A dynamically impedance-adapting plasma surgical system

Abstract

The application relates to a dynamic impedance self-adaptive plasma surgery system, which comprises a plasma surgery electrode, a plasma signal output control circuit, an impedance detection circuit and a control unit. The control unit controls the plasma signal output control circuit and the impedance detection circuit to alternately work on the same plasma surgery electrode, so that the same electrode can output plasma energy for surgery and can reversely measure tissue impedance, and the electrode does not need to be replaced. Meanwhile, the control unit adjusts the output power in real time according to the measured impedance value, the doctor does not need to manually adjust the power gear according to experience, the output power is automatically reduced for the tissue with more bleeding, the output is automatically adjusted for the coagulated tissue, energy-induced tissue thermal damage is avoided, and the surgery is safer and more stable.

Description

Technical Field

[0001] This invention relates to the field of medical devices, specifically to a dynamic impedance adaptive plasma surgical system. Background Technology

[0002] Radiofrequency plasma surgery systems are commonly used energy devices in electrosurgery. They use radiofrequency energy to ionize a working medium, forming low-temperature plasma, which is then used to precisely cut, coagulate, or ablate tissue using a directionally jetted plasma beam. Currently, plasma surgery systems typically use fixed output power levels, requiring doctors to manually set the power based on experience, without the ability to dynamically adjust it according to the real-time tissue condition at the surgical site.

[0003] While some existing plasma surgical devices have temperature regulation functions, their temperature sampling points are located further back, resulting in significant measurement deviations. Furthermore, they can only prevent overheating and stop output, not dynamically control the output power. In addition, existing products cannot achieve real-time dynamic feedback and precise control, requiring surgeons to constantly adjust the settings during the procedure, affecting the continuity and smoothness of the surgery.

[0004] In impedance measurement, existing technologies include solutions that achieve impedance detection through multi-electrode separation or filter isolation. However, multi-electrode solutions require changes to the electrode structure, increasing system complexity; filter isolation solutions cannot completely block radio frequency high voltage, and continuously applying monitoring current can interfere with normal surgical output. Currently, there is no mature technology solution that can safely switch between radio frequency high voltage output and low voltage impedance measurement on the same electrode through pure software timing control. Summary of the Invention

[0005] The purpose of this invention is to solve the problems in the background art and provide a dynamic impedance adaptive plasma surgical system.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A dynamic impedance adaptive plasma surgical system includes a plasma surgical electrode, a plasma signal output control circuit, an impedance detection circuit, and a control unit. The plasma signal output control circuit is connected to the plasma surgical electrode and outputs a plasma surgical signal to the electrode. The impedance detection circuit is connected to the plasma surgical electrode and injects a measurement signal into the electrode to obtain the impedance value of the surgical site. The control unit is connected to both the plasma signal output control circuit and the impedance detection circuit. The control unit controls the plasma signal output control circuit and the impedance detection circuit to alternately connect to the plasma surgical electrode in a time-division multiplexing manner, and adjusts the output power of the plasma signal output control circuit according to the impedance value measured by the impedance detection circuit.

[0007] Preferably, it further includes a DC-to-AC modulation circuit, which is connected upstream of the plasma signal output control circuit. The control unit is connected to the DC-to-AC modulation circuit through a drive control isolation circuit, which is used to isolate the control side from the power side.

[0008] This invention isolates the microcontroller from the high-voltage power stage through a drive control isolation circuit, preventing the high-voltage plasma signal from the high-voltage side from entering the low-voltage control side via the control line and causing damage to the main control chip. At the same time, the control unit sends a drive signal to the DC-to-AC modulation circuit through the isolation circuit, which can amplify the small signal of the microcontroller into a strong signal that can drive the power transistor, and firmly block the high voltage on the other side, ensuring reliable control and chip safety.

