A dual-channel low-frequency modulation intermediate frequency bipolar pulse signal generation system

Abstract

The application provides a kind of dual-channel low-frequency modulation intermediate frequency bipolar pulse signal generation system, it is related to integrated circuit technical field, including: power supply and signal isolation circuit, signal generation master module and signal generation slave module respectively connected with power supply and signal isolation circuit;The circuit structure in signal generation master module and signal generation slave module is identical;Signal generation master module includes the first step-down power supply circuit connected in turn, first MCU controller circuit, first intermediate frequency bipolar pulse signal generation circuit and first signal output interface, it also includes the first output current detection circuit and the first low-frequency current signal generation circuit connected with first MCU controller circuit, and first low-frequency current signal generation circuit is also connected with first intermediate frequency bipolar pulse signal generation circuit.The technical scheme of the application overcomes the problem that the medical device in the prior art cannot stimulate multiple acupoints simultaneously.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and in particular to a dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generating system. Background Art

[0002] Low-frequency modulated medium-frequency bipolar current signals combine the stimulation characteristics of both low- and medium-frequency currents. However, due to the constant changes in waveform, amplitude, frequency, and modulation, the human body is less susceptible to adaptation, thus maintaining a continuous stimulation effect. Transcutaneous Electrical Acupoint Stimulation (TEAS), which combines modern bioelectrical stimulation technology with traditional Chinese medicine acupuncture theory, has been widely used in the medical, rehabilitation, and healthcare fields, and is a hot topic in modern medical device research.

[0003] According to the theory and practice of traditional Chinese medicine acupuncture, the treatment of human diseases, the rehabilitation of human functions and daily health care often require stimulation of multiple acupoints to achieve better results. The existing medium-frequency eye therapy instrument system generally has fewer low-frequency signals and a single channel, and cannot synchronously generate multiple acupoint electrical stimulation signals, thereby failing to achieve simultaneous synchronous stimulation of multiple acupoints.

[0004] Therefore, there is a need for a dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generation system that can simultaneously and synchronously stimulate multiple acupoints. Summary of the Invention

[0005] The main purpose of the present invention is to provide a dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generation system to solve the problem that medical devices in the prior art cannot stimulate multiple acupoints simultaneously and synchronously.

[0006] To achieve the above-mentioned objectives, the present invention provides a dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generating system, comprising: a power supply and signal isolation circuit, a signal generating main module and a signal generating slave module respectively connected to the power supply and signal isolation circuit; the circuit structures in the signal generating main module and the signal generating slave module are consistent.

[0007] The signal generating main module includes a first buck-boost power supply circuit, a first MCU controller circuit, a first intermediate frequency bipolar pulse signal generating circuit and a first signal output interface connected in sequence. It also includes a first output current detection circuit and a first low-frequency current signal generating circuit connected to the first MCU controller circuit. The first low-frequency current signal generating circuit is also connected to the first intermediate frequency bipolar pulse signal generating circuit.

[0008] Furthermore, the power supply and signal isolation circuit includes: a power supply isolation circuit; the power supply isolation circuit is: a power isolation chip U6, the GND1 end of the power isolation chip U6 is connected to AGND, the Vin end of the power isolation chip U6 is connected to VDD12, VDD12 and AGND are the power signals of the signal generating main module; the GND2 end of the power isolation chip U6 is connected to AGND2, the Vout end of the power isolation chip U6 is connected to VDD12_2, VDD12_2 and AGND2 are the power signals of the signal generating slave module.

[0009] Furthermore, the power supply and signal isolation circuit also includes: a serial communication isolation circuit, the serial communication isolation circuit includes an optoelectronic isolation device U13 and an optoelectronic isolation device U14, U13 and U14 in the signal generating main module respectively generate a transmitting signal UART2_TX and a receiving signal UART2_RX, which are connected to the pins of the first MCU controller circuit in the signal generating main module; and then pass through U13 and U14 in the signal generating slave module, and are connected to the receiving signal UART2_RX_2 and transmitting signal UART2_TX_2 pins of the second MCU controller circuit in the signal generating slave module.

[0010] Furthermore, the first buck-boost power supply circuit includes: a buck circuit; VDD12 is the input voltage of the buck circuit, VDD12 is connected to the capacitor C18, the capacitor C52 and the resistor R76, and then connected to the EN terminal of the buck chip U10, the BS terminal and the SW terminal of the buck chip U10 are respectively connected to the two ends of the capacitor C48, the capacitor C48, the inductor L2, the filter capacitor C53, the filter capacitor C54, the transient suppression diode D15 and the fuse F1 are connected in sequence to output a DC power signal; wherein, the inductor L2, the resistor R64 and the resistor R65 are connected in sequence, and the voltage of the output DC power supply is determined by the resistor R64 and the resistor R65, that is, the output voltage V of the buck circuit OUT for: The output voltage of the step-down circuit is the input voltage of the serial communication isolation circuit.

[0011] Furthermore, the first buck-boost power supply circuit further includes: a boost circuit; VDD12 is the input voltage of the boost circuit, which is input to the boost chip U11 through the input filter capacitor C16, the resistor R58, and the jumper inductor L3; the power supply voltage is output after passing through the jumper inductor L3, the feedback voltage divider resistor R56, the feedback voltage divider resistor R59, the feedback loop oscillation suppression capacitor C43, the output filter capacitor C44, the diode D32, the transient suppression diode D22 and the fuse F4, wherein the output voltage V OUT' for:

[0012] Furthermore, the filter capacitor C16, the resistor R58 and the VIN terminal of the boost chip U11 are connected to VDD12, and the other end of the resistor R58 is connected to the SHDN terminal of the boost chip U11; one end of the jumper inductor L3 is connected to the VIN terminal of the boost chip U11, and the other end is connected to the SW terminal of the boost chip U11. The SW terminal of the boost chip U11, the diode D32, the output filter capacitor C44, the transient suppression diode D22 and the fuse F4 are connected in sequence, and the FB terminal of the boost chip U11 is respectively connected to the feedback loop oscillation suppression capacitor C43, the feedback voltage divider resistor R56 and the feedback voltage divider resistor R59, and the other ends of the feedback loop oscillation suppression capacitor C43 and the feedback voltage divider resistor R56 are connected to the cathode of the diode D32.

