Programmable nerve electrical stimulation system based on ultrasonic energy supply

Abstract

The invention discloses a programmable electrical nerve stimulation system based on ultrasonic energy supply. The programmable electrical nerve stimulation system comprises an ultrasonic transmitter, a piezoelectric receiver, a rectifier, a power management module, a data demodulation circuit, a control module, an H-bridge driving circuit, a current digital-to-analog converter and an H-bridge circuit, the external ultrasonic transmitter can transmit ultrasonic waves to supply power to the system and transmit data, and the piezoelectric receiver receives ultrasonic signals and converts the ultrasonic signals into alternating current signals. The rectifier and the power management module can convert alternating current signals into direct current signals to provide power for other circuits of the system, the data demodulation circuit processes the alternating current signals to recover data information in ultrasonic waves, the control module controls the H-bridge driving circuit and the current digital-to-analog converter according to the data information, and finally electrical stimulation is achieved through the H-bridge. The system provided by the invention has the characteristics of wireless energy supply, high safety and programmable stimulation parameters, and can realize accurate control of output current parameters.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a programmable neural electrical stimulation system based on ultrasound power. Background Technology

[0002] In recent years, with the continuous integration and development of electronic technology and the biomedical field, electrical stimulators have developed rapidly and are highly promising in the field of biomedical engineering. Due to their wide application in the treatment of various diseases, they have gradually become an important research direction in the medical field. Electrical stimulators are mainly used in the treatment of neurological diseases, rehabilitation of muscle atrophy, and treatment of heart disease. Traditional implantable electrical stimulators face problems such as large size, high power consumption, single function, and poor adjustability, which limit their application in miniaturization, long-term use, and personalized treatment.

[0003] To achieve a safer and more controllable electrical stimulator, wireless power supply and control methods can be used. For example, the technical solution provided in the literature [Chia-Chi Hsieh, Yi-Hui Wu, Ming-Dou Ker. Design of a low-voltage CMOS dual-configuration dual-mode stimulator for neuromodulation, IEEE Journal of Biomedical Circuits and Systems, April 2023, Vol. 17, No. 2, pp. 273-285] supports voltage and current stimulation modes, but still requires wired power supply. The technical solution provided in the literature [Chang-ChunYang, Ming-Dou Ker. Miniaturized wirelessly powered biphase current stimulator for implantable neurostimulation, IEEE International Conference on Circuits and Systems, London, UK, May 2025] integrates a wireless power supply module, but the stimulation frequency is fixed and cannot be adjusted, limiting its applicability. Summary of the Invention

[0004] In view of the above, the present invention provides a programmable neurostimulation system based on ultrasound power supply. The system achieves wireless charging and data transmission through ultrasound and uses an H-bridge circuit for output, which enables precise control of the output current parameters.

[0005] A programmable neurostimulation system powered by ultrasound includes an ultrasound transmitter, a piezoelectric receiver, a rectifier, a power management module, a data demodulation circuit, an H-bridge circuit, an off-chip energy storage capacitor, a current source, an H-bridge drive circuit, a current-to-analog converter, and a control module, wherein: The ultrasonic transmitter powers the system and transmits data by emitting ultrasonic waves. The piezoelectric receiver is used to receive ultrasonic waves and convert them into alternating current signals. The rectifier is used to convert the AC signal into a DC voltage V. REC ; The power management module is based on DC voltage V. REC The conversion process charges the off-chip energy storage capacitor and simultaneously provides the system with operating voltage and reference current I. REF ; The data demodulation circuit is used to demodulate the AC signal to recover the data information contained in the ultrasound. The H-bridge circuit is used to output current stimulation through electrodes; The H-bridge drive circuit is used to drive the switching devices in the H-bridge circuit to adjust the pulse width and frequency of the output current. The control module converts the demodulated data information into control signals to control the H-bridge drive circuit and the current-to-analog converter. The current-to-analog converter is based on a reference current I. REF In addition to the control signals provided by the control module, an adjustable current I is generated. DAC Used to control the magnitude of the current source in order to adjust the amplitude of the output current; The input power supply terminal of the current source is connected to the H-bridge circuit, and the output terminal is grounded, used for copying I. DAC And amplified by a certain factor, it is used as the output current.