[0009] Preferably, it further includes a dynamic DC modulation circuit, which is connected upstream of the DC-to-AC modulation circuit and is used to output a reference voltage to the DC-to-AC modulation circuit. The control unit is also connected to the dynamic DC modulation circuit through the drive control isolation circuit.

[0010] The system employs a dynamic DC modulation circuit and a DC-to-AC modulation circuit, which work together to regulate voltage and invert power, respectively. The dynamic DC modulation circuit first adjusts the fixed DC 320V power supply to a variable reference voltage; a higher voltage results in higher output power, and a lower voltage results in lower power. The DC-to-AC modulation circuit then inverts this variable voltage into high-voltage, high-frequency AC power, which is then boosted to the required several hundred volts for surgery via a high-frequency switching transformer. The two stages have clearly defined roles: voltage regulation in the front and voltage inversion and boosting in the back. Together, they enable precise adjustment of the output power, providing a stable energy source for accurate surgery.

[0011] It also includes a power input circuit, which includes an AC220V input terminal, a fuse, a power switch, a power filter, and an AC220V power rectifier and filter circuit and a switching power supply connected in parallel to the output terminal of the power filter; the AC220V power rectifier and filter circuit outputs DC320V to the dynamic DC modulation circuit; the switching power supply outputs DC12V, which is converted to 3.3V / 5V by a linear voltage regulator circuit to power the control unit.

[0012] This invention employs a tiered power supply design, where AC220V is filtered and then output in two paths: one path is rectified and filtered to DC320V for the power stage, and the other path is converted to DC12V via a switching power supply and then linearly regulated to 3.3V / 5V for the control stage. The high-power circuit and the small-signal circuit are independent of each other, avoiding mutual interference and making the system more stable. At the same time, protective components such as fuses and power filters provide primary protection in case of overcurrent or electromagnetic interference.

[0013] Preferably, the control unit uses software timing control to alternately connect the plasma signal output control circuit and the impedance detection circuit to the plasma surgical electrode. During the period when the plasma signal output control circuit outputs a plasma surgical signal to the plasma surgical electrode, the impedance detection circuit stops working; during the period when the impedance detection circuit injects a measurement signal into the plasma surgical electrode, the plasma signal output control circuit stops outputting, and a preset delay is provided between the two periods.

[0014] This invention uses software timing control to alternately occupy the electrode for the main output and impedance detection. Instead of relying on additional hardware switching devices, the main control CPU directly controls the start and stop timing of the two circuits. When the main output is working, the measurement circuit is in sleep mode, and when the measurement window is open, the main output is turned off. A preset delay is left in between to allow residual energy to dissipate. No additional electrical switching devices are needed, making the system simpler, lower in cost, and more reliable. At the same time, it realizes time-division multiplexing of the same electrode.

[0015] Preferably, the impedance detection circuit includes a high-frequency signal source and a measurement circuit. The high-frequency signal source is generated by the on-chip PWM module of the control unit and outputs a measurement signal with a frequency of 100kHz. The measurement circuit includes a digital isolator. The control side of the digital isolator is connected to the control unit, and the isolation side of the digital isolator is connected to the plasma surgical electrode through a signal conditioning network. The signal conditioning network includes a resistor network and a filter inductor.

[0016] This invention uses a 100kHz, 1-5V low-voltage high-frequency signal to measure impedance. The low voltage and small current ensure absolute safety for the human body. Furthermore, 100kHz and RF operating frequencies are not in the same frequency band, preventing interference and resulting in more accurate impedance measurements. Simultaneously, a digital isolator, such as the ADUM2401, is employed to achieve electrical isolation between the control side and the electrode side, preventing high-voltage plasma from entering the measurement circuit and damaging the chip. The signal conditioning network includes a resistor network for current limiting protection and a filtering inductor to remove high-frequency noise, ensuring a clean and reliable measurement signal.

