An Impedance Detection Method and Circuit for High-Frequency Ultrasonic Surgical Operations

Abstract

The present invention relates to the field of clinical surgical techniques, and specifically relates to an impedance detection method and circuit for high-frequency ultrasonic surgical operations; it includes a full-bridge frequency drive circuit, a full-bridge isolation circuit, a bipolar output interface, a constant current source circuit, a signal amplification module, and an embedded single-chip microcomputer CPU module. The bipolar output interface is used to output high-frequency energy and send out a feedback voltage signal; the full-bridge isolation circuit is used to obtain the feedback voltage signal sent out by the bipolar output interface; the embedded single-chip microcomputer CPU module is used to identify the optimal voltage signal from the feedback voltage signal; the full-bridge frequency drive circuit is used to form a frequency oscillator and change the adjustable output frequency; through the arithmetic amplification of the feedback signal, a stable DC voltage signal is obtained; the DC voltage signal is filtered and converted into a contact resistance, which is fed back to the high-frequency energy output to complete blood vessel closure. Through the above method, the impedance error of the calculation is reduced, thereby avoiding affecting the clinical surgical effect of blood vessel closure.

Description

Technical Field

[0001] The present invention relates to the technical field of clinical surgery, and particularly relates to a method and circuit for detecting the impedance of an ultrasonic high-frequency surgical operation. Background Art

[0002] The ultrasonic high-frequency surgical system is applied to clinical surgeries and is widely used in various departments. It is a combined system of an ultrasonic scalpel and a high-frequency bipolar vessel sealing device. The ultrasonic scalpel is mainly used for cutting biological tissues and vessel sealing operations. When the knife head works, no current passes through the human body, and high-frequency electrical energy is output. Combining the pressure between the electric heads, the collagen and fibrin of the blood vessels to be cut are melted and denatured, and the blood vessel walls are fused to form a transparent zone, resulting in permanent lumen closure. During the clinical surgical process, the high-frequency bipolar vessel sealing device can receive the impedance signal of the target tissue between the jaw blades through the feedback host control system. When the tissue is coagulated to the optimal degree, the host control system automatically stops the high-frequency energy output, and there is an accompanying prompt sound to indicate that the coagulation is completed. Therefore, impedance detection is a key technology that affects whether the blood vessel walls can be fused to form a transparent zone during clinical surgery, enabling permanent lumen closure of blood vessels. Impedance detection directly improves the safety of clinical surgeries for vessel closure.

[0003] Currently, in clinical vessel closure surgeries, since the bipolar output is an approximate high-frequency sine wave circuit, the effective voltage Vorms and effective current Iorms of the bipolar output high-frequency energy are detected, and the impedance is calculated using the method of R = Vorms 2 ÷Iorms. Due to the complex characteristics of capacitance reactance, inductive reactance, impedance, etc. in the circuit, the above calculation method has a large error, which affects the clinical surgical effect of vessel closure. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and circuit for detecting the impedance of an ultrasonic high-frequency surgical operation, aiming to solve the technical problem in the prior art that the calculation of impedance in clinical vessel closure surgeries has a large error, which affects the clinical surgical effect of vessel closure.

[0005] To achieve the above purpose, an impedance detection circuit for an ultrasonic high-frequency surgical operation adopted by the present invention includes a full-bridge frequency drive circuit, a full-bridge isolation circuit, a bipolar output interface, a constant current source circuit, a signal amplification module, and an embedded single-chip microcomputer CPU module. The full-bridge frequency drive circuit, the bipolar output interface, and the constant current source circuit are respectively electrically connected to the full-bridge isolation circuit. The full-bridge isolation circuit is electrically connected to the signal amplification module, and the signal amplification module is electrically connected to the embedded single-chip microcomputer CPU module;

[0006] The bipolar output interface is used to output high-frequency energy and send out a feedback voltage signal;

[0007] The constant current source circuit is used to control the power supply voltage of the full-bridge isolation circuit;

[0008] The full-bridge isolation circuit is used to obtain the feedback voltage signal sent by the bipolar output interface;

[0009] The signal amplification module is used to amplify the feedback voltage signal;

[0010] The embedded single-chip microcomputer CPU module is used to identify the optimal voltage signal from the feedback voltage signal, obtain the low-ripple DC voltage signal, and perform interference processing on the signal using the digital embedded filtering algorithm;

[0011] The full-bridge frequency drive circuit is used to form a frequency oscillator, change the adjustable output frequency, and adjust the maximum output voltage of the full-bridge isolation circuit in the open state of the bipolar output interface.

