Electrical stimulation therapeutic apparatus for ear vagus nerve

Abstract

The invention discloses an electrical stimulation therapeutic apparatus for ear vagus nerves, which comprises a USB power supply, a battery management module, an LDO voltage reduction and stabilization module, an MCU module, a Boost module, two stimulation current driving modules, an ear electrode and an ear electrode detection module, and is characterized in that the power supply management module is composed of a TP4056 chip, an external element, a power supply input USB Type-C interface and a battery connection interface; the external element is used for setting charging current, filtering and other functions, the power supply input interface can be connected with a USB power supply, the USB power supply is a lithium ion battery, and the battery connection interface is connected with the lithium ion battery. The therapeutic apparatus has flexible stimulation parameter adjusting functions including stimulation intensity, stimulation frequency, current direction, pulse width and the like so as to adapt to different diseases, different disease severity degrees and tolerance and reactivity differences of different individuals to stimulation, and accurate personalized treatment is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of electrical stimulation therapeutic apparatus, and in particular to an electrical stimulation therapeutic apparatus for ear vagus nerve. Background Art

[0002] As an emerging neuromodulation technology, ear vagus nerve electrical stimulation has received widespread attention in recent years. It is based on the rich nerve distribution in the human ear, especially the close connection with the vagus nerve, and regulates the function of the nervous system through specific electrical stimulation methods, thereby affecting a variety of diseases and physiological conditions.

[0003] Traditional vagus nerve stimulation methods, such as cervical vagus nerve stimulation, require surgical implantation of electrodes, which not only increases the surgical risk and pain of the patient, but may also cause complications such as infection and electrode displacement. Moreover, its stimulation parameters are relatively fixed, making it difficult to achieve personalized and precise adjustment.

[0004] Therefore, it is necessary to design an electrical stimulation therapeutic device for the auricular vagus nerve to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings existing in the prior art, and to propose an electrical stimulation therapeutic device for the ear vagus nerve. The therapeutic device has a flexible stimulation parameter adjustment function, including stimulation intensity, stimulation frequency, current direction and pulse width, etc., to adapt to different diseases, different disease severity and different individuals' tolerance and responsiveness to stimulation, so as to achieve precise personalized treatment.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An electrical stimulation therapeutic device for ear vagus nerve, including a USB power supply, a battery management module, an LDO step-down voltage regulator module, an MCU module, a Boost step-up module, two stimulation current drive modules, ear electrodes and an ear electrode detection module. The power management module is composed of a TP4056 chip, external components, a power input USB The device consists of a Type-C interface and a battery connection interface. External components are used to set charging current, filtering and other functions. The power input interface can be connected to a USB power supply, which is a lithium-ion battery. The battery connection interface is connected to the lithium-ion battery to realize the battery charging function. The battery management module adopts constant current / constant voltage charging. The LDO step-down voltage regulator module can provide a relatively stable output voltage to power the MCU module. The MCU module is used to control the workflow of the entire stimulator, including signal generation, adjustment of stimulation parameters, and data collection and processing. The Boost boost module is used to boost the battery voltage to 120V. The stimulation current drive module includes left ear current drive and right ear current drive. The stimulation current drive module is used to accurately control the current size and direction. The ear motor has good conductivity and biocompatibility. The ear motor is a silver-silver chloride electrode. The shape and size of the ear motor are adapted to the anatomical structure of the ear.

[0008] Preferably, the battery management module adopts a charging management chip of model TP4056. The TP4056 chip can realize constant current / constant voltage charging mode. The charging management chip has overvoltage protection, overcharge protection and overheat protection functions. The lithium-ion battery is a 1200mAH polymer lithium-ion battery with a battery voltage range of 3.0V-4.2V. The charging management chip communicates with the MCU module and feeds back the charging status information to the MCU for corresponding processing and display. The battery management module is provided with a sleep mode and a wake-up mechanism. When the battery management module is in an idle state, the MCU module enters the sleep mode and only keeps the necessary monitoring circuit working. When data collection or an event occurs, the MCU module is awakened by an interrupt for corresponding processing.

[0009] Preferably, the LDO step-down voltage regulator module adopts a low-dropout linear regulator of model TPS7A80. TPS7A80 is a low-dropout 1A regulator with an enable function, which provides extremely high power supply ripple suppression at the output end.

