Waveform modulation circuit and intermediate frequency electrotherapy instrument

Abstract

The utility model discloses a kind of waveform modulation circuit and intermediate frequency electrotherapy instrument, the waveform modulation circuit includes: amplitude adjustment circuit, with external controller connection, for according to the amplitude modulation processing of input waveform signal from the intensity adjustment signal of the external controller, to obtain the waveform signal after amplitude modulation;Analog switch, with the output end of external controller and the amplitude adjustment circuit connection, for according to the control signal from the external controller and the waveform signal after amplitude modulation generation basic frequency wave;Waveform synthesis circuit, with the output end of the amplitude adjustment circuit and the analog switch connection, for the signal modulation of the waveform signal after amplitude modulation and the basic frequency wave, output with the zero point of waveform signal voltage after amplitude modulation bidirectional equal-amplitude waveform;Waveform amplification circuit, with the output end of the waveform synthesis circuit connection, for the signal amplification of the bidirectional equal-amplitude waveform, obtain treatment waveform.

Description

Technical Field

[0001] This utility model relates to the field of medical equipment technology, specifically to a waveform modulation circuit and a medium-frequency electrotherapy device. Background Technology

[0002] An electrotherapy device is a medical instrument that treats diseases and relieves pain through electrotherapy. Electrotherapy devices can generate various types of current, such as direct current, pulsed current, and alternating current, which are transmitted to human tissues through electrodes to produce a certain electrical stimulation effect. They can be widely used in rehabilitation medicine, physical therapy, traditional Chinese medicine physiotherapy, and beauty treatments. Currently, commercially available electrotherapy devices typically use integrated devices such as microprocessors or FPGAs to generate waveforms and modulate the amplitude, frequency, and envelope of these waveforms to generate and output therapeutic waveforms. However, the concentrated modulation of the waveform during the debugging process makes the debugging software process complex and the debugging difficult. Utility Model Content

[0003] This invention provides a waveform modulation circuit and a medium-frequency electrotherapy device, aiming to solve the problem that current medium-frequency electrotherapy devices use integrated devices such as microprocessors or FPGAs to generate and centrally modulate waveforms, resulting in complex software processes and high debugging difficulty during debugging.

[0004] To solve the above-mentioned technical problems, according to one aspect of the present invention, a waveform modulation circuit is provided, comprising:

[0005] An amplitude adjustment circuit, connected to an external controller, is used to perform amplitude modulation processing on the input waveform signal according to the intensity adjustment signal from the external controller, so as to obtain an amplitude-modulated waveform signal.

[0006] An analog switch, connected to the output of an external controller and the amplitude adjustment circuit, is used to generate a fundamental frequency wave based on a control signal from the external controller and the amplitude-modulated waveform signal.

[0007] A waveform synthesis circuit, connected to the output terminals of the amplitude adjustment circuit and the analog switch, is used to modulate the amplitude-modulated waveform signal and the fundamental frequency wave, and output a bidirectional constant amplitude waveform with the amplitude-modulated waveform signal voltage as the zero point.

[0008] A waveform amplification circuit, connected to the output of the waveform synthesis circuit, is used to amplify the bidirectional constant amplitude waveform to obtain a therapeutic waveform.

[0009] The further technical solution is as follows: the amplitude adjustment circuit includes a digital potentiometer, the input terminal of which is used to receive waveform signals, and the control terminal of which is connected to an external controller to receive intensity adjustment signals from the external controller, and to perform amplitude modulation processing on the received waveform signals according to the intensity adjustment signals to obtain amplitude-modulated waveform signals.

[0010] The further technical solution is as follows: the amplitude adjustment circuit further includes a first voltage follower, the output terminal of the analog switch is also connected to a second voltage follower, the input terminal of the first voltage follower is connected to the output terminal of the digital potentiometer, and the output terminals of the first voltage follower and the second voltage follower are both connected to the waveform synthesis circuit.

[0011] The further technical solution is as follows: the waveform synthesis circuit includes a subtractor, which includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, and a ninth resistor. The inverting input of the first operational amplifier is connected to the output of the amplitude adjustment circuit through the first resistor. One end of the ninth resistor is connected to the end where the first resistor and the first operational amplifier are connected, and the other end of the ninth resistor is grounded. The non-inverting input of the first operational amplifier is connected to the output of the analog switch through the second resistor. The output of the first operational amplifier is connected to its inverting input through the third resistor, and the output of the first operational amplifier serves as the output of the waveform synthesis circuit. One end of the fourth resistor is connected to the end where the second resistor and the first operational amplifier are connected, and the other end of the fourth resistor is grounded.

