Intermediate-frequency electro-therapeutic apparatus

Abstract

The invention discloses an intermediate frequency electro-therapeutic apparatus, which comprises a controller and a waveform synthesis circuit, and is characterized in that the waveform synthesis circuit comprises a first amplitude adjusting circuit, a second amplitude adjusting circuit and a synthesis adjusting circuit, and the controller generates a first PWM signal according to the overall amplitude information; the first amplitude adjusting circuit performs amplitude modulation processing on an input original waveform according to the first PWM signal to generate a first analog waveform signal; the controller obtains amplitude information corresponding to the frequency of the modulation waveform by using the phase accumulator, and generates a second PWM signal; a second amplitude adjusting circuit performs multiplication operation on the second PWM signal and the first analog waveform signal to obtain a second analog waveform signal and obtain an inverted waveform signal; the controller obtains amplitude information corresponding to the frequency of the fundamental frequency waveform by using a phase accumulator, and generates a third PWM signal; and the synthesis adjusting circuit performs multiplication operation on the third PWM signal and the second analog waveform signal or the inverted waveform signal to generate an intermediate frequency treatment waveform.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to a medium-frequency electrotherapy apparatus. Background Art

[0002] A medium-frequency electrotherapy device is a medical device that creates an interference field at the intersection of power lines by inputting two alternating currents of different frequencies into the human body, generating pulse currents in deep tissues to relieve pain, exercise muscles, promote blood circulation, soften scars, and loosen adhesions.

[0003] One of the core implementation technologies of medium-frequency interferential electrotherapy devices is to generate a modulated medium-frequency waveform. Currently, this waveform is usually directly generated by a low-frequency modulated waveform through a PWM chopping method generated by a timer. However, this generation method is limited by the timer frequency of the main control chip and has low frequency accuracy. Summary of the Invention

[0004] The present invention provides a medium-frequency electrotherapy instrument, which aims to solve the problem that the low-frequency modulation waveform in the current medium-frequency electrotherapy instrument is directly generated by the PWM chopping method generated by a timer, resulting in the waveform generation rate being limited by the timer frequency of the main control chip and the frequency accuracy being low.

[0005] To solve the above technical problems, the present invention provides a medium-frequency electrotherapy device, comprising: a controller and at least one waveform synthesis circuit connected to the controller, each of the waveform synthesis circuits comprising a first amplitude adjustment circuit, a second amplitude adjustment circuit, and a synthesis adjustment circuit, wherein the medium-frequency electrotherapy device generates a medium-frequency treatment waveform using the following steps:

[0006] The controller obtains the overall amplitude information of the intermediate frequency treatment waveform to be generated, the type and frequency of the modulation waveform, and the frequency of the fundamental frequency waveform according to the external modulation information, and generates a first PWM signal according to the overall amplitude information;

[0007] The first amplitude adjustment circuit performs amplitude modulation processing on the input original waveform according to the first PWM signal to generate an amplitude-modulated first analog waveform signal;

[0008] The controller further uses a phase accumulator in combination with a pre-stored phase-amplitude mapping relationship table corresponding to the acquired type of modulation waveform to obtain amplitude information corresponding to the frequency of the modulation waveform, thereby generating a second PWM signal;

[0009] The second amplitude adjustment circuit performs a multiplication operation on the second PWM signal and the first analog waveform signal, performs amplitude adjustment, obtains a second analog waveform signal, and obtains an inverted waveform signal of the second analog waveform signal;

[0010] The controller further uses the phase accumulator in combination with a pre-stored phase-amplitude mapping relationship table of the fundamental frequency waveform to obtain amplitude information corresponding to the frequency of the fundamental frequency waveform, thereby generating a third PWM signal;

[0011] The synthesis regulation circuit performs a multiplication operation on the third PWM signal and the second analog waveform signal or the inverted waveform signal to generate an intermediate frequency treatment waveform.

[0012] A further technical solution is: using a phase accumulator in combination with a pre-stored phase-amplitude mapping relationship table corresponding to the type of the acquired modulation waveform to obtain amplitude information corresponding to the frequency of the modulation waveform, specifically including:

[0013] Obtaining a corresponding pre-stored phase-amplitude mapping relationship table according to the type of the acquired modulation waveform;

[0014] Using a phase accumulator to accumulate the frequency of the modulation waveform to obtain a phase value of the current modulation waveform cycle;

[0015] The preset number of bits in the phase value is taken as an index, and the obtained phase-amplitude mapping relationship table is queried to obtain the amplitude information of the modulated waveform.

