High-frequency electrotome automatic blood coagulation and automatic output stopping circuit

Abstract

The invention belongs to the technical field of high-frequency electrotomes, and particularly relates to a high-frequency electrotome automatic blood coagulation and automatic output stopping circuit which thoroughly gets rid of dependence on external button control and does not need to depend on subjective operation of doctors to control start and stop of blood coagulation. According to the device, the tissue state can be sensed in real time through a built-in monitoring mechanism, the tissue resistance can be accurately recognized, the blood coagulation process is automatically adjusted according to the tissue resistance, accurate control over blood coagulation operation is achieved, unfavorable conditions such as tissue carbonization or insufficient blood coagulation are effectively avoided, and the safety and accuracy of blood coagulation operation are greatly improved. In addition, starting, stopping and process control of double-pole blood coagulation or single-pole blood coagulation can be carried out under the conditions of no pedal and the like, and the cost of accessories is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of high-frequency electric knife, and in particular relates to an automatic coagulation and automatic stop output circuit of a high-frequency electric knife. Background Art

[0002] The power output of existing high-frequency electrosurgical units relies on foot pedals or pen buttons for control, and the start and stop of coagulation operations are entirely dependent on the doctor's subjective judgment. This not only increases the complexity of the operation, but may also lead to inaccurate coagulation due to human judgment bias, and even problems such as tissue carbonization and insufficient coagulation. Chinese patent document CN213283321U (202022008618.6) discloses a control circuit for automatic fine electrocoagulation in a high-frequency electrosurgical unit. The circuit comprises a multiplier U1, a multiplier U2, an operational amplifier U3, an operational amplifier U4, an operational amplifier U5, an analog switch U6, resistors R1, R2, R3, R4, potentiometers W1, and W2. This control circuit continuously samples the output voltage and current of the power amplifier, calculates the load resistance, and compares it with a threshold resistance. If the load resistance RL exceeds the threshold resistance R0, coagulation is complete. The control circuit then reduces the output voltage of the switching power supply, reducing the power output of the power amplifier, leaving only a small amount of energy to continuously monitor changes in the load resistance, thereby preventing tissue adhesion to the electrode after coagulation is complete. While this control circuit solves the problem of inaccurate coagulation, it only detects whether coagulation is complete and cannot precisely control the coagulation process based on different tissue states. Furthermore, it cannot automatically control the start and stop of the high-frequency electrosurgical unit. Summary of the Invention

[0003] In response to the shortcomings of existing product technologies, the present invention discloses a high-frequency electrosurgical unit with automatic coagulation and automatic stop output circuit. The circuit of the present invention completely gets rid of the reliance on external button control, and no longer needs to rely on the doctor's subjective operation to control the start and stop of coagulation. The device can sense the tissue state in real time through a built-in monitoring mechanism, accurately identify the size of tissue resistance, and automatically adjust the coagulation process accordingly, achieving precise control of the coagulation operation, effectively avoiding the occurrence of adverse conditions such as tissue carbonization or insufficient coagulation, and greatly improving the safety and accuracy of the coagulation operation. In addition, bipolar coagulation or unipolar coagulation can be started and stopped without a pedal, reducing the cost of accessories.

[0004] The technical problem to be solved by the present invention is achieved by adopting the following technical solution: a high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit, comprising a CPU control module, a waveform switching drive module, a low-voltage detection module, a high-voltage output module, an analog detection feedback system and a device output port; The analog detection feedback system is connected to the device output port and the CPU control module respectively, and is used to collect the power, voltage and current signals of the device output port in real time; The CPU control module is connected to the waveform switching drive module, and the waveform switching drive module is connected to the device output port through the low voltage detection module and the high voltage output module respectively; The CPU control module is used to obtain the corresponding tissue resistance at the device output port based on the power, voltage and current signals fed back by the analog detection feedback system, and control the waveform switching drive module to connect to the low-voltage detection module or the high-voltage output module based on the tissue resistance, and control the modulation drive waveform of the waveform switching drive module; The low voltage detection module is used to provide a modulated sine wave of a preset frequency based on the modulated driving waveform of the waveform switching driving module; The high-voltage output module is used to provide a modulated sine wave that matches the tissue resistance based on the modulated driving waveform of the waveform switching driving module.