[0012] The further technical solution is as follows: the analog switch is a single-pole double-throw switch, the selection control terminal of the single-pole double-throw switch is connected to the external controller, the first input terminal and the second input terminal of the single-pole double-throw switch are respectively connected to the output terminal of the amplitude adjustment circuit and ground, and the output terminal of the single-pole double-throw switch is connected to the waveform synthesis circuit.

[0013] The further technical solution is as follows: the waveform amplification circuit includes a second operational amplifier, a seventh resistor and a first capacitor. The non-inverting input terminal of the second operational amplifier is connected to the output terminal of the waveform synthesis circuit through a fifth resistor. The inverting input terminal of the second operational amplifier is grounded through a sixth resistor. The output terminal of the second operational amplifier serves as the output terminal of the waveform amplification circuit. The seventh resistor and the first capacitor are connected in parallel between the output terminal and the inverting input terminal of the second operational amplifier.

[0014] The further technical solution is as follows: the waveform amplification circuit further includes an eighth resistor and a second capacitor. One end of the eighth resistor and the second capacitor are connected in series and connected to the output terminal of the second operational amplifier. The other end of the eighth resistor and the second capacitor are connected in series and serve as the output terminal of the waveform amplification circuit to output the treatment waveform.

[0015] To solve the above-mentioned technical problems, according to another aspect of this utility model, a medium-frequency electrotherapy device is provided, comprising a controller, a waveform modulation circuit, a power amplification circuit, and an isolation conversion circuit, wherein...

[0016] The controller is connected to the waveform modulation circuit and is used to generate waveform signals, intensity adjustment signals and control signals according to the external current setting signal.

[0017] The waveform modulation circuit is the waveform modulation circuit described above, used to generate a therapeutic waveform based on the intensity adjustment signal, the waveform signal, and the control signal;

[0018] The power amplifier circuit is connected to the output terminal of the waveform modulation circuit and is used to amplify the treatment waveform.

[0019] The isolation transformation circuit is connected to the output terminal of the power amplifier circuit and is used to perform isolation transformation on the amplified treatment waveform to obtain the corresponding treatment waveform.

[0020] The further technical solution is as follows: the intermediate frequency electrotherapy device also includes a detection feedback circuit, which includes a current transformer and a resistor voltage divider circuit. The primary side of the current transformer is connected to the output terminal of the isolation conversion circuit. The input terminal of the resistor voltage divider circuit is connected to one end of the secondary side of the current transformer. The output terminal of the resistor voltage divider circuit is connected to an input pin of the controller. The other end of the secondary side of the current transformer is grounded.

[0021] The further technical solution is as follows: the intermediate frequency electrotherapy device also includes electrode pads, which are connected to the output terminal of the isolation conversion circuit.

[0022] Compared with existing technologies, the waveform modulation circuit of this invention includes an amplitude adjustment circuit and an analog switch. The amplitude adjustment circuit modulates the input waveform signal according to the intensity adjustment signal from the external controller to obtain an amplitude-modulated waveform signal. The analog switch generates a fundamental frequency wave according to the control signal from the external controller and the amplitude-modulated waveform signal. The amplitude-modulated waveform signal and the fundamental frequency wave are input to the waveform synthesis circuit for signal modulation, thereby generating and outputting a bidirectional constant amplitude waveform with the amplitude-modulated waveform signal voltage as zero. The bidirectional constant amplitude waveform is then amplified by the waveform amplification circuit to obtain the therapeutic waveform. It can be seen that this invention achieves the generation and modulation of the therapeutic waveform through the cooperation of the amplitude adjustment circuit, the analog switch, the waveform synthesis circuit, and the waveform amplification circuit. That is, the generation and modulation of the therapeutic waveform are achieved through the collaboration of circuit modules built by individual hardware devices. The single-module implementation is simpler than the centralized implementation. Moreover, when the software algorithm of this modular waveform modulation circuit is used for debugging of the electrotherapy device, it focuses on the implementation of the single-module function. Each module can be debugged separately and synchronously, reducing the overall debugging difficulty and increasing the response speed. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a specific embodiment of the waveform modulation circuit of this utility model.

[0025] Figure 2 This is a schematic diagram of the circuit structure of a specific embodiment of the waveform modulation circuit of this utility model.