[0013] Furthermore, the first low-frequency current signal generating circuit is composed of a voltage follower circuit and a voltage-current conversion and amplification circuit. The voltage follower circuit is a voltage follower voltage chip U16, and the voltage-current conversion and amplification circuit is a voltage-current conversion and amplification chip U15. The OUT end of the voltage follower voltage chip U16 is connected to the In end of the voltage-current conversion and amplification chip U15.

[0014] Furthermore, the first intermediate frequency bipolar pulse signal generating circuit includes: a first full-bridge drive circuit, a second full-bridge drive circuit and a full-bridge circuit, the first full-bridge drive circuit is the first full-bridge drive chip U6, the second full-bridge drive circuit is the second full-bridge drive chip U5, the first MCU controller circuit generates two complementary PWM pulse signals PWM1_A and PWM1_B, which are respectively input into the pins of the first full-bridge circuit drive chip U6 and the second full-bridge circuit drive chip U5; the full-bridge circuit includes four NMOS devices: Q7, Q8, Q9 and Q10.

[0015] Furthermore, the current detection circuit includes: a first-stage amplifier circuit, a voltage follower and a second-stage amplifier circuit; the first-stage amplifier circuit includes: a single-channel operational amplifier U4, the input signal CURRENT_TEST of the single-channel operational amplifier U4 is the output of the full-bridge circuit, that is, the current sampling resistor R21 in the full-bridge circuit; the voltage follower and second-stage amplifier circuit includes: a two-channel operational amplifier U3, the two-channel operational amplifier U3 includes: a first op amp channel and a second op amp channel, wherein the first op amp channel includes: -INA terminal, +INA terminal and OUTA terminal; the second op amp channel includes: -INB terminal, +INB terminal, OUTB terminal and other peripheral circuits; the first op amp channel constitutes a voltage follower, and the second op amp channel constitutes a second-stage amplifier circuit; the output signal VO1 of the first-stage amplifier circuit is input to the +INA terminal of the voltage follower, and the output voltage signal VO2 of the voltage follower is used as the input signal of the second-stage amplifier circuit, and the voltage signal AD_CURRENT after the second-stage amplification is connected to the analog / digital terminal of the first MCU controller circuit.

[0016] Furthermore, the input voltage signal of the first low-frequency current signal generating circuit is the SOURCE_CTRL signal of the first MCU controller circuit, the current source signal CURRENT_SOURCE generated by the first low-frequency current signal generating circuit serves as the power supply signal of the full-bridge circuit, and the AD_CURRENT signal generated by the first MCU controller circuit is input to the OUTB end of the operational amplifier chip U3 of the current detection circuit; the first MCU controller circuit outputs different analog voltage signals SOURCE_CTRL and inputs them to the IN+ end of the first low-frequency current signal generating circuit, the serial output and receiving pins of the first MCU controller circuit, namely the UART0_TX port and the UART0_RX port, are connected to the Bluetooth / Wifi module through a double-row connector, and the 3.3V voltage output by the step-down circuit powers the MCU chip.

[0017] The present invention has the following beneficial effects:

[0018] While enabling the modulation of intermediate-frequency current signals using a wider range of low-frequency signals, the present invention also designs and implements a dual-channel signal generation system with no crosstalk between channels. This system can be further expanded to multiple channels, thereby achieving electrical stimulation of multiple eye-related acupuncture points, further aiding the treatment, rehabilitation, and health care of eye diseases. The system also implements real-time detection of output current, ensuring safety during use. By connecting to a mobile phone or personal computer software system via a designed Bluetooth / Wi-Fi communication interface, it also enables data management and intelligent analysis of the system's operational processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0020] Figure 1 The structure diagram of a dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generation system of the present invention is shown.

[0021] Figure 2 Shows the power supply isolation circuit diagram.

[0022] Figure 3 Shows the serial communication isolation circuit diagram.

[0023] Figure 4 shows a step-down circuit diagram.

[0024] Figure 5 A boost circuit diagram is shown.

[0025] Figure 6 Shown is a first MCU controller circuit diagram.

[0026] Figure 7 Shown is a circuit diagram for generating a low-frequency current signal.

[0027] Figure 8 A first full-bridge drive circuit diagram is shown.

[0028] Figure 9 A second full-bridge drive circuit diagram is shown.

[0029] Figure 10 A full bridge circuit diagram is shown.

[0030] Figure 11 Shown is the first stage amplifier circuit diagram.

[0031] Figure 12 The circuit diagram of voltage follower and secondary amplifier is shown.