[0005] Preferably, in the present invention, when the tissue resistance is greater than the preset resistance, the device does not start, and the waveform switching drive module is connected to the device output port via the low voltage detection module; When the tissue resistance is less than or equal to the preset resistance, the device is started, and the waveform switching drive module is connected to the device output port through the high-voltage output module.

[0006] Preferably, the waveform switching drive module is connected to the primary coil of the transformer T3; The low voltage detection module and the high voltage output module are connected to the first secondary coil and the high voltage output module of the transformer T3 respectively; The CPU control module controls the transformer T3 through the relay K2 to be connected to the low voltage detection module through the first secondary coil or to be connected to the high voltage output module through the second secondary coil.

[0007] Preferably, the waveform switching driving module includes a PWM generator, a gate driver, a MOS tube and a resonant network connected in sequence; The CPU control module is used to control the duty cycle of the PWM generator. Driving the MOS transistor through the gate driver not only achieves electrical isolation and voltage upgrade of the drive signal, meeting the stringent requirements for MOS transistor gate drive, but also controls dead-zone distortion to less than 1% through timing fidelity and fast response, reducing MOS transistor switching losses by 30%-50%, ultimately improving the efficiency, waveform quality, and reliability of the entire power conversion system.

[0008] Preferably, the PWM generator is a phase-shift controller or a PWM controller. The phase-shift controller controls the switching timing of the full-bridge by adjusting the phase difference of the PWM drive waveform, flexibly changing the duty cycle of the transformer primary voltage, and achieving precise regulation of the output voltage and power.

[0009] Preferably, an isolation transformer is provided between the gate driver and the MOS transistor. By providing the isolation transformer between the gate driver and the MOS transistor, electrical insulation is achieved, high-frequency interference is suppressed, and stable driving of the transformer is achieved.

[0010] Preferably, the analog detection feedback system includes a voltage detection circuit, a power detection circuit and a current detection circuit; The voltage detection circuit is used to detect the real-time voltage value of the device output port and feed back the difference between the real-time voltage value and the voltage limit to the CPU control module; The power detection circuit is used to detect the real-time power value of the device output port and feed back the difference between the real-time power value and the power limit value to the CPU control module; The current detection circuit is used to detect the real-time current value of the device output port and feed back the difference between the real-time current value and the current limit value to the CPU control module; The CPU control module controls the waveform switching drive module to output different PWM waveforms based on the minimum difference between power, voltage and current, achieving precise control while avoiding exceeding the power, voltage or current limits, thereby ensuring equipment safety.

[0011] Preferably, the low voltage detection module of the present invention includes a low voltage detection feedback transformer L5; The high voltage output module includes a high voltage detection feedback transformer L4; The CPU control module controls the relay K2 through the relay K1 to be connected to the low voltage detection feedback transformer L5 or the high voltage detection feedback transformer L4; The voltage detection circuit and the power detection circuit are connected in parallel and then connected in series with the relay RLY1; The CPU control module controls the voltage detection circuit and the power detection circuit to be connected to the low voltage detection feedback transformer or the high voltage detection feedback transformer through the relay RLY1; The current detection circuit is connected to the CPU control module via the current transformer L3.

[0012] Preferably, the CPU control module performs short-circuit protection based on the real-time current value fed back by the current detection circuit, and avoids circuit short circuit by performing real-time detection on the current value of the device output port, thereby reducing erroneous operation of multiple devices.

[0013] Preferably, the CPU control module is a single chip microcomputer; The voltage detection circuit, power detection circuit and current detection circuit all include a multiplier, an amplifier follower and a comparator connected in series. The voltage limit, voltage limit and voltage limit are set by the comparator using a single chip microcomputer.