[0006] Furthermore, the power management module includes a charge pump circuit, a bandgap reference circuit, and an LDO (low dropout linear regulator), wherein the charge pump circuit is used to regulate the DC voltage V. REC After amplification, the external energy storage capacitor is charged, and then the capacitor voltage V on the capacitor is utilized. DDH Power is supplied to the H-bridge circuit and the H-bridge drive circuit; the bandgap reference circuit is used to convert the DC voltage V REC Converted to reference voltage V REF This generates a reference current I. REF The LDO is based on V REC and V REF Generate a DC voltage V of 1.8V. LDO It is used to provide operating voltage for the control module and the current-to-analog converter.

[0007] Furthermore, the H-bridge circuit consists of four switching transistors M1 to M4, wherein the source of M1 is connected to the source of M2 and connected to the input power supply terminal of the current source, and the drain of M3 is connected to the drain of M4 and connected to the capacitor voltage V. DDHThe drain of M1 is connected to the source of M3 and connected to one end of the electrode. The drain of M2 is connected to the source of M4 and connected to the other end of the electrode. The gates of M1 to M4 are respectively connected to the switching clock signals Φ1 to Φ4 provided by the H-bridge driver circuit. The switching transistors are turned on or off by controlling the gate voltage, thereby realizing four modes: forward current stimulation, reverse current stimulation, disconnection, and grounding.

[0008] Furthermore, the switching transistors M1 to M4 are NLDMOS (N-type laterally diffused metal-oxide-semiconductor field-effect transistors).

[0009] Furthermore, the H-bridge drive circuit includes four PMOS transistors M 10 M 11 M 17 M 18 Eight NMOS transistors M5~M8 and M 12 ~M 15 Two NLDMOS transistors, M9 and M 16 Two capacitors C1 and C2, two current sources I1 and I2, and four resistors R1~R4, where M 17 The source and M 18 The source of I1 is connected to the input power supply terminal of I1 and connected to a DC voltage V. REC M 10 The source and M 11 The source of I2 is connected to the input power supply terminal of I2 and connected to a DC voltage V. REC M 17 The drain and M 18 gate, M 17 The gate and M 15 The drains are connected, M 10 The drain and M 11 gate, M 10 The gate of M8 is connected to the drain of M8, and the gate of M8 is connected to the drain of M8. 15 The gates of M8 and M6 are respectively connected to control signals V1 and V2 provided by the control module. The source of M8 is connected to the drain of M6. 15 The source and M 13 The drain of I1 is connected to M. 12 Drain, M 12 gate, M 13 The gate and M 14 The gates of M5, M6, and M7 are connected together. The output of I2 is connected to the drain of M5, the gate of M5, the gate of M6, and the gate of M7. 18 The drain of M is connected to one end of R3 and generates the switching clock signal Φ2. 11 The drain of R1 is connected to one end of R1 to generate the switching clock signal Φ1. One end of R2 is connected to one end of R4 and connected to the capacitor voltage V. DDHThe other end of R2 is connected to the drain of M9 and one end of C1 to generate the switching clock signal Φ3. The other end of R4 is connected to M9. 16 The drain of M1 and one end of C2 are connected to generate the switching clock signal Φ4. The gate of M9 and M2 are connected to the gate of M1. 16 The gates of M9 and M7 are respectively connected to control signals V3 and V4 provided by the control module. The source of M9 is connected to the drain of M7. 16 The source and M 14 The drains are connected, M 12 The source and M 13 The source, M 14 The source of M5, the other end of R3, and the other end of C2 are connected to ground. The source of M5 is connected to the source of M6, the source of M7, the other end of R1, and the other end of C1, and grounded. The magnitudes of I1 and I2 are the reference current I. REF .

[0010] Furthermore, when the external energy storage capacitor has sufficient charge, the control module outputs a high-level stimulation enable signal, and the system begins electrical stimulation. After a single stimulation is completed, due to the release of a large amount of charge, the charge on the external energy storage capacitor is greatly reduced, making it impossible to perform the next electrical stimulation. At this time, the control module outputs a low-level stimulation enable signal, and the power management module charges the external energy storage capacitor. The entire process from the start of electrical stimulation to the completion of charging of the external energy storage capacitor is one stimulation cycle.