[0016] A further technical solution is: using a phase accumulator to accumulate the frequency of the modulation waveform to obtain the phase value of the current modulation waveform cycle, specifically including:

[0017] Using the phase accumulator, the formula fo=(M*fc) / 2 n Calculate the phase step value M corresponding to the frequency of the modulation waveform, and accumulate the phase step value in each clock cycle to obtain the phase value, thereby obtaining the phase value of the current modulation waveform cycle; where n is the bit width of the phase accumulator, fc is the phase accumulator clock frequency, and fo is the frequency of the modulation waveform.

[0018] A further technical solution is: using the phase accumulator in combination with a pre-stored phase-amplitude mapping relationship table of the fundamental frequency waveform to obtain amplitude information corresponding to the frequency of the fundamental frequency waveform, specifically including:

[0019] Using a phase accumulator to accumulate the frequency of the fundamental frequency waveform to obtain a phase value of the current fundamental frequency waveform period;

[0020] The preset number of bits in the phase value is taken as an index, and a pre-stored phase-amplitude mapping relationship table of the fundamental frequency waveform is searched to obtain the amplitude information of the fundamental frequency waveform.

[0021] Its further technical solution is: the first amplitude adjustment circuit includes a first chopping circuit and a first filtering circuit connected in sequence, the second amplitude adjustment circuit includes a second chopping circuit, a second filtering circuit and an inverter connected in sequence, and the synthetic adjustment circuit includes a third chopping circuit and a third filtering circuit connected in sequence, wherein the first chopping circuit, the second chopping circuit and the third chopping circuit are all connected to the controller and receive the first PWM signal, the second PWM signal and the third PWM signal respectively, the first chopping circuit receives the input original waveform, the second chopping circuit is connected to the output end of the first filtering circuit, and the third chopping circuit is connected to the output end of the second filtering circuit and the inverter.

[0022] A further technical solution is that the first amplitude adjustment circuit performs amplitude modulation processing on the input original waveform according to the first PWM signal to generate an amplitude-modulated first analog waveform signal, specifically including:

[0023] The first chopping circuit performs amplitude modulation processing on the input original waveform according to the first PWM signal to obtain a first analog waveform signal;

[0024] The first analog waveform signal is filtered by the first filtering circuit, and the amplitude-modulated first analog waveform signal is output.

[0025] A further technical solution is as follows: the first chopping circuit includes a first single-pole double-throw analog switch, the second input terminal and the selection control terminal of the first single-pole double-throw analog switch respectively receive the original waveform and the first PWM signal, and the first input terminal is connected to the analog ground, wherein,

[0026] The first chopping circuit performs amplitude modulation processing on the input original waveform according to the first PWM signal to obtain a first analog waveform signal, specifically including:

[0027] The first input terminal and the second input terminal of the first single-pole double-throw analog switch are controlled to switch on and off according to the first PWM signal, so as to adjust the amplitude of the original waveform and obtain a first analog waveform signal.

[0028] A further technical solution is as follows: the second chopping circuit includes a second single-pole double-throw analog switch, the second input terminal and the first input terminal of the second single-pole double-throw analog switch are respectively connected to the output terminal of the first amplitude adjustment circuit and the analog ground, and the selection control terminal of the second single-pole double-throw analog switch is connected to the controller, wherein,

[0029] The second amplitude adjustment circuit performs a multiplication operation on the second PWM signal and the first analog waveform signal to perform amplitude adjustment to obtain a second analog waveform signal, and obtains an inverted waveform signal of the second analog waveform signal, specifically including:

[0030] controlling the switching of the first input terminal and the second input terminal of the second single-pole double-throw analog switch according to the second PWM signal to implement a multiplication operation of the second PWM signal and the first analog waveform signal to obtain a preliminary second analog waveform signal;

[0031] filtering the preliminary second analog waveform signal through a second filtering circuit to obtain a second analog waveform signal;

[0032] The second analog waveform signal obtained after filtering is inverted by an inverter to obtain an inverted waveform signal.

