A novel plasma surgical device and control method

Abstract

The application provides a novel plasma surgical device and control method, which solves the problem of low arc starting rate of the plasma system of the surgical device, and comprises a power supply board and a main control board, the power supply board is internally provided with a common mode filter and a rectifier module, the common mode filter and the rectifier module are connected with a power amplifier circuit through a full-bridge DC / DC module, the power amplifier circuit is connected with an output connecting electrode through an output resonant circuit; the main control board is internally provided with an MCU module, the MCU module is connected with the full-bridge DC / DC module through a PWM controller, the MCU module is connected with the power amplifier circuit through a MOS drive module, the output resonant circuit is connected with the MCU module through a current sampling module and a voltage sampling module, and an effective value conversion module is arranged between the output resonant circuit and the MCU module, and the output connecting electrode is connected with the MCU module through an electrode recognition module. The application has the advantages of high arc starting rate, good safety and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of plasma surgical equipment, and particularly relates to a plasma surgical device and a control method. BACKGROUND

[0002] The plasma surgical equipment in the industry can realize plasma electrotomy and electrocoagulation operation on human soft tissue in a physiological saline environment, and the key core is how to quickly and smoothly cut the tissue while reducing thermal damage to the tissue when the plasma arc is used to cut the tissue. In actual application, the plasma surgery roughly goes through the following process: after the plasma electrotomy is started, the plasma surgical electrode first loads an initial power P0 to make the front end of the plasma surgical electrode generate plasma, which is commonly called arc striking. After the arc striking, the load impedance becomes larger, the plasma surgical electrode continuously outputs an electrotomy power P1 to realize cutting of the tissue, and the energy output is turned off after the cutting is completed. In the arc striking stage, the instantaneous power P0 needs to be much larger than the output power P1 to quickly strike the arc at the front end of the plasma surgical electrode, which is generally between a few milliseconds and a few tens of milliseconds. If the P0 power is too small, the arc striking is not easy or the arc striking time is too long, which affects the clinical effect. Similarly, in the tissue cutting, the load impedance changes in real time and changes between a few hundred ohms and a few thousand ohms. If the constant power is maintained before the entire load changes the impedance, especially during the high impedance period, a peak voltage that is too high will be output, which will cause excessive thermal damage to the tissue and even carbonization, and the advantages of low-temperature electrotomy of the plasma surgery cannot be reflected. At the same time, the high energy output will also increase the safety risk.

[0003] In order to solve the problems in the prior art, people have carried out long-term exploration and proposed various solutions. For example, a low-temperature plasma surgical system constant power circuit [201721465089.4] is disclosed in Chinese patent documents. The output current is sampled by a current transformer, the current signal is converted into a voltage signal by a sampling resistor, and two signals are respectively subjected to a precision half-wave rectification circuit and a filter circuit to obtain a direct current signal and a direct voltage signal. The two direct current signals are respectively input to a single-chip microcomputer for AD conversion, the single-chip microcomputer adjusts the voltage reference value, thereby changing the output voltage and current, so as to ensure the constant output power regardless of the load change.

[0004] The above-mentioned scheme solves the output gear control problem to some extent, but the scheme still has many deficiencies, such as low arc striking rate. SUMMARY

[0005] The application aims at the above-mentioned problems and provides a plasma surgical device with reasonable design and high arc striking rate.

[0006] The application aims at the above-mentioned problems, and provides a control method of a plasma surgical device with good operation safety.

[0007] To achieve the above-mentioned purpose, the application adopts the following technical scheme: a novel plasma surgical device, comprising a power board and a main control board, the power board is internally provided with a common mode filter and rectifier module, the common mode filter and rectifier module is connected with a power amplifier circuit through a full-bridge DC / DC module, the power amplifier circuit is connected with an output connecting electrode through an output resonant circuit; the main control board is internally provided with an MCU module, the MCU module is connected with the full-bridge DC / DC module through a PWM controller, the MCU module is connected with the power amplifier circuit through a MOS drive module, the output resonant circuit is connected with the MCU module through a current sampling module and a voltage sampling module, and an effective value conversion module is arranged between the output resonant circuit and the MCU module, and the output connecting electrode is connected with the MCU module through an electrode recognition module.

