A calibration device and calibration method for a high-frequency electrosurgical unit analyzer

Abstract

The present invention discloses a high-frequency electrosurgical analyzer calibration device and a calibration method thereof. The purpose of the present invention is to overcome the shortcomings and deficiencies of existing calibration devices and methods, thereby achieving a high-frequency power analyzer calibration device and a high-frequency electrosurgical analyzer calibration method based on the device, which can achieve a theoretical high-frequency power of 1000W or more and a current of 5A or more at different impedances (10Ω to 5000Ω) at a frequency of 50kHz to 5MHz through an impedance converter, and can adjust the output power in real time via a computer. The present invention can calibrate a high-frequency electrosurgical analyzer with a high-frequency power of (1 to 500)W, a frequency of 30Hz to 5MHz, a current of 5mA to 5A, and a resistance of (0 to 6400)Ω. Calibration parameters include high-frequency power, high-frequency current, load resistance, bandwidth, frequency response, peak voltage, effective value voltage, peak-to-peak voltage, and crest factor.

Description

Technical Field

[0001] The present invention relates to the field of metrological calibration of high-frequency electric knife analyzers, and in particular to a calibration device and a calibration method for high-frequency electric knife analyzers. Background Art

[0002] High-frequency electrosurgical generators are widely used in the medical aesthetics industry and are important medical devices. The National Metrology and Calibration Standard JJF1217-2009 for High-Frequency Electrosurgical Generators provides the technical basis for traceability of their measurement values. This standard specifies the measurement standards for high-frequency electrosurgical generators, the most important of which is the high-frequency electrosurgical analyzer. The standard also describes the metrological characteristics of high-frequency electrosurgical analyzers.

[0003] A high-frequency electrosurgical analyzer is a multi-parameter measuring instrument. Its main parameters include high-frequency current (high-frequency leakage current), high-frequency voltage (peak or RMS value), high-frequency power, and crest factor. The technical requirements for high-frequency electrosurgical power detection devices specified in the JJF1217-2009 High-Frequency Electrosurgical Calibration Specification are: a high-frequency ammeter (0.001 to 0.5) A, a high-frequency power meter (1 to 500) W, and a frequency (0.3 to 5.0) MHz. The maximum allowable error for current is ±2.5%, and the maximum allowable error for high-frequency power is: ±5% for ≥50 W, ±(5% × F + 1) W for <50 W, where F is the power range. The non-inductive resistance box is: (10 to 2000) Ω (in steps no greater than 50 Ω), with a maximum allowable error of ±2.5%. The main issues with the regulations regarding high-frequency electrosurgical unit power detection devices are as follows: First, the specific resistance values or resistance ranges for power and high-frequency current are not specified. High-frequency power, high-frequency current, and non-inductive resistance are interrelated. Measuring high-frequency power and high-frequency current requires a specific resistance value, meaning that high-frequency power and high-frequency current are measured under a specific load resistance. For example, if the non-inductive resistance is 200Ω and 500W is achieved, the high-frequency current range must be significantly greater than 0.5A. Similarly, if the non-inductive resistance is 10Ω, achieving 500W requires approximately 7.07A. Second, the specific meaning of frequency is not clearly defined. In practical applications, the commonly used range for high-frequency current is generally (0.3-0.5) MHz. A few in the beauty industry use a frequency range of (1.0-4.0) MHz, and 5MHz is rarely used, despite the fact that bandwidths up to 5MHz are possible.

[0004] Many metrology institutions, enterprises, and institutions directly purchase high-frequency electrosurgical analyzers as primary measurement standards when establishing high-frequency electrosurgical unit calibration systems. Currently, high-frequency electrosurgical analyzers are largely imported, while domestically produced ones are in the initial stages of development. The more mature products have a very low domestic market share. Their key parameters are high-frequency current (high-frequency leakage current), high-frequency voltage (peak or RMS value), high-frequency power, crest factor, and bandwidth (or frequency response). High-frequency electrosurgical analyzer manufacturers are unclear about the frequency of high-frequency current, typically only providing a bandwidth range in their instruction manuals. For example, bandwidth is defined as a 3dB drop, meaning that at 5MHz, the high-frequency current does not meet the maximum allowable error of ±2.5%. Furthermore, the load resistance for measuring bandwidth is not clearly defined. Radio metrology professionals use 50Ω impedance for bandwidth measurement, while the most commonly used resistors for high-frequency electrosurgical analyzers are 100Ω, 200Ω, 300Ω, 500Ω, and 800Ω.

[0005] The technical specifications of current domestic high-frequency electrosurgical unit calibration devices do not fully meet the calibration requirements of high-frequency electrosurgical unit analyzers, and their stability and reliability need to be improved. A major drawback is their limited frequency coverage, measuring only high-frequency current and power at 300–500 kHz and 1 MHz. The maximum power is 400 W, which does not provide sufficient margin, and the corresponding load resistance range is limited to 200–500 Ω. They are unable to measure parameters such as crest factor, load resistance, and bandwidth (frequency response), failing to meet the traceability requirements of mainstream high-frequency electrosurgical unit analyzers or the frequency and power ranges required for calibration by customers ("Research on Calibration Methods for High-Frequency Electrosurgical Unit Analyzers," by Chen Guangfei and Zhou Dan, Medical Support Department, PLA General Hospital; TD7200 (High-Frequency Electrosurgical Unit Calibration Device) - Changsha Tianheng Measurement & Control Technology Co., Ltd.). Therefore, there is an urgent need to establish an effective traceability system and calibration device or system to address the traceability issues for parameters such as high-frequency current, high-frequency power, peak voltage (RMS voltage), and crest factor. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings and deficiencies of the above-mentioned existing calibration devices and calibration methods, and to invent a high-frequency power analyzer calibration device and a high-frequency electric knife analyzer calibration method based on the device, which can achieve a theoretical high-frequency power of more than 1000W and a current of more than 5A at different impedances (10Ω to 5000Ω) at a frequency of 50kHz to 5MHz through an impedance converter, and can adjust the output power in real time through a computer.

[0007] The purpose of the present invention is achieved by at least one of the following technical solutions.