[0011] Furthermore, before the electrical stimulation begins, the stimulation enable signal is at a low level, the switching clock signals Φ1~Φ4 are also at a low level, and the switching transistors M1~M4 in the H-bridge circuit are all in the off state, with no current flowing through the electrodes. When electrical stimulation begins, the stimulation enable signal is high, entering the positive stimulation mode. Φ1 and Φ4 are high, M1 and M4 are turned on, Φ2 and Φ3 are low, and M2 and M3 remain off. Current flows from the external energy storage capacitor through M4 → electrode → M1 → current source to ground. After positive stimulation ends, Φ1 and Φ4 become low, Φ2 and Φ3 remain low, M1~M4 are all turned off, and no current flows through the electrodes. Then, the reverse stimulation mode is entered. Φ2 and Φ3 are at high level, M2 and M3 are turned on, Φ1 and Φ4 are at low level, and M1 and M4 remain off. The current flows from the external energy storage capacitor through M3 → electrode → M2 → current source and then into the ground. After the reverse stimulation ends, Φ1 and Φ2 become high level, Φ3 and Φ4 become low level, M1 and M2 are turned on, and M3 and M4 are turned off. The electrodes are grounded for charge balance. At this point, a single stimulation is completed. The stimulation enable signal becomes low level, Φ1~Φ4 also become low level, and M1~M4 are all turned off. The power management module charges the external energy storage capacitor. After charging is completed, the next stimulation cycle begins.

[0012] Furthermore, the programmable neural electrical stimulation system transmits information by modulating ultrasound waves, and then controls the output current stimulation parameters (amplitude, pulse width, frequency) by demodulating and restoring the data information contained in the ultrasound waves.

[0013] This invention relates to a programmable neurostimulation system powered by ultrasound. It can wirelessly power the system using ultrasound in conjunction with a piezoelectric receiver and rectifier. At the same time, it uses ultrasound to transmit data information to control and adjust stimulation parameters. By controlling the amplitude, pulse width and frequency of the stimulation current and designing the working mode, it can achieve safe, reliable and efficient electrical stimulation. Attached Figure Description

[0014] Figure 1 This is a structural block diagram of the programmable neural electrical stimulation system of the present invention.

[0015] Figure 2 This is a schematic diagram of the circuit structure of the programmable neural electrical stimulation system in an embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram of the driving circuit structure of transistors M1 and M3 in an embodiment of the present invention.

[0017] Figure 4 This is a schematic diagram of the H-bridge and its driving circuit in an embodiment of the present invention.

[0018] Figure 5 This is a schematic diagram of the H-bridge circuit in the disconnected mode in an embodiment of the present invention.

[0019] Figure 6 This is a schematic diagram of the H-bridge circuit in the positive stimulation mode in an embodiment of the present invention.

[0020] Figure 7 This is a schematic diagram of the H-bridge circuit in the reverse stimulation mode in an embodiment of the present invention.

[0021] Figure 8 This is a schematic diagram of the H-bridge circuit in the grounding mode in an embodiment of the present invention.

[0022] Figure 9 This is a waveform diagram of the system-related signals under a single stimulus in an embodiment of the present invention.

[0023] Figure 10 This is a schematic diagram of the current stimulation waveform after the amplitude and frequency are adjusted to their maximum values ​​in an embodiment of the present invention.

[0024] Figure 11 This is a schematic diagram of the current stimulation waveform after the pulse width is adjusted to the maximum value in an embodiment of the present invention. Detailed Implementation

[0025] To describe the present invention in more detail, the technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figure 1 As shown, the programmable neurostimulation system based on ultrasound power supply of this invention includes an ultrasound transmitter, a piezoelectric receiver, a rectifier, a power management module, a data demodulation circuit, a control module, an H-bridge drive circuit, a current-to-analog converter, and an H-bridge circuit, wherein: An external ultrasonic transmitter emits ultrasonic waves to power the system and transmit data; a piezoelectric receiver receives the ultrasonic signals and converts them into AC signals; a rectifier converts the AC signals into DC signals to provide a DC voltage source V for the system. REC The data demodulation circuit processes AC signals and recovers the data information from the ultrasound waves. The control module controls the H-bridge drive circuit (including four sets of switches SW1~SW4) and the current-to-analog converter based on the data information. The power management module includes a charge pump circuit and a bandgap reference circuit. The charge pump amplifies the DC voltage V. REC A relatively large voltage V is generated DDH It is then stored in an off-chip storage capacitor, and the bandgap reference circuit generates a reference current I. REF The current-to-digital converter relies on the reference current I. REF The signal from the control module generates an adjustable current.