[0008] In the novel plasma surgical device, the MCU module is connected with a loudspeaker through an audio drive module.

[0009] In the novel plasma surgical device, the MCU module is connected with a touch screen and a foot pedal switch through a foot pedal detection module.

[0010] In the novel plasma surgical device, the main control board is internally provided with an isolation DC-DC module.

[0011] A control method of a novel plasma surgical device, comprising the following steps:

[0012] S1: AC 220V power from a network is supplied to a low-voltage module through a switching power supply to output +12V power, and another path is output through a common mode filter and rectifier module on a power board to output +310V DC voltage;

[0013] S2: when a foot pedal switch is stepped on, an MCU module of a main control board controls to enable +310V voltage to be output as a digital adjustable DC voltage VCT through a full-bridge DC / DC module;

[0014] S3: the adjusted VCT voltage is supplied to a power amplifier circuit, and a high-frequency high-voltage square wave voltage is output to an output resonant circuit after being processed by the power amplifier circuit;

[0015] S4: a high-voltage sinusoidal wave voltage of a corresponding frequency is output after resonance, and is applied to human tissues through an output connecting electrode to realize electrocutting or electrocoagulation operation.

[0016] In the control method of the novel plasma surgical device, the voltage of the DC voltage VCT in step S2 is set by a DA output module from the MCU module through a PWM controller.

[0017] In the control method of the new plasma surgical device, the voltage and current signals output by the output resonant circuit in step S4 are sampled and converted into effective values, and are transmitted to the AD sampling module in the MCU module to realize digital sampling. The impedance and power parameters of the current load tissue are calculated through the MCU module, and are compared with the preset gear parameters. The size of the VCT voltage is adjusted through the DA output module, so that the output power reaches the expected target value.

[0018] In the control method of the new plasma surgical device, the VCT voltage output by the power amplifier circuit in step S4 is positively correlated with the power loaded on the load tissue, and the specific conversion is as follows:

[0019] V vct1 / V vct0 =V p1 / V p0 =I p1 / I p0 =SQRT(P p1 / P p0 );

[0020] V vct0 : The DC voltage output by VCT at t0;

[0021] V vct1 : The DC voltage output by VCT at t1;

[0022] V p0 : The effective value voltage loaded on the patient at t0;

[0023] V p1 : The effective value voltage loaded on the patient at t1;

[0024] I p0 : The effective value current loaded on the patient at t0;

[0025] I p1 : The effective value current loaded on the patient at t1;

[0026] P p0 : The power loaded on the patient at t0;

[0027] P p1 : The power loaded on the patient at t1;

[0028] SQRT(): square root function.

[0029] In the control method of the new plasma surgical device, the output adjustment in step S4 is realized by using a segmented type, and the constant power and constant voltage are controlled in parallel in the electrocision stage. The specific conversion is as follows:

[0030] V vct1_p =V vct0 *SQRT(P p1 / P p0 );

[0031] V vct1_v =V vct0 *V p1 / V p0 ;

[0032] V vct1_p : the VCT voltage that should be output at t1 calculated by using the constant power mode;

[0033] V vct1_v : the VCT voltage that should be output at t1 calculated by using the constant voltage mode.

[0034] In the control method of the novel plasma surgical device, step S4 compares the absolute value between V vct1_p and V vct1_v , and the smaller value competes successfully to obtain the control right to control the DA output module to output the DA voltage corresponding to the VCT voltage, and the VCT voltage is in proportional relationship with the DA voltage, as shown below:

[0035] V vct1 =k*V DA ;

[0036] V DA : the DC voltage output by the DA module;

[0037] k: gain coefficient.

