Ultrasonic knife hemostasis equipment and control method

Abstract

The invention relates to the technical field of medical instruments, in particular to ultrasonic knife hemostasis equipment and a control method. The ultrasonic knife hemostasis equipment comprises a main controller, a high-voltage direct-current power supply, a power driving module, a matching network, a voltage sampling part and a current sampling part, the main controller is used for generating an SPWM signal with adjustable frequency and amplitude, the high-voltage direct-current power supply is used for providing a power supply for equipment, the power driving module is used for driving and amplifying the SPWM signal generated by the main controller, and the matching network is used for filtering a signal output by the power driving module to generate a standard sine wave signal so as to drive the transducer. The voltage sampling part is used for acquiring a driving voltage signal of the transducer, and the current sampling part is used for acquiring a driving current signal of the transducer. According to the ultrasonic knife hemostasis equipment, by introducing SPWM signals, FFT signal processing and a dynamic detection algorithm, the problems that heat dissipation is difficult, control is complex and the like in a traditional scheme are solved; the system has the advantages that the system precision and reliability are improved, and equipment miniaturization and high performance are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a hemostatic device using an ultrasonic scalpel and a control method thereof. Background Art

[0002] An ultrasonic scalpel is a medical device widely used in surgical operations, which cuts and coagulates tissues through mechanical energy generated by high-frequency vibration. As Figure 1 shown, the traditional ultrasonic scalpel system uses a linear power amplifier for driving, and two power tubes are used to generate the positive and negative half-cycles of a sinusoidal driving voltage respectively. However, this traditional solution has the following problems: (1) Large power tube losses. The power tubes operate in the linear amplification region, and most of the electrical energy will be dissipated in the form of heat, which not only reduces the efficiency but also causes serious self-heating of the power amplifier. To dissipate heat, a large area of heat sinks and fans need to be added, which limits the reduction of the device volume; (2) Poor reliability. When cutting tissues, the impedance of the transducer may change suddenly, resulting in overvoltage and overcurrent of the power tubes and causing damage, which limits the further improvement of the driving ability for the ultrasonic transducer; (3) Low signal processing accuracy. In the traditional solution, the voltage and current signals of the transducer are sampled through a transformer, and the phase difference is obtained through a simple comparator. This measurement method has high requirements for the amplitude and waveform of the voltage and current signals, and the analog circuit processing of the two signals needs to be perfectly consistent, otherwise test errors will be introduced; (4) Complex power control. The traditional solution controls the current of the transducer by adjusting the bus power supply, and complex voltage and current feedback is required to achieve power regulation; (5) Problem of matching inductance. The traditional solution is equipped with a matching inductance at the power output stage to compensate for the static capacitance C0 of the transducer. However, the heat generation of the transducer will cause C0 to drift, and the unchanged matching inductance will cause the resonance point to shift, further reducing the efficiency of the transducer and increasing the temperature rise. Summary of the Invention

[0003] The object of the present invention is to provide a hemostatic device using an ultrasonic scalpel that is convenient for miniaturization, has high signal processing accuracy, and good reliability.

[0004] To achieve the above object, the present invention adopts an ultrasonic scalpel hemostasis device, which includes a main controller, a high-voltage DC power supply, a power drive module, a matching network, a voltage sampling section, and a current sampling section; the main controller is used to generate an SPWM signal with adjustable frequency and amplitude, the high-voltage DC power supply is used to provide power for the device, the power drive module is used to drive and amplify the SPWM signal generated by the main controller, the matching network is used to filter the signal output by the power drive module to generate a standard sine wave signal to drive the transducer, the voltage sampling section is used to collect the drive voltage signal of the transducer, and the current sampling section is used to collect the drive current signal of the transducer. Among them, the main controller processes the collected voltage and current signals through FFT operation, obtains real-time voltage values, current values, and phase difference information, and adjusts the frequency and amplitude of the SPWM signal based on the PID control algorithm, so that the transducer works near the resonance point and the current is stabilized at a preset level.

[0005] The device of the present invention is driven by an SPWM signal, which can reduce the power tube loss and the heat dissipation requirement, and smaller heat sinks and fans can be selected, facilitating the miniaturization of the device volume; at the same time, directly controlling the power drive module avoids complex bus power supply regulation and simplifies the control logic. At the same time, the SPWM signal driving method makes the power tube work in the switching mode rather than the linear interval, avoiding damage caused by overcurrent and overheating, thereby improving the reliability.

[0006] The FFT signal processing method is more accurate than the traditional phase difference measurement. Especially in the case of detuning, it can improve the signal processing accuracy more. The matching network can reduce the influence of high-frequency harmonics on the transducer through filtering, thereby improving the output signal quality of the transducer, optimizing the power transmission path, reducing the power loss during transmission, and improving the overall efficiency of the system. The matching network can adapt to these changes by dynamically adjusting parameters (such as dynamically compensating the static capacitance through an algorithm in the present invention) to maintain the stable operation of the system.