[0008] A high-frequency electric knife analyzer calibration device includes a power generation part and a parameter measurement part;

[0009] The power generation part includes a signal generator / microwave signal source, a power amplifier, a directional coupler, a dual-channel power meter and an impedance converter;

[0010] The parameter measurement part includes current sensor, digital oscilloscope, high-voltage differential probe and digital multimeter;

[0011] The signal output end of the signal generator / microwave signal source is connected to the input port of the power amplifier to provide an input signal to the power amplifier; the output port of the power amplifier is connected to the input port of the directional coupler;

[0012] The output port of the directional coupler is connected to the input port of the impedance converter, and the reflected power port and the forward power port of the directional coupler are connected to a dual-channel power meter through a power probe;

[0013] The positive output end of the impedance converter is connected to the positive input end of the high-frequency electrosurgical analyzer to be calibrated after passing through the current sensor, and the negative output end of the impedance converter is connected to the negative input end of the high-frequency electrosurgical analyzer to be calibrated;

[0014] The current sensor has a bandwidth of up to 200 MHz, a rise time of 1.75 ns, and an effective current measurement range of up to 20 A. The output port of the current sensor is connected to the first input channel CH1 of the digital oscilloscope to measure high-frequency leakage current and high-frequency current under high-frequency power;

[0015] The high-voltage differential probe has a peak-to-peak voltage measurement range of up to 10 kV and a DC voltage attenuation ratio of 100:1 or 1000:1. The positive and negative input terminals of the high-voltage differential probe are connected to the positive and negative input terminals of the calibrated high-frequency electrosurgical analyzer, respectively. The output port of the high-voltage differential probe is connected to the second input channel CH2 of the digital oscilloscope to measure the high-frequency voltage signal across the load resistor using the peak-to-peak value and RMS value of the digital oscilloscope.

[0016] The two resistance measurement input terminals of the digital multimeter are connected to the positive and negative terminals of the load resistor of the high-frequency electric knife analyzer under test through 4mm banana plug test leads to measure the load resistance value of the high-frequency electric knife analyzer.

[0017] Furthermore, a computer is used to connect the signal generator / microwave signal source, the power amplifier and the dual-channel power meter via a GPIB-USB data cable to perform power output control;

[0018] The output end of the signal generator / microwave signal source is an N-type interface, which is connected to the power amplifier through an N-type coaxial cable. The output is a sinusoidal signal with low harmonic content and no DC component;

[0019] The signal frequency of the signal generator / microwave signal source covers 9kHz to 6GHz, covering the frequency range of high-frequency electrosurgical analyzers. The bandwidth (-3dB) range of high-frequency electrosurgical analyzers is usually 30Hz to 5MHz, and the operating range is 100kHz to 1MHz. The output level of the signal generator / microwave signal source can be adjusted, and the output level range is: -100dBm to +20dBm.

[0020] Furthermore, the input impedance of the impedance converter is 50Ω, which is used for impedance conversion to match the load resistance of the calibrated high-frequency electrosurgical analyzer. The output impedance after conversion is an integer multiple of 50 ohms, which matches the load resistance of the calibrated high-frequency electrosurgical analyzer.

[0021] The impedance converter has a frequency range of 50kHz to 5MHz and a power of 0.6kW. The input port is connected to the output of a power amplifier with an impedance of 50Ω. The impedance after passing through the converter is 50Ω, 100Ω, 200Ω, 300Ω, 500Ω, 800Ω, 1250Ω, 1800Ω, 2450Ω, 3200Ω, 4050Ω, 5000Ω, 6050Ω, and so on (i.e., the impedance after conversion is an integer multiple of 50 ohms). The output of the impedance converter is connected to the high-frequency electrosurgical analyzer under test through a current sensor.

[0022] Furthermore, the current sensor is a through-type current loop, and the output port is a BNC female connector, which can be connected to the input channel of the digital oscilloscope through a 4mm banana plug cable and a BNC coaxial cable.

[0023] Furthermore, the power output of the power amplifier is monitored in real time through a directional coupler and a dual-channel power meter. The forward power port of the directional coupler is connected to the first power sensor A of the dual-channel power meter, and the reflected power port is connected to the second power sensor B of the dual-channel power meter.

[0024] The frequency range of the power amplifier at least covers the operating frequency range of the high-frequency electrosurgical analyzer, and is used to generate a high-frequency power signal. The power output can reach 0.6kW, and the amplification gain is 60dB.

[0025] Furthermore, a function / arbitrary wave generator and a voltage amplifier are used to amplify the high-frequency signal;

[0026] Connect the output of the function / arbitrary waveform generator to the input of the voltage amplifier. Connect the output of the voltage amplifier to the positive and negative inputs of a high-voltage differential probe and the positive and negative terminals of the load resistor of a high-frequency electrosurgical analyzer. Adjust the second and third harmonic content of the function / arbitrary waveform generator, and use a high-voltage differential probe and a digital oscilloscope to measure the ratio of its peak-to-peak value to the effective value to obtain the standard crest factor value.

[0027] The frequency range of the function / arbitrary wave generator is 1μHz to 120MHz, and the peak-to-peak value of the output voltage can reach 10V. Its output port is connected to the 50Ω variable load resistor of the high-frequency electrosurgical analyzer.

[0028] The voltage amplifier has a voltage input of 10V peak to peak and an output voltage of 800V peak to peak.

[0029] Furthermore, the output of the function / arbitrary wave generator is connected to both ends of a load resistor of the high-frequency electrosurgical analyzer to be calibrated through a high-performance BNC split cable, and the load resistor is set to 50Ω.

[0030] A calibration method for a high-frequency electrosurgical analyzer, using a high-frequency electrosurgical analyzer calibration device, includes calibration of the following parameters:

[0031] S1. Calibration of high-frequency current: The power amplifier provides high-frequency power output, which is matched with the load resistance of the high-frequency electrosurgery analyzer through the impedance converter. The output level of the signal generator / microwave signal source is adjusted. The current measured by the high-frequency electrosurgery analyzer is the current indication value. After passing through the current sensor, the effective value of the current measured on the digital oscilloscope is the current standard value.