[0014] The inventive concept of this invention is that a high-frequency electrosurgical analyzer generates a comparison curve based on the feedback voltage and the test resistance. The device's feedback voltage can then be used to infer the resistance of the current target tissue. The resistance can then be used to determine the bleeding state. The epidermal load of non-bleeding human skin is very high. On palms and soles, 10,000Ω to over 1,000,000Ω (1MΩ) is common, and can even reach several megohms. On dry arms and torsos, the range of 2,000Ω to 100,000Ω is typical. Moist, bleeding skin resistance may drop to a few hundred ohms (e.g., 500Ω-2,000Ω). The resistance of damaged skin or mucous membranes approaches internal tissue resistance, reaching as low as 300Ω-1,000Ω. Therefore, as long as the tissue resistance is below 2,000Ω, it is certain that the tissue is bleeding and requires treatment. Therefore, the device can be started and stopped based on tissue resistance, enabling rapid switching between coagulation states. The drive power parameters required for bipolar or unipolar coagulation can also be automatically matched based on tissue type.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The automatic coagulation and automatic stop output circuit of the high-frequency electrosurgical unit of the present invention utilizes an analog detection feedback system to collect the power, voltage and current of the output port of the device in real time and feeds them back to the CPU control module. The CPU control module obtains the tissue resistance corresponding to the output port of the device based on the power, voltage and current values ​​fed back by the analog detection feedback system, and controls the waveform switching drive module to be connected with the low-voltage detection module or the high-voltage output module based on the tissue resistance, and controls the modulation drive waveform of the waveform switching drive module; thereby, when the output port of the device is unloaded or when the output port of the device contacts tissue and does not need coagulation, the coagulation function of the device is not started, and only the modulation drive waveform of the waveform switching drive module based on the low-voltage detection module is used. The device provides a modulated sine wave of preset frequency for real-time detection; when it detects that the output port of the device is in contact with tissue and coagulation is required, the coagulation function of the device is started, and the high-voltage output module provides a modulated sine wave that matches the tissue resistance based on the modulated driving waveform of the waveform switching driver module. By accurately identifying the tissue resistance and automatically adjusting the coagulation process accordingly, precise control of the coagulation operation is achieved. When coagulation is completed, it further switches to low-voltage detection, effectively avoiding the occurrence of adverse conditions such as tissue carbonization or insufficient coagulation, greatly improving the safety and accuracy of the coagulation operation, and completely getting rid of the dependence on external button control. There is no need to rely on the doctor's subjective operation to control the start and stop of coagulation.

[0016] The present invention can start and stop bipolar coagulation or monopolar coagulation and perform process control without pedals, etc., thus reducing the cost of accessories. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural diagram of the automatic coagulation and automatic stop output circuit of the high-frequency electrosurgical unit; Figure 2 This is the circuit diagram of the automatic coagulation and automatic stop output circuit of the high-frequency electrosurgical unit; In the figure, 1 is the CPU control module, 2 is the waveform switching drive module, 3 is the low-voltage detection module, 4 is the high-voltage output module, 5 is the analog detection feedback system, and 6 is the device output port. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings.

[0019] like Figure 1 and Figure 2 As shown, a high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit includes a CPU control module 1, a waveform switching drive module 2, a low-voltage detection module 3, a high-voltage output module 4, an analog detection feedback system 5, and a device output port 6.

[0020] The analog detection feedback system 5 is connected to the device output port 6 and the CPU control module 1 respectively, and is used to collect the power, voltage and current signals of the device output port 6 in real time.

[0021] The CPU control module 1 is connected to the waveform switching drive module 2 , and the waveform switching drive module 2 is connected to the device output port 6 through the low voltage detection module 3 and the high voltage output module 4 respectively.

[0022] The CPU control module 1 is used to obtain the corresponding tissue resistance size at the device output port 6 based on the power, voltage and current signals fed back by the analog detection feedback system 5, and control the waveform switching drive module 2 to be connected to the low-voltage detection module 3 or the high-voltage output module 4 based on the tissue resistance size, and control the modulation drive waveform of the waveform switching drive module 2.

[0023] The low voltage detection module 3 is configured to provide a modulated sine wave of a preset frequency based on the modulated driving waveform of the waveform switching driving module 2 .

[0024] The high-voltage output module 4 is used to provide a modulated sine wave that matches the tissue resistance based on the modulated driving waveform of the waveform switching driving module 2.

