Load detection circuit of physiotherapy instrument and terahertz intermediate-frequency physiotherapy instrument

Abstract

The utility model discloses a physiotherapy instrument load detection circuit and a terahertz intermediate frequency physiotherapy instrument using the physiotherapy instrument load detection circuit. The electric pulse output circuit of the terahertz intermediate-frequency physiotherapy instrument comprises a direct-current pulse output circuit and an alternating-current pulse output circuit, the direct-current pulse output circuit and the alternating-current pulse output circuit both output direct-current pulses to human skin, and the positive half cycle of the alternating-current pulses of the alternating-current pulse output circuit flows out of the positive end of the electric pulse output circuit and flows to the human skin through the skin contact end. The alternating current pulse flows from the human skin to the skin contact end and the positive clamping diode and then flows back to the negative end of the electric pulse output circuit, and the negative half cycle of the alternating current pulse flows out from the negative end of the electric pulse output circuit, flows through the reverse clamping diode and the skin contact end to the human skin, flows from the human skin to the skin contact end and then flows back to the positive end of the electric pulse output circuit. Therefore, an alternating current pulse loop is formed, and the terahertz intermediate-frequency physiotherapy instrument can maintain a continuous working state under the direct current pulse and the alternating current pulse.

Description

TECHNICAL FIELD

[0001] The utility model relates to physiotherapy instrument technical field especially, relates to a kind of physiotherapy instrument load detection circuit and the terahertz intermediate frequency physiotherapy instrument of application of this physiotherapy instrument load detection circuit. BACKGROUND

[0002] Terahertz wave refers to the electromagnetic wave in the frequency range of 0.1-10 THz. Intermediate frequency terahertz wave can penetrate human skin and directly act on deep tissues, promoting the growth and proliferation of some cells in the human body. The terahertz intermediate frequency physiotherapy instrument for skin physiotherapy outputs an electric pulse to the skin by contacting the human skin, thereby achieving the effects of relieving pain, relieving inflammation, and promoting blood circulation. The physiotherapy instrument is provided with an electric pulse output circuit, which has a positive terminal and a negative terminal. The positive terminal of the electric pulse output circuit is connected to a skin contact terminal for contact physiotherapy of the human skin. The human skin is the load of the physiotherapy instrument. In order to detect whether the load exists, the skin contact terminal is also connected to a physiotherapy instrument load detection circuit. The physiotherapy instrument load detection circuit includes an optocoupler and a load detection terminal. One end of the input terminal of the optocoupler is connected to the negative terminal of the electric pulse output circuit, and the other end is connected to the skin contact terminal. The output terminal of the optocoupler is connected to the load detection terminal. The positive terminal of the electric pulse output circuit outputs a direct current pulse. The direct current pulse flows through the skin contact terminal to the human skin and then flows back to the negative terminal of the electric pulse output circuit through the optocoupler, forming a loop. The physiotherapy instrument can output a direct current pulse to the human skin. The direct current pulse flowing through the optocoupler makes the optocoupler conductive. If the signal output from the load detection terminal to the controller is identified as detecting the conduction of the optocoupler, the controller determines that the load exists and the physiotherapy instrument is working normally. The optocoupler in the prior art is composed of a forward-conducting light-emitting diode and a photosensitive tube. The light-emitting diode of the optocoupler cannot be turned on by an alternating current pulse, and an alternating current pulse loop cannot be formed, resulting in that the physiotherapy instrument cannot work continuously under alternating current pulse, limiting the use of the physiotherapy instrument. SUMMARY

[0003] The technical problem to be solved by the utility model is to provide a physiotherapy instrument load detection circuit applied to a terahertz intermediate frequency physiotherapy instrument. The terahertz intermediate frequency physiotherapy instrument can maintain a continuous working state under direct current pulse and alternating current pulse.