[0026] Figure 3 yes Figure 2 The diagram shows a waveform modulation process in the waveform synthesis circuit of the waveform modulation circuit shown.

[0027] Figure 4 yes Figure 2 The diagram shows another waveform modulation process in the waveform synthesis circuit of the waveform modulation circuit shown.

[0028] Figure 5 This is a schematic diagram of the circuit structure of a specific embodiment of the medium-frequency electrotherapy device of this utility model. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0030] Reference Figures 1 to 2 , Figures 1 to 2 A specific embodiment of the waveform modulation circuit 10 of this utility model is shown. The waveform modulation circuit 10 of this utility model can be applied to a medium-frequency electrotherapy device. In the embodiment shown in the accompanying drawings, the waveform modulation circuit 10 includes an amplitude adjustment circuit 11, an analog switch S1, a waveform synthesis circuit 13, and a waveform amplification circuit 14. The amplitude adjustment circuit 11 is connected to an external controller and is used to perform amplitude modulation processing on the input waveform signal according to the intensity adjustment signal from the external controller to obtain an amplitude-modulated waveform signal. Understandably, the input waveform signal can be generated by the external controller or by an external waveform generation device. The analog switch S1 is connected to the output terminals of the external controller and the amplitude adjustment circuit 11 and is used to generate a fundamental frequency wave according to the control signal from the external controller and the amplitude-modulated waveform signal. The waveform synthesis circuit 13 is connected to the output terminals of the amplitude adjustment circuit 11 and the analog switch S1 and is used to perform signal modulation on the amplitude-modulated waveform signal and the fundamental frequency wave, outputting a bidirectional constant-amplitude waveform with the amplitude-modulated waveform signal voltage as zero. The waveform amplification circuit 14 is connected to the output terminal of the waveform synthesis circuit 13 and is used to amplify the bidirectional constant-amplitude waveform to obtain a therapeutic waveform. Based on the above design, the generation and modulation of the therapeutic waveform are achieved through the cooperation of the amplitude adjustment circuit 11, the analog switch S1, the waveform synthesis circuit 13, and the waveform amplification circuit 14. This decomposes the task of generating and centrally modulating the waveform by integrated devices such as microprocessors or FPGAs in the existing technology into different tasks and assigns them to different functionally independent hardware modules. The generation and modulation of the therapeutic waveform are achieved through the collaborative circuit modules built by each separate hardware device. The single-module implementation is simpler than the centralized implementation. Moreover, when the waveform modulation circuit 10 of this modular design is used for debugging the electrotherapy device, the software algorithm focuses on the implementation of single-module functions. Each module can be debugged separately and synchronously, which reduces the overall debugging difficulty and increases the response speed.

[0031] In some embodiments, the amplitude adjustment circuit 11 includes a digital potentiometer U202 and a first voltage follower U200. The input terminal (pin 8) of the digital potentiometer U202 is used to receive a waveform signal. The control terminal of the digital potentiometer is connected to an external controller to receive an intensity adjustment signal from the external controller and to perform amplitude modulation processing on the received waveform signal according to the intensity adjustment signal to obtain an amplitude-modulated waveform signal. The input terminal (pin 1) of the first voltage follower U200 is connected to the output terminal of the digital potentiometer U202, and the output terminal (pin 4) of the first voltage follower U200 is connected to the waveform synthesis circuit 13. Based on the above design, after receiving the intensity adjustment signal and the waveform signal, the digital potentiometer U202 adjusts the resistance value of its output terminal to realize amplitude modulation processing, correspondingly realizing intensity, amplitude modulation, and low-frequency envelope modulation of the waveform.

[0032] In some embodiments, such as Figure 2 As shown, the analog switch S1 can be a single-pole double-throw switch, model SGM3157. The first input terminal A1 of the single-pole double-throw switch is connected to the output terminal of the first voltage follower U200 in the amplitude adjustment circuit 11 through a resistor R208. The second input terminal A2 of the single-pole double-throw switch is grounded. The selection control terminal (pin 6) of the single-pole double-throw switch is connected to the external controller through a resistor R214 to receive control signals and connect the output terminal and the first input terminal A1 / second input terminal A2 according to the control signals, so that the first input terminal A1 and the second input terminal A2 are alternately connected to their output terminals, thereby generating a fundamental frequency wave. The output terminal of the single-pole double-throw switch is connected to the waveform synthesis circuit 13. Understandably, the control signal can be generated by a timer in the external controller, and the fundamental frequency of the waveform signal can be changed by the timer. Based on the above design, the output of the digital potentiometer U202 is used as the reference voltage for the input of the analog switch S1, and the intensity, amplitude, and low-frequency envelope waveform of the waveform are output in the form of pulses.