[0032] S2. Calibration of high-frequency power: The power amplifier provides high-frequency power output, which is matched to the load resistance of the high-frequency electrosurgery analyzer through an impedance converter. The output level of the signal generator / microwave signal source is adjusted. The power measurement value of the high-frequency electrosurgery analyzer is the power indication value. The current standard value is obtained by measuring the effective value of the current on the digital oscilloscope after the current sensor. The DC resistance standard value is measured using the resistance measurement function of the digital multimeter. The power standard value is calculated.

[0033] S3. Calibration of high-frequency voltage: The power amplifier provides high-frequency power output, which is matched with the load resistance of the high-frequency electrosurgical analyzer through an impedance converter. The output level of the signal generator / microwave signal source is adjusted. The peak-to-peak voltage measured by the high-frequency electrosurgical analyzer is the high-frequency voltage indication value. The peak-to-peak voltage on the digital oscilloscope after passing through the high-voltage differential probe is the standard value.

[0034] S4. Crest factor calibration: Connect the output of the function / arbitrary wave generator to the input of the voltage amplifier. Connect the output of the voltage amplifier to the variable resistor of the high-frequency electrosurgical analyzer being calibrated. Adjust the output level of the function / arbitrary wave generator, superimpose the set second and third harmonics, and adjust the amplification gain of the voltage amplifier. Measure the peak-to-peak value and the effective value on a digital oscilloscope using a high-voltage differential probe. Divide the two to obtain the standard crest factor value. The crest factor measured on the high-frequency electrosurgical analyzer is the indicated value.

[0035] S5. Calibration of frequency response: The power amplifier provides high-frequency power output, which is matched to the load impedance of the high-frequency electrosurgical analyzer through an impedance converter. Set the output frequency of the signal generator / microwave signal source to 500kHz, and adjust its output level so that the power of the high-frequency electrosurgical analyzer is 100 watts. Using the current measurement at this time as a reference value, change the output signal frequency, and record the current and power values at this frequency. Calculate its frequency response.

[0036] S6. Calibration of bandwidth: Set the output signal frequency and output impedance of the function / arbitrary wave generator, set the variable resistor of the high-frequency electrosurgical analyzer, set the measurement mode to high-frequency current measurement mode, record the high-frequency current value at this time as the reference value, increase or decrease the output frequency of the function / arbitrary wave generator until the high-frequency current value indicated by the high-frequency electrosurgical analyzer is 0.707 times the reference value, record the output frequency of the function / arbitrary wave generator at this time, and calculate the bandwidth of the high-frequency electrosurgical analyzer.

[0037] S7. High-frequency leakage current calibration: The power amplifier provides high-frequency power output, which is matched to the load resistance of the high-frequency electrosurgical analyzer through an impedance converter. Adjust the output level of the signal generator / microwave signal source, set the high-frequency electrosurgical analyzer to high-frequency leakage current measurement mode, set the load resistance to 200Ω, and set the high-frequency leakage current limit. The leakage current measured by the high-frequency electrosurgical analyzer is the leakage current indication value. The effective value of the current measured on the digital oscilloscope after passing through the current sensor is the actual leakage current value.

[0038] S8. Load resistance calibration: Use a 6.5-digit or higher digital multimeter (DMM) and set it to the two-wire resistance measurement function. Set the high-frequency electrosurgical analyzer to power measurement mode and set the resistance value to be calibrated within the resistance range. Click the Start Measurement button to start the measurement. Read the DMM reading as the actual load resistance value. To improve load resistance measurement accuracy, eliminate the resistance of the test leads.

[0039] Furthermore, in step S2, the high-frequency power standard value is obtained by formula (1) or formula (2), and formula (1) is:

[0040] P M =I RMS ×U RMS (1)

[0041] Among them, P M is the actual value of high frequency power, in W; I RMS is the measured value of high-frequency current, in A; U RMS is the measured value of high-frequency voltage, in V;

[0042] Formula (2) is:

[0043] P M =I RMS ×I RMS ×R (2)

[0044] Among them, P M is the actual value of high frequency power, in W; I RMS is the measured value of high-frequency current, in A; R is the measured value of DC resistance, in Ω.

[0045] Compared with the prior art, the present invention has at least the following beneficial effects:

[0046] (1) The present invention proposes to use a microwave signal generator and a power amplifier as a power standard source for calibration. The microwave signal source provides a wide frequency range, which can be from 9kHz to 6GHz, and the power level output can be from -100dBm to +23dBm, with a frequency accuracy of up to 1×10 -7 The above features good frequency stability, low harmonic distortion, no DC signal or signal leakage, and complete coverage of the frequency and bandwidth range of the calibrated high-frequency electrosurgical analyzer. It can be continuously adjusted and has good scalability. The power amplifier has an amplification power of at least 500W, which can achieve seamless interface connection with the microwave signal source. The power amplifier has an input high-level protection function. When the signal exceeds the maximum input level of the power amplifier, the protection function is activated and the output is stopped, thereby better protecting the calibrated high-frequency electrosurgical analyzer and preventing the calibrated high-frequency electrosurgical analyzer from being damaged due to excessive power.

[0047] (2) The present invention proposes to use an impedance converter to perform unbalanced and balanced conversion, which can achieve complete matching with the load resistance of the high-frequency electrosurgical analyzer being calibrated. The impedance converter uses the transformer principle and realizes impedance transformation through the transformer's turns ratio. Because the output impedance of the power amplifier is 50Ω, the desired load impedance transformation can be achieved through the transformer's turns ratio. For example, to achieve complete matching with a load resistance of 200Ω, as long as the transformer's turns ratio is 1:2, when the power at the balanced end and the unbalanced end is equal, the impedance ratio is 1:4 (the ratio of the square of the turns ratio). When the unbalanced end is connected to 50Ω, the impedance at the balanced end is 50×4=200Ω. At this time, setting the load resistance of the high-frequency electrosurgical analyzer to 200Ω can achieve impedance matching. In this way, the output impedance matching problem of conventional power standard sources in the frequency range of 9kHz~10MHz and higher and the problem that the impedance matching range is too narrow, that is, it cannot cover the entire load resistance range of the high-frequency electrosurgical analyzer.