[0027] Example like Figure 2 As shown, in this embodiment, the H-bridge circuit consists of four NLDMOS transistors M1~M4; the sources of M1 and M2 are connected to a current source, and the drains of M3 and M4 are connected to V. DDH The drain of M1 and the source of M3 are connected to the right end of the electrode, and the drain of M2 and the source of M4 are connected to the left end of the electrode. The gate voltages Φ1 to Φ4 of M1 to M4 are controlled by the H-bridge drive circuit.

[0028] like Figure 3 As shown, in this embodiment, the H-bridge drive circuit, taking the drive circuits of M1 and M3 as an example, consists of four NMOS transistors M5~M8, one NLDMOS transistor M9, and two PMOS transistors M1 and M2. 10 ~M 11 A current source I REF It consists of a capacitor C1 and two resistors R1~R2; the drain of M5 is connected to the current source I. REF The source of M5 is grounded, and the gate and drain of M5 are connected together, forming a current mirror structure with the gates of M6 and M7. The drain of M6 is connected to the source of M8, and the source of M6 is grounded. The gate voltage V1 of M8 is generated by the control module, and the drain of M8 is connected to M... 10The drain, M 10 The source pole is connected to V REC M 10 The gate and drain are connected together and simultaneously connected to M. 11 The gate of the current mirror is composed of M. 11 The source pole is connected to V REC M 11 The drain of M is connected to R1, and the other end of R1 is grounded. 11 The drain voltage Φ1 serves as the gate drive voltage for the H-bridge circuit M1. The source of M7 is grounded, and the drain of M7 is connected to the source of M9. The gate voltage V3 of M9 is generated by the control module. The drain of M9 is connected to R2 and C1, and the other end of R2 is connected to V... DDH The other end of C1 is grounded, and the drain voltage Φ3 of M9 serves as the gate drive voltage of M3 in the H-bridge circuit.

[0029] The drive circuits for M2 and M4 are the same as those for M1 and M3. The entire H-bridge circuit and its drive circuit are as follows: Figure 4 As shown.

[0030] In this embodiment, the circuit charges the storage capacitor as soon as the piezoelectric receiver receives the ultrasonic wave. Electrical stimulation can only be performed when the storage capacitor has sufficient charge.

[0031] The operating mode of the H-bridge circuit is controlled by the H-bridge driver circuit, which controls the operating state of the four NLDMOS transistors by controlling the gate voltages Φ1~Φ4 of the four NLDMOS transistors.

[0032] In this embodiment, each stimulation cycle can be divided into 5 stages S0 to S4, and the time of each stage can be flexibly adjusted, as follows: Before stimulation begins, Φ1~Φ4 are all at low levels, and M1~M4 are all in the cutoff region, with no current flowing through the electrodes. Figure 5 As shown.

[0033] Phase S1: At the start of positive stimulation, Φ1 and Φ4 become high level, M1 and M4 become conductive, Φ2 and Φ3 remain low level, and M2 and M3 remain disconnected. Current flows from the storage capacitor through M4, the electrode, M1, the current source, and then into ground. The current flows from left to right through the electrode, completing the positive stimulation. Figure 6 As shown.

[0034] Phase S2: After the positive stimulation ends, Φ1 and Φ4 become low, while Φ2 and Φ3 remain low. M1 to M4 are all disconnected, and no current flows through the electrodes. The process returns to normal. Figure 5 The state.

[0035] Stage S3: At the start of reverse stimulation, Φ2 and Φ3 become high level, M2 and M3 become conductive, Φ1 and Φ4 remain low level, and M1 and M4 remain disconnected. Current flows from the storage capacitor through M3, the electrode, M2, the current source, and then into ground. The current flows from right to left through the electrode, completing the reverse stimulation. Figure 7 As shown.

[0036] Phase S4: After the reverse stimulation ends, Φ1 and Φ2 become high level, Φ3 and Φ4 become low level, M1 and M2 are turned on, and M3 and M4 are turned off. The electrodes are connected to ground to balance the charge and prevent the accumulation of charge in human tissue from causing damage. Figure 8 As shown.

[0037] After the stimulation ends, Φ1, Φ2, Φ3, and Φ4 all go low, and M1, M2, M3, and M4 are disconnected, returning to normal. Figure 5 The state.

[0038] After a single stimulation is completed, the charge on the load capacitor is greatly reduced due to the release of a large amount of charge, so the next stimulation cannot be performed immediately. The circuit will continue to charge the load capacitor. During this period, M1, M2, M3, and M4 remain disconnected. When the next stimulation cycle arrives, the above process will be repeated.