[0012] Among them, the full-bridge frequency drive circuit includes a control chip U1, a resistor R1, a resistor R2, a resistor R3, an oscillation module CT1, an oscillation module RT1, a full-bridge drive transformer T1, a full-bridge drive transformer T2, a capacitor C1, and a capacitor C2. The resistor R1, the resistor R2, the resistor R3, the oscillation module CT1, and the oscillation module RT1 are respectively electrically connected to the control chip U1. The resistor R1 is electrically connected to the oscillation module CT1. The capacitor C1 is respectively electrically connected to the resistor R2 and the full-bridge drive transformer T1. The capacitor C2 is respectively electrically connected to the resistor R3 and the full-bridge drive transformer T2.

[0013] Among them, the ultrasonic high-frequency surgical impedance detection circuit further includes a VDV power supply, and the VDV power supply is respectively electrically connected to the constant current source circuit and the signal amplification module;

[0014] The VDV power supply is used to provide power for the constant current source circuit and the signal amplification module respectively.

[0015] The present invention also provides an ultrasonic high-frequency surgical impedance detection method, which is applied to the ultrasonic high-frequency surgical impedance detection circuit, and includes the following steps:

[0016] Connect the ultrasonic high-frequency surgical system to the bipolar instrument, insert the bipolar instrument into the bipolar output interface, and turn on the power supply;

[0017] Adjust the frequency and maximum voltage of the bipolar instrument output impedance detection circuit;

[0018] Obtain a stable DC effective voltage signal, drive a high-frequency isolation transformer through the full-bridge frequency drive circuit, control the detection full-bridge circuit, measure the control voltage of the full-bridge constant current source, obtain a feedback signal through voltage limiting and filtering, and obtain a stable DC voltage signal through operational amplification of the feedback signal;

[0019] Perform digital-to-analog conversion on the DC voltage signal, filter the DC voltage signal, convert it into contact resistance, and feedback it to the high-frequency energy output. Compare according to the calibration parameters and accurately output high-frequency energy to complete blood vessel closure.

[0020] Among them, in the step of adjusting the frequency and maximum voltage of the bipolar device output impedance detection circuit:

[0021] The full-bridge frequency drive circuit forms a frequency oscillator circuit, changes the adjustable output frequency, and obtains a square-wave circuit through dual-channel complementarity. The waveform duty cycle is 32% - 52%. In the open-circuit state of the bipolar circuit, adjust the maximum voltage output by the full-bridge isolation circuit.