[0010] Preferably, the Boost circuit is mainly composed of an inductor, a power switch tube, a diode, an output capacitor and a load. When the power switch tube is turned on, the input voltage is applied to both ends of the inductor, and the inductor current increases linearly. At this time, the diode is cut off, and the capacitor supplies power to the load. When the power switch tube is cut off, the inductor generates an induced electromotive force, and its polarity is reversed. After being superimposed with the input voltage, it charges the capacitor through the diode and supplies power to the load.

[0011] Preferably, the stimulation current driving module consists of three parts: a PWM DAC circuit, a constant current source circuit and a current direction selection circuit. PWM DAC is a technology that uses PWM signals to achieve digital-to-analog conversion. When the PWM signal passes through a low-pass filter, the high-frequency component is filtered out, and the remaining DC component is proportional to the duty cycle of the PWM signal, thereby realizing the conversion from digital signal to analog signal. The sampling resistor in the constant current source circuit samples the load current and converts the current change into a voltage change. The sampled voltage is compared with the reference voltage input op amp to generate an error signal. After the op amp amplifies the error signal, it adjusts the output current by driving the transistor Q10 to reduce the error signal until the load current reaches a constant value. Relying on the ear electrode detection module, when the load impedance or other factors change and cause the current to fluctuate, the circuit can automatically adjust the output current to keep it stable, thereby ensuring stable operation of the circuit.

[0012] Preferably, the ear electrode material is composed of SUS304, ABS and silicone.

[0013] The present invention has the following beneficial effects:

[0014] 1. Compared with the prior art, the battery management module of the present invention adopts a constant current / constant voltage charging mode, which can quickly charge with a constant current at the initial charging stage, and automatically switch to a constant voltage mode to slowly charge until fully charged when approaching the termination voltage. This refined charging control effectively protects the battery and prolongs the battery life;

[0015] 2. Compared with the existing technology, the LDO step-down voltage regulator module can provide stable and low-noise power supply for chips such as MCU modules, has good power ripple suppression effect, and has small output voltage fluctuation, which ensures the stable operation of the chip and the accuracy of data processing;

[0016] 3. Compared with the existing technology, the MCU module can flexibly set the stimulation parameters according to the user's key input, and accurately convert them into control signals and send them to the stimulation circuit, so as to achieve comprehensive and precise control of the stimulator's workflow, including signal generation, stimulation parameter adjustment, data acquisition and processing, etc.

[0017] 4. Compared with the existing technology, the stimulation current driving module can accurately control the current size and direction, and clearly gives a reasonable safety range of current intensity, stimulation frequency, pulse width, etc. For example, the starting current intensity should be set to 0.1-0.5mA, the maximum current should not exceed 5mA, and the frequency range is safer at 1-120Hz, which helps to avoid nerve damage.

[0018] In summary, the electronic stimulator of the present invention combines electronic technology with traditional acupuncture meridian theory, and has a wide range of central nervous system regulatory effects. It has broad application prospects in the field of epilepsy treatment by regulating the functions of the brain's neutral and cognitive-related cerebral cortex and nerve nuclei, promoting neurotransmitter transmission, etc. It can also improve symptoms such as anxiety, depression, insomnia, and cognitive disorders. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A system block diagram of an electrical stimulation therapeutic device for the ear vagus nerve proposed by the present invention;

[0020] Figure 2 A flowchart showing the charging status of the therapeutic device;

[0021] Figure 3 This is a flow chart of the pause state of the therapeutic device;

[0022] Figure 4 This is a flow chart of the idle state of the therapeutic device;