[0007] The device of the present invention dynamically detects the transducer to achieve dynamic adjustment of the resonance point, so that the matching inductor can be not used, reducing the hardware complexity and volume. At the same time, dynamically detecting and real-time adjusting the resonance frequency can better adapt to load and temperature changes.

[0008] Preferably, the main controller includes at least one of a single-chip microcomputer, an SOC chip, a DSP (Digital Signal Processor), or an FPGA (Field Programmable Gate Array).

[0009] Preferably, the matching network is used to convert the SPWM signal into a standard sine wave signal to drive the transducer, and the matching inductor of the output-stage transducer of the device is cancelled.

[0010] Preferably, the main controller obtains discrete data of voltage and current through synchronous ADC sampling, and performs FFT operation on the discrete data to obtain the amplitude and phase difference information of the current and voltage signals.

[0011] The present invention also discloses a control method for the above ultrasonic knife hemostasis device, including the following steps: S1. Before each startup, the main controller generates a fixed SPWM signal far from the resonance frequency to drive the transducer; S2. Synchronously collect the driving voltage of the transducer and current signal ; S3. Utilize the collected voltage signal and current signal , calculate the phase difference through FFT operation, and combine the known output frequency, voltage and current phase and amplitude information to calculate the equivalent static capacitance C0 of the transducer.

[0012] Preferably, in step S2, according to the current SPWM signal drive, sample back the voltage signal of the transducer and current signal .

[0013] Preferably, in step S3, utilize the sampled-back voltage signal and current signal and the static capacitance C0 to calculate the current flowing through the static capacitance , and obtain the actual resonance current through vector calculation ; Calculate the phase difference and amplitude information of the transducer operation according to the resonance current; Adjust the output frequency of the SPWM signal to make the phase difference zero; According to the amplitude of the resonance current , adjust the output amplitude of the SPWM signal through PID control to make the current of the dynamic branch maintain at the current value of the preset gear.

[0014] The ultrasonic knife hemostasis device of the present invention solves the problems of difficult heat dissipation and complex control in the traditional scheme by introducing SPWM signals, FFT signal processing and dynamic detection algorithms. It not only improves the accuracy and reliability of the system, but also simplifies the hardware design, facilitating the miniaturization and high performance of the device. Description of the Drawings

[0015] Figure 1 It is the schematic diagram of the existing ultrasonic knife system.

[0016] Figure 2 This is the circuit schematic diagram of the ultrasonic scalpel hemostasis device of the present invention.

[0017] Figure 3 This is the logic control diagram of the ultrasonic scalpel hemostasis device of the present invention. Detailed implementation manners

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] As Figure 2 and Figure 3 shown, this embodiment discloses an ultrasonic scalpel hemostasis device, including a main controller 100, a high-voltage DC power supply, a power drive module 200, a matching network 300, a voltage sampling part 400, and a current sampling part 500; the main controller 100 is used to generate an SPWM signal with adjustable frequency and amplitude, the high-voltage DC power supply is used to provide power for the device, the power drive module 200 is used to drive and amplify the SPWM signal generated by the main controller 100, the matching network 300 is used to filter the signal output by the power drive module 200 to generate a standard sine wave signal to drive the transducer 600, the voltage sampling part 400 is used to collect the drive voltage signal of the transducer 600, and the current sampling part 500 is used to collect the drive current signal of the transducer 600.

[0020] Among them, the main controller is also used to perform synchronous ADC sampling on the collected voltage signal and current signal, and obtain real-time voltage value, current value, and phase difference information through FFT operation. According to the phase difference information, the frequency and amplitude of the SPWM signal are adjusted through the PID control algorithm, so that the transducer works near the resonance point and the current is stabilized at a preset level. The device cancels the output-stage matching inductor in the traditional scheme and realizes the dynamic adjustment of the resonance point by dynamically detecting the static capacitance C0 of the transducer.

[0021] The main controller processes the collected voltage and current signals through FFT operation. Compared with the traditional method of processing through a dual-channel analog link of voltage and current and zero-crossing detection, it can more accurately obtain the phase difference between the current and voltage signals, especially providing more accurate measurement results in the case of detuning.

[0022] Among them, the main controller of this embodiment can be implemented by FPGA, the high-voltage DC power supply provides 24V DC voltage, and the power drive module adopts a MOSFET power amplification circuit. The matching network is designed as an LC filter circuit, and the voltage and current sampling parts respectively adopt high-precision voltage sensors and current sensors. The main controller obtains the voltage and current signals through ADC sampling and processes the signals through FFT operation. The parameters of the PID control algorithm are determined according to experimental debugging to ensure the stable operation of the system.

[0023] Regarding the SPWM signal driving of this embodiment: The main controller generates an SPWM signal with adjustable frequency and amplitude. After being amplified by the power driving module and filtered by the matching network, a standard sine wave signal is generated to drive the transducer.

[0024] Regarding the signal acquisition and FFT processing of this embodiment: The main controller performs synchronous ADC sampling on the collected voltage and current signals, and obtains real-time voltage values, current values, and phase difference information through FFT operation. The FFT method has higher accuracy compared to traditional methods, especially providing more accurate measurement results in the case of detuning.