[0033] A further technical solution is as follows: the third chopping circuit includes a third single-pole double-throw analog switch, wherein the first input terminal and the second input terminal of the third single-pole double-throw analog switch are respectively connected to the second filter circuit and the output terminal of the inverter, and the selection control terminal of the third single-pole double-throw analog switch is connected to the controller, wherein:

[0034] The synthesis regulation circuit performs a multiplication operation on the third PWM signal and the second analog waveform signal or the inverted waveform signal to generate an intermediate frequency treatment waveform, specifically including:

[0035] Controlling the switching of the first input terminal and the second input terminal of the third single-pole double-throw analog switch according to the third PWM signal to select the second analog waveform signal and the inverted waveform signal to generate a preliminary intermediate frequency treatment waveform;

[0036] The preliminary intermediate frequency treatment waveform is filtered by the third filter circuit to obtain an intermediate frequency treatment waveform for treatment.

[0037] Its further technical solution is: the model of the controller is STM32F103VC.

[0038] Compared with the prior art, the controller in the medium frequency electrotherapy device of the present invention uses a phase accumulation method to control the generation of modulation waveforms and baseband waveforms. The generation rate is not controlled by the timer in the controller, and higher frequency accuracy can be achieved. At the same time, multiplication operations are performed through the first amplitude adjustment circuit, the second amplitude adjustment circuit and the synthesis adjustment circuit. The coordination of the three hardware circuits and the controller realizes the modulation generation of the medium frequency treatment waveform. The controller does not need to be generated entirely by software, which can reduce the computing power required for the medium frequency electrotherapy device to synthesize the medium frequency treatment waveform. One controller can realize the modulation generation of multiple groups of medium frequency treatment waveforms, so that the medium frequency electrotherapy device of the present invention can support multi-channel treatment and the cost is also relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 It is a structural schematic diagram of a specific embodiment of the medium-frequency electrotherapy device of the present invention.

[0041] Figure 2 It is a schematic diagram of the process of generating a medium frequency treatment waveform by the medium frequency electrotherapy apparatus of the present invention.

[0042] Figure 3 It is a schematic diagram of the specific circuit structure of the first amplitude adjustment circuit and the second amplitude adjustment circuit in the waveform synthesis circuit of the medium frequency electrotherapy device of the present invention.

[0043] Figure 4 The present invention is a schematic diagram of the specific circuit structure of the synthesis adjustment circuit in the waveform synthesis circuit of the medium frequency electrotherapy device.

[0044] Figure 5 It is a waveform diagram of the waveform generation process in the medium frequency electrotherapy device of the present invention. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0046] Reference Figures 1 to 4 , Figures 1 to 4A specific embodiment of the medium-frequency electrotherapy device of the present invention is shown. In the embodiment shown in the accompanying drawings, the medium-frequency electrotherapy device includes a controller and at least one waveform synthesis circuit connected to the controller. Each waveform synthesis circuit includes a first amplitude adjustment circuit 11, a second amplitude adjustment circuit 12, and a synthesis adjustment circuit 13. Preferably, in this embodiment, the controller pre-stores a phase-amplitude mapping relationship table corresponding to different modulation waveforms and a phase-amplitude mapping relationship table of the fundamental frequency waveform; and the first amplitude adjustment circuit 11 includes a first chopping circuit 111 and a first filtering circuit 112 connected in sequence, the second amplitude adjustment circuit 12 includes a second chopping circuit 121, a second filtering circuit 122 and an inverter 123 connected in sequence, and the synthesis adjustment circuit 13 includes a third chopping circuit 131 and a third filtering circuit 132 connected in sequence, wherein the first chopping circuit 111, the second chopping circuit 121 and the third chopping circuit 131 are all connected to the controller, the second chopping circuit 121 is connected to the output end of the first filtering circuit 112, and the third chopping circuit 131 is connected to the output end of the second filtering circuit 122 and the inverter 123. It can be understood that the controller is composed of an MCU, a timer, and some peripheral circuits. In this embodiment, the MCU generates a first PWM signal, a second PWM signal, and a third PWM signal according to external modulation information, and outputs them to the first chopping circuit 111, the second chopping circuit 121, and the third chopping circuit 131 respectively through the x-th PWM output channel TIMx PWM CHx of the timer x; and the MCU can simultaneously process the signal generation of multiple groups of intermediate frequency treatment waveforms. In this embodiment, Figure 1 Only one waveform synthesis circuit is shown, but in some other embodiments, there may be multiple corresponding waveform synthesis circuits to support multi-channel therapy.

