Plasma operation system capable of rapidly generating plasma state and control method

Abstract

The invention provides a plasma operation system capable of rapidly generating plasma state and a control method, and solves the problem that plasma arc starting and arc retreating reaction is slow, the plasma operation system comprises an MCU module, the MCU module is connected with a switching power supply through a PWM controller, the MCU module is connected with a high-frequency power amplifier module through an MOS driving module, and the high-frequency power amplifier module is connected with a power supply. A voltage division circuit connected with the MCU module is connected between the switching power supply and the high-frequency power amplifier module, a fault detection module is connected between the high-frequency power amplifier module and the MCU module, the high-frequency power amplifier module is connected with an operation electrode, a voltage detection module and a current detection module which are connected with the MCU module are arranged between the high-frequency power amplifier module and the operation electrode, and the operation electrode is connected with the MCU module. The method has the advantages of being high in use safety, high in response speed and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical electrosurgical equipment, and in particular relates to a plasma surgery system for rapidly generating a plasma state and a control method thereof. Background Art

[0002] At present, plasma surgical equipment in the industry can realize plasma electrocuting and electrocoagulation operations on human soft tissues in a physiological saline environment. The key lies in how to cut quickly and smoothly while causing less thermal damage to the tissue when using a plasma arc to electrocute the tissue. The existing technology does not have a related technical implementation specifically for rapid plasma arc starting. It only uses a power amplifier circuit to output a large power under low load impedance to achieve ionization arc starting. In actual applications, this technology only limits the maximum output power of the plasma arc starting stage, which protects the equipment while reducing the maximum energy output to the patient to protect the patient. Although the implementation of this method can generate a plasma arc to a certain extent, the arc starting time is not fast enough, and the difficulty of arc starting will also increase. At the same time, after arc starting, it cannot quickly exit the arc starting state to the normal electrocuting state, which increases the risk of thermal damage to the tissue. Especially when performing plasma electrocautery on the surface of the endometrium of human tissue (such as the endometrium), if the surface is uneven, the arc will start too slowly or cannot be maintained during the cutting process (after arc starting, the arc will go out when the tip of the electrode slightly leaves the tissue during the movement, and the arc cannot be started again quickly after extinguishing), which will seriously affect the smoothness of the cutting, bring great inconvenience to the doctor's operation, and affect the clinical effect.

[0003] In order to solve the deficiencies of the prior art, people have conducted long-term exploration and proposed various solutions. For example, a Chinese patent document discloses a plasma energy control switch circuit and its control system [201911003169.1], which includes a peak power control circuit, a single-chip microcomputer and a switch module for being connected in series in the plasma energy control system circuit, wherein: the peak power control circuit is used to dynamically sample and filter the current of the plasma energy control system, and adjust the amplification factor of the generated voltage signal to adjust the peak power point, and then send it to the single-chip microcomputer; the single-chip microcomputer is used to receive and process the voltage signal sent by the peak power control circuit, and control the working cycle of the switch module according to the processed voltage signal, so that the output power of the plasma energy control system does not exceed the preset peak power and meets the preset power curve.

[0004] The above solution solves the problem of plasma arc generation to a certain extent, but the solution still has many shortcomings, such as slow arc starting and arc exiting reactions. Summary of the invention

[0005] The object of the present invention is to provide a plasma surgical system with reasonable design, good electro-cutting effect and rapid generation of plasma state in view of the above problems.

[0006] Another object of the invention is to provide a control method for a plasma surgery system that can quickly generate a plasma state with a fast arc starting and arc exiting response rate in order to solve the above-mentioned problem.

[0007] To achieve the above-mentioned purpose, the present invention adopts the following technical solutions: a plasma surgical system for rapidly generating a plasma state, comprising an MCU module, the MCU module being connected to a switching power supply via a PWM controller, the MCU module being connected to a high-frequency power amplifier module via a MOS driving module, a voltage divider circuit connected to the MCU module being connected between the switching power supply and the high-frequency power amplifier module, a fault detection module being connected between the high-frequency power amplifier module and the MCU module, a surgical electrode being connected to the high-frequency power amplifier module and a voltage detection module and a current detection module connected to the MCU module being arranged therebetween, and the surgical electrode being connected to the MCU module.

