real time through the EEG signal acquisition and analysis equipment, and control the ultrasonic stimulation component to perform closed-loop stimulation based on the analysis results;

[0053] Step S4: adjusting the ultrasound stimulation parameters in real time based on the user's EEG signal feedback and subjective feelings to optimize the sleep improvement effect;

[0054] Step S5: The treatment time is once a day, 30 minutes / time, and 7 consecutive days constitute a course of treatment. Multiple courses of treatment can be performed as needed.

[0055] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A closed-loop ultrasound stimulation system for ear acupoints based on sleep EEG signal feedback, characterized by: It includes an EEG acquisition module, a control module, an ultrasonic emission module and a dynamic association module; the EEG acquisition module is used to collect EEG signals within a limited time specified by the user according to the specified sampling frequency, amplify and filter the collected signals, and send the processed signals to the control module; The control module determines the user's current sleep stage and drives the ultrasonic transmission module to perform variable parameter closed-loop ultrasonic stimulation on the user, automatically adjusting the stimulation parameters and duration according to the current sleep stage; the dynamic association module sets a multi-threshold trigger mechanism based on real-time EEG characteristic parameters to identify specific physiological states.

2. The closed-loop ultrasound stimulation system for ear acupoints based on sleep EEG signal feedback according to claim 1, characterized in that: The EEG acquisition module includes an electrode module, a preamplifier module, a prefilter module, a common-mode rejection filter module, and an analog-to-digital conversion module, forming a complete bioelectric signal front-end acquisition path.

3. The closed-loop ultrasound stimulation system for ear acupoints based on sleep EEG signal feedback according to claim 2, characterized in that: The electrode module serves as the entrance of the EEG signal, and forms a conductive path with the user through the electrodes to obtain the EEG signal; The preamplifier module uses a high-precision instrumentation operational amplifier to receive EEG signal input in a differential manner, suppress common-mode noise and improve signal quality, and perform primary amplification processing on weak bioelectric signals; the prefilter module cooperates with the preamplifier module to filter out undesirable components such as DC bias, electrode polarization voltage, myoelectric interference and high-frequency noise in the electrode input signal, and optimize the signal bandwidth and spectrum purity; the common-mode suppression filter module combines differential amplification and negative feedback mechanism to further suppress common-mode signals through a secondary differential circuit, thereby improving the system's common-mode rejection ratio (CMRR) and enhancing the signal-to-noise ratio of the EEG signal.

4. The closed-loop ultrasound stimulation system for ear acupoints based on sleep EEG signal feedback according to claim 3, characterized in that: The analog-to-digital conversion module uses the ADS1299 highly integrated multi-channel analog front-end chip as the core to process downstream signals. The chip integrates a high-performance programmable gain amplifier (PGA) and a 24-bit Σ-Δ analog-to-digital converter (ADC) to perform further gain control and high-resolution digital conversion on the signal after pre-stage filtering and amplification. The converted digital signal is transmitted to the control module via the SPI interface for subsequent real-time analysis and feedback control.

5. The closed-loop ultrasound stimulation system for ear acupoints based on sleep EEG signal feedback according to claim 4, characterized in that: The control module includes an EEG signal processing module and a driving module; After comparing the EEG signals, the EEG signal processing module determines the user's current sleep stage and sends it to the driving module for driving. The driving module buffers the level signal and drives the ultrasonic transmitting module through gate driving to act on the user object.

6. The closed-loop ultrasound stimulation system for ear acupoints based on sleep EEG signal feedback according to claim 5, characterized in that: The EEG signal processing module uses a microprocessor and generates a PWM waveform with stable frequency and adjustable pulse width according to preset ultrasonic stimulation parameters through the output comparison function PWM Output Compare of the internal high-precision timer peripheral, which serves as the reference control signal of the driving module.