[0039] In this embodiment, during a single stimulation cycle, the stimulation enable signal ST, the input control signals V1~V4 of the H-bridge drive circuit, the gate signals Φ1~Φ4 of M1~M4 in the H-bridge, and the output current stimulation I are all included. ST The waveform is as follows Figure 9 As shown, S0 represents the period before the stimulus has started or the period after the stimulus has ended, and S1 to S4 correspond to the four stages of the single stimulus cycle mentioned above.

[0040] In this embodiment, the amplitude of the final output current can be controlled by controlling the magnitude of the current generated by the current-to-analog converter. Alternatively, the duration of switches S1 and S3 and the state of the four switching transistors M1 to M4 can be controlled by controlling the H-bridge drive circuits V1 to V4, thereby controlling the pulse width t of the output current. pw and frequency f. For example Figure 10 As shown, by adjusting the electrode output current, I can be stimulated. ST The amplitude was increased to 4.53mA (maximum value), and the frequency was increased to 125Hz (maximum value); for example Figure 11 As shown, by adjusting the electrode output current, I can be stimulated. ST pulse width t pw Increase it to 1ms (maximum value).

[0041] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. Those skilled in the art can readily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made to the present invention by those skilled in the art based on the disclosure thereof should be within the scope of protection of the present invention.

Claims

1. A programmable neural electrical stimulation system based on ultrasound power supply, characterized in that, It includes an ultrasonic transmitter, a piezoelectric receiver, a rectifier, a power management module, a data demodulation circuit, an H-bridge circuit, an off-chip energy storage capacitor, a current source, an H-bridge drive circuit, a current-to-analog converter, and a control module, among which: The ultrasonic transmitter powers the system and transmits data by emitting ultrasonic waves. The piezoelectric receiver is used to receive ultrasonic waves and convert them into alternating current signals. The rectifier is used to convert the AC signal into a DC voltage V. REC ; The power management module is based on DC voltage V. REC The conversion process charges the off-chip energy storage capacitor and simultaneously provides the system with operating voltage and reference current I. REF ; The data demodulation circuit is used to demodulate the AC signal to recover the data information contained in the ultrasound. The H-bridge circuit is used to output current stimulation through electrodes; The H-bridge drive circuit is used to drive the switching devices in the H-bridge circuit to adjust the pulse width and frequency of the output current. The control module converts the demodulated data information into control signals to control the H-bridge drive circuit and the current-to-analog converter. The current-to-analog converter is based on a reference current I. REF In addition to the control signals provided by the control module, an adjustable current I is generated. DAC Used to control the magnitude of the current source in order to adjust the amplitude of the output current; The input power supply terminal of the current source is connected to the H-bridge circuit, and the output terminal is grounded, used for copying I. DAC And amplified by a certain factor, it is used as the output current.

2. The programmable neural electrical stimulation system based on ultrasound power supply according to claim 1, characterized in that: The power management module includes a charge pump circuit, a bandgap reference circuit, and an LDO, wherein the charge pump circuit is used to regulate the DC voltage V. REC After amplification, the external energy storage capacitor is charged, and then the capacitor voltage V on the capacitor is utilized. DDH Power is supplied to the H-bridge circuit and the H-bridge drive circuit; the bandgap reference circuit is used to convert the DC voltage V REC Converted to reference voltage V REF This generates a reference current I. REF The LDO is based on V REC and V REF Generate a DC voltage V of 1.8V. LDO It is used to provide operating voltage for the control module and the current-to-analog converter.

3. The programmable neural electrical stimulation system based on ultrasound power supply according to claim 2, characterized in that: The H-bridge circuit consists of four switching transistors M1 to M4. The source of M1 is connected to the source of M2 and then to the input power supply of the current source. The drain of M3 is connected to the drain of M4 and then to the capacitor voltage V. DDH The drain of M1 is connected to the source of M3 and connected to one end of the electrode. The drain of M2 is connected to the source of M4 and connected to the other end of the electrode. The gates of M1 to M4 are respectively connected to the switching clock signals Φ1 to Φ4 provided by the H-bridge drive circuit.

4. The programmable neural electrical stimulation system based on ultrasound power supply according to claim 3, characterized in that: The switching transistors M1 to M4 are NLDMOS.