[0008] In the above-mentioned plasma surgery system for rapidly generating a plasma state, the MCU module is connected to a speaker via a sound control module.

[0009] In the above-mentioned plasma surgery system for rapidly generating a plasma state, the MCU module is connected to a touch screen and a foot switch.

[0010] A control method for a plasma surgery system for rapidly generating a plasma state comprises the following steps:

[0011] S1: When the foot switch is connected to the surgical electrode, the MCU module scans the status of the foot switch in real time. When the electrosurgical cutting pedal of the foot switch is pressed, the state change is detected by the MCU module, and the electrosurgical cutting mode is started, first entering the pre-processing mode;

[0012] S2: Determine whether there is an abnormality in preprocessing, if not, enter arc starting control;

[0013] S3: Determine whether the arc is successfully started, if successful, enter the tissue cutting stage;

[0014] S4: The system detects the status of the foot switch. When the foot switch is released, all outputs are turned off and the electric cutting mode is exited; otherwise, the tissue cutting stage continues.

[0015] In the above-mentioned control method for a plasma surgery system for rapidly generating a plasma state, the pre-processing mode in step S1 includes the following steps:

[0016] S11: The MCU module controls the switching power supply to output a preset VCT DC voltage through the DA module, and samples the VCT voltage through the voltage divider circuit to determine whether the actual output VCT voltage is within the preset range;

[0017] S12: Control the high-frequency power amplifier output through complementary PWM signals, and detect the working state of the high-frequency power amplifier module through a feedback circuit. When the high-frequency power amplifier module is normal, detect the high-frequency voltage and high-frequency current output by the high-frequency power amplifier module, and calculate the current initial impedance R0.

[0018] In the above-mentioned control method of a plasma surgery system that quickly generates a plasma state, when the initial impedance R0 of step S2 is less than a certain value, arc starting control is entered; if any step is abnormal, all outputs are directly turned off to end the operation of the electric cutting mode.

[0019] In the above-mentioned control method for a plasma surgery system for rapidly generating a plasma state, step S3 includes the following steps:

[0020] S31: The system will control the switching power supply to output the VCT voltage through the DA module, record V vct1 ;

[0021] S32: The system detects the high-frequency voltage and high-frequency current output by the high-frequency power amplifier module, and calculates the current load impedance R1;

[0022] S33: The system increases the VCT voltage output, record V vct2 ;

[0023] S34: After a delay of about 1 millisecond according to the above steps, a new load impedance R2 is obtained, and the load impedance R is obtained by analogy. n When multiple newly acquired load impedances are greater than R0, it is considered that the system ionization arc is successful and enters the tissue cutting stage.

[0024] In the above-mentioned control method of a plasma surgery system that quickly generates a plasma state, when the arc starting is successfully judged in step S3, the longest arc starting time is simultaneously counted. When the time overflows, the energy output is turned off, and after a delay, step S3 is re-entered to perform arc starting control.

[0025] In the above-mentioned control method of a plasma surgery system for rapidly generating a plasma state, step S3 is to, during the tissue cutting stage, detect the load impedance R m and load power P m , the system output power is adjusted in real time in a closed loop. The adjustment algorithm adopts a dual competition method, that is, to ensure that the output constant power and constant voltage modes compete. The module corresponding to the expected smaller VCT voltage obtains a competitive advantage, and the switching power supply output is controlled through the DA module.

[0026] In the above-mentioned control method of a plasma surgery system that quickly generates a plasma state, the tissue cutting stage in step S3 is changed to the tissue coagulation stage, and the adjustment algorithm adopts a three-competition method, namely, ensuring that the output constant current, constant power and constant voltage modes compete, and the module corresponding to the expected smaller VCT voltage obtains a competitive advantage, and the switching power supply output is controlled through the DA module.