[0032] The reference numerals in the above drawings are:

[0033] 01. Signal generation main module; 10. First buck-boost power supply circuit; 11. First MCU controller circuit; 12. First intermediate frequency bipolar pulse signal generating circuit; 13. First low-frequency current signal generating circuit; 14. First output current detection circuit; 15. First signal output interface; 02. Signal generation slave module; 20. Second buck-boost power supply circuit; 21. Second MCU controller circuit; 22. Second first intermediate frequency bipolar pulse signal generating circuit; 23. Second low-frequency current signal generating circuit; 24. Second output current detection circuit; 25. Second signal output interface; 301. Power supply isolation circuit; 302. Serial communication isolation circuit; 101. Buck circuit; 102. Boost circuit; 130. Voltage follower circuit; 131. Voltage-current conversion and amplification circuit; 120. First full-bridge drive circuit; 121. Second full-bridge drive circuit; 122. Full-bridge circuit; 140. First-stage amplification circuit; 141. Voltage follower and second-stage amplification circuit. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0035] like Figure 1The dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generation system shown in the figure includes a power supply and signal isolation circuit, a signal generation master module, and a signal generation slave module, each connected to the power supply and signal isolation circuit. The circuit structures of the signal generation master module and the signal generation slave module are identical. The components of the signal generation master module 01 and the signal generation slave module 02 have the same circuit structure. After passing through the signal isolation circuit, two identical and mutually isolated low-frequency modulated intermediate-frequency bipolar pulse signals are generated.

[0036] The signal generating main module 01 includes a first buck-boost power supply circuit 10, a first MCU controller circuit 11, a first intermediate frequency bipolar pulse signal generating circuit 12 and a first signal output interface 15 connected in sequence, and also includes a first output current detection circuit 14 and a first low-frequency current signal generating circuit 13 connected to the first MCU controller circuit 11. The first low-frequency current signal generating circuit 13 is also connected to the first intermediate frequency bipolar pulse signal generating circuit 12.

[0037] The signal generating main module also includes: a control signal interface circuit, namely, an asynchronous serial receiving / transmitting (UART) interface circuit of a touch screen and an asynchronous serial receiving / transmitting (UART) interface circuit of a Bluetooth / wifi module.

[0038] The signal generating module 02 includes a second buck-boost power supply circuit 20, a second MCU controller circuit 21, a second intermediate frequency bipolar pulse signal generating circuit 22 and a second signal output interface 25 connected in sequence, and also includes a second output current detection circuit 24 and a second low-frequency current signal generating circuit 23 connected to the second MCU controller circuit 21. The second low-frequency current signal generating circuit 23 is also connected to the second intermediate frequency bipolar pulse signal generating circuit 22.

[0039] The master and slave signal generation modules are connected via power supply and signal isolation circuits. A 12V external DC power supply is directly connected to the master module's buck-boost circuit. It's also isolated via a 12V power supply isolation circuit before being connected to the slave module's buck-boost circuit. Optoelectronic isolation is also implemented between the master and slave modules, enabling a two-wire serial communication connection between the two modules. Control information sent to the slave module via the touchscreen communication interface and Bluetooth and Wi-Fi interfaces is first received by the master module and then sent to the slave module via the optoelectronically isolated two-wire serial communication interface.

[0040] The present invention realizes the generation of two-channel low-frequency modulated intermediate-frequency bipolar current pulse signals through a signal generating master module and a signal generating slave module, and the signals of the two channels do not interfere with each other. The first MCU controller circuit of the signal generating module is connected to the first low-frequency current generating circuit and the signal generating circuit of the first bipolar pulse, and realizes the generation of two-channel low-frequency modulated intermediate-frequency bipolar current pulse signals controlled by the first MCU controller circuit. Compared with low-frequency pulse stimulation, it can have the functional effect of low-frequency electrical stimulation and can act on deeper areas of the skin surface to achieve analgesia or functional recovery. At the same time, the present invention can realize dual-channel signal output and can act on different eye-benefiting acupuncture points of the human body at the same time, thereby improving the treatment efficiency. Moreover, the first or second output current detection circuit in the present invention can well monitor the current size of the output channel in real time, thereby improving the safety and reliability of eye treatment.

[0041] The present invention comprises two mutually isolated low-frequency modulated intermediate-frequency bipolar pulse current signal generating circuit modules, one of which is a signal generating main module 01 and the other is a signal generating slave module 02, and the circuit structures for generating low-frequency modulated intermediate-frequency bipolar pulse current signals in the two modules are the same; wherein, taking the signal generating module as an example, the boost circuit in the first boost-buck circuit 10 boosts the 12V DC voltage to 40V voltage to power the current source of the first low-frequency current signal generating circuit 13; the buck circuit provides 5V and 3.3V power supplies to power other circuits. The first MCU controller circuit generates two complementary intermediate frequency pulse width modulation (PWM) signals and inputs them into the first intermediate frequency bipolar pulse signal generating circuit 12; at the same time, the first MCU controller circuit 11 generates an analog signal, which is input into the first low-frequency current signal generating circuit 13 and generates low-frequency current signals with different waveforms; the low-frequency current signals with different waveforms generated by the first low-frequency current signal generating circuit 13 serve as the power supply of the first intermediate frequency bipolar pulse signal generating circuit 12, thereby realizing the modulation of the amplitude of the bipolar intermediate frequency pulse signal, and finally generating a low-frequency modulated intermediate frequency bipolar current pulse signal 15 at the first signal output interface 15; in order to achieve overcurrent protection, the two signal generating modules are respectively designed with a first output current detection circuit 14 to monitor the current in their respective signal output channels in real time.

[0042] Specifically, the power supply and signal isolation circuit includes: a power supply isolation circuit 301; the power supply isolation circuit is: a power supply isolation chip U6, a VRB1212S chip can be selected, the GND1 end of the power supply isolation chip U6 is connected to AGND, the Vin end of the power supply isolation chip U6 is connected to VDD12, VDD12 and AGND are the power supply signals of the signal generating main module; the GND2 end of the power supply isolation chip U6 is connected to AGND2, the Vout end of the power supply isolation chip U6 is connected to VDD12_2, VDD12_2 and AGND2 are the power supply signals of the signal generating slave module.

