Automatic calibration method and system for high-frequency electrosurgical unit neutral electrode impedance detection

Abstract

The present invention provides an automatic calibration method and system for neutral electrode impedance detection of a high-frequency electric knife, and relates to the technical field of neutral electrode detection. The method specifically comprises the following steps: S1: obtaining an optimal resonant frequency; S2: when the frequency of an excitation signal source is the optimal resonant frequency, recording a plurality of second voltages by switching a preset impedance connected between two neutral electrodes, and obtaining a voltage-impedance fitting curve by performing interval curve fitting according to a mapping relationship between the preset impedance and the second voltage; S3: when obtaining a measured voltage obtained by performing neutral electrode impedance detection at the optimal resonant frequency, performing impedance calibration on the voltage-impedance fitting curve according to the measured voltage, so as to avoid calibration errors and improve the calibration rate.

Description

Technical Field

[0001] The invention relates to the technical field of neutral electrode detection, and specifically designs an automatic calibration method and system for neutral electrode impedance detection of a high-frequency electric knife. Background Art

[0002] In high-frequency electrosurgical units, neutral electrode impedance detection can be used to determine whether the neutral electrode is well adhered to the patient, thereby avoiding safety accidents such as unexpected burns caused by defects in neutral electrode adhesion.

[0003] The current neutral electrode detection circuit is generally a low-voltage resonant circuit, and its detection accuracy and consistency are not high. Moreover, the errors caused by the magnetic and capacitive components themselves will also affect the accuracy of impedance detection. Therefore, it is necessary to calibrate the impedance detection during equipment production. Currently, the calibration production process is time-consuming, and there is a certain probability of error in the calibration by production personnel. Summary of the invention

[0004] The purpose of the present invention is to provide an automatic calibration method and system for high-frequency electrosurgical unit neutral electrode impedance detection. The method mainly adopts an interval curve fitting method, first finds the optimal resonant frequency under a fixed impedance, and then performs segmented curve calibration fitting under the optimal resonant frequency, divides the voltage and the corresponding impedance into multiple reference intervals, measures the voltage value corresponding to the reference impedance under the optimal resonant frequency, performs curve fitting within the reference interval, and realizes curve calibration. The whole process can be fully realized by an automatic calibration program, thereby improving the calibration rate and impedance detection accuracy.

[0005] In order to solve the above technical problems, the present invention adopts the following solutions:

[0006] An automatic calibration method for high-frequency electrosurgical unit neutral electrode impedance detection, the method specifically comprising the following steps:

[0007] S1: When a fixed impedance is connected between the two neutral electrodes, multiple first voltages are recorded by switching the frequency of the excitation signal source, and the frequency generating the maximum first voltage is taken as the optimal resonant frequency;

[0008] S2: when the frequency of the excitation signal source is the optimal resonant frequency, a plurality of second voltages are recorded by switching the preset impedance connected between the two neutral electrodes, and an interval curve fitting is performed according to a mapping relationship between the preset impedance and the second voltage to obtain a voltage-impedance fitting curve;

[0009] S3: When the measured voltage obtained by performing neutral electrode impedance detection at the optimal resonant frequency is obtained, impedance calibration is performed on the voltage-impedance fitting curve according to the measured voltage.

[0010] Furthermore, the S2 specifically includes the following steps:

[0011] S21: when the frequency of the excitation signal source is the optimal resonant frequency, recording a plurality of second voltages by switching a preset impedance connected between two neutral electrodes;

[0012] S22: Establishing a mapping relationship between a plurality of preset impedances and corresponding second voltages;

[0013] S23: Divide the plurality of preset impedances into interval segments to form a plurality of reference interval segments including the second voltage and the preset impedance;

[0014] S24: performing curve fitting according to the second voltage in the reference interval and the preset impedance to obtain voltage-impedance fitting curves corresponding to a plurality of reference intervals.

[0015] Further, in S3, the impedance calibration process is specifically as follows:

[0016] Obtain the measured voltage obtained by performing neutral electrode impedance detection at the optimal resonant frequency and the current preset impedance; find the corresponding reference interval and its voltage-impedance fitting curve based on the measured voltage; substitute the measured voltage into the corresponding voltage-impedance fitting curve to calculate the current preset impedance; readjust the reference interval and the voltage-impedance fitting curve based on the current preset impedance and the current preset impedance.