[0027] Compared with the existing technology, the advantages of the present invention are: a dynamic energy loading method is used to realize plasma ionization of Na ions in a physiological saline solution, the plasma arc starts faster, the arc is not easy to extinguish during the electric cutting process, the cutting performance is smoother, and the clinical performance is better; it avoids the shortcomings brought by a fixed energy loading method, prevents too small a loading energy setting from causing insufficient energy and making it difficult to start the plasma arc; prevents too high a loading energy setting from causing an instantaneous burst of excessive energy to cause greater thermal damage to the tissue, thereby improving the safety of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a system principle diagram of the present invention;

[0029] Figure 2 is a flow chart of the method of the present invention;

[0030] In the figure, MCU module 1, sound control module 11, speaker 12, touch screen 13, foot switch 14, PWM controller 2, switching power supply 3, MOS drive module 4, high-frequency power amplifier module 5, voltage divider circuit 6, fault detection module 7, surgical electrode 8, voltage detection module 81, and current detection module 82. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1-2As shown, a plasma surgical system that rapidly generates a plasma state generates high-frequency energy through a generator, and excites physiological saline solution to form a high-energy-density plasma thin layer around the surgical electrode, which is a highly ionized and highly vaporized plasma layer (50um-100um). The thin layer has enough energy to crush the organic molecular chains in the tissue, thereby separating the molecules and reducing the tissue volume, achieving the purpose of cutting, coagulation and hemostasis, and realizing the localized separation of the patient's tissue. It includes an MCU module 1, the MCU module 1 is connected to a switching power supply 3 through a PWM controller 2, the MCU module 1 is connected to a high-frequency power amplifier module 5 through a MOS driver module 4, a voltage divider circuit 6 connected to the MCU module 1 is connected between the switching power supply 3 and the high-frequency power amplifier module 5, a fault detection module 7 is connected between the high-frequency power amplifier module 5 and the MCU module 1, the high-frequency power amplifier module 5 is connected to a surgical electrode 8, and a voltage detection module 81 and a current detection module 82 connected to the MCU module 1 are arranged between the high-frequency power amplifier module 5, and the surgical electrode 8 is connected to the MCU module 1.

[0033] The AC220V mains power supply is isolated and outputs an adjustable DC voltage (VCT for short) through a switching power supply 3. The VCT voltage is loaded into a high-frequency power amplifier module 5 composed of a full-bridge topology structure. The high-frequency power amplifier module 5 is driven by a complementary PWM signal generated by the MCU module 1 through a dedicated MOS tube driver chip. The high-voltage sinusoidal wave voltage output by the high-frequency power amplifier module 5 acts on the patient's surgical site through a surgical electrode 8. The surgical site is in a saline environment, and the Na ions therein are excited by high frequency and high voltage, and a high-energy plasma thin layer is quickly generated at the front end of the surgical electrode to form a plasma arc. The arc carries a large amount of energy, acts on the lesion tissue, crushes the organic molecular chains in the tissue, and achieves effective cutting of the tissue and coagulation and hemostasis.

[0034] Specifically, the MCU module 1 is connected to the speaker 12 via the sound control module 11 .

[0035] Furthermore, the MCU module 1 is connected to a touch screen 13 and a foot switch 14 .

[0036] In this embodiment, the switching power supply 3 adopts a full-bridge topology to achieve the isolated output of the VCT DC voltage, and the high-frequency power amplifier module 5 adopts a full-bridge topology to achieve the voltage output of the high-frequency AC sine wave. The key power transformer and the power amplifier transformer are wound with EE55 magnetic cores, and the output inductor is wound with iron silicon aluminum magnetic rings. A high-power MOS tube (such as FDA24N50) is used in the circuit to achieve high-voltage and high-current switching. The output voltage of the high-frequency power amplifier module 5 adopts an isolation transformer (optionally wound with UF16 magnetic core) for voltage sampling, and the output current adopts a current transformer (such as PE-51688NL) to convert the current signal into voltage for sampling. The AC signal is converted into a DC signal using a dedicated effective value chip. The MCU module 1 adopts a general 32-bit ARM chip (such as STM32F407), which has its own AD sampling module and DA output module, and can also be connected to a dedicated ADC chip and / or DAC chip. The output of the PWM controller 2 is realized by the built-in hardware PWM module of the MCU module 1, and the software sets its operating frequency and the phase difference between the signals. The MCU module 1 has a built-in communication module to realize communication with the external capacitive touch screen. The speaker 12 uses a general 8-ohm 2W speaker. The input of the foot switch 14 is isolated by an optical coupler (such as TLP291) and then input to the MCU module 1 to realize foot level sampling. The above circuit is easy to implement, components are easy to obtain, the cost is low, and the performance is stable and reliable.