[0022] An ultrasonic high-frequency surgical impedance detection method and circuit of the present invention output high-frequency energy through the bipolar output interface and emit a feedback voltage signal; the constant current source circuit is used to control the power supply voltage of the full-bridge isolation circuit; the full-bridge isolation circuit is used to obtain the feedback voltage signal emitted by the bipolar output interface; the signal amplification module is used to amplify the feedback voltage signal; the embedded single-chip microcomputer CPU module is used to identify the optimal voltage signal from the feedback voltage signal, obtain a low-ripple DC voltage signal, and perform interference processing on the signal using a digital embedded filtering algorithm; the full-bridge frequency drive circuit is used to form a frequency oscillator, change the adjustable output frequency, and adjust the maximum voltage output by the full-bridge isolation circuit in the open state of the bipolar output interface; connect the ultrasonic high-frequency surgical system to the bipolar instrument, insert the bipolar instrument into the bipolar output interface, and turn on the power supply; adjust the output frequency and maximum voltage of the bipolar instrument; obtain a stable DC effective voltage signal and a dual-channel waveform, drive the full-bridge through a high-frequency isolation transformer, control the detection of the full-bridge circuit, measure the control voltage of the full-bridge constant current source, obtain a feedback signal through voltage limiting and filtering, perform operational amplification on the feedback signal to obtain a stable DC voltage signal; perform digital-to-analog conversion on the DC voltage signal, filter the DC voltage signal, convert it into contact resistance, and feedback it to the high-frequency energy output. According to the comparison of calibration parameters, accurately output high-frequency energy to complete blood vessel closure. Through the above method, the signal reliability is improved, the impedance value with a resolution of 2Ω can be measured, and the impedance measurement range can reach 10Ω to 1000Ω. When the bipolar high-frequency energy is not activated, by detecting the feedback signal, the embedded single-chip microcomputer CPU module operates on the signal to obtain the high-frequency energy parameters suitable for tissue closure. When the high-frequency energy is output for closure, there is no carbonization, the local temperature is low, the heat diffusion is small, the heat conduction distance is short, and there is no damage to the surrounding tissues, which efficiently liberates medical staff, improves the safety of the ultrasonic high-frequency surgical system during the clinical closure operation, reduces the calculated impedance error, and thus avoids affecting the clinical surgical effect of blood vessel closure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0024] Figure 1 FIG. is a schematic structural diagram of the ultrasonic high-frequency surgical impedance detection circuit of the present invention.

[0025] Figure 2 FIG. is a schematic structural diagram of the full-bridge frequency drive circuit of the present invention.

[0026] Figure 3 This is the circuit diagram of the impedance detection circuit for ultrasonic high-frequency surgical operations of the present invention.

[0027] Figure 4 This is the flowchart of the steps of the impedance detection method for ultrasonic high-frequency surgical operations of the present invention.

[0028] 1 - Full-bridge frequency drive circuit, 2 - Full-bridge isolation circuit, 3 - Bipolar output interface, 4 - Constant current source circuit, 5 - Signal amplification module, 6 - Embedded single-chip microcomputer CPU module, 7 - VDV power supply. Specific implementation mode

[0029] Please refer to Figures 1 to 3 , wherein Figure 1 This is the structural schematic diagram of the impedance detection circuit for ultrasonic high-frequency surgical operations, Figure 2 This is the structural schematic diagram of the full-bridge frequency drive circuit, Figure 3 This is the circuit diagram of the impedance detection circuit for ultrasonic high-frequency surgical operations.

[0030] The present invention provides an impedance detection circuit for ultrasonic high-frequency surgical operations, including a full-bridge frequency drive circuit 1, a full-bridge isolation circuit 2, a bipolar output interface 3, a constant current source circuit 4, a signal amplification module 5, and an embedded single-chip microcomputer CPU module 6. The full-bridge frequency drive circuit 1, the bipolar output interface 3, and the constant current source circuit 4 are respectively electrically connected to the full-bridge isolation circuit 2. The full-bridge isolation circuit 2 is electrically connected to the signal amplification module 5, and the signal amplification module 5 is electrically connected to the embedded single-chip microcomputer CPU module 6;

[0031] The bipolar output interface 3 is used to output high-frequency energy and send out a feedback voltage signal;

[0032] The constant current source circuit 4 is used to control the supply voltage of the full-bridge isolation circuit 2;

[0033] The full-bridge isolation circuit 2 is used to obtain the feedback voltage signal sent out by the bipolar output interface 3;

[0034] The signal amplification module 5 is used to amplify the feedback voltage signal;

[0035] The embedded single-chip microcomputer CPU module 6 is used to identify the optimal voltage signal from the feedback voltage signal, obtain a low-ripple DC voltage signal, and perform interference processing on the signal using a digital embedded filtering algorithm;

[0036] The full-bridge frequency drive circuit 1 is used to form a frequency oscillator, change the adjustable output frequency, and adjust the maximum voltage output by the full-bridge isolation circuit 2 in the open state of the bipolar output interface 3.