[0048] (3) The present invention uses a current sensor plus an oscilloscope to measure high-frequency current. The high-frequency current sensor used has a current sensor bandwidth of 100Hz to 200MHz, an effective value current measurement range of up to 20A, and a maximum allowable error of ±0.5%. The bandwidth of the digital oscilloscope is 500MHz, and the sampling rate is 2.5Gsa / s. By connecting the current sensor to the input channel of the digital oscilloscope to measure the high-frequency current signal, it is possible to observe and record the distortion of the high-frequency current waveform and measure the effective value of the current. In particular, by using the high-resolution measurement mode, the dynamic effective number of bits of the digital oscilloscope is optimized, which can improve the current measurement accuracy.

[0049] (4) The present invention provides two high-frequency power calibration methods, using a current sensor and a digital oscilloscope to measure the high-frequency current, and using a digital multimeter to measure the load resistance, that is, the resistance in the DC state, and the power is the square of the effective value current multiplied by the resistance; a high-frequency voltage probe can also be used to measure the effective value of the AC voltage across the load resistance, and the high-frequency power can be obtained by multiplying the effective value current by the effective value voltage.

[0050] (5) The present invention provides a peak-to-peak voltage calibration method for a high-frequency electrosurgical knife analyzer, which uses a digital oscilloscope and a high-voltage differential probe to measure the peak-to-peak voltage. The two ends of the load resistor are connected to the input end of the high-voltage differential probe, and the output end of the high-voltage differential probe is connected to the input channel of the digital oscilloscope. The probe magnification is set, and the horizontal time base and vertical deflection coefficient of the digital oscilloscope are adjusted. The voltage waveform is captured until it occupies 80% of the screen. The peak measurement function or cursor measurement function of the digital oscilloscope is used to measure the peak-to-peak value of the voltage across the load resistor.

[0051] (6) The present invention provides a method for calibrating the effective value voltage of a high-frequency electrosurgical analyzer, using a digital oscilloscope and a high-voltage differential probe to measure the effective value voltage. The two ends of the load resistor are connected to the input end of the high-voltage differential probe, and the output end of the high-voltage differential probe is connected to the input channel of the digital oscilloscope. The probe magnification is set, and the horizontal time base and vertical deflection coefficient of the digital oscilloscope are adjusted. The voltage waveform is captured until it occupies 80% of the screen. The effective value measurement function of the digital oscilloscope is used to measure the effective value of the voltage across the load resistor.

[0052] (7) The present invention provides a method for calibrating the peak factor of a high-frequency electrosurgical analyzer. Calibration is performed using a function generator and a voltage amplifier. The function generator is set to amplitude modulation, and a certain amount of third and fifth harmonics are superimposed to distort the waveform, thereby generating a high-frequency voltage waveform with a certain peak factor. The two ends of the load resistor are connected to the input end of a high-voltage differential probe, and the output end of the high-voltage differential probe is connected to the input channel of a digital oscilloscope. The probe magnification is set, and the horizontal time base and vertical deflection coefficient of the digital oscilloscope are adjusted to capture the voltage waveform occupying 80% of the screen. The effective value measurement function and peak-to-peak value measurement function of the digital oscilloscope are used to measure the effective value and peak value of the voltage at both ends of the load resistor respectively. The measured peak value is divided by the effective value to obtain the actual measured value of the peak factor. The peak value is compared with the peak factor indication value on the high-frequency electrosurgical analyzer to obtain the indication error of the peak factor.

[0053] (8) The present invention provides a method for calibrating the bandwidth of a high-frequency electrosurgery analyzer. The output voltage of the function / arbitrary wave generator (10) is 5V or 10V peak-to-peak, the output frequency is 500kHz, the output impedance is 50Ω, the variable resistance of the high-frequency electrosurgery analyzer is set to 50Ω, the measurement mode is the high-frequency power measurement mode, the high-frequency current value at this time is recorded as a reference value, the output frequency of the function / arbitrary wave generator is increased or decreased until the high-frequency current value indicated by the high-frequency electrosurgery analyzer is 0.707 times the reference value, and the maximum and minimum values of the output frequency of the function / arbitrary wave generator at this time are recorded respectively. The bandwidth is the maximum value minus the minimum value.

[0054] (9) The present invention provides a method for calibrating the frequency response of a high-frequency electrosurgical analyzer. The frequency and output level of the signal generator / microwave signal source are adjusted through software control or manually, and the frequency and power offset (offset, gain calibration value of the directional coupler) of the power meter's power measurement are set. The input channel CH1 of the digital oscilloscope is set as a current probe, and the probe magnification is set; the horizontal time base of the digital oscilloscope is set to an appropriate position according to the signal frequency.

[0055] Set the high-frequency electrosurgical analyzer to power measurement mode with a load resistance of 200Ω or 50Ω. Set the microwave signal source output frequency to 500kHz and adjust the output level so that the power meter outputs 100 watts. Record the power and current values of the high-frequency electrosurgical analyzer at this frequency as a reference. Change the signal output frequency and output level so that the dual-channel power meter still indicates 100 watts. Record the power and current values of the high-frequency electrosurgical analyzer at this time. Continue to change the signal source output frequency to the nominal bandwidth value and adjust the output level so that the power meter still indicates 100 watts. Record the power and current values at this frequency. Calculate the frequency response of the high-frequency electrosurgical analyzer using the formula. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 A schematic diagram of the composition of a calibration device provided in an embodiment of the present invention.

[0057] Figure 2 This is a schematic diagram of the high-frequency power, high-frequency current, and high-frequency voltage calibration connections in an embodiment of the present invention.

[0058] Figure 3 Schematic diagram of peak factor calibration connection in an embodiment of the present invention.

[0059] Figure 4 FIG. 4 is a schematic diagram of connection for frequency response calibration in an embodiment of the present invention.

[0060] Figure 5 Schematic diagram of the connection between the output of the function / arbitrary waveform generator and the load resistor of the calibrated high-frequency electrosurgical analyzer through a high-performance BNC split cable in an embodiment of the present invention.