[0025] When the tissue resistance is greater than the preset resistance, the device does not start, and the waveform switching driving module 2 is connected to the device output port 6 through the low voltage detection module 3 .

[0026] When the tissue resistance is less than or equal to the preset resistance, the device is started, and the waveform switching driving module 2 is connected to the device output port 6 through the high-voltage output module 4 .

[0027] Working Principle: CPU control module 1 detects the user's selection of the high-frequency electrosurgical unit's automatic monopolar or bipolar gentle coagulation mode. It then controls waveform switching module 2 to output a modulated drive waveform, which in turn transmits a modulated sine wave of a certain frequency to the device's output port 6 via low-voltage detection module 3. The high-frequency waveform at this port is then fed back to CPU control module 1 via analog detection feedback system 5. CPU control module 1 then uses an algorithm to analyze the voltage, current, and power transmitted from analog detection feedback system 5 to calculate the current tissue resistance of the device. If the device is in non-contact mode and no load is applied, or if the tissue resistance is high, the device will detect a high voltage value and will not start.

[0028] If the device is in low-load mode (a load value less than 1800 ohms, indicating coagulation), the device detects a low voltage value and, based on the voltage, knows it needs to activate bipolar or monopolar coagulation output power. The CPU control module 1 then switches the waveform to the driver module 2, which then transmits high-voltage power to the device output port 6 via the high-voltage output module 4. The waveform at the device output port 6 is now a high-voltage waveform, and the power, voltage, and current are transmitted to the CPU control module 1 via the analog detection feedback system 5. The CPU control module 1 controls power output based on the measured tissue resistance. If the tissue resistance exceeds 2000 ohms, the device stops operating and switches to the low-voltage detection module 3.

[0029] In this embodiment, the CPU control module 1 is a single-chip microcomputer STM32F334 (other single-chip microcomputers such as ST series or TI series single-chip microcomputers may also be used).

[0030] Specifically, the waveform switching driving module 2 is connected to the primary coil of the transformer T3.

[0031] The low voltage detection module 3 and the high voltage output module 4 are respectively connected to the first secondary coil and the second secondary coil of the transformer T3.

[0032] The CPU control module 1 controls the transformer T3 through the relay K2 to connect to the low voltage detection module 3 through the first secondary coil or to connect to the high voltage output module 4 through the second secondary coil.

[0033] The waveform switching driving module 2 includes a PWM generator, a gate driver, a MOS tube and a resonant network connected in sequence.

[0034] The CPU control module 1 is used to control the duty cycle of the PWM generator. Through the above structure, the transformer T3 can be operated in the low voltage detection module or the high voltage output module through the single chip control relay K2.

[0035] The PWM generator is a phase-shift controller UCC2895 output device, and may also be other phase-shift controllers such as UCC3895, SG3525, or other phase-shift controllers or PWM controllers.

[0036] An isolation transformer is provided between the gate driver and the MOS tube.

[0037] The waveform driver module 2 operates as follows: Phase-shift controller U1 controls pin 20 of phase-shift controller U1 via the enable signal (EN) at pin 19 and the feedback signal (DA) from the analog detection feedback system 5 (the feedback network). A high-level EN signal enables the four PWM waveforms of phase-shift controller U1, while a low-level signal disables them. DA determines the phase shift angles of the four PWM waveforms, outputting different duty cycles. The four drive waveforms then pass through gate drivers (U2, U3, U4, and U5), MOSFETs (Q1, Q2, Q3, and Q4), and a resonant network before outputting the desired waveforms through transformer T3. For example, if the output is in high-voltage mode and the user selects bipolar soft condenser mode, the EN waveform of phase-shift controller U1 is always enabled. The analog voltage value of the DA signal from the feedback circuit is used to control pin 20 of phase-shift controller U1 according to the required power, voltage, and current. This analog voltage causes phase-shift controller U1 to output the required PWM drive waveform. This waveform then passes through the gate drivers (U2, U3, U4, U5), MOS transistors (Q1, Q2, Q3, Q4), and the resonant network, and outputs the required high-voltage modulated waveform through transformer T3. If the output is in low-voltage mode, the EN waveform of phase-shift controller U1 is modulated and enabled. The analog voltage value of the DA signal from the feedback circuit is used to control pin 20 of phase-shift controller U1. This analog voltage causes phase-shift controller U1 to output the required low-duty-cycle PWM drive waveform. This waveform then passes through the gate drivers (U2, U3, U4, U5), MOS transistors (Q1, Q2, Q3, Q4), and the resonant network, and outputs the required modulated sine wave with a peak-to-peak value controlled below 72V through transformer T3.