[0037] In actual operation, in order to ensure better plasma arc starting effect and cutting effect, the system collects the high-frequency voltage and high-frequency current loaded on the tissue in real time through the voltage detection module 81 and the current detection module 82, and converts the collected effective value voltage into a digital signal through the built-in ADC chip of the MCU module 1. Through software operation, the real-time impedance R and real-time power P currently loaded on the tissue are calculated, as follows:

[0038] R=V rms / I rms

[0039] P=V rms *I rms

[0040] V rms : Effective value of high-frequency voltage loaded into the tissue;

[0041] I rms : Effective value of high-frequency current loaded into tissue.

[0042] According to the changes in impedance and power, corresponding software adjustments are made, and finally the DA output module outputs an adjustable DC voltage. The PWM controller controls the switching power supply and outputs a VCT voltage corresponding to the DA voltage. The relationship is as follows:

[0043] Vvct = k*V DA

[0044] V vct : The adjustable DC voltage output by the switching power supply can generally be selected between 0 and 150 V or other approximate values;

[0045] V DA :The DC voltage output by the DA module can generally be selected as 0~3.3V or 0~5.0V or other approximate values;

[0046] k: Gain coefficient, determined by the hardware circuit, generally selectable between 20 and 60.

[0047] Through the above adjustment, the high-frequency power amplifier module 5 loaded with the changed VCT voltage generates a corresponding high-frequency and high-voltage output, thereby effectively controlling the energy loaded on the tissue.

[0048] A control method for a plasma surgery system for rapidly generating a plasma state comprises the following steps:

[0049] S1: When the foot switch 14 is connected to the surgical electrode 8, the MCU module 1 performs real-time scanning of the state of the foot switch 14. When the electrosurgical cutting pedal of the foot switch 14 is stepped on, the state change is detected by the MCU module 1, and the electrosurgical cutting mode is started, and the pre-treatment mode is first entered;

[0050] S2: Determine whether there is an abnormality in preprocessing, if not, enter arc starting control;

[0051] S3: Determine whether the arc is successfully started, if successful, enter the tissue cutting stage;

[0052] S4: The system detects the state of the foot switch 14. When the foot switch 14 is released, all outputs are turned off and the electrocuting mode is exited; otherwise, the tissue cutting phase is continued and the load impedance R detected in real time is adjusted. m , judge the current plasma arc state, such as R m When reducing a certain value, R is generally selected m ≤2*R0, the arc is considered to be extinguished, and the system re-enters step S2 to perform arc striking control again.

[0053] Furthermore, the preprocessing mode in step S1 includes the following steps:

[0054] S11: The MCU module 1 controls the switching power supply 3 to output a preset VCT DC voltage (the VCT voltage can be selected as 20V-40V) through the DA module, and samples the VCT voltage through the voltage divider circuit 6 to determine whether the actual output VCT voltage is within a preset range; the preset deviation can generally be selected as ±20% to ±40%;

[0055] S12: Control the high-frequency power amplifier output through complementary PWM signals, and detect the working state of the high-frequency power amplifier module 5 through a feedback circuit. When the working state is normal, detect the high-frequency voltage and high-frequency current output by the high-frequency power amplifier module 5, and calculate the current initial impedance R0.

[0056] Furthermore, when the initial impedance R0 of step S2 is less than a certain value, which can generally be selected as 200-300 ohms, the arc starting control is entered; if any step is abnormal, all outputs are directly turned off to end the operation of the electric cutting mode.

[0057] In addition, step S3 includes the following steps:

[0058] S31: The system will control the switch power supply 3 to output the VCT voltage through the DA module, record V vct1 , the voltage can be selected between 80 and 100V;

[0059] S32: After a delay of about 1 millisecond, the system detects the high-frequency voltage and high-frequency current output by the high-frequency power amplifier module 5, and calculates the current load impedance R1;

[0060] S33: The system increases the VCT voltage output, record V vct2 , V vct2 -V vct1 A value between 0.5V and 2V can be selected;

[0061] S34: After a delay of about 1 millisecond according to the above steps, a new load impedance R2 is obtained, and the load impedance R is obtained by analogy. n When multiple newly acquired load impedances are greater than R0, R n ≥(3~5)*R0, the system is considered to have successfully ionized and started the arc, entering the tissue cutting stage.