[0033] In some embodiments, the waveform synthesis circuit 13 includes a subtractor, which includes a first operational amplifier U203, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a ninth resistor R9. The inverting input of the first operational amplifier U203 is connected to the output of the amplitude adjustment circuit 11 via the first resistor R1. One end of the ninth resistor R9 is connected to the first resistor R1 and the first operational amplifier U203 at one end, and the other end of the ninth resistor R9 is grounded. The non-inverting input of the first operational amplifier U203 is connected to the output of the analog switch S1 via the second resistor R2. The output of the first operational amplifier U203 is connected to its inverting input via the third resistor R3, and the output of the first operational amplifier U203 serves as the output of the waveform synthesis circuit 13. One end of the fourth resistor R4 is connected to the second resistor R2 and the first operational amplifier U203 at one end, and the other end of the fourth resistor R4 is grounded. Preferably, in this embodiment, a second voltage follower U206 is connected between the output terminal of the analog switch S1 and the non-inverting input terminal of the first operational amplifier U203. The first operational amplifier U203 is an AS321KTR-G1 operational amplifier. Furthermore, to satisfy the symmetry of the synthesized waveform, a dual positive and negative power supply is used. In this invention, the waveform signal generated after amplitude modulation by the digital potentiometer U202 is input to the inverting input terminal of the first operational amplifier U203 in the subtractor after passing through the first voltage follower U200. The fundamental frequency wave generated by the analog switch S1 is input to the non-inverting input terminal of the first operational amplifier U203 in the subtractor after passing through the second voltage follower U206. After being superimposed in the first operational amplifier U203, a bidirectional constant amplitude waveform with the waveform signal generated after amplitude modulation by the digital potentiometer U202 as the zero point is output. For example, as Figure 3 As shown, if the waveform signal generated after amplitude modulation is a continuous signal, the output after superposition in the first operational amplifier U203 is a bidirectional constant amplitude waveform as shown in the figure. However, if the waveform signal generated after amplitude modulation is a square wave (such as...), the output is a bidirectional constant amplitude waveform as shown in the figure. Figure 4 As shown), the output after superposition in the first operational amplifier U203 is as follows: Figure 4 The waveform shown is a bidirectional constant amplitude waveform.

[0034] Continue to refer to Figure 2The waveform amplification circuit 14 includes a second operational amplifier U204, a seventh resistor R7, and a first capacitor C1. The non-inverting input of the second operational amplifier U204 is connected to the output of the waveform synthesis circuit 13 through a fifth resistor R5, and the inverting input of the second operational amplifier U204 is grounded through a sixth resistor R6. The output of the second operational amplifier U204 serves as the output of the waveform amplification circuit 14. The seventh resistor R7 and the first capacitor C1 are connected in parallel between the output of the second operational amplifier U204 and its inverting input. Further, in this embodiment, the waveform amplification circuit 14 also includes an eighth resistor R8 and a second capacitor C2. One end of the series connection of the eighth resistor R8 and the second capacitor C2 is connected to the output of the second operational amplifier U204, and the other end of the series connection serves as the output of the waveform amplification circuit 14, outputting a therapeutic waveform. Based on the above design, the second operational amplifier U204 and the external resistor constitute a high input impedance amplifier with series voltage negative feedback configuration. It can be used to adapt the output waveform amplitude and suppress the high-frequency interference signal of the bidirectional constant amplitude waveform output by the waveform synthesis circuit 13. After being amplified by the second operational amplifier U204, the treatment waveform can be transmitted to the subsequent circuit in the form of alternating current when used in the medium frequency electrotherapy device through the capacitor, which improves the anti-interference performance of the waveform, isolates the DC component, and makes the waveform bidirectional symmetrical.

[0035] Understandably, both the digital potentiometer U202 and the analog switch S1 can be connected to external controllers to receive intensity adjustment signals, waveform signals, control signals, clock signals, chip select signals, etc., during normal operation. Figure 2 For example, receiving SPI1_MOSI-PB5, DACout1_PA4, PlusA_PB6, SPI1_SCK-PB3, and SPI2_CS-PB1 signals.