[0004] In order to solve the above technical problems, the utility model provides a kind of terahertz intermediate frequency physiotherapy apparatus, including controller and respectively with the electric pulse output circuit and load detection circuit for detecting whether load exists of electric connection of the controller, further include the contact skin end for the contact physiotherapy of human skin load, the contact skin end includes terminal 1 and terminal 3;Terminal 1 connects the positive pole of the output end of electric pulse output circuit, the negative pole of the output end of electric pulse output circuit is grounded;Terminal 3 connects the input end of load detection circuit;The load detection circuit includes the anode of forward rectifier diode D6, optocoupler U5 and load detection terminal LOAD_DETECTION1 connected in turn, the load detection terminal LOAD_DETECTION1 is electrically connected controller, further include the clamping circuit between terminal 3 and the intermediate node of forward rectifier diode D6 to ground, the clamping circuit includes two groups of diodes in parallel, one group is a plurality of series forward clamping diodes, another group is a plurality of series reverse clamping diodes, the model and quantity of the two groups of diodes are identical;Terminal 3 is connected with the anode of forward clamping diode, the cathode of reverse clamping diode and the anode of forward rectifier diode D6 respectively;Optocoupler U5 includes the light-emitting diode arranged at input, the anode of the light-emitting diode is connected with the cathode of forward rectifier diode D6, and the cathode of the light-emitting diode is grounded;The negative pole of the output end of electric pulse output circuit, the ground of clamping circuit and the cathode of the light-emitting diode of optocoupler U5 are common.

[0005] Further, the electric pulse output circuit includes amplitude modulation input circuit, frequency modulation input circuit and transformer circuit, the input end of the amplitude modulation input circuit and the frequency modulation input circuit is electrically connected with the controller respectively to receive PWM control signal, and the output end of the amplitude modulation input circuit and the frequency modulation input circuit is shared;The transformer circuit includes step-up transformer, one end of the input side of the step-up transformer is used to connect power supply, and the other end is connected with the shared output end through NPN power tube Q6, specifically: the base of the NPN power tube Q6 is connected with the shared output end, the collector of the NPN power tube Q6 is connected with step-up transformer, and the emitter of the NPN power tube Q6 is grounded;The output end of the step-up transformer is used as the output end of the electric pulse output circuit.

[0006] Further, the amplitude modulation input circuit is connected with the controller through amplitude modulation signal input terminal Voltage_PWM1, and includes resistance R29, charge and discharge capacitor C10 and the base of NPN triode tube Q5 with model S8050 connected in turn, the charge and discharge capacitor C10 is used to drive triode Q5, and the higher the discharge voltage of the charge and discharge capacitor C10, the more sufficient the conduction of NPN triode tube Q5.

[0007] Further, the amplitude modulation input circuit is connected with the controller through a frequency modulation signal input terminal Frequency_PWM1, which comprises a resistor R30 and a base of a PNP triode Q8 with a model number of S8550 connected in sequence; an emitter of the PNP triode Q8 is connected with an emitter of an NPN triode Q5 of the amplitude modulation input circuit; a collector of the PNP triode Q8 is connected to a base of the NPN power triode Q6 as the common output terminal through a resistor R31.

[0008] Further, the voltage transformation circuit comprises a spike absorption circuit connected between two ends of an input side of the voltage boosting transformer, the spike absorption circuit comprises a diode D2, a resistor R32 and a capacitor C14, the resistor R32 and the capacitor C14 are connected in parallel and then connected with a negative electrode of the diode D2, and a positive electrode of the diode D2 is connected with a collector of the NPN power triode Q6.

[0009] Further, the NPN power triode Q6 is specifically a triode with a model number of BU508A.

[0010] Further, a transient voltage suppressor TVS4 with a model number of SMBJ300CA_C57661 is connected between the wiring terminal 1 and the wiring terminal 3 of the skin end.

[0011] The utility model also provides a kind of physiotherapy instrument load detection circuit, like the load detection circuit of above-mentioned terahertz intermediate frequency physiotherapy instrument.

[0012] Further, the load detection circuit receives pulse signal from the electric pulse output circuit, and the pulse signal is direct current signal or alternating current signal.

[0013] Further, the load detection circuit receives alternating current signal as pulse signal from the electric pulse output circuit;If current skin end is not connected with load, then the load detection terminal LOAD_DETECTION1 outputs high level to the controller;If current skin end is connected with load, then the load detection terminal LOAD_DETECTION1 outputs alternating current waveform of alternating current signal received from the electric pulse output circuit to the controller.

[0014] Further, the waveform of the alternating current signal includes triangular wave, sine wave, trapezoidal wave or pulse wave.