[0047] Combine Figure 2 The intermediate frequency electrotherapy device generates the intermediate frequency treatment waveform, which includes the following steps:

[0048] S101. The controller obtains overall amplitude information of a to-be-generated intermediate frequency therapeutic waveform, the type and frequency of the modulation waveform, and the frequency of the fundamental frequency waveform according to external modulation information, and generates a first PWM signal according to the overall amplitude information.

[0049] In this embodiment, the external modulation information includes the overall amplitude and frequency of the intermediate frequency treatment waveform to be generated, the type and frequency of the modulation waveform, and / or the frequency of the fundamental frequency waveform.

[0050] In this step, the first PWM signal is a digital signal that transmits the overall amplitude information a of the modulated intermediate frequency waveform in the form of a duty cycle.

[0051] S102 : The first amplitude adjustment circuit 11 performs amplitude modulation on the input original waveform according to the first PWM signal to generate an amplitude-modulated first analog waveform signal.

[0052] In the present invention, the original waveform may be generated by a controller or an external waveform generating device.

[0053] Specifically, this step includes: the first chopping circuit 111 performs amplitude modulation processing on the input original waveform according to the first PWM signal to obtain a first analog waveform signal; the first filtering circuit 112 filters the first analog waveform signal and outputs the amplitude modulated first analog waveform signal.

[0054] In this embodiment, Figure 3 As shown, the first chopping circuit 111 includes a first single-pole double-throw analog switch U101, and the second input terminal (pin 1) and the selection control terminal of the first single-pole double-throw analog switch U101 respectively receive the original waveform and the first PWM signal, and the first input terminal thereof is connected to the analog ground AGND. Then, the first chopping circuit 111 performs amplitude modulation processing on the input original waveform according to the first PWM signal to obtain a first analog waveform signal, specifically including: controlling the selection switching of the first input terminal and the second input terminal of the first single-pole double-throw analog switch U101 according to the first PWM signal PWM-STR1 to achieve amplitude adjustment of the original waveform to obtain the first analog waveform signal.

[0055] Preferably, the first filtering circuit 112 is an RC low-pass filtering circuit, such as Figure 3 As shown, the first filtering circuit 112 includes a fourth-order RC filtering circuit 1121, a first operational amplifier U1A, a resistor R123, a resistor R125 and a capacitor C101, wherein the non-inverting input terminal of the first operational amplifier U1A is connected to the output terminal of the fourth-order RC filtering circuit 1121, the input terminal of the fourth-order RC filtering circuit 1121 is connected to the output terminal of the first single-pole double-throw analog switch U101, and the inverting input terminal of the first operational amplifier U1A is connected to its output terminal; one end of the resistor R125 and the resistor R123 are both connected to the output terminal of the first operational amplifier U1A, and the other end of the resistor R125 is connected to one end of the capacitor C101 and serves as the output terminal of the first amplitude adjustment circuit 11, outputting the first analog waveform signal AS-MOD (with an amplitude of U REF *a analog signal) to the second amplitude adjustment circuit 12, and the other ends of the capacitor C101 and the resistor R123 are grounded.

[0056] S103 : The controller uses a phase accumulator in combination with a pre-stored phase-amplitude mapping table corresponding to the acquired modulation waveform type to obtain amplitude information corresponding to the frequency of the modulation waveform, thereby generating a second PWM signal.

[0057] This step specifically includes: obtaining a corresponding pre-stored phase-amplitude mapping table based on the acquired modulation waveform type; utilizing a phase accumulator to accumulate the modulation waveform's frequency to obtain a phase value for the current modulation waveform cycle; and using a preset number of bits in the phase value as an index to query the obtained phase-amplitude mapping table to obtain the amplitude information of the modulation waveform. It is understood that the pre-stored phase-amplitude mapping table for the modulation waveform records the corresponding digital amplitude information for a complete cycle of different types of modulation waveforms.

[0058] In this embodiment, the phase accumulator is used to accumulate the frequency of the modulation waveform to obtain the phase value of the current modulation waveform cycle, specifically including: using the phase accumulator to use the formula fo = (M*fc) / 2 n Calculate the phase step value M corresponding to the frequency of the modulation waveform, and accumulate the phase step value in each clock cycle to obtain the phase value, thereby obtaining the phase value of the current modulation waveform cycle; where n is the bit width of the phase accumulator, fc is the phase accumulator clock frequency, and fo is the output frequency of the modulation waveform.