[0061] Figure 6 FIG. 4 is a schematic diagram of the calibration connection of the load resistor in an embodiment of the present invention. DETAILED DESCRIPTION

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0063] like Figure 1 and Figure 2 As shown, the present invention provides a high-frequency electrosurgical analyzer calibration device, which mainly consists of a power generation section and a parameter measurement section. Specifically, it includes a signal generator / microwave signal source 1, a power amplifier 2, a dual-channel power meter 3, a directional coupler 4, an impedance converter 5, a current sensor 6, a digital oscilloscope 7, a high-voltage differential probe 8, a digital multimeter 9, a function / arbitrary waveform generator 10, a voltage amplifier 11, and a computer 12 for output power control.

[0064] The power generation part includes a signal generator / microwave signal source 1, a power amplifier 2, a directional coupler 4, a dual-channel power meter 3, and an impedance converter 5.

[0065] Signal generator / microwave signal source 1 has a frequency range of 9 kHz to 6 GHz, covering the frequency range of a high-frequency electrosurgical analyzer. The bandwidth (-3 dB) of a high-frequency electrosurgical analyzer typically ranges from 30 Hz to 5 MHz, and its operating range is 100 kHz to 1 MHz. The output level of signal generator / microwave signal source 1 is adjustable, ranging from -100 dBm to +20 dBm. Its signal output port is connected to the input port of power amplifier 2, providing an input signal to power amplifier 2.

[0066] The frequency range of the power amplifier 2 at least covers the operating frequency range of the high-frequency electrosurgical analyzer, and is used to generate a high-frequency power signal. The output port of the power amplifier 2 is connected to the directional coupler 4 .

[0067] The frequency range of directional coupler 4 covers at least the operating frequency range of the high-frequency electrosurgical analyzer, with a power output of up to 0.6 kW and a coupling coefficient of 50 dB. Its output port is connected to impedance converter 5. Its reflected power port and forward power port are connected to a dual-channel power meter 3 via power probes. If a single-channel power meter is used, the reflected port of the directional coupler is connected to a 50Ω terminal load to provide a bridge for monitoring the high-frequency power output.

[0068] Impedance converter 5 has a frequency range of 50kHz to 5MHz and a power output of 600W. Its input port is connected to the output of power amplifier 2 and has an impedance of 50Ω. This impedance converter is used for impedance conversion to match the impedance load of the high-frequency electrosurgical analyzer under test. The converted impedance is an integer multiple of 50 ohms. The output of impedance converter 5 is connected to the high-frequency electrosurgical analyzer under test through current sensor 6.

[0069] The control computer 12 is connected to the signal generator / microwave signal source 1, the power amplifier 2 and the dual-channel power meter 3 via a GPIB-USB data line. The power output is controlled by software.

[0070] The parameter measurement part includes measurement standards such as a current sensor 6, a digital oscilloscope 7, a high-voltage differential probe 8, and a digital multimeter 9.

[0071] The current sensor 6 has a bandwidth of up to 200 MHz, a rise time of 1.75 ns, and an effective current measurement range of up to 20 A. The output port of the current sensor 6 is connected to the input channel of a digital oscilloscope 7 for measuring high-frequency leakage current and high-frequency current under high-frequency power.

[0072] The voltage peak-to-peak measurement range of the high-voltage differential probe 8 can reach 14kV, and the DC voltage attenuation ratio is 100:1 and 1000:1. The input end of the high-voltage differential probe 8 is connected to the two ends of the load of the high-frequency electric knife analyzer, and its output port is connected to the input port of the digital oscilloscope 7 for measuring the high-frequency voltage signal at both ends of the load.

[0073] The two resistance measurement input terminals of the digital multimeter 9 are connected to the load of the high-frequency electric knife analyzer through 4mm banana plug test leads, so as to measure the load resistance value of the high-frequency electric knife analyzer.

[0074] The frequency range of the output of the function / arbitrary wave generator 10 is 1 μHz to 120 MHz, and the peak-to-peak voltage can reach 10 V. The output port thereof is connected to a 50Ω variable resistor of a high-frequency electrosurgical analyzer.

[0075] like Figure 5 As shown, the output of the function / arbitrary wave generator 10 is connected to both ends of the load resistor of the calibrated high-frequency electrosurgical analyzer through a high-performance BNC split cable, and the load resistor is set to 50Ω.

[0076] The voltage input of the voltage amplifier 11 is 10V peak-to-peak, and the output voltage is 800V peak-to-peak. The input end of the voltage amplifier 11 is connected to the output end of the function / arbitrary wave generator 10, and the output end of the voltage amplifier 11 is connected to the high-frequency electric knife load resistor for high-frequency signal amplification.

[0077] In one embodiment of the present invention, the model of the signal generator / microwave signal source 1 is SMB100A, the frequency range is 9 kHz to 6 GHz, and the output signal level is -100 dBm to +20 dBm.

[0078] In one embodiment of the present invention, the power amplifier 2 is of model BBA150-400, with a frequency of 9 kHz to 400 MHz, a power of 600 watts, and N-type input and output interfaces.

[0079] In one embodiment of the present invention, the model of the dual-channel power meter 3 is NRP2, the model of the power sensor is NRP18A, the frequency range is 9kHz~18GHz, and the power measurement dynamic range is -70dBm

[0080] +23dbm.

[0081] In one embodiment of the present invention, the model of the directional coupler 4 is DC3401A, with a frequency range of DC to 400 MHz, a coupling coefficient of 50 dB, and a power of 500 watts.

[0082] In one embodiment of the present invention, the impedance converter 5 has a model of 1:4200Ω and 1:6300Ω, a power of 600 watts, a frequency range of 50 kHz to 5 MHz, and a voltage standing wave ratio of less than 1.5.

[0083] In one embodiment of the present invention, the model of the current sensor 6 is 6595, the frequency range is 100 Hz to 150 MHz, the maximum effective current is 20 A, and the current-to-voltage conversion ratio is 0.5 V / A.

[0084] In one embodiment of the present invention, the model of the digital oscilloscope 7 is MDO32, with a bandwidth of 500 MHz, a rise time of 0.7 ns, a vertical offset coefficient of 1 mV / div to 10 V / div (1 MΩ), and a horizontal time base of 1 ns / div to 10 s / div.

[0085] In one embodiment of the present invention, the high-voltage differential probe 8 is of model N1140A, with a peak voltage measurement range of ±7 kV and a maximum allowable error of DC voltage of ±1%.