[0017] Preferably, the system further includes a plasma signal output anomaly monitoring circuit connected between the plasma signal output control circuit and the control unit. This circuit uses a current transformer to continuously monitor the output current of the plasma signal output control circuit in real time. When an overcurrent, short circuit, or open circuit anomaly is detected, the anomaly signal is fed back to the control unit, which then performs a protection action. This anomaly monitoring is independent of the periodic measurement of the impedance detection circuit; the plasma signal output anomaly monitoring circuit maintains real-time monitoring within the few microsecond measurement window of the impedance detection circuit.

[0018] This invention utilizes a plasma signal output anomaly monitoring circuit to monitor the output status in real time. When an overcurrent or short-circuit anomaly is detected, the anomaly signal is fed back to the control unit, which then executes protective actions to achieve rapid response and timely protection, preventing the fault from escalating. The anomaly monitoring and impedance detection are two independently operating systems: the plasma signal output anomaly monitoring circuit continuously monitors the output current in real time during the period when the plasma signal output control circuit outputs a plasma surgical signal to the plasma surgical electrode; within the measurement window of the impedance detection circuit, since the plasma signal output control circuit has stopped outputting, the plasma signal output anomaly monitoring circuit is in a standby state with no output current. Safety within this measurement window is ensured by the control unit's software-timed shutdown and preset delay. The two systems have clearly defined functions and do not interfere with each other, resulting in higher system safety.

[0019] Preferably, the system also includes a foot switch, a foot switch drive circuit, and a human-machine interface module. The foot switch drive circuit is connected between the foot switch and the control unit. The human-machine interface module includes an LCD display and a touch screen connected to the control unit, as well as an output sound prompt circuit. By retaining the foot switch and drive circuit, doctors can control the system by foot, complementing the automatic mode and catering to the operating habits of different doctors, making switching during surgery more flexible. Through the LCD touch screen and sound prompts, doctors can see the parameters and hear the prompts, eliminating the need to guess the machine's status. The operation interface is intuitive, making the surgical process smoother.

[0020] Preferably, the control unit includes a data storage unit that pre-stores a mapping relationship between impedance values ​​and output power. The control unit determines the target output power by querying the mapping relationship based on the measured impedance value, and judges the tissue state based on the impedance value measured by the impedance detection circuit. The tissue state includes fluid-rich or bleeding state, normal soft tissue state, and dry coagulation state. Let Z represent the measured impedance value, and the corresponding impedance ranges are 15Ω≤Z<50Ω, 50Ω≤Z<250Ω, and 250Ω≤Z≤900Ω, respectively. The control unit pre-stores a table of the correspondence between impedance values ​​and output power. After measuring the impedance, the system can directly look up the table to know how much power to give without performing complex real-time calculations. This results in a fast response speed and intelligent output. At the same time, by linking the impedance value with the specific tissue state, the system automatically identifies the tissue state and automatically matches the energy, providing precise output for different surgical sites and avoiding thermal damage caused by uniform power output.

[0021] In summary, the beneficial effects of this invention are as follows: 1. This invention controls the plasma signal output control circuit and impedance detection circuit to work alternately on the same plasma surgical electrode through a control unit. This allows the same electrode to both output plasma energy for surgery and measure tissue impedance, without the need to change the electrode or modify its structure. At the same time, the control unit adjusts the output power in real time based on the measured impedance value, eliminating the need for doctors to manually adjust the power level based on experience. Energy output and impedance measurement can be reused without changing or modifying the electrode structure. The invention adaptively reduces the output power for low-impedance fluid-rich tissues and adjusts the output strategy for high-impedance coagulated tissues, avoiding excessive energy deposition that could cause tissue thermal damage. This makes the surgery safer and the results more stable.