[0059] Preferably, the controller model is STM32F103VC, and the phase accumulator clock frequency fc is 7.2kHz. Since STM32F103VC is a 32-bit core microcontroller, in this embodiment, the first 8 bits are used to output the cycle count to record how many cycles are output in total. The bit width n of the phase accumulator is the last 24 bits, that is, n is 24 bits, and the phase step value M is the value of each cumulative count. It can be understood that the minimum step value is fc / 2 n , that is, the frequency accuracy is 7.2kHz / (2^ 24 )≈4.29*10^- 4 Hz.

[0060] In this embodiment, the preset number of bits is the first 7 bits of the phase point, that is, the 9th to 15th phase of the phase accumulation count, and the amplitude information of the modulated waveform is obtained by looking up the value in the corresponding phase-amplitude mapping relationship table. Thus, a second PWM signal is generated. The second PWM signal is a digital signal that transmits the amplitude information of the modulated waveform in the form of a duty cycle. The frequency of the second PWM signal can be 0.1 Hz to 150 Hz. When the highest frequency is 150 Hz, there will be at least 7.2 kHz / 150 Hz=48 data points in each cycle, and the modulation waveform has good quality.

[0061] Understandably, simple logical judgments can also be performed during each phase accumulation calculation to control the switching between different modulation waveforms required for different treatment effects, that is, the modulation waveforms can be switched according to the different modulation waveforms selected by the user within a treatment cycle. For example, if the modulation waveforms in the current treatment cycle are set to b B modulation waveforms and c C modulation waveforms, the number of current modulation waveforms output is accumulated. If the number of modulation waveforms obtained by the accumulated calculation is greater than or equal to b, the modulation waveform is switched to the C modulation waveform. According to the pre-stored phase-amplitude mapping relationship table corresponding to the switched modulation waveform type, the amplitude information corresponding to the frequency of the C modulation waveform is obtained, and the count is cleared at the same time. The number of current modulation waveforms output is accumulated again until c C modulation waveforms are output.

[0062] S104 , the second amplitude adjustment circuit 12 performs a multiplication operation on the second PWM signal and the first analog waveform signal, performs amplitude adjustment, obtains a second analog waveform signal, and acquires an inverted waveform signal of the second analog waveform signal.

[0063] In this embodiment, Figure 3 As shown, the second chopping circuit 121 includes a second single-pole double-throw analog switch U103, the second input terminal and the first input terminal of the second single-pole double-throw analog switch U103 are respectively connected to the output terminal of the first amplitude adjustment circuit 11 and the analog ground AGND, and the selection control terminal of the second single-pole double-throw analog switch U103 is connected to the controller to receive the second PWM signal PWM-MOD1; then, step S104 specifically includes:

[0064] The first input terminal and the second input terminal of the second single-pole double-throw analog switch U103 are controlled to be switched on and off according to the second PWM signal to implement a multiplication operation of the second PWM signal and the first analog waveform signal to obtain a preliminary second analog waveform signal; the preliminary second analog waveform signal is filtered by the second filtering circuit 122 to obtain a second analog waveform signal; the second analog waveform signal obtained after filtering is inverted by the inverter 123 to obtain an inverted waveform signal.

[0065] In this embodiment, the second filtering circuit 122 is also an RC low-pass filtering circuit. Specifically, the second filtering circuit 122 includes a fourth-order RC filtering circuit 1221, a second operational amplifier U3A, a resistor R128, a resistor R132 and a capacitor C107. The non-inverting input terminal of the second operational amplifier U3A is connected to the output terminal of the fourth-order RC filtering circuit 1221, the input terminal of the fourth-order RC filtering circuit 1221 is connected to the output terminal of the second single-pole double-throw analog switch U103, the inverting input terminal of the second operational amplifier U3A is connected to its output terminal, one end of the resistor R128 and the resistor R132 are both connected to the output terminal of the second operational amplifier U3A, the other end of the resistor R132 is connected to one end of the capacitor C107, and serves as the output of the second amplitude adjustment circuit 12, outputting the second analog waveform signal AS-NMOD1 (amplitude is The output of the inverter 123 is also used as the output of the second amplitude adjustment circuit 12, outputting the inverted waveform signal AS-MOD1 (amplitude of the second analog waveform signal) analog signal).