[0062] At the same time, when the arc is successfully judged in step S3, the longest arc time is counted at the same time, which can generally be selected as 50 to 100 milliseconds. When the time exceeds, the energy output is turned off, and after a delay, step S3 is re-entered to perform arc control.

[0063] It can be seen that in step S3, during the tissue cutting stage, according to the detected load impedance R m and load power P m , the system output power is adjusted in real time in a closed loop. The adjustment period can generally be selected as 1 to 10 milliseconds, preferably 2 milliseconds. The adjustment algorithm adopts a double competition method, that is, to ensure that the output constant power and constant voltage modes compete. It is expected that the module corresponding to the smaller VCT voltage will gain a competitive advantage. The output of the switching power supply 3 is controlled by the DA module, in order to maintain the cutting of the tissue with the lowest possible energy and reduce thermal damage.

[0064] According to the above steps S1-S4, a plasma arc can be quickly generated, and power output can be performed according to the power level preset by the software (the power value or power gear is set through the user interface), thereby improving the cutting smoothness while minimizing thermal damage and improving clinical effects.

[0065] The system can also realize electrocoagulation of tissues, and its working steps are slightly different from the above steps. After step S1 and step S2, in step S3, the tissue cutting stage is changed to the tissue coagulation stage, and the adjustment algorithm adopts a three-competition method, that is, to ensure that the output constant current, constant power and constant voltage modes compete. It is expected that the module corresponding to the smaller VCT voltage will gain a competitive advantage, and the output of the switching power supply 3 is controlled by the DA module, so as to coagulate the bleeding tissue with the lowest possible energy to reduce thermal damage.

[0066] Compared with the existing technology, the output power is also controlled by MCU to achieve electrocoagulation and electrocutting operations, but the mainstream technology on the market, such as "controlling the maximum power through the peak control circuit", only controls the maximum output power at the initial stage of arcing to protect patients from greater harm. It does not detect the state of the plasma arc and cannot achieve free energy switching between arcing and non-arcing, that is, after the plasma arc is started, the electric cutting is still performed at the maximum power, or during the normal electric cutting process, when the arc is extinguished due to the short-term separation of the electrode tip from the tissue, it cannot quickly enter the arcing program to achieve plasma secondary arcing, which affects the clinical experience and actual cutting effect.

[0067] The present invention gradually increases the energy applied to the plasma electrode in a physiological saline environment, thereby causing orderly ionization of Na ions in the physiological saline solution. In this way, plasma arcing is faster, the arc is not easily extinguished during the electrocuting process, the cutting performance is smoother, and the clinical performance is better. At the same time, the use of this dynamic energy loading method can also avoid the shortcomings of a fixed energy loading method: first, too small a loading energy setting leads to insufficient energy and difficulty in plasma arcing; second, too high a loading energy setting leads to an instantaneous burst of excessive energy, causing greater thermal damage to the tissue and bringing safety risks.

[0068] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0069] Although this article uses more terms such as MCU module 1, sound control module 11, speaker 12, touch screen 13, foot switch 14, PWM controller 2, switching power supply 3, MOS drive module 4, high-frequency power amplifier module 5, voltage divider circuit 6, fault detection module 7, surgical electrode 8, voltage detection module 81, current detection module 82, etc., it does not exclude the possibility of using other terms. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. A plasma surgery system for rapidly generating a plasma state, comprising an MCU module (1), characterized in that: The MCU module (1) is connected to a switching power supply (3) via a PWM controller (2); the MCU module (1) is connected to a high-frequency power amplifier module (5) via a MOS driver module (4); a voltage divider circuit (6) connected to the MCU module (1) is connected between the switching power supply (3) and the high-frequency power amplifier module (5); a fault detection module (7) is connected between the high-frequency power amplifier module (5) and the MCU module (1); the high-frequency power amplifier module (5) is connected to a surgical electrode (8) and a voltage detection module (81) and a current detection module (82) connected to the MCU module (1) are arranged therebetween; the surgical electrode (8) is connected to the MCU module (1).