[0037] In this embodiment, the bipolar output interface 3 is used to output high-frequency energy and send out a feedback voltage signal. The constant current source circuit 4 is used to control the supply voltage of the full-bridge isolation circuit 2. The full-bridge isolation circuit 2 is used to obtain the feedback voltage signal sent out by the bipolar output interface 3. The signal amplification module 5 is used to amplify the feedback voltage signal. The embedded single-chip microcomputer CPU module 6 is used to identify the optimal voltage signal from the feedback voltage signal, obtain a low-ripple DC voltage signal, and perform interference processing on the signal using a digital embedded filtering algorithm. The full-bridge frequency drive circuit 1 is used to form a frequency oscillator, change the adjustable output frequency. In the open-circuit state of the bipolar output interface 3, the output maximum voltage of the full-bridge isolation circuit 2 is adjusted. By the above method, the signal reliability is improved, the impedance value with a measurable resolution of 2Ω can be measured, and the impedance measurement range can reach 10Ω to 1000Ω. When the high-frequency energy of the bipolar is not activated, by detecting the feedback signal, the embedded single-chip microcomputer CPU module 6 performs signal operation to obtain the high-frequency energy parameters suitable for tissue closure. When the high-frequency energy is output and closed, carbonization does not occur, the local temperature is low, the heat diffusion is small, the heat conduction distance is short, and there is no damage to the surrounding tissues, which efficiently liberates medical staff, improves the safety of the ultrasonic high-frequency surgical system during the clinical closure operation, reduces the calculated impedance error, and thus avoids affecting the clinical surgical effect of blood vessel closure.

[0038] Further, the full-bridge frequency drive circuit 1 includes a control chip U1, a resistor R1, a resistor R2, a resistor R3, an oscillation module CT1, an oscillation module RT1, a full-bridge drive transformer T1, a full-bridge drive transformer T2, a capacitor C1, and a capacitor C2. The resistor R1, the resistor R2, the resistor R3, the oscillation module CT1, and the oscillation module RT1 are respectively electrically connected to the control chip U1. The resistor R1 is electrically connected to the oscillation module CT1. The capacitor C1 is respectively electrically connected to the resistor R2 and the full-bridge drive transformer T1. The capacitor C2 is respectively electrically connected to the resistor R3 and the full-bridge drive transformer T2.

[0039] Further, the ultrasonic high-frequency surgical impedance detection circuit further includes a VDV power supply 7. The VDV power supply 7 is respectively electrically connected to the constant current source circuit 4 and the signal amplification module 5;

[0040] The VDV power supply 7 is used to provide power for the constant current source circuit 4 and the signal amplification module 5 respectively.

[0041] In this embodiment, the control chip U1 uses a dedicated control chip KA3525 or SG3525. The resistor R1 is the dead-time control resistor for the A path and the B path. The oscillation modules CT1 and RT1 are RC oscillation circuits. The full-bridge drive transformers T1 and T2 are full-bridge drive transformers. In the ultrasonic high-frequency surgical impedance detection circuit, when JP1 is not connected to the neutral electrode and is in an open-circuit state, use an oscilloscope to measure the waveform voltage amplitudes of pins 1 and 3 of JP1. Adjust the oscillation module RT1 to make the waveform voltage amplitude maximum. At this time, the frequency is the optimal frequency for controlling the outputs of the A path and the B path. The constant current source circuit 4 composed of U2A, R4, R6, R9, and RT2 controls the supply voltage. Through the secondary side of the high-voltage isolation transformer TR1, C7, C8, an output impedance network for tissue formation is formed. Since the primary side of the transformer is under constant current control, according to the law of conservation of energy, different impedance changes of the tissue are detected, and the feedback voltage signal changes the full-bridge control voltage. The feedback voltage signal passes through voltage limiting and filtering, and is amplified by an operational amplifier circuit to the embedded single-chip microcomputer CPU module 6 to identify a stable low-ripple DC voltage signal. Through high-speed ADC sampling by the embedded single-chip microcomputer CPU module 6, the CPU performs a digital embedded filtering algorithm to process signal interference, obtains an impedance value with a resolution of 2Ω, and the impedance measurement range can reach 10Ω to 1000Ω, obtaining high-frequency energy parameters suitable for tissue closure. The CPU controls the output of the high-frequency energy for closure through timely feedback and control.