[0086] In one embodiment of the present invention, the model of the digital multimeter 9 is 34465A, with a DC voltage measurement range of ±1 kV, an AC voltage measurement range of ±700 V, and a resistance measurement range of 1 GΩ.

[0087] In one embodiment of the present invention, the model of the function / arbitrary wave generator 10 is 33622A, the frequency range is 1 μHz to 120 MHz, and the peak-to-peak output voltage can reach 10V.

[0088] In one embodiment of the present invention, the voltage amplifier 11 is of model HA-805, with a frequency range of DC to 300 kHz, an input voltage of ±10 V peak-to-peak, and an output voltage range of ±400 V peak-to-peak.

[0089] In the embodiment of the present invention, a signal generator / microwave signal source 1 outputs a sinusoidal signal with a frequency range of at least 9kHz to 10MHz and an output signal level range of at least (-70dBm to 0dBm). The output of the signal generator / microwave signal source 1 is connected to the input port of a power amplifier 2, which has a frequency range of at least 9kHz to 10MHz. The amplification gain of the power amplifier 2 is fixed, and the output frequency and output level of the signal generator / microwave signal source 1 can be adjusted to enable the power amplifier 2 to output a high-frequency power of 1mW to 600W. When adjusting the output level of the signal generator / microwave signal source 1, the maximum output level of the power amplifier must not be exceeded, otherwise the power amplifier 2 will protect itself and stop power output. The output port of the power amplifier 2 is connected to the input port of a directional coupler 4. The forward and reverse interfaces of the directional coupler 4 are connected to the power sensors of a dual-channel power meter 3, which monitors the forward output power and reflected power in real time. The output port of the directional coupler 4 is connected to the input port of the impedance converter 5. The impedance converter 5 can select different conversion ratios to match the load resistance of the high-frequency electrosurgical analyzer being calibrated. The power of the impedance converter 5 is 600W, the voltage standing wave ratio of the port is less than 1.5, and the frequency range is at least 100kHz to 10MHz. The output port of the impedance converter 5 is a banana plug, which is connected to the input port of the high-frequency electrosurgical analyzer being calibrated after passing through the current sensor 6. The output of the current sensor 6 is connected to the input channel 1 of the digital oscilloscope 7 for measuring high-frequency current. The input of the high-voltage differential probe 8 is connected to both ends of the load resistance of the high-frequency electrosurgical analyzer being calibrated. The output of the high-voltage differential probe 8 is connected to the input channel 2 of the digital oscilloscope 7 for measuring high-frequency voltage, peak voltage, peak-to-peak voltage and crest factor. Figure 3 As shown, the output of the function / arbitrary wave generator 10 is connected to the input of a voltage amplifier 11, and the output port of the voltage amplifier 11 is connected to the high-frequency electrosurgical analyzer being calibrated. The crest factor is calibrated by adjusting the output frequency and level of the function / arbitrary wave generator 10 and superimposing varying amounts of third and fifth harmonics. The input of the digital multimeter 9 is connected across the load resistor of the high-frequency electrosurgical analyzer being calibrated to calibrate the load resistor. The calibrated device can measure the high-frequency electrosurgical analyzer's parameters, including high-frequency power of 500 watts, high-frequency current of 5 mA to 5 A, bandwidth of 30 Hz to 5 MHz, and resistance of 0 to 6400 Ω.

[0090] The present invention also provides a method for calibrating parameters of a high-frequency electrosurgical analyzer, such as high-frequency power, high-frequency current, and rated load resistance, using the aforementioned device for calibration.

[0091] In one embodiment of the present invention, a method for calibrating high-frequency power, high-frequency current, and rated load resistance of a high-frequency electrosurgical analyzer is provided, comprising the following steps:

[0092] Step 1: The high-frequency current calibration connection diagram is as follows Figure 2 As shown, preheat each standard and the calibrated high-frequency electrosurgery analyzer. Use software control or manual adjustment of the frequency and output level of the signal generator / microwave signal source, set the frequency and power compensation (offset, gain calibration value of the directional coupler) of the power measurement of the dual-channel power meter, so that the power measurement value of the dual-channel power meter is the set power calibration point (or the power indication value of the calibrated high-frequency electrosurgery analyzer is the set calibration point). Set the input channel CH1 of the digital oscilloscope to the current probe and set the probe magnification; set the horizontal time base of the digital oscilloscope to the appropriate position according to the frequency of the signal. Set the load resistance of the high-frequency electrosurgery analyzer (such as 200Ω) and click the start button on the touch screen of the calibrated high-frequency electrosurgery analyzer panel to perform high-frequency power measurement. Use the current effective value measurement function of the digital oscilloscope to measure the high-frequency current I RMS .

[0093] Step 2: How to calibrate the high frequency power: The calibration connection diagram is as follows: Figure 2 As shown, the measurement of high-frequency current is performed according to step 1. The DC resistance measurement function of the digital multimeter is used to measure the load resistance of the high-frequency electric knife analyzer, and the actual value of the high-frequency power is calculated using formula (2).

[0094] Step 3: Calibration connection of load resistor as shown Figure 6 As shown, warm up the DMM and the high-frequency electrosurgical analyzer to be calibrated. Use a DMM with 6.5-digit accuracy or higher and set the DMM to the two-wire resistance measurement function. Set the high-frequency electrosurgical analyzer to power measurement mode and set the resistance value to be calibrated within the resistance range. Click the Start Measurement button to start the measurement and read the reading on the DMM as the actual value of the load resistance.

[0095] In one embodiment of the present invention, Figure 4 As shown, adjust the frequency and output level of the signal generator / microwave source through software control or manually, and set the power meter's power measurement frequency and power offset (offset, directional coupler gain calibration value). Set the digital oscilloscope's input channel CH1 as a current probe and the probe magnification; set the digital oscilloscope's horizontal time base to the appropriate position based on the signal frequency.

[0096] Set the high-frequency electrosurgical analyzer to power measurement mode with a load resistance of 200Ω or 50Ω. Set the microwave signal source output frequency to 500kHz and adjust the output level so that the power meter outputs 100 watts. Record the power and current values of the high-frequency electrosurgical analyzer at this frequency as a reference. Change the signal output frequency and output level so that the dual-channel power meter still indicates 100 watts. Record the power and current values of the high-frequency electrosurgical analyzer at this time. Continue to change the signal source output frequency to the nominal bandwidth value and adjust the output level so that the power meter still indicates 100 watts. Record the power and current values at this frequency. Calculate the frequency response of the high-frequency electrosurgical analyzer using the formula.