[0036] As can be seen from the above, the waveform modulation circuit 10 of this utility model is built with discrete components. The task of generating therapeutic waveforms by microprocessors or FPGAs and other integrated devices in the prior art is decomposed into different tasks and implemented by different hardware architectures in the waveform modulation circuit 10 of this utility model, which can reduce the difficulty and complexity of overall software debugging.

[0037] Reference Figure 5 , Figure 5This is a schematic diagram of the circuit structure of a specific embodiment of the intermediate frequency electrotherapy device of this utility model. In the embodiment shown in the figure, the intermediate frequency electrotherapy device includes a controller 20, a waveform modulation circuit 10, a power amplifier circuit 30, an isolation conversion circuit, and electrode pads P200. The controller 20 is connected to the waveform modulation circuit 10 and is used to generate a waveform signal and an intensity adjustment signal according to an external current setting signal, while simultaneously generating a control signal. The waveform modulation circuit 10 is the waveform modulation circuit described in the above embodiment, used to generate a therapeutic waveform according to the intensity adjustment signal, the waveform signal, and the control signal. The power amplifier circuit 30 is connected to the output terminal of the waveform modulation circuit 10 and is used to control the therapeutic waveform. The signal is amplified; the isolation transformation circuit is connected to the output terminal of the power amplifier circuit 30, and is used to isolate and transform the amplified treatment waveform to obtain the corresponding treatment waveform; specifically, the controller 20 can be implemented using a microcontroller or a single-chip microcomputer, and the isolation transformation circuit includes a transformer T1. The primary side of the transformer T1 is connected to the output terminal of the power amplifier circuit 30, and the secondary side is connected to the electrode plate P200, so that the treatment waveform modulated and output by the waveform modulation circuit 10 drives the transformer T1 through the power amplifier circuit 30, and is applied to the human body through the electrode plate P200 to achieve the purpose of treatment. It can be seen that when the medium frequency electrotherapy instrument of this utility model is used, the electrode plate P200 is attached to the treatment site of the human body. The controller 20 generates a waveform signal and an intensity adjustment signal according to the current setting signal selected by the user (i.e., the external current setting signal), and at the same time generates a control signal. The signals are modulated by each individual circuit module in the waveform modulation circuit 10, then amplified by the power amplifier circuit 30, and then isolated and transformed by the isolation transformation circuit to output the corresponding treatment waveform, which is transmitted to the human body through the electrode plate P200 for treatment.

[0038] Furthermore, in this embodiment, the intermediate frequency electrotherapy device also includes a detection feedback circuit 50. The detection feedback circuit 50 includes a current transformer T201 and a resistor divider circuit 52 (composed of resistors R213 and R218). The primary side of the current transformer T201 is connected to the output terminal of the isolation conversion circuit. The input terminal of the resistor divider circuit 52 is connected to one end of the secondary side of the current transformer T201. The output terminal of the resistor divider circuit 52 is connected to an input pin of the controller 20. The other end of the secondary side of the current transformer T201 is grounded. Based on the above design, the current transformer T201 detects the operating current of the electrode plate P200. The contact impedance between the patient and the electrode is monitored in real time based on the operating current. Treatment output is interrupted when a difference in contact impedance is detected.

[0039] In summary, this invention achieves the generation and modulation of therapeutic waveforms through the combined use of amplitude adjustment circuits, analog switches, waveform synthesis circuits, and waveform amplification circuits. That is, the generation and modulation of therapeutic waveforms are achieved through the collaborative operation of circuit modules built from individual, separate hardware components. The single-module implementation is simpler than the centralized implementation. Furthermore, when this modular waveform modulation circuit is applied to the debugging of the electrotherapy device, the software algorithm focuses on the implementation of single-module functions, and each module can be debugged separately and synchronously, reducing the overall debugging difficulty and increasing the response speed.

[0040] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A waveform modulation circuit, characterized in that, The waveform modulation circuit includes: An amplitude adjustment circuit, connected to an external controller, is used to perform amplitude modulation processing on the input waveform signal according to the intensity adjustment signal from the external controller, so as to obtain an amplitude-modulated waveform signal. An analog switch, connected to the output of an external controller and the amplitude adjustment circuit, is used to generate a fundamental frequency wave based on a control signal from the external controller and the amplitude-modulated waveform signal. A waveform synthesis circuit, connected to the output terminals of the amplitude adjustment circuit and the analog switch, is used to modulate the amplitude-modulated waveform signal and the fundamental frequency wave, and output a bidirectional constant amplitude waveform with the amplitude-modulated waveform signal voltage as the zero point. A waveform amplification circuit, connected to the output of the waveform synthesis circuit, is used to amplify the bidirectional constant amplitude waveform to obtain a therapeutic waveform.