2. A plasma surgery system for rapidly generating a plasma state according to claim 1, characterized in that: The MCU module (1) is connected to a loudspeaker (12) via a sound control module (11).

3. The plasma surgery system for rapidly generating a plasma state according to claim 1, characterized in that: The MCU module (1) is connected to a touch screen (13) and a foot switch (14).

4. A control method for a plasma surgery system capable of rapidly generating a plasma state, the method comprising: The steps include: S1: When the foot switch (14) is in a connected state with the surgical electrode (8), the MCU module (1) performs a real-time scan of the state of the foot switch (14); when the electrosurgical cutting pedal of the foot switch (14) is pressed, the state change is detected by the MCU module (1), and the electrosurgical cutting mode is started, and the pre-processing mode is first entered; S2: Determine whether there is an abnormality in preprocessing, if not, enter arc starting control; S3: Determine whether the arc is successfully started, if successful, enter the tissue cutting stage; S4: The system detects the state of the foot switch (14). When the foot switch (14) is released, all outputs are turned off and the electrocuting mode is exited; otherwise, the operation of the tissue cutting stage continues.

5. The control method of a plasma surgery system for rapidly generating a plasma state according to claim 4, characterized in that: The pre-processing mode in step S1 includes the following steps: S11: The MCU module (1) controls the switching power supply (3) to output a preset VCT DC voltage through the DA module, and samples the VCT voltage through the voltage divider circuit (6) to determine whether the actually output VCT voltage is within a preset range; S12: Control the high-frequency power amplifier output through complementary PWM signals, and detect the working state of the high-frequency power amplifier module (5) through a feedback circuit. When the working state is normal, detect the high-frequency voltage and high-frequency current output by the high-frequency power amplifier module (5) and calculate the current initial impedance R0.

6. The control method of a plasma surgery system for rapidly generating a plasma state according to claim 4, characterized in that: When the initial impedance R0 of step S2 is less than a certain value, arc starting control is entered; if any step is abnormal, all outputs are directly turned off to end the operation of the electric cutting mode.

7. The control method of a plasma surgery system for rapidly generating a plasma state according to claim 4, characterized in that: The step S3 comprises the following steps: S31: The system will control the switching power supply (3) to output the VCT voltage through the DA module, record V vct1 ; S32: The system detects the high-frequency voltage and high-frequency current output by the high-frequency power amplifier module (5), and calculates the current load impedance R1; S33: The system increases the VCT voltage output, record V vct2 ; S34: After a delay of about 1 millisecond according to the above steps, a new load impedance R2 is obtained, and the load impedance R is obtained by analogy. n When multiple newly acquired load impedances are greater than R0, it is considered that the system ionization arc is successful and enters the tissue cutting stage.

8. The control method of a plasma surgery system for rapidly generating a plasma state according to claim 7, characterized in that: In the step S3, when the arcing is judged to be successful, the longest arcing time is counted at the same time. When the time is exceeded, the energy output is turned off, and after a delay, the process re-enters the step S3 to perform arcing control.

9. The control method of a plasma surgery system for rapidly generating a plasma state according to claim 7, characterized in that: In the tissue cutting stage, step S3 is performed according to the detected load impedance R m and load power P m , the system output power is adjusted in real time in a closed loop. The adjustment algorithm adopts a dual competition method, that is, to ensure that the output constant power and constant voltage modes compete. The module corresponding to the expected smaller VCT voltage obtains a competitive advantage and controls the output of the switching power supply (3) through the DA module.

10. The control method of a plasma surgery system for rapidly generating a plasma state according to claim 4, characterized in that: In step S3, the tissue cutting stage is changed to the tissue coagulation stage, and the adjustment algorithm adopts a three-competition method, that is, to ensure that the output constant current, constant power and constant voltage modes compete, and the module corresponding to the smaller VCT voltage is expected to gain a competitive advantage, and the output of the switching power supply (3) is controlled by the DA module.

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