[0097] In one embodiment of the present invention, Figure 5 As shown,

[0098] In one embodiment of the present invention, the calibration data of high-frequency current, high-frequency power, and high-frequency resistance of a high-frequency electrosurgical analyzer produced by FLUKE, model QA-ESIII, and factory serial number 5544022, are shown in Table 1;

[0099] In one embodiment of the present invention, the calibration data of high-frequency current, high-frequency power, and high-frequency resistance of a high-frequency electrosurgical analyzer produced by DATREND, model vPad-RF, and factory serial number VEF17100101, are shown in Table 2;

[0100] In one embodiment of the present invention, the calibration data of high-frequency current, high-frequency power, and high-frequency resistance of a high-frequency electrosurgical analyzer produced by Sichuan Zhongce Radiation Technology Co., Ltd., with a model specification of NT7800 and a factory serial number of 7190154, are shown in Table 3;

[0101] As can be seen from Tables 1, 2, and 3, when the high-frequency current, high-frequency power, and load resistance are calibrated using the high-frequency electrosurgical analyzer calibration device provided by the present invention, the measured values obtained by the present invention are very close to the instrument indication values, and the measurement error is much smaller than the allowable error, which illustrates the effectiveness of the present invention.

[0102] Table 1 High-frequency electrosurgical analyzer QA-ESIII calibration data

[0103]

[0104]

[0105]

[0106] Table 2 Calibration data of high-frequency electrosurgical analyzer vPad-RF

[0107]

[0108]

[0109]

[0110] Table 3 Calibration data of high-frequency electrosurgical analyzer NT7800

[0111]

[0112]

[0113] As described above, the present invention proposes a high-frequency electrosurgical analyzer calibration device based on an impedance converter for calibrating (transferring measurement values) a high-frequency electrosurgical analyzer. The present invention innovatively proposes a method using an impedance converter. This solves the problem of matching the load impedance of the calibrated high-frequency electrosurgical analyzer. Simultaneously, a power amplifier is used to provide high-frequency power output, a high-frequency current sensor is used to measure high-frequency current, and a digital multimeter's resistance measurement function is used to calibrate the load resistance. This achieves traceability of the high-frequency current, high-frequency power, and load resistance, achieving high stability, good repeatability, and measurement uncertainty that meets measurement traceability requirements.

[0114] The implementation methods of the present invention are not limited to the above-mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be considered as equivalent replacement methods and shall be included in the scope of protection of the present invention.

Claims

1. A high-frequency electrosurgical analyzer calibration device, characterized in that: Including power generation part and parameter measurement part; The power generation part includes a signal generator / microwave signal source (1), a power amplifier (2), a directional coupler (4), a dual-channel power meter (3) and an impedance converter (5); The parameter measurement part includes a current sensor (6), a digital oscilloscope (7), a high-voltage differential probe (8) and a digital multimeter (9); The signal output end of the signal generator / microwave signal source (1) is connected to the input port of the power amplifier (2) to provide an input signal to the power amplifier (2); the output port of the power amplifier (2) is connected to the input port of the directional coupler (4); The output port of the directional coupler (4) is connected to the input port of the impedance converter (5), and the reflected power port and the forward power port of the directional coupler (4) are connected to the dual-channel power meter (3) through a power probe; The positive output end of the impedance converter (5) is connected to the positive input end of the calibrated high-frequency electrosurgery analyzer after passing through the current sensor (6), and the negative output end of the impedance converter (5) is connected to the negative input end of the calibrated high-frequency electrosurgery analyzer; The output port of the current sensor (6) is connected to the first input channel CH1 of the digital oscilloscope (7) for measuring high-frequency leakage current and high-frequency current under high-frequency power; The positive input terminal and the negative input terminal of the high-voltage differential probe (8) are respectively connected to the positive input terminal and the negative input terminal of the calibrated high-frequency electric knife analyzer, and the output port of the high-voltage differential probe (8) is connected to the second input channel CH2 of the digital oscilloscope (7) for measuring the high-frequency voltage signal across the load resistor using the peak-to-peak value and the effective value of the digital oscilloscope (7); Two resistance measurement input terminals of a digital multimeter (9) are connected to the positive terminal and the negative terminal of the load resistor of the high-frequency electric knife analyzer to be measured, and are used to measure the load resistance value of the high-frequency electric knife analyzer.

2. A high-frequency electrosurgical analyzer calibration device according to claim 1, characterized in that: A computer (12) is used to connect a signal generator / microwave signal source (1), a power amplifier (2) and a dual-channel power meter (3) via a GPIB-USB data cable to perform power output control; The output end of the signal generator / microwave signal source (1) is an N-type interface, which is connected to the power amplifier (2) through an N-type coaxial cable. The output is a sinusoidal signal with low harmonic content and no DC component.

3. The high-frequency electrosurgical analyzer calibration device according to claim 1, characterized in that: The input impedance of the impedance converter (5) is 50Ω, which is used for impedance conversion to match the load resistance of the calibrated high-frequency electrosurgery analyzer. The output impedance after conversion is an integer multiple of 50 ohms, which matches the load resistance of the calibrated high-frequency electrosurgery analyzer.

4. The high-frequency electrosurgical analyzer calibration device according to claim 1, characterized in that: The current sensor (6) is a through-type current loop, and the output port is a BNC female connector, which can be connected to the input channel of the digital oscilloscope (7) through a 4mm banana plug cable and a BNC coaxial cable.

5. The high-frequency electrosurgical analyzer calibration device according to claim 1, characterized in that: The power output of the power amplifier (2) is monitored in real time via a directional coupler (4) and a dual-channel power meter (3); the forward power port of the directional coupler (4) is connected to a first power probe A of the dual-channel power meter (3), and the reflected power port is connected to a second power probe B of the dual-channel power meter (3).