[0023] Figure 5 This is a flow chart of the working status of the therapeutic device. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0025] Reference Figure 1-Figure 5, an electrical stimulation therapeutic device for ear vagus nerve, including a USB power supply, a battery management module, an LDO buck regulator module, an MCU module, a Boost boost module, two stimulation current drive modules, ear electrodes and ear electrode detection modules, the power management module is composed of a TP4056 chip, external components, a power input USB Type-C interface and a battery connection interface, the external components are used to set charging current, filtering and other functions, the power input interface can be connected to a USB power supply, the USB power supply is a lithium-ion battery, the battery connection interface is connected to the lithium-ion battery, and the battery charging function is realized, the battery management module adopts constant current / constant voltage charging, and this charging method can effectively protect the battery and extend the battery life, and charges quickly with a constant current at the initial charging stage, and automatically switches to a constant voltage mode when the battery voltage approaches the set termination voltage, and charges slowly until it is fully charged, the LDO buck regulator module can provide a relatively stable output voltage to power the MCU module, has a good suppression effect on the ripple in the power supply, and the output voltage fluctuates less. The MCU module usually requires a stable 3.3V power supply to ensure its normal operation. The LDO step-down voltage regulator module can provide these chips with a stable, low-noise power supply to ensure the stable operation of the chip and the accuracy of data processing. The MCU module is used to control the entire stimulator workflow, including signal generation, stimulation parameter adjustment, data collection and processing. According to the user's key input to set the stimulation parameters, such as stimulation current intensity and stimulation mode, the MCU converts these parameters into actual control signals and sends them to the stimulation circuit through DAC. The MCU module is equipped with key detection, buzzer, LED display and LCD display. The Boost boost module is used to boost the battery voltage to 120V (the battery voltage is usually only 3.0~4.2V, and the Boost boost module can boost the battery voltage to 120V). The stimulation current drive module includes left ear current drive and right ear current drive. The stimulation current drive module is used to accurately control the current size and direction. In the process of stimulating the ear vagus nerve, it is very important to accurately control the current size to avoid nerve damage. Different individuals have different tolerance to current. Generally, the starting current intensity should be set lower, such as 0.1-0.5mA. During the treatment, the current intensity should be carefully adjusted based on the patient's feelings and feedback, such as whether there is tingling or burning sensation.Normally, the maximum current intensity should not exceed 5mA, because too high current may cause damage to nerve fibers. The stimulation frequency and pulse width also need to be reasonably controlled. For the stimulation frequency, avoid using too high a frequency, especially long-term high-frequency stimulation. Generally speaking, a frequency range of 1-120Hz is safer. Too high a frequency may cause the nerves to be overexcited, increasing the risk of nerve fatigue and injury. The ear electrodes have good conductivity and biocompatibility. The ear electrodes are silver-silver chloride electrodes. This electrode material has a low electrode-skin interface impedance, which can effectively reduce charge accumulation and reduce the risk of charge accumulation. The ear electrode has a low risk of causing damage to the nerves. At the same time, it is less irritating to the skin and is suitable for long-term stimulation. The shape and size of the ear electrode are adapted to the anatomical structure of the ear. Since the surface of the ear is irregular, the electrode is designed to fit the shape of the ear skin tightly, such as using a curved electrode that conforms to the shape of the concha cavity or the concha boat. This design can ensure that the current is evenly distributed and avoid damage to the nerves due to excessive local current. The ear electrode is made of SUS304, ABS and silicone, and has a low electrode-skin interface impedance, which can effectively reduce charge accumulation, thereby reducing the risk of damage to the ear vagus nerve caused by charge accumulation. Moreover, it has a low irritation to the skin and is suitable for long-term nerve stimulation.

[0026] Among them, the battery management module adopts a charging management chip of model TP4056. The TP4056 chip can realize constant current / constant voltage charging mode. The charging management chip has overvoltage protection, overcharge protection and overheat protection functions. The lithium ion battery is a 1200mAH polymer lithium ion battery. The battery voltage range is 3.0V-4.2V. The appropriate charging current and charging voltage are set according to the type and capacity of the battery. The charging current selected by the present invention is 0.2C, that is, 240mA, and the charging voltage is 4.2V. The charging management chip communicates with the MCU module and feeds back the charging status information to the MCU for corresponding processing and display. The battery management module is provided with a sleep mode and a wake-up mechanism. When the battery management module is in an idle state, the MCU module enters the sleep mode and only retains the necessary monitoring circuit work. When data collection or an event occurs, the MCU module is awakened by interruption and corresponding processing is performed, such as RT1. An NTC thermistor is set to detect the temperature of the battery. The NTC thermistor is attached to the surface of the battery or close to the battery, and its resistance value changes with the change of temperature. When the battery temperature is too high (over 65°C) or too low (such as below -20°C), the charging process is stopped in time to ensure that the battery works within a suitable temperature range and prolong the battery life. A resistor divider network connected to the USB VBUS is set up to detect the insertion and removal of the USB. In order to extend the battery life, the battery management module should adopt a low-power design. In terms of software, the program code is optimized to reduce the running time and power consumption of the MCU.