[0043] Specifically, the power supply and signal isolation circuit also includes: a serial communication isolation circuit 302, the serial communication isolation circuit includes an optoelectronic isolation device U13 and an optoelectronic isolation device U14, U13 and U14 in the signal generating main module respectively generate a transmitting signal UART2_TX and a receiving signal UART2_RX, which are connected to the pins of the first MCU controller circuit in the signal generating main module; and then pass through U13 and U14 in the signal generating slave module, and are connected to the receiving signal UART2_RX_2 and transmitting signal UART2_TX_2 pins of the second MCU controller circuit in the signal generating slave module.

[0044] Specifically, the step-up and step-down circuits in the signal generating main module and the signal generating slave module include a step-up circuit and a step-down circuit, wherein the step-up circuit increases the 12V voltage to 40V, providing a power supply connection for the low-frequency current signal generating circuit; the 3.3V step-down circuit steps down the 12V input voltage to 3.3V, and provides a power supply connection for the first or second MCU microcontroller circuit, the medium-frequency bipolar pulse signal generating circuit and the output current detection circuit; in the signal generating main module, there is also a step-down circuit that reduces 12V to 5V, and the generated 5V power supply is used to power the touch screen interface circuit.

[0045] Specifically, the first buck-boost power supply circuit includes: a buck circuit 101; VDD12 is the input voltage of the buck circuit (the input voltage of the buck circuit of the signal generating module is VDD12_2) VDD12 is connected to the capacitor C18, the capacitor C52 and the resistor R76, and then connected to the EN end of the buck chip U10 (the PW2163 chip can be selected), the BS end and the SW end of the buck chip U10 are respectively connected to the two ends of the capacitor C48, the capacitor C48, the inductor L2, the filter capacitor C53, the filter capacitor C54, the transient suppression diode D15 and the fuse F1 are connected in sequence to output a DC power signal; wherein, the inductor L2, the resistor R64 and the resistor R65 are connected in sequence, and the voltage of the output DC power supply is determined by the resistor R64 and the resistor R65, that is, the output voltage V OUT for: The output voltage of the step-down circuit is the input voltage of the serial communication isolation circuit.

[0046] Specifically, the first step-up / down power supply circuit also includes: a boost circuit 102; VDD12 is the input voltage of the boost circuit (the input voltage of the boost circuit of the signal generation module is VDD12_2) and is input to the boost chip U11 (LGS6302 chip can be selected) through the input filter capacitor C16, the resistor R58, and the jumper inductor L3; after passing through the jumper inductor L3, the feedback voltage divider resistor R56, the feedback voltage divider resistor R59, the feedback loop oscillation suppression capacitor C43, the output filter capacitor C44, the diode D32, the transient suppression diode D22 and the fuse F4, the power supply voltage is output, wherein the output voltage V OUT' for:

[0047] Specifically, the filter capacitor C16, the resistor R58 and the VIN terminal of the boost chip U11 are connected to VDD12, and the other end of the resistor R58 is connected to the SHDN terminal of the boost chip U11; one end of the jumper inductor L3 is connected to the VIN terminal of the boost chip U11, and the other end is connected to the SW terminal of the boost chip U11. The SW terminal of the boost chip U11, the diode D32, the output filter capacitor C44, the transient suppression diode D22 and the fuse F4 are connected in sequence, and the FB terminal of the boost chip U11 is respectively connected to the feedback loop oscillation suppression capacitor C43, the feedback voltage divider resistor R56 and the feedback voltage divider resistor R59. The other ends of the feedback loop oscillation suppression capacitor C43 and the feedback voltage divider resistor R56 are connected to the cathode of the diode D32.

[0048] Specifically, the first low-frequency current signal generating circuit is formed by connecting a voltage follower circuit 130 and a voltage-current conversion and amplification circuit 131. The voltage follower circuit is a voltage follower pressure chip U16 (an RS8538 chip can be selected), and the voltage-current conversion and amplification circuit is a voltage-current conversion and amplification chip U15 (a TPA1881 chip can be selected). The OUT terminal of the voltage follower pressure chip U16 is connected to the IN terminal of the voltage-current conversion and amplification chip U15. The first low-frequency current signal generating circuit is composed of the voltage follower circuit and the voltage-current conversion and amplification circuit. The function of the voltage-current conversion and amplification circuit is to convert and amplify voltage signals of different waveforms into current signals of corresponding waveforms.

[0049] Specifically, taking the first MCU controller circuit in the signal generating main module as an example, an analog voltage signal with different waveforms emitted by the first MCU controller circuit is first input into the voltage follower circuit in the first low-frequency current signal generating circuit; then the analog voltage signal with different waveforms output by the voltage follower circuit is input into the voltage-current conversion and amplification circuit, thereby generating an amplified current signal with different waveforms, and the waveform of the current signal is any one of square wave, exponential wave, triangle wave, sawtooth wave, trapezoidal wave or a combination of waves, and the waveform frequency range of the output current signal is 1Hz~1KHz. At the same time, the amplitude of the current signal can be controlled by the first MCU controller circuit.

[0050] Specifically, the first intermediate frequency bipolar pulse signal generating circuit includes: a first full-bridge drive circuit 120, a second full-bridge drive circuit 121 and a full-bridge circuit 122. The first full-bridge drive circuit is the first full-bridge drive chip U6, and the second full-bridge drive circuit is the second full-bridge drive chip U5. The first MCU controller circuit generates two complementary PWM pulse signals PWM1_A and PWM1_B, which are respectively input into the pins of the first full-bridge circuit drive chip U6 and the second full-bridge circuit drive chip U5; the full-bridge circuit includes four NMOS devices: Q7, Q8, Q9 and Q10.