[0015] The terahertz intermediate frequency physiotherapy instrument is used, the operation contact skin end contacts the human body skin, if the electric pulse output circuit is a direct current electric pulse output circuit, the direct current electric pulse will be output from the electric pulse output circuit positive output, flow through the contact skin end to the human body skin, and then flow from the human body skin to the contact skin end, the forward clamping diode and then flow back to the electric pulse output circuit negative end, so as to form a direct current electric pulse loop, and the physiotherapy instrument can output the direct current electric pulse to the human body skin; if the electric pulse output circuit is an alternating current electric pulse output circuit, the positive half cycle of the alternating current electric pulse will flow out from the electric pulse output circuit positive end, flow through the contact skin end to the human body skin, and then flow from the human body skin to the contact skin end, the forward clamping diode and then flow back to the electric pulse output circuit negative end, the negative half cycle of the alternating current electric pulse will flow out from the electric pulse output circuit negative end, flow through the reverse clamping diode, the contact skin end to the human body skin, and then flow from the human body skin to the contact skin end and then flow back to the electric pulse output circuit positive end, so as to form an alternating current electric pulse loop, and the physiotherapy instrument can output the direct current electric pulse to the human body skin. The load detection process is as follows: the electric pulse flows from the contact skin end to the forward rectifier diode D6 to filter out the negative half cycle rectification, and then flows to the optocoupler U5 to make the optocoupler U5 conductive, the load detection terminal transmits the corresponding waveform signal to the controller, and the controller detects that the optocoupler U5 is conductive, so as to identify that the load exists, and judge that the physiotherapy instrument works normally under the current alternating current electric pulse working state. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the overall circuit principle diagram of the physiotherapy instrument.

[0017] Figure 2 It is the electric pulse output circuit principle diagram of the physiotherapy instrument.

[0018] Figure 3 It is the load detection circuit principle diagram of the physiotherapy instrument. DETAILED DESCRIPTION

[0019] The application will be further described in detail in combination with the specific embodiments.

[0020] The terahertz intermediate frequency physiotherapy instrument of the embodiment comprises a controller (the controller of the embodiment is an MCU) and a plurality of groups of treatment units connected with the controller, each group of treatment units is like Figure 1As shown, the device comprises an electric pulse output circuit and a load detection circuit electrically connected with the controller respectively, and a skin contact end for contact therapy on human skin load. The skin contact end is specifically a HDGC3963WV-3P wire pair board needle base for plugging contact electrode sheet and other skin contact devices. The skin contact end comprises a terminal 1 and a terminal 3, and a transient voltage suppressor TVS4 with a model of SMBJ300CA_C57661 is connected between the terminal 1 and the terminal 3 of the skin contact end to realize electrostatic and surge protection. The terminal 1 is connected with the positive pole of the output end of the electric pulse output circuit, and the negative pole of the output end of the electric pulse output circuit is grounded. The terminal 3 is connected with the input end of the load detection circuit. The load detection circuit comprises a forward rectifier diode D6, an optical coupler U5 and a load detection terminal LOAD_DETECTION1 connected in sequence. The load detection terminal LOAD_DETECTION1 is electrically connected with the controller to output a signal to the controller for judging the conduction of the optical coupler U5. The load detection circuit further comprises a clamping circuit connected between the terminal 3 and the node between the forward rectifier diode D6 and the ground. The clamping circuit comprises two groups of diodes in parallel, one group is a plurality of forward clamping diodes connected in series, and the other group is a plurality of reverse clamping diodes connected in series. The two groups of diodes are the same in type and number. The terminal 3 is connected with the anode of the forward clamping diode, the cathode of the reverse clamping diode and the anode of the forward rectifier diode D6 respectively. The optical coupler U5 comprises a light emitting diode arranged at the input end. The anode of the light emitting diode is connected with the cathode of the forward rectifier diode D6, and the cathode of the light emitting diode is grounded. The negative pole of the output end of the electric pulse output circuit, the ground of the clamping circuit and the cathode of the light emitting diode of the optical coupler U5 are common. The electric pulse output from the positive end of the electric pulse output circuit flows through the terminal 1 of the skin contact end to the human skin, and then flows from the human skin to the terminal 3 of the skin contact end, and then flows back to the negative end of the electric pulse output circuit through the common ground state, thus forming an electric pulse loop, and the physiotherapy device can output electric pulse to the human skin to realize physiotherapy work.

[0021] The electric pulse output circuit comprises an amplitude modulation input circuit, a frequency modulation input circuit and a transformer circuit. The input ends of the amplitude modulation input circuit and the frequency modulation input circuit are electrically connected with the controller respectively to receive the PWM control signal. The amplitude modulation input circuit and the frequency modulation input circuit share a common output end. The transformer circuit comprises a step-up transformer. One end of the input side of the step-up transformer is used for connecting a power supply, and the other end is connected with the common output end through an NPN power tube Q6. The NPN power tube Q6 is specifically a triode with a model of BU508A. Specifically, the base of the NPN power tube Q6 is connected with the common output end, the collector of the NPN power tube Q6 is connected with the step-up transformer, and the emitter of the NPN power tube Q6 is grounded. The output end of the step-up transformer is used as the output end of the electric pulse output circuit.