[0027] Among them, the LDO step-down voltage regulator module adopts a low-dropout linear regulator model TPS7A80. TPS7A80 is a low-dropout 1A regulator with an enable function, which provides extremely high power supply ripple suppression at the output. The setting of a resistor divider network connected to the output as a feedback loop can stabilize the output at 3.3V. The high PSRR can quickly respond to load changes and input voltage fluctuations to maintain the stability of the output voltage. The overall accuracy of TPS7A80 can be maintained within 3% under all loads, input voltages, processes and temperature changes, ensuring that a stable and accurate voltage is provided to the load, which is conducive to improving the reliability and stability of the circuit.

[0028] Among them, the Boost circuit is mainly composed of an inductor, a power switch tube, a diode, an output capacitor and a load. When the power switch tube is turned on, the input voltage is applied to both ends of the inductor, and the inductor current increases linearly. At this time, the diode is cut off and the capacitor supplies power to the load. When the power switch tube is cut off, the inductor generates an induced electromotive force with reversed polarity. After being superimposed with the input voltage, it charges the capacitor through the diode and supplies power to the load.

[0029] Among them, the stimulation current driving module consists of three parts: PWM DAC circuit, constant current source circuit and current direction selection circuit. PWM DAC is a technology that uses PWM signal to realize digital-to-analog conversion. When the PWM signal passes through the low-pass filter, the high-frequency component is filtered out, and the remaining DC component is proportional to the duty cycle of the PWM signal, thereby realizing the conversion from digital signal to analog signal. The sampling resistor in the constant current source circuit samples the load current and converts the current change into a voltage change. The sampled voltage is compared with the reference voltage input op amp to generate an error signal. After the op amp amplifies the error signal, it adjusts the output current by driving the transistor Q10 to reduce the error signal until the load current reaches a constant value. Relying on the ear electrode detection module, when the load impedance or other factors change and cause the current to fluctuate, the circuit can automatically adjust the output current to keep it stable, thereby ensuring the stable operation of the circuit.

[0030] It should be noted that compared with the traditional DAC chip, the present invention does not require a complex internal circuit structure to achieve high-precision AD, but instead uses a 3rd-order RC low-pass filter and a low-cost operational amplifier to achieve DA conversion with a step size of 10mV and an accuracy of 5%, thereby saving costs. The PWM DAC circuit is used to set the size of the drive current. Since the operational amplifier has a minimum output voltage problem, if the output end and the inverting end are directly connected as a feedback loop like a traditional voltage follower, the output voltage will not be able to reach 0V. In this way, the output current size of the electrical stimulation therapeutic device for the ear vagus nerve will be inaccurate at low gear. The present invention introduces a diode into the feedback loop of the voltage follower U8 and then connects it to the inverting end. The diode voltage drop as part of the feedback forces the operational amplifier output to exceed the diode voltage drop, and finally it can reach a true 0V.

[0031] It should be noted that the reference voltage of the present invention is provided by a PWM DAC, and the driving current is DAC / R65. The current adjustment range of the present invention is 0-5mA, which is divided into 50 levels, each level is 0.1mA. Corresponding to the voltage adjustment range of 0-500mV, a controller is provided, and the controller is provided with an [Intensity +] button and an [Intensity -] button to output the current intensity. Each time the [Intensity +] button is pressed, the intensity increases by one level until the maximum output intensity of level 50, and then it will no longer increase. Each time the [Intensity -] button is pressed, the intensity decreases by one level until the minimum output intensity of level 0, and then it will no longer decrease, and no therapeutic current is output.

[0032] It should be noted that the present invention has four different modes:

[0033] (1) Pulse frequency: 20Hz±5%, positive pulse time: 250us±5%; negative pulse time: 500us±5%; current pulse amplitude: adjustable from level 0 to the set level;

[0034] (2) Pulse frequency: 25Hz±5%, positive pulse time: 250us±5%; negative pulse time: 500us±5%. Current pulse amplitude: adjustable from level 0 to the set level;

[0035] (3) Pulse frequency: randomly changed within the range of 1-120Hz, positive pulse time: 250us±5%; negative pulse time: 500us±5%; current pulse amplitude: randomly changed between level 0 and set level;

[0036] (4) Pulse frequency: 20Hz for 7s, 4Hz for 3s. Pulse time: 200us±5%. Current pulse amplitude: adjustable from level 0 to the set level.