[0017] Furthermore, in S23, the process of dividing the multiple preset impedances into interval segments to form multiple reference interval segments including the second voltage and the preset impedance is specifically as follows:

[0018] The preset impedances are sorted by size, and the sorted preset impedances are segmented into intervals, and two consecutive preset impedances are used as the head / tail of the reference interval segment respectively, that is, segmenting the n sorted preset impedances into intervals will form n-1 reference interval segments.

[0019] Furthermore, in S24, the process of performing curve fitting according to the second voltage in the reference interval and the preset impedance is specifically as follows:

[0020] A fitting formula is constructed for each reference interval segment, wherein the fitting formula is: y=ax+b, wherein y represents the impedance value, x represents the voltage value, and a and b are fitting parameters;

[0021] Obtaining a preset impedance at the head and tail of each reference interval; obtaining a second voltage mapped by the preset impedance at the head and tail according to a mapping relationship between the preset impedance and the second voltage;

[0022] The preset impedance at the head and tail of each reference interval and the corresponding second voltage are substituted into the fitting formula to solve the unknown coefficients, and a and b in the fitting formula are solved to form a voltage-impedance fitting curve.

[0023] Furthermore, in S1, the frequency of the excitation signal source is switched by a controllable PWM to make the excitation signal source output different frequencies, and the frequency generation can realize frequency self-increment according to the step preset frequency size.

[0024] Furthermore, the neutral electrode impedance detection is used to determine the pasting quality of the neutral electrode by detecting the resistance between the two neutral electrodes.

[0025] An automatic calibration system for high-frequency electrosurgical unit neutral electrode impedance detection, comprising:

[0026] Optimal resonant frequency acquisition module: when a fixed impedance is connected between two neutral electrodes, multiple first voltages are recorded by switching the frequency of the excitation signal source, and the frequency generating the maximum first voltage is taken as the optimal resonant frequency;

[0027] Voltage-impedance fitting curve acquisition module: when the frequency of the excitation signal source is the optimal resonant frequency, multiple second voltages are recorded by switching the preset impedance connected between the two neutral electrodes, and the voltage-impedance fitting curve is obtained by performing interval curve fitting according to the mapping relationship between the preset impedance and the second voltage;

[0028] Impedance calibration module: when the measured voltage obtained by neutral electrode impedance detection at the best resonant frequency is obtained, impedance calibration is performed on the voltage-impedance fitting curve according to the measured voltage.

[0029] Furthermore, the voltage impedance fitting curve obtaining module also includes the following submodules:

[0030] A second voltage acquisition module: when the frequency of the excitation signal source is the optimal resonant frequency, a plurality of second voltages are recorded by switching a preset impedance connected between two neutral electrodes;

[0031] Impedance-voltage mapping module: establishes a mapping relationship between a plurality of preset impedances and corresponding second voltages;

[0032] An interval segmentation module: divides the multiple preset impedances into interval segments to form multiple reference interval segments including the second voltage and the preset impedance;

[0033] Curve fitting module: Perform curve fitting according to the second voltage and preset impedance in the reference interval to obtain voltage-impedance fitting curves corresponding to multiple reference intervals.

[0034] Beneficial effects of the present invention:

[0035] The present invention provides an automatic calibration method and system for high-frequency electrosurgical unit neutral electrode impedance detection. The method mainly adopts an interval curve fitting method, firstly divides the voltage and the corresponding impedance into a plurality of reference interval segments, and performs curve fitting in the reference interval segment through the optimal resonant frequency to realize curve calibration. In addition, the reference interval segment and the voltage-impedance fitting curve can be readjusted according to the actual measurement value to avoid calibration errors and improve the calibration rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The figure is a flow chart of an automatic calibration method for detecting the neutral electrode impedance of a high-frequency electrosurgical unit in Embodiment 1 of the present invention.

[0037] Figure 2 It is an interactive schematic diagram of an automatic calibration method for high-frequency electrosurgical unit neutral electrode impedance detection in Embodiment 1 of the present invention.

[0038] Figure 3 Schematic diagram of the neutral electrode impedance detection circuit of the high-frequency electrosurgical unit in Embodiment 1 of the present invention.

[0039] Figure 4 This is a schematic diagram of a module when a fixed impedance is connected between two neutral electrodes in Example 1 of the present invention.