[0022] 2. This invention employs a two-stage dynamic DC modulation circuit and a DC-to-AC modulation circuit, which are responsible for voltage regulation and inversion, respectively. The dynamic DC modulation circuit first adjusts the fixed DC 320V power supply to a variable reference voltage. A higher voltage results in higher output power, and a lower voltage results in lower power. After receiving this variable voltage, the DC-to-AC modulation circuit inverts it into high-voltage, high-frequency AC power, which is then boosted to the several hundred volts required for surgery via a high-frequency switching transformer. The two stages have clear division of labor: the first stage regulates the voltage, and the second stage inverts and boosts it. Only by working together can the output power be precisely adjusted, providing a stable energy source for accurate surgery.

[0023] 3. This invention uses a plasma signal output anomaly monitoring circuit to monitor the output status in real time. When an overcurrent or short-circuit anomaly is detected, the anomaly signal is fed back to the control unit, which then executes protective actions to achieve rapid response and timely protection, preventing the fault from escalating. The anomaly monitoring and impedance detection are two independently operating systems: the plasma signal output anomaly monitoring circuit continuously monitors the output current in real time during the period when the plasma signal output control circuit outputs a plasma surgical signal to the plasma surgical electrode; within the measurement window of the impedance detection circuit, since the plasma signal output control circuit has stopped outputting, the plasma signal output anomaly monitoring circuit is in a standby state with no output current. Safety within this measurement window is ensured by the control unit's software-timed shutdown and preset delay. The two systems have clear division of labor and do not interfere with each other, resulting in higher system safety. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating the principle of the present invention; Figure 2 This is a schematic diagram of the impedance detection circuit of the present invention; Figure 3 This is a schematic diagram of the working process of the plasma surgical system of the present invention; Figure 4 This is a schematic diagram of the retractable insulating sleeve of the present invention; Figure 5This is a schematic diagram showing the separation of the sliding ring and the fixed ring of the present invention; 1-Plasma surgical electrode, 2-Plasma signal output control circuit, 3-Impedance detection circuit, 4-Control unit, 5-Drive control isolation circuit, 6-DC to AC modulation circuit, 7-Dynamic DC modulation circuit, 8-Power input circuit, 9-Plasma signal output abnormality monitoring circuit, 10-Foot switch, 11-Foot switch drive circuit, 12-Human machine interaction module, 31-Measurement circuit, 81-AC220V input terminal, 82-Fuse, 83-Power switch, 84-Power filter, 85-AC220V power supply rectification and filtering circuit, 86-Switching power supply, 87-Linear voltage regulator circuit, 101-Retractable insulating sleeve, 102-Plasma gas delivery channel, 103-Side air inlet, 104-Piston chamber, 121-LCD display and touch screen, 122-Output sound prompt circuit, 1011-Fixing ring, 1012-Sliding ring, 1013-Reset spring, 1014-Spring energy storage sealing ring. Detailed Implementation

[0025] The following specific embodiments are merely illustrative of the present invention and are not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of the present invention.