[0037] Four different current waveforms are generated through the above four different modes.

[0038] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An electrical stimulation therapeutic device for ear vagus nerve, comprising a USB power supply, a battery management module, an LDO step-down voltage regulator module, an MCU module, a Boost step-up module, two stimulation current drive modules, ear electrodes and an ear electrode detection module, characterized in that: The power management module is composed of a TP4056 chip, external components, a power input USB Type-C interface and a battery connection interface. The external components are used to set functions such as charging current and filtering. The power input interface can be connected to a USB power supply, which is a lithium-ion battery. The battery connection interface is connected to the lithium-ion battery to realize the battery charging function. The battery management module adopts constant current / constant voltage charging. The LDO buck regulator module can provide a relatively stable output voltage to power the MCU module. The MCU module is used to control the workflow of the entire stimulator, including signal generation, adjustment of stimulation parameters, and data collection and processing. The Boost boost module is used to boost the battery voltage to 120V. The stimulation current drive module includes left ear current drive and right ear current drive. The stimulation current drive module is used to accurately control the current size and direction. The ear motor has good conductivity and biocompatibility. The ear electrode is a silver-silver chloride electrode. The shape and size of the ear motor are compatible with the anatomical structure of the ear.

2. The electrical stimulation therapeutic device for the auricular vagus nerve according to claim 1, characterized in that: The battery management module adopts a charging management chip of model TP4056. The TP4056 chip can realize constant current / constant voltage charging mode. The charging management chip has overvoltage protection, overcharge protection and overheat protection functions. The lithium-ion battery is a 1200mAH polymer lithium-ion battery with a battery voltage range of 3.0V-4.2V. The charging management chip communicates with the MCU module and feeds back the charging status information to the MCU for corresponding processing and display. The battery management module is provided with a sleep mode and a wake-up mechanism. When the battery management module is in an idle state, the MCU module enters the sleep mode and only keeps the necessary monitoring circuit working. When data collection or an event occurs, the MCU module is awakened by an interruption and corresponding processing is performed.

3. The electrical stimulation therapeutic device for the auricular vagus nerve according to claim 1, characterized in that: The LDO step-down voltage regulator module adopts a low-dropout linear voltage regulator of model TPS7A80. The TPS7A80 is a low-dropout 1A voltage regulator with an enable function, which provides extremely high power supply ripple suppression at the output end.

4. The electrical stimulation therapeutic device for the auricular vagus nerve according to claim 1, characterized in that: The Boost circuit is mainly composed of an inductor, a power switch tube, a diode, an output capacitor and a load. When the power switch tube is turned on, the input voltage is applied to both ends of the inductor, and the inductor current increases linearly. At this time, the diode is cut off, and the capacitor supplies power to the load. When the power switch tube is cut off, the inductor generates an induced electromotive force, and its polarity is reversed. After being superimposed with the input voltage, it charges the capacitor through the diode and supplies power to the load.

5. The electrical stimulation therapeutic device for the auricular vagus nerve according to claim 1, characterized in that: The stimulation current driving module consists of three parts: a PWM DAC circuit, a constant current source circuit and a current direction selection circuit. The PWM DAC is a technology that uses a PWM signal to achieve digital-to-analog conversion. When the PWM signal passes through a low-pass filter, the high-frequency component is filtered out, and the remaining DC component is proportional to the duty cycle of the PWM signal, thereby realizing the conversion from a digital signal to an analog signal. The sampling resistor in the constant current source circuit samples the load current and converts the current change into a voltage change. The sampled voltage is compared with the reference voltage input operational amplifier to generate an error signal. After the operational amplifier amplifies the error signal, it adjusts the output current by driving the transistor Q10 to reduce the error signal until the load current reaches a constant value. Relying on the ear electrode detection module, when the load impedance or other factors change and cause the current to fluctuate, the circuit can automatically adjust the output current to keep it stable, thereby ensuring stable operation of the circuit.

6. The electrical stimulation therapeutic device for the auricular vagus nerve according to claim 1, characterized in that: The ear electrodes are made of SUS304, ABS and silicone.

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