[0040] Figure 5 It is a module schematic diagram when the frequency of the excitation signal source in Example 1 of the present invention is the optimal resonant frequency.

[0041] Figure 6 Schematic diagram of the voltage impedance fitting curve in Example 1 of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0044] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0045] Additionally, descriptions of well-known structures, functions, and configurations may be omitted for clarity and conciseness.One of ordinary skill in the art will recognize that various changes and modifications may be made to the examples described herein without departing from the spirit and scope of the present disclosure.

[0046] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0047] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0048] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments:

[0049] Example 1

[0050] like Figure 1 As shown, an automatic calibration method for high-frequency electrosurgical unit neutral electrode impedance detection comprises the following steps:

[0051] S1: When a fixed impedance is connected between the two neutral electrodes, multiple first voltages are recorded by switching the frequency of the excitation signal source, and the frequency generating the maximum first voltage is taken as the optimal resonant frequency;

[0052] S2: when the frequency of the excitation signal source is the optimal resonant frequency, a plurality of second voltages are recorded by switching the preset impedance connected between the two neutral electrodes, and an interval curve fitting is performed according to a mapping relationship between the preset impedance and the second voltage to obtain a voltage-impedance fitting curve;

[0053] S3: When the measured voltage obtained by performing neutral electrode impedance detection at the optimal resonant frequency is obtained, impedance calibration is performed on the voltage-impedance fitting curve according to the measured voltage.

[0054] Preferably, S2 specifically includes the following steps:

[0055] S21: when the frequency of the excitation signal source is the optimal resonant frequency, recording a plurality of second voltages by switching a preset impedance connected between two neutral electrodes;

[0056] S22: Establishing a mapping relationship between a plurality of preset impedances and corresponding second voltages;

[0057] S23: Divide the plurality of preset impedances into interval segments to form a plurality of reference interval segments including the second voltage and the preset impedance;

[0058] S24: performing curve fitting according to the second voltage in the reference interval and the preset impedance to obtain voltage-impedance fitting curves corresponding to a plurality of reference intervals.

[0059] Preferably, in S3, the impedance calibration process is specifically as follows:

[0060] Obtain the measured voltage obtained by performing neutral electrode impedance detection at the optimal resonant frequency and the current preset impedance; find the corresponding reference interval and its voltage-impedance fitting curve based on the measured voltage; substitute the measured voltage into the corresponding voltage-impedance fitting curve to calculate the current preset impedance; readjust the reference interval and the voltage-impedance fitting curve based on the current preset impedance and the current preset impedance.

[0061] Preferably, in S23, the process of dividing the multiple preset impedances into interval segments to form multiple reference interval segments including the second voltage and the preset impedance is specifically as follows:

[0062] The preset impedances are sorted by size, and the sorted preset impedances are segmented into intervals, and two consecutive preset impedances are used as the head / tail of the reference interval segment respectively, that is, segmenting the n sorted preset impedances into intervals will form n-1 reference interval segments.

[0063] Preferably, in S24, the process of performing curve fitting according to the second voltage in the reference interval and the preset impedance is specifically as follows:

[0064] A fitting formula is constructed for each reference interval segment, wherein the fitting formula is: y=ax+b, wherein y represents the impedance value, x represents the voltage value, and a and b are fitting parameters;

[0065] Obtaining a preset impedance at the head and tail of each reference interval; obtaining a second voltage mapped by the preset impedance at the head and tail according to a mapping relationship between the preset impedance and the second voltage;

[0066] The preset impedance at the head and tail of each reference interval and the corresponding second voltage are substituted into the fitting formula to solve the unknown coefficients, and a and b in the fitting formula are solved to form a voltage-impedance fitting curve.

[0067] Preferably, in S1, the frequency of the excitation signal source is switched by a controllable PWM to make the excitation signal source output different frequencies, and the frequency generation can realize frequency self-increment according to the step preset frequency size.

[0068] Preferably, the neutral electrode impedance detection is used to determine the pasting quality of the neutral electrode by detecting the resistance between the two neutral electrodes.

[0069] Based on the above principles, the present invention is further described:

[0070] The present invention mainly provides an automatic calibration method for high-frequency electrosurgical knife neutral electrode impedance detection during production, such as Figure 2 As shown, relatively accurate calibration values ​​can be obtained according to the automatic calibration method in the first time period and the second time period, and then the calibration values ​​are provided to the customer, so that the customer can have an accurate reference value when using the high-frequency electric knife, which is convenient for the customer to operate and can quickly judge the pasting quality between the neutral electrodes.