[0051] Specifically, taking the first MCU controller circuit in the signal generating main module as an example, the first MCU controller circuit is respectively connected to the first intermediate frequency bipolar pulse signal generating circuit, the first low frequency current signal generating circuit and the first output current detection circuit; the current output by the first low frequency current signal generating circuit is input to the first intermediate frequency bipolar pulse signal generating circuit; the low frequency modulated intermediate frequency bipolar current pulse signal output by the first intermediate frequency bipolar pulse signal generating circuit is also used as the input signal of the first output current detection circuit, thereby realizing the connection between the first intermediate frequency bipolar pulse signal generating circuit and the first output current detection circuit.

[0052] Specifically, taking the first MCU controller circuit in the signal generating main module as an example, the first MCU controller circuit generates an analog voltage signal and outputs it to the first low-frequency current signal generating circuit, thereby realizing the connection between the first MCU controller circuit and the first low-frequency current signal generating circuit, wherein the waveform of the analog voltage signal generated by the first MCU controller circuit is any one of square wave, exponential wave, triangle wave, left sawtooth wave, right sawtooth wave, trapezoidal wave or a combination of waves, and the waveform frequency range of the output analog voltage signal is 1Hz~1KHz.

[0053] Specifically, the amplitude of the current signals of different waveforms or combinations generated by the first low-frequency current signal generating circuit is adjustable between 0mA-36mA, and the current amplitude adjustment gear is 36 gears, the current difference between each two gears is 1mA, and the allowable error of the current amplitude adjustment is less than or equal to 5%.

[0054] Specifically, the intermediate frequency bipolar pulse current signal generating circuit is directly connected to the MCU controller circuit, and the MCU controller circuit generates two complementary intermediate frequency pulse width modulation (PWM) signals and outputs them to the intermediate frequency bipolar pulse signal generating circuit. The main parameters of the two complementary PWM signals are signal frequency fM and pulse width τ M , period TM, duty cycle D, and satisfy:

[0055] frequency f M =1KHz~10KHz;

[0056] Duty cycle

[0057] The main characterization parameters of the intermediate frequency pulse width modulation signal are: f M =2.5KHZ±10%, pulse width τ M =200μs±10%, duty cycle D=50%.

[0058] Specifically, the first intermediate frequency bipolar pulse signal generating circuit is composed of a full-bridge circuit composed of four NMOS devices and two corresponding full-bridge driver chips. The two full-bridge driver chips use two complementary intermediate frequency PWM signals output by the first MCU controller circuit as logic control signals. Each intermediate frequency PWM signal simultaneously controls the switching state of two NMOS devices. Under the control of the two complementary intermediate frequency PWM signals, the four NMOS switches are alternately turned on and off in pairs, so that the voltage or current at both ends of the load of the full-bridge circuit presents bipolar (two directions) switching; at the same time, the current signal generated by the first low-frequency current signal generating circuit is used as the power supply signal of the full-bridge circuit; the switching of the polarity of the current flowing through the load is controlled by the two complementary intermediate frequency PWM signals, and is combined with the current signals of different waveforms generated by the first low-frequency current signal generating circuit, so that a low-frequency modulated intermediate frequency bipolar pulse current signal is obtained at both ends of the load of the full-bridge circuit, and the signal is output to the electrode through the first signal output interface.

[0059] Specifically, the first output current detection circuit converts the collected load current into a voltage signal through a sampling resistor connected in series with the load, and after amplification by a voltage follower circuit and a two-stage voltage amplifier circuit, inputs it into the analog / digital (D / A) acquisition port of the first MCU controller, thereby realizing the detection of the output current size.

[0060] Specifically, the control signal interface circuit in the signal generation master module connects to the serial touch screen via one of the asynchronous serial receive / transmit (UART) ports of the first MCU controller, and connects to a Bluetooth / Wi-Fi module with a serial communication interface via another asynchronous serial receive / transmit (UART) port of the first MCU controller. Through the Bluetooth or Wi-Fi communication connection, a mobile phone or personal computer can wirelessly control the operation of the signal generation master module and the signal generation slave module.

[0061] Specifically, the current detection circuit includes: a first-stage amplifier circuit 140, a voltage follower and secondary amplifier circuit 141; the first-stage amplifier circuit includes: a single-channel operational amplifier U4, the input signal CURRENT_TEST of the single-channel operational amplifier U4 is the output of the full-bridge circuit, that is, the current sampling resistor R21 in the full-bridge circuit; the voltage follower and secondary amplifier circuit includes: a two-channel operational amplifier U3, the two-channel operational amplifier U3 includes: a first op amp channel and a second op amp channel, wherein the first op amp channel includes: -INA terminal, +INA terminal and OUTA terminal; the second op amp channel includes: -INB terminal, +INB terminal, OUTB terminal and other peripheral circuits; the first op amp channel constitutes a voltage follower, and the second op amp channel constitutes a second-stage amplifier circuit; the output signal VO1 of the first-stage amplifier circuit is input to the +INA terminal of the voltage follower, and the output voltage signal VO2 of the voltage follower is used as the input signal of the second-stage amplifier circuit, and the voltage signal AD_CURRENT after the second-stage amplification is connected to the analog / digital terminal of the first MCU controller circuit.

[0062] Specifically, the input voltage signal of the first low-frequency current signal generating circuit is the SOURCE_CTRL signal of the first MCU controller circuit, the current source signal CURRENT_SOURCE generated by the first low-frequency current signal generating circuit serves as the power supply signal of the full-bridge circuit, and the AD_CURRENT signal generated by the first MCU controller circuit is input to the OUTB end of the operational amplifier chip U3 of the current detection circuit; the first MCU controller circuit outputs different analog voltage signals SOURCE_CTRL and inputs them into the IN+ end of the first low-frequency current signal generating circuit, the serial output and receiving pins of the first MCU controller circuit, namely the UART0_TX port and the UART0_RX port, are connected to the Bluetooth / Wifi module through a double-row connector, and the 3.3V voltage output by the step-down circuit powers the MCU chip.