[0026] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] Example 1

[0028] according to Figures 1-3As shown, a dynamic impedance adaptive plasma surgical system includes a plasma surgical electrode 1, a plasma signal output control circuit 2, an impedance detection circuit 3, and a control unit 4. The plasma signal output control circuit 2 is connected to the plasma surgical electrode 1 and is used to output a plasma surgical signal to the plasma surgical electrode 1. The impedance detection circuit 3 is connected to the plasma surgical electrode 1 and is used to inject a measurement signal into the plasma surgical electrode 1 and obtain the impedance value of the surgical site. The control unit 4 is connected to the plasma signal output control circuit 2 and the impedance detection circuit 3. The control unit 4 controls the plasma signal output control circuit 2 and the impedance detection circuit 3 to alternately connect to the plasma surgical electrode 1 in a time-division multiplexing manner, and the control unit 4 adjusts the output power of the plasma signal output control circuit 2 according to the impedance value measured by the impedance detection circuit 3. The system also includes a DC-to-AC modulation circuit 6, which is connected to the plasma signal output control circuit 4. Upstream of circuit 2, the control unit 4 is connected to the DC-to-AC modulation circuit 6 via a drive control isolation circuit 5. The drive control isolation circuit 5 isolates the control side from the power side. It also includes a dynamic DC modulation circuit 7, connected upstream of the DC-to-AC modulation circuit 6, which outputs a reference voltage to the DC-to-AC modulation circuit 6. The control unit 4 is also connected to the dynamic DC modulation circuit 7 via the drive control isolation circuit 5. Furthermore, it includes a power input circuit 8, which includes an AC220V input terminal 81, a fuse 82, a power switch 83, and a power filter 84 connected in sequence. The output terminal of the power filter 84 is connected in parallel to an AC220V power rectifier and filter circuit 85 and a switching power supply 86. The AC220V power rectifier and filter circuit 85 outputs DC 320V to the dynamic DC modulation circuit 7. The switching power supply 86 outputs DC 12V, which is converted to 3V by a linear regulator circuit 87.The control unit 4 is powered by 3V / 5V. The control unit 4 uses software timing control to alternately connect the plasma signal output control circuit 2 and the impedance detection circuit 3 to the plasma surgical electrode 1. During the period when the plasma signal output control circuit 2 outputs a plasma surgical signal to the plasma surgical electrode 1, the impedance detection circuit 3 stops working; during the period when the impedance detection circuit 3 injects a measurement signal into the plasma surgical electrode 1, the plasma signal output control circuit 2 stops outputting, and a preset delay is provided between the two periods. The system also includes a foot switch 10, a foot switch drive circuit 11, and a human-machine interface module 12. The foot switch drive circuit 11 is connected between the foot switch 10 and the control unit 4, and the human-machine interface module 12 includes an LCD display connected to the control unit 4. The control unit 4 includes a touchscreen 121 and an output sound prompt circuit 122. It has a data storage unit that pre-stores a mapping relationship between impedance values ​​and output power. The control unit 4 determines the target output power by querying the mapping relationship based on the measured impedance value and judges the tissue state based on the impedance value measured by the impedance detection circuit 3. The tissue state includes fluid-rich or bleeding state, normal soft tissue state, and dry coagulation state, with corresponding impedance ranges of 15Ω≤Z<50Ω, 50Ω≤Z<250Ω, and 250Ω≤Z≤900Ω, respectively. When the measured impedance value is less than 15Ω, it is determined to be an abnormally low impedance state, and a protection action of reducing power or cutting off output is executed. When the measured impedance value is greater than 900Ω, it is determined to be an abnormally high impedance state, and a protection action of stopping output or prompting electrode replacement is executed.

[0029] according to Figure 2 As shown, the impedance detection circuit 3 includes a high-frequency signal source and a measurement circuit 31. The high-frequency signal source is generated by the on-chip PWM module of the control unit 4 and outputs a measurement signal with a frequency of 100kHz. The measurement circuit 31 includes a digital isolator U5. The control side of the digital isolator U5 is connected to the control unit 4, and the isolation side of the digital isolator U5 is connected to the plasma surgical electrode 1 through a signal conditioning network. The signal conditioning network includes a resistor network RN8 and filter inductors L19-L22.

[0030] according to Figure 1As shown, it also includes a plasma signal output anomaly monitoring circuit 9, connected between the plasma signal output control circuit 2 and the control unit 4. The plasma signal output anomaly monitoring circuit 9 uses a current transformer to continuously monitor the output current of the plasma signal output control circuit 2 in real time. When an overcurrent, short circuit, or open circuit anomaly is detected, the anomaly signal is fed back to the control unit 4, which then performs a protection action. This anomaly monitoring is independent of the periodic measurement of the impedance detection circuit 3; the plasma signal output anomaly monitoring circuit 9 maintains real-time monitoring within the few microsecond measurement window of the impedance detection circuit 3.