7. The closed-loop ultrasound stimulation system for ear acupoints based on sleep EEG signal feedback according to claim 6, characterized in that: The driver module is used to drive the ultrasonic transmitter module. The module is equipped with an integrated UCC27524DR dual-channel high-speed gate driver, which synchronously controls two completely identical power amplifier channels to achieve dual-channel parallel ultrasonic output. At the same time, the TVL3501AIDR high-speed rail-to-rail buffer amplifier is introduced to perform level conversion, edge shaping and isolation driving on the control signal.

8. The closed-loop ultrasound stimulation system for ear acupoints based on sleep EEG signal feedback according to claim 7, characterized in that: The ultrasonic transmitter module constructs a complete acoustic output link from signal generation to energy release through the Class E power amplifier module and the ultrasonic transducer; the Class E power amplifier module adopts the Class E high-efficiency power amplifier module, including the driving signal V in , field effect tube Q1, working power supply VDD, choke RFC, parallel capacitor C1, series resonant capacitor C r , series resonant inductor L r , phase-shift inductor L x And the standard design load R load The output end of the Class E power amplifier module is connected by an L-shaped impedance matching network, which is constructed based on resonant inductance and capacitance, so that the high input impedance of the customized ultrasonic transducer is effectively matched with the low impedance of the power amplifier output.

9. The closed-loop ultrasound stimulation system for ear acupoints based on sleep EEG signal feedback according to claim 8, characterized in that: The ultrasonic transducer adopts a piezoelectric ceramic transducer, and the matched signal drives the piezoelectric ceramic transducer to operate at its mechanical resonance frequency, thereby achieving directional ultrasonic control output to the target tissue.

10. A closed-loop ultrasonic stimulation method for ear acupoints based on sleep EEG signal feedback, characterized by: Using the ultrasonic stimulation system according to any one of claims 1 to 9 to perform ultrasonic stimulation comprises the following steps: Step S1: EEG signal acquisition and preprocessing: The EEG acquisition module collects the user's EEG signals within a limited time at a specified sampling frequency, forms a conductive path through the electrode module in contact with the user to obtain the signal, and then undergoes primary amplification in a differential manner through the preamplifier module. The prefilter module filters out undesirable components such as DC bias and myoelectric interference, and then suppresses power frequency interference through the secondary differential circuit of the common-mode rejection filter module to improve the common-mode rejection ratio and signal-to-noise ratio. Finally, the ADS1299 chip completes 24-bit analog-to-digital conversion and gain control. The converted digital signal is transmitted to the control module via the SPI interface; Step S2: Sleep stage identification and stimulation parameter generation: The EEG signal processing module of the control module performs real-time comparison of the received EEG signals. By calculating the power spectrum energy and monitoring rhythm changes and other features, it determines the user's current sleep stage based on the multi-threshold trigger mechanism preset by the dynamic association module. It then generates corresponding ultrasonic stimulation parameters for different sleep stages, forming a reference control signal for driving the ultrasonic transmission module. Step S3: Ultrasonic stimulation drive and execution: The driver module of the control module buffers the control signal generated by the EEG signal processing module, implements level conversion and drive enhancement through the UCC27524DR dual-channel high-speed gate driver and TVL3501AIDR high-speed rail-to-rail buffer amplifier, and then activates the Class E power amplifier module of the ultrasonic transmitter module to drive the piezoelectric ceramic transducer to operate at its mechanical resonant frequency, providing targeted ultrasonic stimulation to the user. The stimulation parameters are automatically adjusted according to the current sleep stage. Step S4: EEG feedback and closed-loop control: After ultrasonic stimulation is implemented, the user's EEG signal changes, and the EEG signal processing module re-identifies the changed EEG signal to determine the new EEG sleep stage and whether ultrasonic stimulation needs to continue; if ultrasonic stimulation is still needed, the stimulation effect is changed according to the current user's EEG sleep stage, and an instruction is sent to the lower computer through the threshold trigger mechanism of the dynamic association module to specify a new set of ultrasonic stimulation parameters and pass them to the ultrasonic transmission module, thereby forming an individualized variable parameter closed-loop ultrasonic stimulation based on EEG feedback.

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