5. The programmable neural electrical stimulation system based on ultrasound power supply according to claim 3, characterized in that: The H-bridge drive circuit includes four PMOS transistors M 10 M 11 M 17 M 18 Eight NMOS transistors M5~M8 and M 12 ~M 15 Two NLDMOS transistors, M9 and M 16 Two capacitors C1 and C2, two current sources I1 and I2, and four resistors R1~R4, where M 17 The source and M 18 The source of I1 is connected to the input power supply terminal of I1 and connected to a DC voltage V. REC M 10 The source and M 11 The source of I2 is connected to the input power supply terminal of I2 and connected to a DC voltage V. REC M 17 The drain and M 18 gate, M 17 The gate and M 15 The drains are connected, M 10 The drain and M 11 gate, M 10 The gate of M8 is connected to the drain of M8, and the gate of M8 is connected to the drain of M8. 15 The gates of M8 and M6 are respectively connected to control signals V1 and V2 provided by the control module. The source of M8 is connected to the drain of M6. 15 The source and M 13 The drain of I1 is connected to M. 12 Drain, M 12 gate, M 13 The gate and M 14 The gates of M5, M6, and M7 are connected together. The output of I2 is connected to the drain of M5, the gate of M5, the gate of M6, and the gate of M7. 18 The drain of M is connected to one end of R3 and generates the switching clock signal Φ2. 11 The drain of R1 is connected to one end of R1 to generate the switching clock signal Φ1. One end of R2 is connected to one end of R4 and connected to the capacitor voltage V. DDH The other end of R2 is connected to the drain of M9 and one end of C1 to generate the switching clock signal Φ3. The other end of R4 is connected to M9. 16 The drain of M1 and one end of C2 are connected to generate the switching clock signal Φ4. The gate of M9 and M2 are connected to the gate of M1. 16 The gates of M9 and M7 are respectively connected to control signals V3 and V4 provided by the control module. The source of M9 is connected to the drain of M7. 16 The source and M 14 The drains are connected, M 12 The source and M 13 The source, M 14 The source of M5, the other end of R3, and the other end of C2 are connected to ground. The source of M5 is connected to the source of M6, the source of M7, the other end of R1, and the other end of C1, and grounded. The magnitudes of I1 and I2 are the reference current I. REF .

6. The programmable neural electrical stimulation system based on ultrasound power supply according to claim 3, characterized in that: When the external energy storage capacitor has sufficient charge, the control module outputs a high-level stimulation enable signal, and the system begins electrical stimulation. After a single stimulation is completed, due to the release of a large amount of charge, the charge on the external energy storage capacitor is greatly reduced, making it impossible to perform the next electrical stimulation. At this time, the control module outputs a low-level stimulation enable signal, and the power management module charges the external energy storage capacitor. The entire process from the start of electrical stimulation to the completion of charging of the external energy storage capacitor is one stimulation cycle.

7. The programmable neural electrical stimulation system based on ultrasound power supply according to claim 6, characterized in that: Before the electrical stimulation begins, the stimulation enable signal is at a low level, the switching clock signals Φ1~Φ4 are also at a low level, the switching transistors M1~M4 in the H-bridge circuit are all in the off state, and no current flows through the electrodes. When electrical stimulation begins, the stimulation enable signal is high, entering the positive stimulation mode. Φ1 and Φ4 are high, M1 and M4 are turned on, Φ2 and Φ3 are low, and M2 and M3 remain off. Current flows from the external energy storage capacitor through M4 → electrode → M1 → current source to ground. After positive stimulation ends, Φ1 and Φ4 become low, Φ2 and Φ3 remain low, M1~M4 are all turned off, and no current flows through the electrodes. Then, the reverse stimulation mode is entered. Φ2 and Φ3 are at high level, M2 and M3 are turned on, Φ1 and Φ4 are at low level, and M1 and M4 remain off. The current flows from the external energy storage capacitor through M3 → electrode → M2 → current source and then into the ground. After the reverse stimulation ends, Φ1 and Φ2 become high level, Φ3 and Φ4 become low level, M1 and M2 are turned on, and M3 and M4 are turned off. The electrodes are grounded for charge balance. At this point, a single stimulation is completed. The stimulation enable signal becomes low level, Φ1~Φ4 also become low level, and M1~M4 are all turned off. The power management module charges the external energy storage capacitor. After charging is completed, the next stimulation cycle begins.

8. The programmable neural electrical stimulation system based on ultrasound power supply according to claim 1, characterized in that: This system transmits information by modulating ultrasound waves, and then modulates and restores the data information contained in the ultrasound waves to regulate the output current stimulation parameters.

Images