[0022] The amplitude modulation input circuit is connected to the controller through the amplitude modulation signal input terminal Voltage_PWM1, and includes a resistor R29, a charge-discharge capacitor C10 and a base of an NPN triode Q5 with a model number of S8050 connected in sequence. The charge-discharge capacitor C10 is used to drive the triode Q5. The higher the discharge voltage of the charge-discharge capacitor C10, the more sufficient the conduction of the NPN triode Q5.

[0023] The amplitude modulation input circuit is connected to the controller through the frequency modulation signal input terminal Frequency_PWM1, and includes a resistor R30 and a base of a PNP triode Q8 with a model number of S8550 connected in sequence. The emitter of the PNP triode Q8 of the amplitude modulation input circuit is connected to the emitter of the NPN triode Q5 of the amplitude modulation input circuit. The collector of the PNP triode Q8 is connected to the base of the NPN power triode Q6 as a common output terminal through a resistor R31.

[0024] The voltage transformation circuit includes a spike absorption circuit connected between the two ends of the input side of the step-up transformer. The spike absorption circuit includes a diode D2, a resistor R32 and a capacitor C14. The resistor R32 and the capacitor C14 are connected in parallel and then connected to the negative pole of the diode D2. The positive pole of the diode D2 is connected to the collector of the NPN power triode Q6.

[0025] The load detection circuit receives a pulse signal from the electric pulse output circuit. The pulse signal is a direct current signal or an alternating current signal. The load detection process is as follows: the electric pulse flows from the skin end to the forward rectifier diode D6, is filtered to a negative half-wave rectification, then flows to the optocoupler U5 to make the optocoupler U5 conductive. The load detection terminal detects that the optocoupler U5 is conductive, and it is judged that the load exists. The anode of the forward clamping diode and the reverse clamping diode both have a voltage clamping function, which clamps the electric pulse voltage within the rated voltage range of the electric components such as the forward rectifier diode D6, the optocoupler U5 and the load detection terminal, so as to avoid damage to the electric components such as the forward rectifier diode D6, the optocoupler U5 and the load detection terminal.

[0026] The operator opens the physiotherapy instrument and selects a physiotherapy function. In the working state of the terahertz intermediate frequency physiotherapy instrument, the controller of the physiotherapy instrument executes the control commands required by the physiotherapy function in sequence according to the pre-recorded control program. The controller outputs an amplitude modulation signal to the amplitude modulation signal input terminal Voltage_PWM1 of the amplitude modulation input circuit, and outputs a frequency modulation signal to the frequency modulation signal input terminal Frequency_PWM1. The input amplitude modulation signal is a pulse signal with a frequency of 10 KHz and a duty cycle of 40%-70%. The signal charges the capacitor C10 (2.2 uF / 50 V) through the resistor R29 (1 K / 1%), and the voltage on the capacitor is adjusted in the range of 1.32 V-2.31 V by adjusting the duty cycle. Then the voltage drives the transistor Q5. The higher the driving voltage, the more sufficient the conduction of the transistor Q5, and the amplitude modulation is completed by adjusting the driving voltage. The input frequency modulation signal is a pulse signal with a frequency of 2.5 KHz and a duty cycle of 50%. The signal frequency is the fundamental frequency of the intermediate frequency signal (below 1 KHz is low frequency, and 1 KHz-10 KHz is intermediate frequency). The intermediate frequency signal pulse drives the transistor Q8, and the transistor Q8 cooperates with the transistor Q5 to output an intermediate frequency driving signal with a certain amplitude. The intermediate frequency driving signal with different amplitudes drives the power transistor Q6 to generate a 24 V intermediate frequency pulse, which is boosted by the step-up transformer to obtain an intermediate frequency pulse with an amplitude of 24 V-150 V. The frequency modulation is completed by inputting different frequencies to Frequency_PWM1. The spike absorption circuit makes the generated pulse signal free of large noise and interference.

[0027] The working processes of the terahertz intermediate frequency physiotherapy instrument in the two cases of direct current signal and alternating current signal are described as follows.