[0038] The analog detection feedback system 5 includes a voltage detection circuit, a power detection circuit and a current detection circuit.

[0039] The voltage detection circuit is used to detect the real-time voltage value of the device output port 6 and feed back the difference between the real-time voltage value and the voltage limit value to the CPU control module 1.

[0040] The power detection circuit is used to detect the real-time power value of the device output port 6 and feed back the difference between the real-time power value and the power limit value to the CPU control module 1.

[0041] The current detection circuit is used to detect the real-time current value of the device output port 6 and feed back the difference between the real-time current value and the current limit value to the CPU control module 1.

[0042] The CPU control module 1 controls the waveform switching drive module 2 to output different PWM waveforms based on the minimum difference between power, voltage and current.

[0043] The low voltage detection module 3 includes a low voltage detection feedback transformer L5.

[0044] The high-voltage output module 4 includes a high-voltage detection feedback transformer L4.

[0045] The CPU control module 1 controls the relay K2 through the relay K1 to connect to the low-voltage detection feedback transformer L5 or the high-voltage detection feedback transformer L4.

[0046] The voltage detection circuit and the power detection circuit are connected in parallel and then connected in series with the relay RLY1.

[0047] The CPU control module 1 controls the voltage detection circuit and the power detection circuit to be connected to the low-voltage detection feedback transformer or the high-voltage detection feedback transformer through the relay RLY1.

[0048] The current detection circuit is connected to the CPU control module 1 through the current transformer L3.

[0049] The CPU control module 1 performs short circuit protection based on the real-time current value fed back by the current detection circuit.

[0050] The voltage detection circuit, the power detection circuit and the current detection circuit all include a multiplier, an amplifier follower and a comparator connected in series.

[0051] The K1 relay selects different feedback circuits based on different modes. Because this device requires both high-voltage and low-voltage outputs, the high-voltage mode involves more modes, with peaks reaching thousands of volts, which are then converted into the analog voltage required by the feedback detection circuit. The analog voltage of the high-voltage feedback is not suitable for the low-voltage load detection module. The voltage and current of the low-voltage detection module are relatively low. If feedback is provided through a single circuit, the feedback accuracy is insufficient. Therefore, two feedback circuits are required, and the analog voltage conversion accuracy of the two feedback circuits varies. The low-voltage load detection driver requires higher precision because it needs to output very small detection power values. Figure 2In the diagram, L4 is the high-voltage detection feedback transformer, L5 is the low-voltage detection feedback transformer, and L3 is the current transformer. The L3 current transformer converts the high-value primary current of the device's feedback loop into a smaller secondary current at a specific ratio. This current transformer then converts the current through a resistor into an analog voltage for feedback comparison.

[0052] like Figure 2 As shown, voltage detection transformers L4 and L5 and current transformer L3 convert the analog voltage values ​​into analog values. L4 and L5 represent voltage conversion values, while L3 represents current conversion values. This generates two analog voltage and current feedback values, P, I, and V, which are then fed back to the phase-shift controller U1 through the analog detection feedback circuit. P = U * I. Based on the following multipliers (U6, a voltage multiplier), U7, a power multiplier, and U8, an AD835 current multiplier (this circuit can also be replaced with other chips, such as the LM358, or other ADI series multipliers), the analog voltage values ​​are amplified by amplifier-followers U9, U10, and U11, such as AD828s. Comparisons are performed with the analog voltage values ​​given by the microcontroller, using comparators U12, U13, and U14, such as AD828s. The resulting voltage, current, and power values ​​are compared, and the minimum error DA value signal is output, forming the analog detection feedback system. The DA value then controls the phase-shift controller U1 to output different PWM waveforms, ultimately resulting in different power outputs.