[0066] S105 , the controller uses the phase accumulator in combination with a pre-stored phase-amplitude mapping relationship table of the fundamental frequency waveform to obtain amplitude information corresponding to the frequency of the fundamental frequency waveform, thereby generating a third PWM signal.

[0067] In this embodiment, the third PWM signal can transmit the amplitude information of the baseband waveform signal in the form of duty cycle. The phase-amplitude mapping relationship table of the fundamental frequency waveform records the corresponding digital amplitude information of a complete sine wave cycle.

[0068] This step specifically includes: using a phase accumulator to accumulate the frequency of the fundamental frequency waveform to obtain the phase value of the current fundamental frequency waveform period; taking the preset number of bits in the phase value as an index, querying a pre-stored phase-amplitude mapping relationship table of the fundamental frequency waveform, and obtaining the amplitude information of the fundamental frequency waveform.

[0069] In this step, the frequency of the fundamental frequency waveform is accumulated and calculated by using the phase accumulator to obtain the phase value of the current fundamental frequency waveform cycle, which specifically includes: using the phase accumulator to use the formula fo=(M*fc) / 2 n Calculate the phase step value M corresponding to the frequency of the fundamental waveform, and accumulate the phase step value in each clock cycle to obtain a phase value, thereby obtaining the phase value of the current fundamental waveform cycle; where n is the bit width of the phase accumulator, fc is the phase accumulator clock frequency, and fo is the frequency of the fundamental waveform.

[0070] In this embodiment, the bit width n of the phase accumulator is 32 bits, fc is 70.3kHz, and its frequency accuracy is 70.3kHz / (2^ 32 )≈1.64*10^ -5 Hz, the preset number of digits is the first 9 digits of the current phase point, and the amplitude information of the fundamental frequency waveform is obtained by looking up the value in the corresponding phase-amplitude mapping relationship table This generates a 1 kHz to 11 kHz intermediate frequency sinusoidal waveform, ie, the third PWM signal.

[0071] S106 , the synthesis adjustment circuit 13 performs a multiplication operation on the third PWM signal and the second analog waveform signal or the inverted waveform signal to generate an intermediate frequency treatment waveform.

[0072] In this embodiment, Figure 4 As shown, the third chopping circuit 131 includes a third single-pole double-throw analog switch U105, wherein a first input terminal and a second input terminal of the third single-pole double-throw analog switch U105 are respectively connected to the second filter circuit 122 and the output terminal of the inverter 123, and a selection control terminal of the third single-pole double-throw analog switch U105 is connected to the controller to receive the second PWM signal PWM-CAR1; then, step S106 specifically includes:

[0073] According to the third PWM signal, the first input terminal and the second input terminal of the third single-pole double-throw analog switch U105 are controlled to switch on and off to realize the selection of the second analog waveform signal and the inverted waveform signal, thereby generating a preliminary intermediate frequency treatment waveform; the preliminary intermediate frequency treatment waveform is filtered by the third filtering circuit 132 to obtain the intermediate frequency treatment waveform for treatment.

[0074] Specifically, the third filtering circuit 132 includes two low-pass filters 1321 connected in sequence. In this embodiment, the low-pass filter is a SallenKey low-pass filter, which uses a two-stage SallenKey low-pass filter to output an analog signal AS-MS1 (amplitude is analog signal), that is, the intermediate frequency treatment waveform.

[0075] In this embodiment, the first single-pole double-throw analog switch U101, the second single-pole double-throw analog switch U103, and the third single-pole double-throw analog switch U105 may be of model SGM3157, and the analog ground AGND may be at a voltage of 2.5 V. In the waveform synthesis circuit of the present invention, the first amplitude adjustment circuit 11, the second amplitude adjustment circuit 12, and the synthesis adjustment circuit 13 respectively receive the first PWM signal, the second PWM signal, and the third PWM signal generated by the controller, and perform multiplication operations in a manner of chopping and then low-pass filtering. The waveform of the synthesis path is shown in the following example. Figure 5 As shown:

[0076] To sum up, the medium frequency electrotherapy instrument of the present invention controls the output waveform by phase accumulation, and its frequency accuracy is extremely high. It can also be combined with a waveform synthesis circuit to perform low-frequency amplitude modulation of any modulated waveform. That is, the controller in the medium frequency electrotherapy instrument uses phase accumulation to control the generation of modulated waveforms and baseband waveforms. The generation rate is not controlled by the timer in the controller, and higher frequency accuracy can be achieved. At the same time, multiplication operations are performed through the first amplitude adjustment circuit, the second amplitude adjustment circuit and the synthesis adjustment circuit. The coordination of the three hardware circuits and the controller realizes the modulation generation of the medium frequency treatment waveform. The controller does not need to be generated entirely by software, which can reduce the computing power required for the medium frequency electrotherapy instrument to synthesize the medium frequency treatment waveform. One controller can realize the modulation generation of multiple groups of medium frequency treatment waveforms, so that the medium frequency electrotherapy instrument of the present invention can support multi-channel treatment, and the main hardware circuit is composed of a controller, an analog switch, an integrated operational amplifier, resistors and capacitors, and the cost is relatively low.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention 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 the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A medium frequency electrotherapy device, characterized in that: The intermediate frequency electrotherapy device includes a controller and at least one waveform synthesis circuit connected to the controller, each of the waveform synthesis circuits includes a first amplitude adjustment circuit, a second amplitude adjustment circuit, and a synthesis adjustment circuit, wherein the intermediate frequency electrotherapy device generates an intermediate frequency treatment waveform using the following steps: The controller obtains the overall amplitude information of the intermediate frequency treatment waveform to be generated, the type and frequency of the modulation waveform, and the frequency of the fundamental frequency waveform according to the external modulation information, and generates a first PWM signal according to the overall amplitude information; The first amplitude adjustment circuit performs amplitude modulation processing on the input original waveform according to the first PWM signal to generate an amplitude-modulated first analog waveform signal; The controller further uses a phase accumulator in combination with a pre-stored phase-amplitude mapping relationship table corresponding to the acquired type of modulation waveform to obtain amplitude information corresponding to the frequency of the modulation waveform, thereby generating a second PWM signal; The second amplitude adjustment circuit performs a multiplication operation on the second PWM signal and the first analog waveform signal, performs amplitude adjustment, obtains a second analog waveform signal, and obtains an inverted waveform signal of the second analog waveform signal; The controller further uses the phase accumulator in combination with a pre-stored phase-amplitude mapping relationship table of the fundamental frequency waveform to obtain amplitude information corresponding to the frequency of the fundamental frequency waveform, thereby generating a third PWM signal; The synthesis regulation circuit performs a multiplication operation on the third PWM signal and the second analog waveform signal or the inverted waveform signal to generate an intermediate frequency treatment waveform.

2. The medium frequency electrotherapy apparatus according to claim 1, characterized in that: The method of using a phase accumulator in combination with a pre-stored phase-amplitude mapping relationship table corresponding to the type of the acquired modulation waveform to obtain amplitude information corresponding to the frequency of the modulation waveform specifically includes: Obtaining a corresponding pre-stored phase-amplitude mapping relationship table according to the type of the acquired modulation waveform; Using a phase accumulator to accumulate the frequency of the modulation waveform to obtain a phase value of the current modulation waveform cycle; The preset number of bits in the phase value is taken as an index, and the obtained phase-amplitude mapping relationship table is queried to obtain the amplitude information of the modulated waveform.

3. The medium frequency electrotherapy apparatus according to claim 2, characterized in that: The step of using a phase accumulator to accumulate the frequency of the modulation waveform to obtain a phase value of a current modulation waveform cycle specifically includes: Using the phase accumulator, the formula fo=(M*fc) / 2 n Calculate the phase step value M corresponding to the frequency of the modulation waveform, and accumulate the phase step value in each clock cycle to obtain the phase value, thereby obtaining the phase value of the current modulation waveform cycle; where n is the bit width of the phase accumulator, fc is the phase accumulator clock frequency, and fo is the frequency of the modulation waveform.