[0028] When the terahertz intermediate frequency physiotherapy instrument is in use, in the state of the direct current pulse output circuit, the operator operates the skin contact to contact the human skin. The direct current pulse is output from the positive output of the pulse output circuit, flows through the skin contact to the human skin, and then flows from the human skin to the skin contact, the positive clamping diode, and then flows back to the negative output of the pulse output circuit, thereby forming a direct current pulse loop. The physiotherapy instrument can output a direct current pulse to the human skin, and the terahertz intermediate frequency physiotherapy instrument can maintain a continuous working state under the direct current pulse.

[0029] The terahertz intermediate frequency physiotherapy instrument in use, in the alternating current pulse output circuit state of the electric pulse output circuit, the operator operates the skin end to contact the human skin, the positive half cycle of the alternating current pulse will flow out from the positive end of the electric pulse output circuit, flow through the skin end to the human skin, and then flow from the human skin to the skin end, the positive direction clamping diode, and then flow back to the negative end of the electric pulse output circuit. The negative half cycle of the alternating current pulse will flow out from the negative end of the electric pulse output circuit, flow through the reverse clamping diode, the skin end to the human skin, and then flow from the human skin to the skin end, and then flow back to the positive end of the electric pulse output circuit. Thus, an alternating current pulse loop is formed, so that the terahertz intermediate frequency physiotherapy instrument can maintain a continuous working state under alternating current pulse.

[0030] The electric pulse output circuit of the terahertz intermediate frequency physiotherapy instrument of the embodiment includes a direct current pulse output circuit and an alternating current pulse output circuit, both of which continuously output electric pulses to the human skin. The load detection circuit receives an alternating current signal from the electric pulse output circuit as a pulse signal; if the current skin end is not connected to a load, the load detection terminal LOAD_DETECTION1 outputs a high level to the controller; if the current skin end is connected to a load, the load detection terminal LOAD_DETECTION1 outputs an alternating current waveform of the alternating current signal received from the electric pulse output circuit to the controller. The waveform of the alternating current signal includes a triangular wave, a sinusoidal wave, a trapezoidal wave, or a pulse wave.

[0031] In the load detection circuit of the physiotherapy instrument of the embodiment, the diodes D3, D4, and D5 constitute a forward clamping, and the diodes D7, D8, and D22 constitute a reverse clamping. When the forward pulse is output, D3, D4, and D5 clamp the voltage at a pulse voltage of about 1.5 V. The pulse voltage is rectified by the diode D6, the R43 resistor limits the current, and the output end of the optocoupler U5 obtains a pulse signal with an amplitude of 3.3 V. The controller MCU judges whether the load exists by detecting the presence or absence of the pulse signal. If the load is not connected, the controller MCU detects only a 3.3 V high level. The anode of the forward clamping diode and the reverse clamping diode both have a voltage clamping function, which clamps the electric pulse voltage within the rated voltage range of the forward rectifier diode D6, the optocoupler U5, and the load detection terminal, so as to avoid damage to the electric pulse to the electric elements such as the forward rectifier diode D6, the optocoupler U5, and the load detection terminal.

[0032] The load detection process is as follows: the electric pulse flows from the skin end to the forward rectifier diode D6 to filter out the negative half cycle rectification, and then flows to the optocoupler U5 to make the optocoupler U5 conductive. The load detection terminal transmits the corresponding waveform signal to the controller. The controller detects that the optocoupler U5 is conductive, recognizes that the load exists, and judges that the physiotherapy instrument works normally under the current alternating current pulse working state.

[0033] The above merely illustrates the embodiments of the present application, and does not limit the patent protection scope. Any non-essential changes or substitutions made by those skilled in the art based on the present application still fall within the patent protection scope.