6. The high-frequency electrosurgical analyzer calibration device according to claim 5, characterized in that: The frequency range of the power amplifier (2) at least covers the operating frequency range of the high-frequency electrosurgery analyzer, and is used to generate a high-frequency power signal.

7. The high-frequency electrosurgical analyzer calibration device according to claim 1, characterized in that: A function / arbitrary wave generator (10) and a voltage amplifier (11) are used to amplify the high-frequency signal; The output of the function / arbitrary wave generator (10) is connected to the input of the voltage amplifier (11), and the output of the voltage amplifier (11) is simultaneously connected to the positive input and negative input of the high-voltage differential probe (8) and the positive terminal and negative terminal of the load resistor of the high-frequency electric knife analyzer. The second and third harmonic contents of the function / arbitrary wave generator (10) are adjusted, and the ratio of the peak-to-peak value to the effective value is measured using the high-voltage differential probe (8) and the digital oscilloscope (7) to obtain the standard value of the crest factor.

8. The high-frequency electrosurgical analyzer calibration device according to claim 1, characterized in that: The output of the function / arbitrary wave generator (10) is connected to both ends of the load resistor of the calibrated high-frequency electrosurgery analyzer through a high-performance BNC split cable.

9. A calibration method for a high-frequency electrosurgical analyzer, characterized in that: Using the high-frequency electrosurgical analyzer calibration device according to any one of claims 1 to 8, the method includes calibrating the following parameters: S1. Calibration of high-frequency current: The power amplifier (2) provides high-frequency power output, which is matched with the load resistance of the high-frequency electrosurgery analyzer through the impedance converter (5). The output level of the signal generator / microwave signal source (1) is adjusted. The current measurement value of the high-frequency electrosurgery analyzer is the current indication value. The effective value of the current measured on the digital oscilloscope (7) after passing through the current sensor (6) is the current standard value. S2. Calibration of high-frequency power: The power amplifier (2) provides high-frequency power output, which is matched with the load resistance of the high-frequency electrosurgery analyzer through the impedance converter (5). The output level of the signal generator / microwave signal source (1) is adjusted. The power measurement value of the high-frequency electrosurgery analyzer is the power indication value. The current standard value is obtained by measuring the effective value of the current on the digital oscilloscope (7) after the current sensor (6). The DC resistance standard value is measured by the resistance measurement function of the digital multimeter (9). The power standard value is calculated; S3. Calibration of high-frequency voltage: The power amplifier (2) provides high-frequency power output, which is matched with the load resistance of the high-frequency electrosurgery analyzer through the impedance converter (5). The output level of the signal generator / microwave signal source (1) is adjusted. The peak-to-peak voltage measurement value of the high-frequency electrosurgery analyzer is the high-frequency voltage indication value. The peak-to-peak voltage on the digital oscilloscope (7) after passing through the high-voltage differential probe (8) is the standard value. S4. Crest factor calibration: the output of the function / arbitrary wave generator (10) is connected to the input of the voltage amplifier (11), the output of the voltage amplifier is connected to the two ends of the variable resistor of the high-frequency electrosurgical analyzer to be calibrated, the output level of the function / arbitrary wave generator (10) is adjusted, and the second harmonic and third harmonic of the set content are superimposed and the amplification gain of the voltage amplifier (11) is adjusted, and the peak-to-peak value and the effective value are measured on the digital oscilloscope (7) through the high-voltage differential probe (8), and the difference between the two is used as the crest factor standard value. The crest factor measurement value on the high-frequency electrosurgical analyzer is the indicated value; S5. Calibration of frequency response: The power amplifier (2) provides high-frequency power output, which is matched with the load impedance of the high-frequency electrosurgery analyzer through the impedance converter (5). The output frequency of the signal generator / microwave signal source (1) is set to 500kHz, and its output level is adjusted so that the power of the high-frequency electrosurgery analyzer is 100 watts. The current measurement value at this time is used as a reference value. The output signal frequency is changed, and the current value and power value at this frequency are recorded. The frequency response is calculated. S6. Calibration of the frequency bandwidth: set the output signal frequency and output impedance of the function / arbitrary wave generator (10), set the variable resistor of the high-frequency electrosurgery analyzer, set the measurement mode to high-frequency current measurement mode, record the high-frequency current value at this time as a reference value, increase or decrease the output frequency of the function / arbitrary wave generator (10) until the high-frequency current value indicated by the high-frequency electrosurgery analyzer is 0.707 times the reference value, record the output frequency of the function / arbitrary wave generator (10) at this time, and calculate the frequency bandwidth of the high-frequency electrosurgery analyzer; S7. High-frequency leakage current calibration: The power amplifier (2) provides high-frequency power output, which is matched with the load resistance of the high-frequency electrosurgery analyzer through the impedance converter (5). The output level of the signal generator / microwave signal source (1) is adjusted. The high-frequency electrosurgery analyzer is set to the high-frequency leakage current measurement mode, the load resistance is 200Ω, and the high-frequency leakage current limit is set. The leakage current measurement value of the high-frequency electrosurgery analyzer is the leakage current indication value. The effective current value measured on the digital oscilloscope (7) after passing through the current sensor (6) is the actual leakage current value. S8. Load resistance calibration: Use a digital multimeter (9) with 6.5 digits or higher accuracy, set the digital multimeter (9) to a two-wire resistance measurement function; set the high-frequency electric knife analyzer to be calibrated to a power measurement mode, set the resistance value to be calibrated within the resistance range, click the start measurement button to start the measurement, and read the reading on the digital multimeter (9) as the actual value of the load resistance; in order to improve the accuracy of the load resistance measurement, it is necessary to eliminate the resistance of the test line.

10. The calibration method of a high-frequency electrosurgical analyzer according to claim 9, characterized in that: In step S2, the high-frequency power standard value is obtained by formula (1) or formula (2). Formula (1) is: P M =I RMS ×U RMS (1) Among them, P M is the actual value of high frequency power, in W; I RMS is the measured value of high-frequency current, in A; U RMS is the measured value of high-frequency voltage, in V; Formula (2) is: P M =I RMS ×I RMS ×R (2) Among them, P M is the actual value of high frequency power, in W; I RMS is the measured value of high-frequency current, in A; R is the measured value of DC resistance, in Ω.

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