[0053] In this embodiment, the power, voltage, and current limits of the low-voltage detection module are also pre-set by the microcontroller assigning an analog voltage value to the third pins of comparators U12.1, U13.1, and U14.1, based on waveform measurements under no-load conditions. Because the maximum no-load voltage is pre-set based on the output waveform, the microcontroller assigns a limit value U to U12.1, and then assigns a maximum current limit value I to U14.1 under a 10 ohm load. Next, a limit value for the power P achievable under 2000 ohms is assigned to U13.1. This allows the load mode to be determined based on the voltage value. The test rating is then compared with the voltage, current, and power feedback values ​​generated by the L5 low-voltage detection transformer ratio through three circuits, generating an analog voltage value DA.

[0054] The difficulty of the present invention lies in the output of the low-voltage detection module. The module must detect the output in real time and avoid voltages that can be felt by the human body (typically less than 72V peak-to-peak). This requires a more rigorous detection algorithm and a power amplifier chip to form a feedback detection circuit. During low-voltage detection, the present invention converts the voltage value into an analog voltage value through the voltage detection transformer L5 and the current transformer L3, with L5 being the voltage conversion value and L3 being the current conversion value. Two analog voltage and current feedback values ​​are generated, and the P, I, and V values ​​are fed back to the phase-shift controller U1 through the analog detection feedback circuit. Since P = U * I, the analog voltage value is amplified by the three AD835 multipliers (voltage multiplier U6), power multiplier U7, and current multiplier U8), and then amplified by the three AD828 amplifier-followers U9, U10, and U11. The analog voltage values ​​are compared with the voltage, current, and power values ​​of the AD828 analog voltage values ​​specified by the single-chip microcomputer (comparators U12, U13, and U14). The minimum error DA value signal is output, forming the analog detection feedback system. Then, according to the size of the DA value, the phase-shift controller U1 is controlled to output different PWM waveforms. Ultimately, the device is designed to output the maximum power, maximum voltage, and maximum current of the waveform according to the size of the human tissue resistance. When the tissue resistance is less than 2000 ohms, the voltage can increase in real time, and when it exceeds 2000 ohms, the saturation voltage value is designed. The maximum voltage limit is given to pin 3 of the comparator U12.1 through the microcontroller. Then, the microcontroller's given power P also needs to be reasonably designed to select a minimum power analog voltage limit that can be achieved under a load of 2000 ohms, so that the voltage value can change with the increase of the load under 2000 ohms. However, after reaching a certain voltage, the voltage limit plays a protective role. In this way, the current load value can be determined according to the size of the voltage value. According to P=U^2 / R, to achieve power P, the voltage U will produce different voltage values ​​according to the different loads R. The voltage U will reach a certain maximum voltage limit according to the increase of the load resistance R, and the feedback value analog voltage UADC will decrease accordingly according to the reduction of the load. In this way, as long as the critical tissue is tested in advance, for example, the output voltage value under 1800 ohms is saved in advance by the microcontroller, if the measured UADC is greater than the critical voltage value under 1800 ohms, the device will not operate. If the measured voltage is less than the critical voltage value under 1800 ohms, the device defaults to requiring coagulation and enters high-voltage mode for coagulation. In addition, the current value of the current U11.1 IADC can also be used to detect the current value of the device in real time. The microcontroller can detect the short-circuit state based on the current value. In the short-circuit state, if the IADC reaches the given critical maximum value, the device will stop outputting low-voltage detection. Remind the user to loosen the clamp bipolar port or unipolar output terminal to reduce the misoperation of multiple devices.