[0038] Compared with the prior art, the advantages of the present application are that: the segmented power output control is adopted, the ionization arc striking is faster, the cutting is smoother, the thermal damage is smaller, and the clinical effect is good; the closed loop control response is faster, the output power control is more accurate, the deviation between devices is small, and the expected power setting does not need to be manually adjusted frequently during use, and the operation is more convenient. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is the device structure principle diagram of the present application;

[0040] In the figure, the power board 1, the main control board 2, the audio drive module 21, the loudspeaker 22, the touch screen 23, the foot pedal detection module 24, the foot pedal switch 25, the isolation DC-DC module 26, the common mode filtering and rectifying module 3, the full-bridge DC / DC module 4, the power amplifier circuit 5, the output resonant circuit 6, the output connection electrode 7, the MCU module 8, the PWM controller 81, the MOS drive module 82, the current sampling module 83, the voltage sampling module 84, the electrode identification module 85, and the effective value conversion module 86. DETAILED DESCRIPTION

[0041] The application will be described in further detail below with reference to the drawings and specific embodiments.

[0042] As Figure 1 shown, a kind of plasma surgical device, including power panel 1 and master control board 2, power panel 1 is built-in common mode filter and rectifier module 3, common mode filter and rectifier module 3 is connected with power amplifier circuit 5 by full-bridge DC / DC module 4, power amplifier circuit 5 is connected with output connection electrode 7 by output resonant circuit 6;Master control board 2 is built-in MCU module 8, MCU module 8 is connected with full-bridge DC / DC module 4 by PWM controller 81, MCU module 8 is connected with power amplifier circuit 5 by MOS drive module 82, output resonant circuit 6 is connected with MCU module 8 and between effective value conversion module 86 is set up, and output connection electrode 7 is connected with MCU module 8 by electrode identification module 85.

[0043] Specifically, MCU module 8 is connected with loudspeaker 22 by audio drive module 21.In the time of electrocision or electrocoagulation, output different frequency sound, prompt user, when the device fails, also can sound alarm prompt user.

[0044] In-depth, MCU module 8 is connected with touch screen 23 and is connected with foot switch 25 by foot pedal detection module 24.Touch screen 23 carries out man-machine interaction with user, and it can realize data interaction between master control board by serial port or other communication mode.In addition, electrode interface is also set, and the radio frequency energy generated by the device is exported to output connection electrode 7 through the interface, and then is acted on patient tissue through output connection electrode 7 to realize electrocision electrocoagulation operation.Electrode interface is also set on the device, and foot switch 25 is connected through the interface, and doctor can control the start and stop of device electrocision or electrocoagulation energy output respectively through foot switch 25.

[0045] Further, master control board 2 is built-in isolation DC-DC module 26.Power panel 1 is provided with power input interface, and is connected with network electricity to supply power to equipment.

[0046] In the embodiment, the power board 1 and the main control board 2 hardware circuit are specially developed, the power board 1 adopts full-bridge topology to realize the isolation output of the switching power supply part VCT direct current voltage and the voltage output of the power amplifier part high-frequency alternating current sine wave, the key power amplifier transformer of the power supply transformer adopts EE55 magnetic core winding, the output inductance adopts ferrosilicon aluminum magnetic ring winding, the high-voltage and high-current switching is realized by using the high-power MOS tube such as FDA24N50 in the circuit, the PWM controller 81 such as UC3879DW is used for the pulse width modulation of the VCT output voltage, the output voltage of the power amplifier circuit 5 adopts the isolation transformer, and the voltage sampling is realized by using the optional UF16 magnetic core winding, the current signal is converted into voltage by using the current transformer such as PE-51688NL, and then the sampling is realized, the MCU module 8 adopts the general 32-bit ARM chip such as STM32F407, and the AD sampling module and the DA output module are provided, the touch screen 23 adopts the general 7-inch capacitive touch serial screen, the loudspeaker 22 adopts the general 8-ohm 2W loudspeaker, the foot switch 25 input is input to the MCU module 8 after being isolated by using the optocoupler such as TLP291 to realize the foot level sampling. By using the above circuit, the technical implementation is relatively easy, the components are easy to obtain, the cost is low, and the performance is stable and reliable.