[0031] Working principle: According to Figures 1-3 As shown, S1: System power-on. The AC220V mains power is split into two paths after passing through fuse 82, power switch 83, and power filter 84. One path is converted into DC320V by AC220V power rectifier and filter circuit 85 and sent to dynamic DC modulation circuit 7. The other path is converted into DC12V by switching power supply 86 and then converted into 3.3V / 5V by linear voltage regulator circuit 87 to power control unit 4.

[0032] S2: Initialize standby. Control unit 4 performs a power-on self-test, checks the impedance-power mapping relationship pre-stored in the data storage unit and the status of the peripheral circuits, and then enters standby mode to wait for foot switch 10 to trigger.

[0033] S3: Trigger plasma output. The doctor presses the foot switch 10, and the control unit 4 sends drive commands to the dynamic DC modulation circuit 7 and the DC-to-AC modulation circuit 6 simultaneously through the drive control isolation circuit 5. The dynamic DC modulation circuit 7 outputs a variable reference voltage through the high-frequency switching transformer T3, and the DC-to-AC modulation circuit 6 inverts it into a high-voltage, high-frequency plasma signal through the high-frequency switching transformer T2. The signal is then sent to the plasma surgical electrode 1 via the plasma signal output control circuit 2 to act on the tissue.

[0034] S4: Impedance detection sleep mode. During the plasma output period, the control unit 4 controls the impedance detection circuit 3 to stop working; at the same time, the plasma signal output abnormality monitoring circuit 9 continuously monitors the output current in real time through a current transformer. This abnormality monitoring is independent of the impedance detection.

[0035] S5: Shutdown and Delay. Control unit 4 shuts down plasma signal output control circuit 2 at a preset period of 1ms, plasma output stops, and the system enters a preset delay of 50μs to wait for residual energy to dissipate.

[0036] S6: Impedance Measurement. After the delay ends, the control unit 4 activates the impedance detection circuit 3, which generates a 100kHz measurement signal from the on-chip PWM module. After being isolated by the digital isolator U5, the signal is sent to the plasma surgical electrode 1 for tissue injection through the signal conditioning network, resistor network RN8, and filter inductors L19-L22. The response signal returns along the original path and is sampled by the on-chip ADC. The real-time impedance value is obtained by calculating the voltage-current ratio.

[0037] S7: Closed-loop regulation. The control unit 4 writes the measured impedance value into the buffer register, queries the impedance-power mapping relationship in the data storage unit to determine the target output power, and judges the organizational state based on the impedance value, dynamically adjusting the PWM duty cycle output to the dynamic DC modulation circuit 7 to achieve adaptive regulation of the output power.

[0038] S8: Repeated cycle. After the measurement is completed, the control unit 4 shuts off the impedance detection circuit 3 and re-enables the plasma signal output control circuit 2. The system repeats S3 to S8 with a period of 1ms until the surgery is over.

[0039] Example 2

[0040] The difference from Embodiment 1 above is that, according to Figures 4-5 As shown, this embodiment provides a plasma surgical electrode structure suitable for a gaseous working medium (such as argon). The head end of the plasma surgical electrode 1 is provided with a retractable insulating sleeve 101. The retractable insulating sleeve 101 is sleeved on the outer periphery of the front end of the electrode rod of the plasma surgical electrode 1 and can slide axially. The electrode rod has a hollow structure, and a plasma gas delivery channel 102 is provided inside the electrode rod. A lateral air inlet 103 is opened on the side wall of the electrode rod. The air inlet is a micro-hole or a throttling hole, which does not affect the main airflow. The retractable insulating sleeve 101 includes a fixing ring 1011 and a sliding ring 1012. 1011 is fixed on the outer wall of the plasma surgical electrode 1. The sliding ring 1012 is movably and slidably disposed outside the fixed ring 1011. A return spring 1013 is provided between the fixed ring 1011 and the sliding ring 1012. A spring energy storage sealing ring 1014 is provided between the sliding ring 1012 and the fixed ring 1011 and between the sliding ring 1012 and the electrode rod. The system also includes an airflow control valve 105 controlled by the control unit 4. The airflow control valve 105 is disposed upstream of the plasma gas delivery channel 102 and is used to control the on / off of the working gas to the plasma gas delivery channel 102.