4. The medium frequency electrotherapy apparatus according to claim 1, wherein: The method of using a phase accumulator in combination with a pre-stored phase-amplitude mapping relationship table of a fundamental frequency waveform to obtain amplitude information corresponding to the frequency of the fundamental frequency waveform specifically includes: Using a phase accumulator to accumulate the frequency of the fundamental frequency waveform to obtain a phase value of the current fundamental frequency waveform period; The preset number of bits in the phase value is taken as an index, and a pre-stored phase-amplitude mapping relationship table of the fundamental frequency waveform is searched to obtain the amplitude information of the fundamental frequency waveform.

5. The medium frequency electrotherapy apparatus according to claim 1, characterized in that: The first amplitude adjustment circuit includes a first chopping circuit and a first filtering circuit connected in sequence, the second amplitude adjustment circuit includes a second chopping circuit, a second filtering circuit and an inverter connected in sequence, and the synthesis adjustment circuit includes a third chopping circuit and a third filtering circuit connected in sequence, wherein the first chopping circuit, the second chopping circuit and the third chopping circuit are all connected to the controller and receive the first PWM signal, the second PWM signal and the third PWM signal respectively, the first chopping circuit receives the input original waveform, the second chopping circuit is connected to the output end of the first filtering circuit, and the third chopping circuit is connected to the output end of the second filtering circuit and the inverter.

6. The medium frequency electrotherapy apparatus according to claim 5, characterized in that: The first amplitude adjustment circuit performs amplitude modulation processing on the input original waveform according to the first PWM signal to generate an amplitude-modulated first analog waveform signal, specifically including: The first chopping circuit performs amplitude modulation processing on the input original waveform according to the first PWM signal to obtain a first analog waveform signal; The first analog waveform signal is filtered by the first filtering circuit, and the amplitude-modulated first analog waveform signal is output.

7. The medium frequency electrotherapy apparatus according to claim 6, characterized in that: The first chopping circuit includes a first single-pole double-throw analog switch, wherein the second input terminal and the selection control terminal of the first single-pole double-throw analog switch receive the original waveform and the first PWM signal respectively, and the first input terminal is connected to the analog ground, wherein: The first chopping circuit performs amplitude modulation processing on the input original waveform according to the first PWM signal to obtain a first analog waveform signal, specifically including: The first input terminal and the second input terminal of the first single-pole double-throw analog switch are controlled to switch on and off according to the first PWM signal, so as to adjust the amplitude of the original waveform and obtain a first analog waveform signal.

8. The medium frequency electrotherapy apparatus according to claim 5, characterized in that: The second chopping circuit includes a second single-pole double-throw analog switch, wherein the second input terminal and the first input terminal of the second single-pole double-throw analog switch are respectively connected to the output terminal of the first amplitude adjustment circuit and the analog ground, and the selection control terminal of the second single-pole double-throw analog switch is connected to the controller, wherein: The second amplitude adjustment circuit performs a multiplication operation on the second PWM signal and the first analog waveform signal to perform amplitude adjustment to obtain a second analog waveform signal, and obtains an inverted waveform signal of the second analog waveform signal, specifically including: controlling the switching of the first input terminal and the second input terminal of the second single-pole double-throw analog switch according to the second PWM signal to implement a multiplication operation of the second PWM signal and the first analog waveform signal to obtain a preliminary second analog waveform signal; filtering the preliminary second analog waveform signal through a second filtering circuit to obtain a second analog waveform signal; The second analog waveform signal obtained after filtering is inverted by an inverter to obtain an inverted waveform signal.

9. The medium frequency electrotherapy apparatus according to claim 8, characterized in that: The third chopping circuit includes a third single-pole double-throw analog switch, wherein the first input terminal and the second input terminal of the third single-pole double-throw analog switch are respectively connected to the second filter circuit and the output terminal of the inverter, and the selection control terminal of the third single-pole double-throw analog switch is connected to the controller, wherein: The synthesis regulation circuit performs a multiplication operation on the third PWM signal and the second analog waveform signal or the inverted waveform signal to generate an intermediate frequency treatment waveform, specifically including: Controlling the switching of the first input terminal and the second input terminal of the third single-pole double-throw analog switch according to the third PWM signal to select the second analog waveform signal and the inverted waveform signal to generate a preliminary intermediate frequency treatment waveform; The preliminary intermediate frequency treatment waveform is filtered by the third filter circuit to obtain an intermediate frequency treatment waveform for treatment.

10. The medium frequency electrotherapy apparatus according to claim 1, characterized in that: The model of the controller is STM32F103VC.

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