[0047] A control method of a plasma surgical device, comprising the following steps:

[0048] S1: one way of the AC 220V power supply from the network power supply outputs +12V power supply to the low-voltage module for power supply, and the other way outputs +310V direct current voltage through the common-mode filter and the rectifier module 3 on the power board 1; wherein the low-voltage module includes the main control board 2, the touch screen 23 and the fan and the like components;

[0049] S2: when the foot switch 25 is stepped on, the MCU module 8 of the main control board 2 controls the +310V voltage to be isolated and output a digital adjustable direct current voltage VCT through the full-bridge DC / DC module 4;

[0050] S3: the adjusted VCT voltage supplies power to the power amplifier circuit 5, and outputs the high-frequency and high-voltage square wave voltage to the output resonant circuit 6 after being processed by the power amplifier circuit 5;

[0051] S4: the high-voltage sine wave voltage of the corresponding frequency is output after the resonance, and the operation of the electric cutting or the electric coagulation is realized by acting on the human tissue through the output connecting electrode 7.

[0052] In addition, the voltage size of the direct current voltage VCT in the step S2 is set by the DA output module from the MCU module 8 through the PWM controller 81.

[0053] Meanwhile, the voltage and current signals output by the output resonant circuit 6 in step S4 are sampled and converted into effective values, and are transmitted to the AD sampling module in the MCU module 8, to realize digital sampling, and the impedance and power parameters of the current load tissue are calculated through the operation of the MCU module 8, and are compared with the preset gear parameters, the size of the VCT voltage is adjusted through the DA output module, and then the output power reaches the expected target value.

[0054] It can be seen that the VCT voltage output by the power amplifier circuit 5 in step S4 is positively correlated with the power loaded on the load tissue, and the specific relationship is as follows:

[0055] V vct1 / V vct0 =V p1 / V p0 =I p1 / I p0 =SQRT(P p1 / P p0 );

[0056] V vct0 : the DC voltage output by the VCT at t0;

[0057] V vct1 : the DC voltage output by the VCT at t1;

[0058] V p0 : the effective value voltage loaded on the patient at t0;

[0059] V p1 : the effective value voltage loaded on the patient at t1;

[0060] I p0 : the effective value current loaded on the patient at t0;

[0061] I p1 : the effective value current loaded on the patient at t1;

[0062] P p0 : the power loaded on the patient at t0;

[0063] P p1 : the power loaded on the patient at t1;

[0064] SQRT(): square root function.

[0065] It is obvious that the output adjustment in step S4 is realized in a segmented manner. When the cutting is in the initial stage, before the arc is started, the load impedance is low, generally about 20-30 ohms, affected by the physiological saline. At this time, a larger output power P0 is controlled, and the instantaneous power of P0 can be selected between 700W-1400W, and the duration period is between 20-100ms. After the arc is started, the output impedance becomes large, generally between several hundred ohms to thousands of ohms. In the cutting stage, the control is performed in a constant power and constant voltage parallel competition mode, and the specific conversion is as follows:

[0066] V vct1_p =V vct0 *SQRT(P p1 / P p0 );

[0067] V vct1_v =V vct0 *V p1 / V p0 ;

[0068] V vct1_p : the VCT voltage that should be output at t1 calculated in the constant power mode;

[0069] V vct1_v : the VCT voltage that should be output at t1 calculated in the constant voltage mode.

[0070] Preferably, step S4 compares the absolute value between V vct1_p and V vct1_v , and the smaller value competes successfully to obtain the control right, and controls the DA output module to output the DA voltage corresponding to the VCT voltage. The VCT voltage and the DA voltage are in a proportional relationship, as shown below:

[0071] V vct1 =k*V DA ;

[0072] V DA : the DC voltage output by the DA module;

[0073] k: gain coefficient.

[0074] The DA module can be a built-in digital-to-analog converter of the MCU, or an external dedicated digital-to-analog conversion chip or module. The output voltage value of the DA module is controlled through the communication between the MCU and the DA module, so as to control the size of the VCT DC voltage, so that the energy loaded to the patient's tissue meets the expected setting.