[0041] When the plasma surgery system is in plasma output mode, such as when the doctor presses the foot switch 10 to trigger continuous output, the control unit 4 controls the airflow control valve 105 to open, and the working gas enters the plasma gas delivery channel 102. The gas pressure in the plasma gas delivery channel 102 enters the piston chamber 104 formed between the fixed ring 1011, the sliding ring 1012 and the electrode rod through the side air inlet 103, pushing the sliding ring 1012 to overcome the elastic force of the reset spring 1013 and retract backward, so that the central electrode head of the plasma surgical electrode 1 is completely exposed to ensure normal plasma discharge.

[0042] When the plasma surgery system switches to the non-output impedance measurement mode or standby mode, if the doctor releases the foot switch 10 or the system enters standby mode, the control unit 4 controls the airflow control valve 105 to close, cutting off the working air source. The air pressure in the piston chamber 104 is slowly released through the side air inlet 103. The reset spring 1013 pushes the retractable insulating sleeve 101 forward, so that the front end of the retractable insulating sleeve 101 extends beyond the outer edge of the central electrode head, exposing only the central area of ​​the central electrode head.

[0043] Physical and dynamic isolation of the electrode tip is achieved through a retractable insulating sleeve: in output mode, argon gas pressure pushes the sleeve back, completely exposing the tip and allowing normal plasma discharge; in measurement / standby mode, the gas supply is cut off, a reset spring pushes the sleeve out, and the tip is insulated, with only the center exposed. This is a double guarantee of software timing and mechanical isolation: the software control circuit is turned off, and the mechanical structure simultaneously physically isolates the residual high voltage, solving the core safety problem of hundreds of volts of residual charge coupling to a few volts of measurement circuit. The side air inlet 103 is a micro-orifice or throttling orifice used to divide the main airflow to the piston chamber 104 to drive the sleeve, and its orifice diameter design does not affect the normal supply of the main airflow.

Claims

1. A dynamically impedance-adaptive plasma surgical system, characterized in that, The device includes a plasma surgical electrode (1), a plasma signal output control circuit (2), an impedance detection circuit (3), and a control unit (4). The plasma signal output control circuit (2) is connected to the plasma surgical electrode (1) and is used to output a plasma surgical signal to the plasma surgical electrode (1). The impedance detection circuit (3) is connected to the plasma surgical electrode (1) and is used to inject a measurement signal into the plasma surgical electrode (1) and obtain the impedance value of the surgical site. The control unit (4) is connected to the plasma signal output control circuit (2) and the impedance detection circuit (3). The control unit (4) controls the plasma signal output control circuit (2) and the impedance detection circuit (3) to alternately connect to the plasma surgical electrode (1) in a time-division multiplexing manner. The control unit (4) adjusts the output power of the plasma signal output control circuit (2) according to the impedance value measured by the impedance detection circuit (3).

2. The dynamically impedance-adaptive plasma surgical system according to claim 1, characterized in that, It also includes a DC-to-AC modulation circuit (6), which is connected upstream of the plasma signal output control circuit (2). The control unit (4) is connected to the DC-to-AC modulation circuit (6) through a drive control isolation circuit (5), which is used to isolate the control side from the power side.

3. The dynamically impedance-adaptive plasma surgical system according to claim 2, characterized in that, It also includes a dynamic DC modulation circuit (7), which is connected upstream of the DC-to-AC modulation circuit (6) and is used to output a reference voltage to the DC-to-AC modulation circuit (6). The control unit (4) is also connected to the dynamic DC modulation circuit (7) through the drive control isolation circuit (5).