[0042] Please refer to Figure 4 , in which Figure 4 is the step flowchart of the ultrasonic high-frequency surgical impedance detection method.

[0043] The present invention also provides an ultrasonic high-frequency surgical impedance detection method, which is applied to the ultrasonic high-frequency surgical impedance detection circuit and includes the following steps:

[0044] S1: Connect the ultrasonic high-frequency surgical system to the bipolar instrument, insert the bipolar instrument into the bipolar output interface 3, and turn on the power supply;

[0045] S2: Adjust the output frequency and the maximum voltage of the bipolar instrument impedance detection circuit. The full-bridge frequency drive circuit 1 forms a frequency oscillator circuit, changes the adjustable output frequency, and a square-wave circuit is obtained through dual-channel complementarity. The waveform duty cycle is 32% - 52%. In the open-circuit state of the bipolar circuit, adjust the maximum voltage output by the full-bridge isolation circuit 2;

[0046] S3: Obtain a stable DC effective voltage signal. Drive the high-frequency isolation transformer through the full-bridge frequency drive circuit 1, control the detection full-bridge circuit, measure the full-bridge constant current source control voltage, obtain a feedback signal through voltage limiting and filtering, and obtain a stable DC voltage signal through operational amplification of the feedback signal;

[0047] S4: Perform digital-to-analog conversion on the DC voltage signal, filter the DC voltage signal, convert it into contact resistance, feedback it to the high-frequency energy output, compare it according to the calibration parameters, accurately output high-frequency energy, and complete blood vessel closure.

[0048] In this embodiment, the bipolar output interface 3 is used to output high-frequency energy and send out a feedback voltage signal; the constant current source circuit 4 is used to control the power supply voltage of the full-bridge isolation circuit 2; the full-bridge isolation circuit 2 is used to obtain the feedback voltage signal sent out by the bipolar output interface 3; the signal amplification module 5 is used to amplify the feedback voltage signal; the embedded single-chip microcomputer CPU module 6 is used to identify the best voltage signal from the feedback voltage signal, obtain a low-ripple DC voltage signal, and use a digital embedded filtering algorithm to process the interference of the signal; the full-bridge frequency drive circuit 1 is used to form a frequency oscillator, change the adjustable output frequency, and adjust the maximum voltage output by the full-bridge isolation circuit 2 in the open state of the bipolar output interface 3; during the operation, first connect the ultrasonic high-frequency surgical system to the bipolar instrument, insert the bipolar instrument into the bipolar output interface 3, and turn on the power supply, adjust the output frequency and maximum voltage of the bipolar instrument, the full-bridge frequency drive circuit 1 forms a frequency oscillator circuit, changes the adjustable output frequency, and obtains a square wave circuit through dual-channel complementarity, with a waveform duty cycle of 32% - 52%. In the open state of the bipolar circuit, adjust the maximum voltage output by the full-bridge isolation circuit 2 to obtain a stable DC effective voltage signal and a dual-channel waveform. Drive the full-bridge through a high-frequency isolation transformer, control and detect the full-bridge circuit, measure the control voltage of the full-bridge constant current source, obtain a feedback signal through voltage limiting and filtering, perform operational amplification on the feedback signal to obtain a stable DC voltage signal, then perform digital-to-analog conversion on the DC voltage signal, filter the DC voltage signal, convert it into contact resistance, feedback it to the high-frequency energy output, compare it according to the calibration parameters, accurately output high-frequency energy, and complete blood vessel closure. Through the above method, the signal reliability is improved, the measurable resolution can reach 2Ω impedance value, and the impedance measurement range can reach 10Ω to 1000Ω. When the high-frequency energy of the bipolar is not activated, by detecting the feedback signal, the embedded single-chip microcomputer CPU module 6 operates on the signal to obtain the high-frequency energy parameters suitable for tissue closure. When the high-frequency energy is output for closure, no carbonization occurs, the local temperature is low, the heat diffusion is small, the heat conduction distance is short, and there is no damage to the surrounding tissues, effectively liberating medical staff, improving the safety of the ultrasonic high-frequency surgical system during the clinical closure operation, reducing the calculated impedance error, and thus avoiding affecting the clinical surgical effect of blood vessel closure.