[0063] like Figure 2 and Figure 3As shown, the isolation circuit includes a power supply isolation circuit 301 and a serial communication isolation circuit 302 between the signal generating master module and the signal generating slave module. In the power supply isolation circuit 301, the signals VDD12 and AGND are the input power supplies of the signal generating master module. After being isolated by the power isolation module U6, the power supplies VDD12_2 and AGND2 required by the signal generating slave module are generated. In the serial communication isolation circuit 302, VDD33 and DGND correspond to the power supply signals of the signal generating master module, and VDD33_2 and DGND2 are the power supply signals of the signal generating slave module, which are generated by the step-down circuits in the signal generating master module and the signal generating slave module, respectively. The sending signal UART2_TX and the receiving signal UART2_RX of the asynchronous serial communication (UART) port of the signal generating master module are connected to the Figure 6 The corresponding 29th and 30th pins of the asynchronous serial communication port UART2 of the MCU chip in the first MCU controller circuit 11 are connected, and after passing through the optoelectronic isolation devices U13 and U14 of the signal generating main module, they are connected to the corresponding receiving signal UART2_RX_2 and transmitting signal UART2_TX_2 of the asynchronous serial communication port UART2 on the MCU chip of the second MCU controller circuit 21 of the signal generating slave module.

[0064] like Figure 4 and Figure 5 As shown, the buck-boost power supply circuit in the signal generation master module includes a buck circuit 101 and a boost circuit 102, which are the same as the buck circuit and boost circuit in the signal generation slave module. In the buck circuit 101, VDD12 is a 12V voltage, which serves as the input voltage of the buck circuit and is connected to the buck chip U10 through capacitors C18, C52 and resistor R76. At the output end, a 3.3V DC power supply signal is output after passing through capacitor C48, inductor L2, filter capacitors C53 and C54, transient suppression diode D15, and fuse. The voltage of the output DC power supply is determined by resistors R64 and R65, that is, the output voltage of the buck circuit is:

[0065] like Figure 5 As shown, in the boost circuit 102, VDD12 is a 12V voltage, which is input to the boost chip U11 through the input filter capacitor C16, resistor R58, and jumper inductor L3. At the output end, after passing through the jumper inductor L3, feedback voltage divider resistors R56 and R59, feedback loop oscillation suppression capacitor C43, output filter capacitor C44, diode D32, transient suppression diode D22, and fuse F4, the output power supply voltage of 40 is output. The output voltage of the boost circuit is:

[0066] like Figure 6As shown in the figure, taking the signal generation main module as an example, the 37th and 38th pins of the MCU chip generate two complementary PWM pulse signals PWM1_A and PWM1_B, which are connected to the Figure 7 The full bridge circuit driver chip U6 and U5 pins in the intermediate frequency bipolar pulse signal generating circuit are connected. The AD_CURRENT signal on pin 25 is connected to the Figure 12 The operational amplifier chip U3 of the output current detection circuit is connected; the 20th pin of the MCU chip outputs different analog voltage signals SOURCE_CTRL, which are connected to the Figure 7 The MCU chip is connected to a low-frequency current signal generation circuit. Pins 58 and 59 of the MCU chip correspond to the serial output and receive pins of the UART0 port. They are connected to the Bluetooth / Wi-Fi module via the dual-row connector P6, enabling wireless communication with a mobile phone or PC. The MCU chip is powered by the 3.3V voltage output of the step-down power supply circuit.

[0067] like Figure 7 As shown, taking the signal generating main module as an example, the low-frequency current signal generating circuit is composed of a voltage follower circuit 130 and a voltage-current conversion and amplification circuit 131. The input voltage signal of the low-frequency current signal generating circuit is Figure 6 The 20th pin signal SOURCE_CTRL of the MCU chip. The SOURCE_CTRL signal is an analog voltage signal of different waveforms and is connected to the voltage follower circuit 130. The output voltage signal of the voltage follower circuit 130 is output to the voltage-current conversion and amplification circuit 131. After the voltage-current conversion and amplification circuit converts the input analog voltage signals of different waveforms into corresponding current signals and amplifies them, it outputs current source signals of different waveforms as CURRENT_SOURCE. Figure 10 The power supply input signal of the full-bridge circuit is shown.

[0068] like Figure 8 、 Figure 9 and Figure 10 As shown in the figure, taking the main module circuit of signal generation as an example, the intermediate frequency bipolar pulse signal generation circuit is composed of two full-bridge drive circuits 120 and 121, and a full-bridge circuit 122. The two full-bridge drive circuits are respectively composed of full-bridge drive chips (optional IR2110) U6 and U5 and peripheral devices. The full-bridge circuit 122 is composed of four NMOS devices Q7, Q8, Q9, and Q10. The two full-bridge drive chips are composed of Figure 6The two complementary intermediate frequency PWM signals PWM1_A and PWM1_B output from the pins 37 and 38 of the MCU chip shown in the figure are used as logic control signals. Each intermediate frequency PWM signal simultaneously controls the switching state of two NMOS devices. Under the control of the two complementary intermediate frequency PWM signals, the four NMOS switches are alternately turned on and off in pairs, so that the voltage or current across the load of the full-bridge circuit presents bipolar (two-directional) switching. Figure 7 The current source signal CURRENT_SOURCE generated by the low-frequency current signal generating circuit shown in FIG is used as the power supply signal of the full-bridge circuit; the polarity switching of the current flowing through the load is controlled by two complementary intermediate frequency PWM signals, and the current source signal CURRENT_SOURCE generated by the low-frequency current signal generating circuit shown in FIG Figure 7 The current signals of different waveforms generated by the low-frequency current signal generating circuit are combined to obtain a low-frequency modulated intermediate-frequency bipolar pulse current signal at both ends of the full-bridge circuit load, wherein Figure 10 VS1 and VS2 in the middle full-bridge circuit 122 are two output electrode signals of the low-frequency bipolar pulse current signal connected to the load.