Claims

1. A high-frequency electrosurgical unit with automatic coagulation and automatic stop output circuit, characterized by: It includes a CPU control module (1), a waveform switching drive module (2), a low voltage detection module (3), a high voltage output module (4), an analog detection feedback system (5) and a device output port (6); The analog detection feedback system (5) is connected to the device output port (6) and the CPU control module (1) respectively, and is used to collect power, voltage and current signals of the device output port (6) in real time; The CPU control module (1) is connected to the waveform switching drive module (2), and the waveform switching drive module (2) is connected to the device output port (6) via the low-voltage detection module (3) and the high-voltage output module (4); The CPU control module (1) is used to obtain the tissue resistance corresponding to the device output port (6) based on the power, voltage and current signals fed back by the analog detection feedback system (5), and to control the waveform switching drive module (2) to be connected to the low voltage detection module (3) or the high voltage output module (4) based on the tissue resistance, and to control the modulation drive waveform of the waveform switching drive module (2); The low voltage detection module (3) is used to provide a modulated sine wave of a preset frequency based on the modulated driving waveform of the waveform switching driving module (2); The high-voltage output module (4) is used to provide a modulated sine wave that matches the tissue resistance based on the modulated drive waveform of the waveform switching drive module (2).

2. The high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit according to claim 1, characterized in that: When the tissue resistance is greater than the preset resistance, the device does not start, and the waveform switching drive module (2) is connected to the device output port (6) via the low voltage detection module (3); When the tissue resistance is less than or equal to the preset resistance, the device is started, and the waveform switching drive module (2) is connected to the device output port (6) via the high-voltage output module (4).

3. The high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit according to claim 1 or 2, characterized in that: The waveform switching drive module (2) is connected to the primary coil of the transformer T3; The low-voltage detection module (3) and the high-voltage output module (4) are respectively connected to the first secondary coil and the second secondary coil of the transformer T3; The CPU control module (1) controls the transformer T3 via the relay K2 to be connected to the low-voltage detection module (3) via the first secondary coil or to be connected to the high-voltage output module (4) via the second secondary coil.

4. The high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit according to claim 1, characterized in that: The waveform switching drive module (2) comprises a PWM generator, a gate driver, a MOS tube and a resonant network connected in sequence; The CPU control module (1) is used to control the duty cycle of the PWM generator.

5. The high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit according to claim 4, characterized in that: The PWM generator is a phase-shift controller or a PWM controller.

6. The high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit according to claim 4, characterized in that: An isolation transformer is provided between the gate driver and the MOS tube.

7. The high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit according to claim 1, characterized in that: The analog detection feedback system (5) includes a voltage detection circuit, a power detection circuit and a current detection circuit; The voltage detection circuit is used to detect the real-time voltage value of the device output port (6), and feed back the difference between the real-time voltage value and the voltage limit value to the CPU control module (1); The power detection circuit is used to detect the real-time power value of the device output port (6), and feed back the difference between the real-time power value and the power limit value to the CPU control module (1); The current detection circuit is used to detect the real-time current value of the device output port (6), and feed back the difference between the real-time current value and the current limit value to the CPU control module (1); The CPU control module (1) controls the waveform switching drive module (2) to output different PWM waveforms based on the minimum difference between power, voltage and current.

8. The high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit according to claim 7, characterized in that: The low voltage detection module (3) includes a low voltage detection feedback transformer L5; The high-voltage output module (4) includes a high-voltage detection feedback transformer L4; The CPU control module (1) controls the relay K2 via the relay K1 to be connected to the low-voltage detection feedback transformer L5 or the high-voltage detection feedback transformer L4; The voltage detection circuit and the power detection circuit are connected in parallel and then connected in series with the relay RLY1; The CPU control module (1) controls the voltage detection circuit and the power detection circuit to be connected to the low-voltage detection feedback transformer or the high-voltage detection feedback transformer through the relay RLY1; The current detection circuit is connected to the CPU control module (1) via a current transformer L3.

9. The high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit according to claim 7, characterized in that: The CPU control module (1) performs short-circuit protection based on the real-time current value fed back by the current detection circuit.

10. The high-frequency electrosurgical unit automatic coagulation and automatic stop output circuit according to claim 7, characterized in that: The CPU control module (1) is a single chip microcomputer; The voltage detection circuit, the power detection circuit and the current detection circuit all include a multiplier, an amplifier follower and a comparator connected in series.

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