[0071] Specifically, the neutral electrode impedance detection of the high-frequency electric knife mainly determines the pasting quality between the two neutral electrodes by detecting the resistance between the two output wire welding holes, and the two output wire welding holes are connected to the external double-piece neutral electrode, such as Figure 3 As shown, U_rem of C77 is the feedback voltage value, and the resistance between the welding holes and the frequency value of drive will affect this value. Choose is the peak detection control signal. When the choose signal is at a low level of drive, the analog switch is closed to transfer the peak voltage of the primary side of the transformer to C77, so that the frequency will affect the voltage. Therefore, the present invention first needs to calibrate the frequency value.

[0072] In this embodiment, if Figure 4 As shown, first, a fixed impedance is connected between the two neutral electrodes. The fixed impedance can be switched by a relay control so that the fixed impedance is connected to the neutral electrode impedance detection circuit; or the production personnel can directly insert the fixed impedance, such as 200Ω, through program prompts.

[0073] When the fixed impedance is set, the frequency automatic adjustment link is entered. By switching the frequency of the excitation signal source, different frequencies are generated in the neutral electrode impedance detection circuit. The frequency can be generated by a controllable PWM, so that the control module controls the frequency of the excitation signal source to achieve frequency self-increase according to the step preset frequency size, for example 0.1khz.

[0074] During the frequency self-increase process, the frequency of the excitation signal source and the first voltage fed back in real time are recorded. According to the recording results, it can be seen that the influence of the frequency on the voltage will produce a peak value, as shown in Table 1:

[0075] Table 1

[0076] Frequency khz 75 76 77 78 79 80 81 82 83 84 85 The first voltage v 0.5 0.8 1.1 1.6 2.0 2.3 2.5 2.2 1.9 1.4 1.1

[0077] The present invention uses the frequency that generates the maximum first voltage as the optimal resonant frequency. Specifically, the frequency that generates the maximum voltage of 2.5V is used as the optimal resonant frequency. The optimal resonant frequency is 81kHz, and the frequency calibration is completed.

[0078] In addition, the optimal resonant frequency can be stored in the flash memory, and the frequency can be adjusted during the production process so that the customer can read the optimal resonant frequency when starting the machine. This frequency can be used to drive the neutral electrode impedance detection circuit to improve the detection accuracy.

[0079] Since the neutral electrode impedance detection circuit is fitted to the external impedance value based on the detected voltage value, there is currently a fitting formula in the high-frequency electrosurgical device. The general fitting formula method is to fit a curve based on the measurement data of the prototype, take the average value, and use it for each device in the same series. The formula is solidified by the program and cannot be changed, resulting in an inaccurate fitting curve.

[0080] Therefore, the present invention performs curve fitting within the reference interval based on the optimal resonant frequency, and can obtain the realized voltage impedance fitting curve corresponding to different reference intervals, and complete the fitting curve calibration. The voltage impedance fitting curve is a curve fitting for different reference intervals, and the detection value can be quickly calibrated in a targeted manner using a segmented form. Specifically, the voltage impedance fitting curve is mainly for changes in the characteristics of the product itself, and the curve is re-fitted, so that the deviation of the impedance detection result caused by the component error can be accurately corrected; it can also be used for correction after component aging.

[0081] In this embodiment, the voltage impedance fitting curve is in a segmented form. By segmenting the curve, each segment can be simplified into a straight line without losing its accuracy. The fitting formula is: y=ax+b, where y represents the impedance value and x represents the voltage value. In the fitting process, the unknown coefficients a and b of each segment are solved to obtain the voltage impedance fitting curves of different reference intervals, and the voltage impedance fitting curves of different reference intervals are stored in the high-frequency electrosurgical device.

[0082] Specifically, when the neutral electrode impedance detection circuit is driven with the optimal resonant frequency and the preset impedance, a measured voltage can be obtained. The corresponding reference interval segment is found by table lookup for the current measured voltage, and then the measured voltage is substituted into the voltage impedance fitting curve in the reference interval segment for solution. A current calibration impedance is calculated and the current calibration impedance can be compared with the current preset impedance. If the difference between the two does not exceed the preset threshold, the current preset impedance meets the current calibration impedance condition; if the difference between the two exceeds the preset threshold, the current preset impedance does not meet the current calibration impedance condition, then the current preset impedance and the measured voltage are not compatible, indicating that the current calibration error is large, and the current reference interval segment can be readjusted, and then the curve fitting is re-performed according to the adjusted reference interval segment to achieve re-calibration of the voltage impedance fitting curve.