[0049] The above-disclosed is only a preferred embodiment of the present invention. Of course, it cannot be used to limit the scope of the rights of the present invention. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. An impedance detection circuit for ultrasonic high-frequency surgical operations, characterized in that it includes a full-bridge frequency drive circuit, a full-bridge isolation circuit, a bipolar output interface, a constant current source circuit, a signal amplification module, and an embedded single-chip microcomputer CPU module. The full-bridge frequency drive circuit, the bipolar output interface, and the constant current source circuit are respectively electrically connected to the full-bridge isolation circuit. The full-bridge isolation circuit is electrically connected to the signal amplification module, and the signal amplification module is electrically connected to the embedded single-chip microcomputer CPU module; the bipolar output interface is used to output high-frequency energy and send out a feedback voltage signal; the constant current source circuit is used to control the supply voltage of the full-bridge isolation circuit; the full-bridge isolation circuit is used to obtain the feedback voltage signal sent out by the bipolar output interface; the signal amplification module is used to amplify the feedback voltage signal; the embedded single-chip microcomputer CPU module is used to identify the optimal voltage signal from the feedback voltage signal, obtain a low-ripple DC voltage signal, and perform interference processing on the signal using a digital embedded filtering algorithm; the full-bridge frequency drive circuit is used to form a frequency oscillator, change the adjustable output frequency, and adjust the maximum voltage output by the full-bridge isolation circuit in the open state of the bipolar output interface.

2. The impedance detection circuit for ultrasonic high-frequency surgical operations according to claim 1, characterized in that the full-bridge frequency drive circuit includes a control chip U1, a resistor R1, a resistor R2, a resistor R3, an oscillation module CT1, an oscillation module RT1, a full-bridge drive transformer T1, a full-bridge drive transformer T2, a capacitor C1, and a capacitor C2. The resistor R1, the resistor R2, the resistor R3, the oscillation module CT1, and the oscillation module RT1 are respectively electrically connected to the control chip U1. The resistor R1 is electrically connected to the oscillation module CT1. The capacitor C1 is respectively electrically connected to the resistor R2 and the full-bridge drive transformer T1. The capacitor C2 is respectively electrically connected to the resistor R3 and the full-bridge drive transformer T2.

3. The impedance detection circuit for ultrasonic high-frequency surgical operations according to claim 1, characterized in that the impedance detection circuit for ultrasonic high-frequency surgical operations further includes a VDV power supply, and the VDV power supply is respectively electrically connected to the constant current source circuit and the signal amplification module; the VDV power supply is used to provide power for the constant current source circuit and the signal amplification module respectively.

4. An ultrasonic high-frequency surgical impedance detection method, applied to the ultrasonic high-frequency surgical impedance detection circuit as described in claim 2, characterized in that, It includes the following steps: Connect the ultrasonic high-frequency surgical system to the bipolar instrument, insert the bipolar instrument into the bipolar output interface, and turn on the power supply; Adjust the output frequency and maximum voltage of the bipolar instrument impedance detection circuit; Obtain a stable DC effective voltage signal. Drive the high-frequency isolation transformer through the full-bridge frequency drive circuit, control the detection full-bridge circuit, measure the full-bridge constant current source control voltage, obtain a feedback signal through voltage limiting and filtering, and obtain a stable DC voltage signal through operational amplification of the feedback signal. Perform digital-to-analog conversion on the DC voltage signal, filter the DC voltage signal, convert it into contact resistance, and feedback it to the high-frequency energy output. Compare according to the calibration parameters and accurately output high-frequency energy to complete blood vessel closure.

5. The ultrasonic high-frequency surgical impedance detection method according to claim 4, wherein, In the step of adjusting the output frequency and maximum voltage of the bipolar device impedance detection circuit: The full-bridge frequency drive circuit forms a frequency oscillator circuit, changes the adjustable output frequency, and obtains a square wave circuit through dual-channel complementarity. The waveform duty cycle is 32% - 52%. In the open state of the bipolar circuit, adjust the maximum voltage output by the full-bridge isolation circuit.

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