[0075] Through the periodic closed-loop control, the energy loaded to the patient tissue is outputted according to the preset value of the software, the cutting smoothness is improved, the thermal damage is minimized, and the clinical effect is improved. The periodic control interval time is generally selected as 1-10 milliseconds, and the preferred value is 2 milliseconds.

[0076] Compared with the prior art, the output power is also controlled by the MCU to realize the electrocision and electrocoagulation operation, but the mainstream technology in the market is to control the maximum power through a peak control circuit, which only controls the maximum output power at the initial stage of the arc to protect the patient from greater harm, or a constant power circuit is used to control the constant power, which excessively emphasizes the constant power without considering that the output voltage is too large due to the constant power control when the impedance is too high during the electrocision, which brings greater thermal damage and increases the safety risk of the patient.

[0077] The present embodiment considers the actual operation of the plasma electrocision in each stage, a larger instantaneous power P0 is outputted at the early stage of the arc, the instantaneous power is set by software, the Na ions in the ionized saline solution are ionized faster to complete the ionization arc operation under the condition of ensuring the safety of the patient, and then the constant power and constant voltage competition output mode is entered, the constant power mode is mainly used for smooth cutting of the tissue, and the constant voltage mode is mainly used for controlling the risk of increased thermal damage caused by the high voltage during the cutting and separation of the tissue. Through the implementation of the technology, the present device can realize smoother plasma electrocision, the cutting edge is smooth, the thermal damage is smaller, and the clinical effect is better.

[0078] The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, without departing from the spirit of the present application or exceeding the scope defined by the appended claims.

[0079] Although the terms such as power board 1, main control board 2, audio drive module 21, loudspeaker 22, touch screen 23, foot pedal detection module 24, foot pedal switch 25, isolation DC-DC module 26, common mode filter and rectifier module 3, full-bridge DC / DC module 4, power amplifier circuit 5, output resonant circuit 6, output connection electrode 7, MCU module 8, PWM controller 81, MOS drive module 82, current sampling module 83, voltage sampling module 84, electrode identification module 85, and effective value conversion module 86 are used more frequently herein, the possibility of using other terms is not excluded. The use of these terms is only for more convenient description and explanation of the essence of the present application; any kind of additional limitation is contrary to the spirit of the present application.

Claims

1. A plasma surgical device, comprising a power supply board (1) and a main control board (2), characterized in that, The power board (1) has a built-in common-mode filter and rectification module (3), which is connected to the power amplifier circuit (5) through a full-bridge DC / DC module (4). The power amplifier circuit (5) is connected to the output connection electrode (7) through an output resonant circuit (6). The main control board (2) has a built-in MCU module (8), which is connected to the full-bridge DC / DC module (4) through a PWM controller (81). The MCU module (8) is connected to the power amplifier circuit (5) through a MOS drive module (82). The output resonant circuit (6) is connected to the MCU module (8) through a current sampling module (83) and a voltage sampling module (84), and an effective value conversion module (86) is provided between them. The output connection electrode (7) is connected to the power amplifier circuit (5) through an output resonant circuit (6). The polarity identification module (85) is connected to the MCU module (8); the MCU module (8) of the main control board (2) controls the +310V voltage to output a digitally adjustable DC voltage VCT through the full-bridge DC / DC module (4); the voltage and current signals output by the output resonant circuit (6) are sampled and converted to effective values, and then transmitted to the AD sampling module inside the MCU module (8) to realize digital sampling. The impedance and power parameters of the current load organization are calculated by the MCU module (8) and compared with the preset gear parameters. The magnitude of the VCT voltage is adjusted by the DA output module, so that the output power reaches the expected target value. The output adjustment of this plasma surgical device is implemented in a segmented manner. The electrocautery stage is controlled by a constant power and constant voltage in parallel competition.

2. The plasma surgical device according to claim 1, characterized in that, The MCU module (8) is connected to the speaker (22) through the audio driver module (21).

3. The plasma surgical device according to claim 1, characterized in that, The MCU module (8) is connected to a touch screen (23) and is connected to a foot switch (25) via a foot detection module (24).

4. The plasma surgical device according to claim 1, characterized in that, The main control board (2) has a built-in isolated DC-DC module (26).

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