[0083] The process of obtaining the voltage impedance fitting curve of different reference intervals based on the segmented method is as follows: first, the frequency of the excitation signal source is set to the optimal resonant frequency, and then the values ​​of multiple preset impedances are set in a segmented manner, for example: 10-20-50-80-100-150-180, then 6 reference intervals can be obtained according to 7 preset impedances, and then, different preset impedances can be switched through relays, such as Figure 5 As shown, the second voltage fed back by each preset impedance at the optimal resonant frequency is recorded, specifically, as shown in Table 2:

[0084] Table 2

[0085] Preset impedance Ω 10 20 50 80 100 150 180 The second voltage mv 304 508 1025 1429 1675 2133 2348

[0086] The second voltage corresponding to each preset impedance can be obtained. According to the mapping relationship between the preset impedance and the second voltage, curve fitting is performed on each reference interval. For example, the preset impedances at the head and tail of the first reference interval are 10 and 20 respectively. Then, 10 and 20 and their corresponding 304 and 508 are substituted into the fitting formula to solve the unknown coefficients, and a=0.049 and b=-4.902 are solved. Figure 6 As shown, the voltage impedance fitting curve is: y=0.049x-4.902, and so on, the voltage impedance fitting curve of each reference interval can be obtained to complete the calibration.

[0087] Example 2

[0088] An automatic calibration system for high-frequency electrosurgical unit neutral electrode impedance detection, comprising:

[0089] Optimal resonant frequency acquisition module: when a fixed impedance is connected between two neutral electrodes, multiple first voltages are recorded by switching the frequency of the excitation signal source, and the frequency generating the maximum first voltage is taken as the optimal resonant frequency;

[0090] Voltage-impedance fitting curve acquisition module: when the frequency of the excitation signal source is the optimal resonant frequency, multiple second voltages are recorded by switching the preset impedance connected between the two neutral electrodes, and the voltage-impedance fitting curve is obtained by performing interval curve fitting according to the mapping relationship between the preset impedance and the second voltage;

[0091] Impedance calibration module: when the measured voltage obtained by neutral electrode impedance detection at the best resonant frequency is obtained, impedance calibration is performed on the voltage-impedance fitting curve according to the measured voltage.

[0092] Preferably, the voltage impedance fitting curve obtaining module also includes the following submodules:

[0093] A second voltage acquisition module: when the frequency of the excitation signal source is the optimal resonant frequency, a plurality of second voltages are recorded by switching a preset impedance connected between two neutral electrodes;

[0094] Impedance-voltage mapping module: establishes a mapping relationship between a plurality of preset impedances and corresponding second voltages;

[0095] An interval segmentation module: performs interval segmentation on a plurality of preset impedances to form a plurality of reference interval segments including a second voltage and a preset impedance;

[0096] Curve fitting module: Perform curve fitting according to the second voltage and preset impedance in the reference interval to obtain voltage-impedance fitting curves corresponding to multiple reference intervals.

[0097] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. According to the technical essence of the present invention, within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the present invention.

Claims

1. An automatic calibration method for high-frequency electrosurgical unit neutral electrode impedance detection, characterized in that: The method specifically comprises the following steps: S1: When a fixed impedance is connected between the two neutral electrodes, multiple first voltages are recorded by switching the frequency of the excitation signal source, and the frequency generating the maximum first voltage is taken as the optimal resonant frequency; S2: when the frequency of the excitation signal source is the optimal resonant frequency, a plurality of second voltages are recorded by switching the preset impedance connected between the two neutral electrodes, and an interval curve fitting is performed according to a mapping relationship between the preset impedance and the second voltage to obtain a voltage-impedance fitting curve; The S2 specifically includes the following steps: S21: when the frequency of the excitation signal source is the optimal resonant frequency, recording a plurality of second voltages by switching a preset impedance connected between two neutral electrodes; S22: Establishing a mapping relationship between a plurality of preset impedances and corresponding second voltages; S23: Divide the plurality of preset impedances into interval segments to form a plurality of reference interval segments including the second voltage and the preset impedance; S24: performing curve fitting according to the second voltage in the reference interval and the preset impedance to obtain voltage-impedance fitting curves corresponding to a plurality of reference intervals; S3: When the measured voltage obtained by performing neutral electrode impedance detection at the optimal resonant frequency is obtained, impedance calibration is performed on the voltage-impedance fitting curve according to the measured voltage.