[0069] like Figure 11 and Figure 12 As shown, taking the signal generation main module as an example, the first output current detection circuit includes a first-stage amplifier circuit 140, a voltage follower and a second-stage amplifier circuit 141. The first-stage amplifier circuit is constructed based on a single-channel operational amplifier U4, and the input signal CURRENT_TEST is taken from Figure 6 The current sampling resistor R21 in the full-bridge circuit 122 shown in the figure. The voltage follower and secondary amplifier circuit 141 is constructed based on a two-channel operational amplifier U3. The operational amplifier channel 1 forms a voltage follower, and the operational amplifier channel 2 forms a second-stage amplifier circuit. The output signal VO1 of the first-stage amplifier circuit 140 is input to the non-inverting terminal (pin 3) of the voltage follower, and the output voltage signal VO2 of the voltage follower is used as the input signal of the second-stage amplifier circuit. The voltage signal AD_CURRENT after the second-stage amplification is connected to Figure 6 The analog / digital (A / D) pin 25 of the MCU controller shown is used to detect the output current of the low-frequency modulated bipolar pulse signal flowing through the sampling resistor R21.

[0070] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generation system, characterized in that: include: A power supply and signal isolation circuit, a signal generation master module and a signal generation slave module respectively connected to the power supply and signal isolation circuit; The circuit structures in the signal generating master module and the signal generating slave module are consistent; The signal generation main module includes a first buck-boost power supply circuit, a first MCU controller circuit, a first intermediate frequency bipolar pulse signal generating circuit and a first signal output interface connected in sequence, and also includes a first output current detection circuit and a first low-frequency current signal generating circuit connected to the first MCU controller circuit. The first low-frequency current signal generating circuit is also connected to the first intermediate frequency bipolar pulse signal generating circuit; The first low-frequency current signal generating circuit is formed by connecting a voltage follower circuit and a voltage-current conversion and amplification circuit. The voltage follower circuit is a voltage follower pressure chip U16, and the voltage-current conversion and amplification circuit is a voltage-current conversion and amplification chip U15. The OUT terminal of the voltage follower pressure chip U16 is connected to the In terminal of the voltage-current conversion and amplification chip U15. The OUT terminal of the voltage-current conversion and amplification circuit U15 is connected to the base of the transistor Q6, and the emitter of the transistor Q6, the resistor R51 and the resistor R61 are connected in sequence and then grounded. The OUT terminal of the voltage-current conversion and amplification circuit U15 is also connected to the capacitor C41, and the capacitor C41 is further connected to the resistor R61 and the -In terminal of the amplification circuit U15, and the resistor R61 is grounded; the emitter of the transistor Q6 is also connected to the resistor R50 and then output, and the resistor R50 is connected in sequence to the resistor R48, the resistor R49, the capacitor C55 and then connected The collector of the transistor Q6 is connected to the capacitor C45 and then to ground, and the collector of the transistor Q6 is also connected to the +Vs terminal of the voltage-current conversion and amplifier circuit U15. The OUT terminal of the voltage follower pressure chip U16 is connected to the capacitor C55 and the resistor R49. The capacitor C55 is connected to the resistor R61 and ground. The resistor R49 is connected to the +In terminal of the amplifier circuit U15 and the resistor R48. The resistor R48 is connected to CURRENT_SOURCE. The -Vs terminal of the voltage follower pressure chip U16 is grounded. The power supply and signal isolation circuit includes: a power supply isolation circuit; the power supply isolation circuit is: a power isolation chip U6, the GND1 end of the power isolation chip U6 is connected to AGND, the Vin end of the power isolation chip U6 is connected to VDD12, VDD12 and AGND are the power supply signals of the signal generation master module; the GND2 end of the power isolation chip U6 is connected to AGND2, the Vout end of the power isolation chip U6 is connected to VDD12_2, VDD12_2 and AGND2 are the power supply signals of the signal generation slave module; The power supply and signal isolation circuit also includes: a serial communication isolation circuit, which includes an optoelectronic isolation device U13 and an optoelectronic isolation device U14. U13 and U14 in the signal generation main module respectively generate a transmission signal UART2_TX and a reception signal UART2_RX, which are connected to the pins of the first MCU controller circuit in the signal generation main module; then pass through U13 and U14 in the signal generation slave module, and are connected to the reception signal UART2_RX_2 pin and the transmission signal UART2_TX_2 pin of the second MCU controller circuit in the signal generation slave module; The current detection circuit includes: a first-stage amplifier circuit, a voltage follower and a second-stage amplifier circuit; the first-stage amplifier circuit includes: a single-channel operational amplifier U4, the input signal CURRENT_TEST of the single-channel operational amplifier U4 is the output of the full-bridge circuit, that is, the current sampling resistor R21 in the full-bridge circuit, one end of the current sampling resistor R21 is connected to the emitter of Q10 and Q8 in the full-bridge circuit, and the other end is connected to the negative electrode of the capacitor C36, and the positive electrode of the capacitor C36 is connected to the collector of Q7 and Q9 in the full-bridge circuit and the ground; the voltage follower and second-stage amplifier circuit includes: a two-channel operational amplifier U3, the two-channel operational amplifier U3 includes: a first operational amplifier channel and a second operational amplifier channel, wherein the first operational amplifier channel includes: -INA terminal, +INA terminal and OUTA terminal; the second operational amplifier channel includes: -INB terminal, +INB terminal, OUTB terminal and other peripheral circuits, other peripheral circuits include resistor R70, capacitor C37, resistor R69, resistor R66, resistor R68, capacitor C38, the +INB terminal of the two-channel operational amplifier U3 is connected to resistor R70, capacitor C37 and resistor R69, the resistor R70 is connected to the VO2 terminal, the capacitor C37 and resistor R69 are grounded, the -INB terminal of the two-channel operational amplifier U3 is connected to resistor R66, resistor R68 and capacitor C38, the resistor R66 is grounded, and the resistor R68 and capacitor C38 are connected to the OUTB terminal of the two-channel operational amplifier U3; the first operational amplifier channel constitutes a voltage follower, and the second operational amplifier channel constitutes a second-stage amplifier circuit; the output signal VO1 of the first-stage amplifier circuit is input to the +INA terminal of the voltage follower, and the output voltage signal VO2 of the voltage follower is used as the input signal of the second-stage amplifier circuit. The voltage signal AD_CURRENT after the second-stage amplification is connected to the analog / digital terminal of the first MCU controller circuit.