Claims

1. A terahertz intermediate frequency physiotherapy device, comprising a controller, an electrical pulse output circuit and a load detection circuit respectively electrically connected to the controller, and further comprising a skin-contact end for applying contact physiotherapy to human skin load, the skin-contact end comprising a terminal 1 and a terminal 3; terminal 1 is connected to the positive terminal of the output terminal of the electrical pulse output circuit, and the negative terminal of the output terminal of the electrical pulse output circuit is grounded; terminal 3 is connected to the input terminal of the load detection circuit; characterized in that, The load detection circuit includes a forward rectifier diode D6, an optocoupler U5, and a load detection terminal LOAD_DETECTION1 connected in sequence. The load detection terminal LOAD_DETECTION1 is electrically connected to a controller. It also includes a clamping circuit connected between the terminal block 3 and the intermediate node of the forward rectifier diode D6 to ground. This clamping circuit includes two sets of diodes connected in parallel: one set consists of multiple forward clamping diodes connected in series, and the other set consists of multiple reverse clamping diodes connected in series. Both sets of diodes are of the same type and quantity. The terminal block 3 is connected to the anode of the forward clamping diode, the cathode of the reverse clamping diode, and the anode of the forward rectifier diode D6, respectively. The optocoupler U5 includes a light-emitting diode (LED) at its input terminal. The anode of the LED is connected to the cathode of the forward rectifier diode D6, and the cathode of the LED is grounded. The negative terminal of the output terminal of the electrical pulse output circuit, the ground of the clamping circuit, and the negative terminal of the LED of the optocoupler U5 share a common ground.

2. The terahertz intermediate frequency physiotherapy device according to claim 1, characterized in that, The electrical pulse output circuit includes an amplitude modulation (AM) input circuit, a frequency modulation (FM) input circuit, and a transformer circuit. The input terminals of the AM and FM input circuits are each electrically connected to a controller to receive PWM control signals. The AM and FM input circuits share a common output terminal. The transformer circuit includes a step-up transformer. One end of the input side of the step-up transformer is connected to a power supply, and the other end is connected to the common output terminal via an NPN power transistor Q6. Specifically, the base of the NPN power transistor Q6 is connected to the common output terminal, the collector of the NPN power transistor Q6 is connected to the step-up transformer, and the emitter of the NPN power transistor Q6 is grounded. The output terminal of the step-up transformer serves as the output terminal of the electrical pulse output circuit.

3. The terahertz intermediate frequency physiotherapy device according to claim 2, characterized in that, The amplitude modulation input circuit is connected to the controller through the amplitude modulation signal input terminal Voltage_PWM1. It includes a resistor R29, a charging and discharging capacitor C10, and the base of an S8050 NPN transistor Q5 connected in sequence. The charging and discharging capacitor C10 is used to drive the transistor Q5. The higher the discharge voltage of the charging and discharging capacitor C10, the more fully the NPN transistor Q5 is turned on.

4. The terahertz intermediate frequency physiotherapy device according to claim 3, characterized in that, The amplitude modulation input circuit is connected to the controller via the frequency modulation signal input terminal Frequency_PWM1, and includes a resistor R30 and the base of a PNP transistor Q8 of type S8550 connected in sequence; the emitter of the PNP transistor Q8 in the amplitude modulation input circuit is connected to the emitter of the NPN transistor Q5 in the amplitude modulation input circuit; the collector of the PNP transistor Q8 serves as the common output terminal and is connected to the base of the NPN power transistor Q6 via resistor R31.

5. The terahertz intermediate frequency physiotherapy device according to claim 2, characterized in that, The transformer circuit includes a spike absorption circuit connected between the two ends of the input side of the step-up transformer. The spike absorption circuit includes a diode D2, a resistor R32 and a capacitor C14. The resistor R32 and the capacitor C14 are connected in parallel and then connected to the negative terminal of the diode D2. The positive terminal of the diode D2 is connected to the collector of the NPN power transistor Q6.

6. The terahertz intermediate frequency physiotherapy device according to claim 2, characterized in that, The NPN power transistor Q6 is specifically a transistor of model BU508A.

7. The terahertz intermediate frequency physiotherapy device according to claim 1, characterized in that, A transient voltage suppressor (TVS4) of model SMBJ300CA_C57661 is connected between terminal 1 and terminal 3 of the skin-contact end.

8. A load detection circuit for a physiotherapy device, characterized in that, The load detection circuit of the terahertz intermediate frequency physiotherapy device as described in any one of claims 1 to 7.

9. The load detection circuit for the physiotherapy device according to claim 8, characterized in that, The load detection circuit receives an AC signal as a pulse signal from the electrical pulse output circuit. If no load is currently connected to the skin contact point, the load detection terminal LOAD_DETECTION1 outputs a high level to the controller. If a load is currently connected to the skin contact point, the load detection terminal LOAD_DETECTION1 outputs the AC waveform of the AC signal received from the electrical pulse output circuit to the controller.

10. The load detection circuit for the physiotherapy device according to claim 9, characterized in that, The AC waveform of the AC signal includes a triangular wave, a sine wave, a trapezoidal wave, or a pulse wave.

Images