2. The automatic calibration method for high-frequency electrosurgical unit neutral electrode impedance detection according to claim 1, characterized in that: In S3, the impedance calibration process is specifically as follows: Obtaining a measured voltage obtained by performing neutral electrode impedance detection at an optimal resonant frequency and a current preset impedance; finding a corresponding reference interval segment and its voltage-impedance fitting curve according to the measured voltage; The measured voltage is substituted into the corresponding voltage impedance fitting curve to calculate the current preset impedance; the reference interval and the voltage impedance fitting curve are readjusted according to the current preset impedance and the current preset impedance.

3. The automatic calibration method for high-frequency electrosurgical unit neutral electrode impedance detection according to claim 1, characterized in that: In S23, the process of dividing the multiple preset impedances into interval segments to form multiple reference interval segments including the second voltage and the preset impedance is specifically as follows: The preset impedances are sorted by size, and the sorted preset impedances are segmented into intervals, and two consecutive preset impedances are used as the head / tail of the reference interval segment respectively, that is, segmenting the n sorted preset impedances into intervals will form n-1 reference interval segments.

4. The automatic calibration method for high-frequency electrosurgical unit neutral electrode impedance detection according to claim 3, characterized in that: In S24, the process of performing curve fitting according to the second voltage in the reference interval and the preset impedance is specifically as follows: A fitting formula is constructed for each reference interval segment, wherein the fitting formula is: y=ax+b, wherein y represents the impedance value, x represents the voltage value, and a and b are fitting parameters; Obtaining a preset impedance at the head and tail of each reference interval; obtaining a second voltage mapped by the preset impedance at the head and tail according to a mapping relationship between the preset impedance and the second voltage; The preset impedance at the head and tail of each reference interval and the corresponding second voltage are substituted into the fitting formula to solve the unknown coefficients, and a and b in the fitting formula are solved to form a voltage-impedance fitting curve.

5. The automatic calibration method for high-frequency electrosurgical unit neutral electrode impedance detection according to claim 1, characterized in that: In S1, the frequency of the switching excitation signal source is controlled by PWM to make the excitation signal source output different frequencies, and the frequency generation can realize frequency self-increment according to the step preset frequency size.

6. The automatic calibration method for high-frequency electrosurgical unit neutral electrode impedance detection according to claim 1, characterized in that: The neutral electrode impedance detection is used to determine the pasting quality of the neutral electrode by detecting the resistance between the two neutral electrodes.

7. An automatic calibration system for high-frequency electrosurgical unit neutral electrode impedance detection, characterized in that: include: Optimal resonant frequency acquisition module: when a fixed impedance is connected between two neutral electrodes, multiple first voltages are recorded by switching the frequency of the excitation signal source, and the frequency generating the maximum first voltage is taken as the optimal resonant frequency; Voltage-impedance fitting curve acquisition module: when the frequency of the excitation signal source is the optimal resonant frequency, multiple second voltages are recorded by switching the preset impedance connected between the two neutral electrodes, and the voltage-impedance fitting curve is obtained by performing interval curve fitting according to the mapping relationship between the preset impedance and the second voltage; Impedance calibration module: when the measured voltage obtained by neutral electrode impedance detection at the best resonant frequency is obtained, impedance calibration is performed on the voltage impedance fitting curve according to the measured voltage; The voltage impedance fitting curve obtaining module also includes Includes the following submodules: A second voltage acquisition module: when the frequency of the excitation signal source is the optimal resonant frequency, a plurality of second voltages are recorded by switching a preset impedance connected between two neutral electrodes; Impedance-voltage mapping module: establishes a mapping relationship between a plurality of preset impedances and corresponding second voltages; An interval segmentation module: performs interval segmentation on a plurality of preset impedances to form a plurality of reference interval segments including a second voltage and a preset impedance; Curve fitting module: Perform curve fitting according to the second voltage and preset impedance in the reference interval to obtain voltage-impedance fitting curves corresponding to multiple reference intervals.

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