2. The waveform modulation circuit as described in claim 1, characterized in that, The amplitude adjustment circuit includes a digital potentiometer. The input terminal of the digital potentiometer is used to receive waveform signals. The control terminal of the digital potentiometer is connected to an external controller to receive intensity adjustment signals from the external controller and to perform amplitude modulation processing on the received waveform signals according to the intensity adjustment signals to obtain amplitude-modulated waveform signals.

3. The waveform modulation circuit as described in claim 2, characterized in that, The amplitude adjustment circuit further includes a first voltage follower, and the output terminal of the analog switch is also connected to a second voltage follower. The input terminal of the first voltage follower is connected to the output terminal of the digital potentiometer, and the output terminals of both the first and second voltage followers are connected to the waveform synthesis circuit.

4. The waveform modulation circuit as described in claim 1, characterized in that, The waveform synthesis circuit includes a subtractor, which comprises a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, and a ninth resistor. The inverting input of the first operational amplifier is connected to the output of the amplitude adjustment circuit via the first resistor. One end of the ninth resistor is connected to the connection between the first resistor and the first operational amplifier, and the other end of the ninth resistor is grounded. The non-inverting input of the first operational amplifier is connected to the output of the analog switch via the second resistor. The output of the first operational amplifier is connected to its inverting input via the third resistor, and the output of the first operational amplifier serves as the output of the waveform synthesis circuit. One end of the fourth resistor is connected to the connection between the second resistor and the first operational amplifier, and the other end of the fourth resistor is grounded.

5. The waveform modulation circuit as described in claim 1, characterized in that, The analog switch is a single-pole double-throw switch. The selection control terminal of the single-pole double-throw switch is connected to the external controller. The first input terminal and the second input terminal of the single-pole double-throw switch are respectively connected to the output terminal of the amplitude adjustment circuit and ground. The output terminal of the single-pole double-throw switch is connected to the waveform synthesis circuit.

6. The waveform modulation circuit as described in claim 1, characterized in that, The waveform amplification circuit includes a second operational amplifier, a seventh resistor, and a first capacitor. The non-inverting input of the second operational amplifier is connected to the output of the waveform synthesis circuit through a fifth resistor, and the inverting input of the second operational amplifier is grounded through a sixth resistor. The output of the second operational amplifier serves as the output of the waveform amplification circuit. The seventh resistor and the first capacitor are connected in parallel between the output of the second operational amplifier and its inverting input.

7. The waveform modulation circuit as described in claim 6, characterized in that, The waveform amplification circuit also includes an eighth resistor and a second capacitor. One end of the eighth resistor and the second capacitor are connected in series and connected to the output terminal of the second operational amplifier. The other end of the eighth resistor and the second capacitor are connected in series and serve as the output terminal of the waveform amplification circuit to output a therapeutic waveform.

8. A medium-frequency electrotherapy device, characterized in that, The intermediate frequency electrotherapy device includes a controller, a waveform modulation circuit, a power amplifier circuit, and an isolation conversion circuit, wherein... The controller is connected to the waveform modulation circuit and is used to generate waveform signals, intensity adjustment signals and control signals according to the external current setting signal. The waveform modulation circuit is the waveform modulation circuit according to any one of claims 1-7, used to generate a therapeutic waveform according to the intensity adjustment signal, the waveform signal and the control signal; The power amplifier circuit is connected to the output terminal of the waveform modulation circuit and is used to amplify the treatment waveform. The isolation transformation circuit is connected to the output terminal of the power amplifier circuit and is used to perform isolation transformation on the amplified treatment waveform to obtain the corresponding treatment waveform.

9. The intermediate frequency electrotherapy device as described in claim 8, characterized in that, The intermediate frequency electrotherapy device also includes a detection feedback circuit, which includes a current transformer and a resistor voltage divider circuit. The primary side of the current transformer is connected to the output terminal of the isolation conversion circuit. The input terminal of the resistor voltage divider circuit is connected to one end of the secondary side of the current transformer. The output terminal of the resistor voltage divider circuit is connected to an input pin of the controller. The other end of the secondary side of the current transformer is grounded.

10. The intermediate frequency electrotherapy device as described in claim 8, characterized in that, The intermediate frequency electrotherapy device also includes electrode pads, which are connected to the output terminal of the isolation conversion circuit.

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