4. The dynamically impedance-adaptive plasma surgical system according to claim 3, characterized in that, It also includes a power input circuit (8), which includes an AC220V input terminal (81), a fuse (82), a power switch (83), and a power filter (84) connected in sequence. The output terminal of the power filter (84) is connected in parallel to an AC220V power rectifier and filter circuit (85) and a switching power supply (86). The AC220V power rectifier and filter circuit (85) outputs DC320V to the dynamic DC modulation circuit (7). The switching power supply (86) outputs DC12V, which is converted to 3.3V / 5V by a linear voltage regulator circuit (87) to power the control unit (4).

5. The dynamically impedance-adaptive plasma surgical system according to claim 1, characterized in that, The control unit (4) uses software timing control to alternately connect the plasma signal output control circuit (2) and the impedance detection circuit (3) to the plasma surgical electrode (1). During the period when the plasma signal output control circuit (2) outputs a plasma surgical signal to the plasma surgical electrode (1), the impedance detection circuit (3) stops working. During the period when the impedance detection circuit (3) injects a measurement signal into the plasma surgical electrode (1), the plasma signal output control circuit (2) stops outputting, and a preset delay is provided between the two periods.

6. The dynamically impedance adaptive plasma surgical system according to claim 1, characterized in that, The impedance detection circuit (3) includes a high-frequency signal source and a measurement circuit (31). The high-frequency signal source is generated by the on-chip PWM module of the control unit (4) and outputs a measurement signal with a frequency of 100kHz. The measurement circuit (31) includes a digital isolator (U5). The control side of the digital isolator (U5) is connected to the control unit (4). The isolation side of the digital isolator (U5) is connected to the plasma surgical electrode (1) through a signal conditioning network. The signal conditioning network includes a resistor network (RN8) and filter inductors (L19-L22).

7. The dynamically impedance adaptive plasma surgical system according to claim 1, characterized in that, It also includes a plasma signal output abnormality monitoring circuit (9), which is connected between the plasma signal output control circuit (2) and the control unit (4).

8. The dynamically impedance-adaptive plasma surgical system according to claim 1, characterized in that, It also includes a foot switch (10), a foot switch drive circuit (11), and a human-machine interaction module (12). The foot switch drive circuit (11) is connected between the foot switch (10) and the control unit (4). The human-machine interaction module (12) includes an LCD display and touch screen (121) connected to the control unit (4) and an output sound prompt circuit (122).

9. The dynamically impedance-adaptive plasma surgical system according to claim 1, characterized in that, The control unit (4) is equipped with a data storage unit. The data storage unit pre-stores the mapping relationship between impedance value and output power. The control unit (4) queries the mapping relationship based on the measured impedance value to determine the target output power, and judges the tissue state based on the impedance value measured by the impedance detection circuit (3). The tissue state includes fluid-rich or bleeding state, normal soft tissue state and dry coagulation state, with corresponding impedance ranges of 15Ω≤Z<50Ω, 50Ω≤Z<250Ω and 250Ω≤Z≤900Ω, respectively.

10. A dynamically impedance-adaptive plasma surgical system according to claim 1, characterized in that, The head end of the plasma surgical electrode (1) is provided with a retractable insulating sleeve (101). The retractable insulating sleeve (101) is sleeved on the outer periphery of the front end of the electrode rod of the plasma surgical electrode (1) and can slide axially. The electrode rod has a hollow structure and a plasma gas delivery channel (102) is provided inside the electrode rod. A lateral air inlet (103) is opened on the side wall of the electrode rod. The retractable insulating sleeve (101) includes a fixing ring (1011) and a sliding ring. The ring (1012) is fixed on the outer wall of the plasma surgical electrode (1). The sliding ring (1012) is movably and slidably disposed outside the fixed ring (1011). A reset spring (1013) is provided between the fixed ring (1011) and the sliding ring (1012). A spring energy storage sealing ring (1014) is provided between the sliding ring (1012) and the fixed ring (1011) and between the sliding ring (1012) and the electrode rod.

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