2. A dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generating system according to claim 1, characterized in that: The first step-up / down power supply circuit includes: a step-down circuit; VDD12 is the input voltage of the step-down circuit, VDD12 is connected to the capacitor C18, the capacitor C52 and the resistor R76, and then connected to the EN terminal of the step-down chip U10, the BS terminal and the SW terminal of the step-down chip U10 are respectively connected to the two ends of the capacitor C48, the capacitor C48, the inductor L2, the filter capacitor C53, the filter capacitor C54, the transient suppression diode D15 and the fuse F1 are connected in sequence to output a DC power signal; wherein, the inductor L2, the resistor R64 and the resistor R65 are connected in sequence, and the voltage of the output DC power supply is determined by the resistor R64 and the resistor R65, that is, the output voltage V of the step-down circuit OUT for: The output voltage of the step-down circuit is the input voltage of the serial communication isolation circuit.

3. A dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generating system according to claim 2, characterized in that: The first step-up / down power supply circuit also includes: a boost circuit; VDD12 is the input voltage of the boost circuit, which is input to the boost chip U11 through the input filter capacitor C16, the resistor R58, and the jumper inductor L3; the power supply voltage is output after passing through the jumper inductor L3, the feedback voltage divider resistor R56, the feedback voltage divider resistor R59, the feedback loop oscillation suppression capacitor C43, the output filter capacitor C44, the diode D32, the transient suppression diode D22 and the fuse F4, wherein the output voltage V OUT’ for:

4. A dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generating system according to claim 3, characterized in that: The filter capacitor C16, resistor R58 and the VIN terminal of the boost chip U11 are connected to VDD12, and the other end of the resistor R58 is connected to the SHDN terminal of the boost chip U11; one end of the jumper inductor L3 is connected to the VIN terminal of the boost chip U11, and the other end is connected to the SW terminal of the boost chip U11. The SW terminal of the boost chip U11, the diode D32, the output filter capacitor C44, the transient suppression diode D22 and the fuse F4 are connected in sequence, and the FB terminal of the boost chip U11 is respectively connected to the feedback loop oscillation suppression capacitor C43, the feedback voltage divider resistor R56 and the feedback voltage divider resistor R59. The other ends of the feedback loop oscillation suppression capacitor C43 and the feedback voltage divider resistor R56 are connected to the cathode of the diode D32.

5. A dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generating system according to claim 4, characterized in that: The first intermediate frequency bipolar pulse signal generating circuit includes: a first full-bridge drive circuit, a second full-bridge drive circuit and a full-bridge circuit, the first full-bridge drive circuit is a first full-bridge drive chip U6, the second full-bridge drive circuit is a second full-bridge drive chip U5, the first MCU controller circuit generates two complementary PWM pulse signals PWM1_A and PWM1_B, which are input into the pins of the first full-bridge circuit drive chip U6 and the second full-bridge circuit drive chip U5 respectively; the full-bridge circuit includes four NMOS devices: Q7, Q8, Q9 and Q10, the collectors of Q7, Q8, Q9 and Q10 Capacitors C34, C29, C35 and 28 are connected between the collector and emitter respectively. The collectors of Q7 and Q9 are connected to the positive electrode of capacitor C36 and resistors R74 and R78. The resistor R74 is connected to the resistor R24. The resistor R78 is connected to the resistor R77. The resistors R24 and R77 are grounded. The emitters of Q7 and Q9 are connected to the collectors of Q8 and Q10 respectively. The emitters of Q8 and Q10 are connected to one end of the current sampling resistor R21. The negative electrode of the capacitor C36 is connected to the other end of the current sampling resistor R21.

6. A dual-channel low-frequency modulated intermediate-frequency bipolar pulse signal generating system according to claim 5, characterized in that: The input voltage signal of the first low-frequency current signal generating circuit is the SOURCE_CTRL signal of the first MCU controller circuit. The current source signal CURRENT_SOURCE generated by the first low-frequency current signal generating circuit serves as the power supply signal of the full-bridge circuit. The AD_CURRENT signal generated by the first MCU controller circuit is input into the OUTB end of the operational amplifier chip U3 of the current detection circuit; the first MCU controller circuit outputs different analog voltage signals SOURCE_CTRL and inputs them into the IN+ end of the first low-frequency current signal generating circuit. The serial output and receiving pins of the first MCU controller circuit, namely the UART0_TX port and the UART0_RX port, are connected to the Bluetooth / Wifi module through a double-row connector, and the 3.3V voltage output by the step-down circuit powers the MCU chip.

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