[0025] Regarding the dynamic detection of the static capacitance C0 of this embodiment: Before the device starts, the main controller generates a fixed SPWM signal far from the resonant frequency to drive the transducer, and synchronously collects the voltage and current signals of the transducer. The phase difference is calculated using the collected signals, and combined with the known output frequency, voltage-current phase, and amplitude information, the equivalent static capacitance C0 of the transducer is dynamically detected.

[0026] Regarding the resonant point frequency calculation of this embodiment: The main controller collects the voltage and current signals of the transducer according to the current SPWM signal driving, calculates the current flowing through the static capacitance and the actual resonant current using the previously calculated static capacitance C0. Information such as the phase difference and amplitude of the transducer's operation is obtained through vector calculation, and the output frequency of the SPWM is adjusted according to the phase difference to make the phase difference zero. According to the calculated current amplitude, the output amplitude of the SPWM is adjusted through the PID algorithm to keep the current in the dynamic branch at the current value of the preset gear.

[0027] Embodiment 2 A control method for the ultrasonic scalpel hemostasis device used in Embodiment 1 includes the following steps: S1. Before each startup, the main controller generates a fixed SPWM signal far from the resonant frequency to drive the transducer; S2. Synchronously collect the driving voltage of the transducer and current signals ; S3. Using the collected voltage signal and current signals , calculate the phase difference through FFT operation, and combine the known output frequency, voltage-current phase, and amplitude information to calculate the equivalent static capacitance C0 of the transducer.

[0028] Among them, according to the current SPWM signal driving, the voltage signal of the transducer is sampled back and current signals ; using the sampled-back voltage signal and current signals and the static capacitance C0, calculate the current flowing through the static capacitance , and obtain the actual resonant current through vector calculation ; calculate the phase difference and amplitude information of the transducer operation according to the resonant current; adjust the output frequency of the SPWM signal to make the phase difference zero; according to the resonant current amplitude, adjust the output amplitude of the SPWM signal through PID control to make the current in the dynamic branch remain at the current value of the preset gear.

[0029] In this embodiment, by introducing the SPWM signal, FFT signal processing and dynamic detection algorithm, the problems of difficult heat dissipation and complex control in the traditional scheme are solved. It not only improves the accuracy and reliability of the system, but also simplifies the hardware design, facilitating the miniaturization and high performance of the device.

Claims

1. An ultrasonic scalpel hemostasis device, characterized in that: include: A main controller is used to generate an SPWM signal with adjustable frequency and amplitude, and perform synchronous ADC sampling on the driving voltage and current signals on the transducer; A high-voltage direct current power supply, connected to the main controller, for providing driving power; A power driving module, connected to the main controller, for amplifying the SPWM signal to drive the transducer; A matching network, connected to the power driving module, for filtering the SPWM signal to generate a standard sine wave signal; A voltage sampling part, connected to the transducer, for collecting a driving voltage signal of the transducer; A current sampling part, connected to the transducer, for collecting a driving current signal of the transducer; The main controller processes the collected voltage and current signals through FFT operation to obtain real-time voltage value, current value, and phase difference information, and adjusts the frequency and amplitude of the SPWM signal based on the PID control algorithm so that the transducer operates near the resonance point and the current is stabilized at a preset gear.

2. The ultrasonic scalpel hemostasis device according to claim 1, characterized in that: The main controller includes at least one of a single chip microcomputer, a SOC chip, a DSP or a FPGA.

3. The ultrasonic scalpel hemostasis device according to claim 1, characterized in that: The matching network is used to convert the SPWM signal into a standard sine wave signal to drive the transducer, and the device cancels the matching inductance of the output stage transducer.

4. The ultrasonic scalpel hemostasis device according to claim 1, characterized in that: The main controller obtains discrete data of voltage and current through synchronous ADC sampling, and performs FFT operation on the discrete data to obtain amplitude and phase difference information of current and voltage signals.

5. A control method for the ultrasonic scalpel hemostasis device according to any one of claims 1 to 4, characterized in that: The steps include: S1. Before each startup, the main controller generates a fixed SPWM signal away from the resonant frequency to drive the transducer; S2. Synchronously collect the driving voltage of the transducer and current signal ; S3. Using the collected voltage signal and current signal The phase difference is calculated by FFT operation, and the equivalent static capacitance C0 of the transducer is calculated by combining the known output frequency, voltage and current phase and amplitude information.

6. The control method according to claim 5, characterized in that: In step S2, according to the current SPWM signal drive, the voltage signal of the transducer is collected and current signal .

7. The control method according to claim 5, characterized in that: In step S3, the voltage signal of the recovery is used and current signal and the static capacitor C0, calculate the current flowing through the static capacitor , and the actual resonant current is obtained by vector calculation ; Calculating the phase difference and amplitude information of the transducer operation according to the resonant current; Adjusting the output frequency of the SPWM signal so that the phase difference is zero; According to the resonant current The output amplitude of the SPWM signal is adjusted by PID control to make the current of the dynamic branch Maintain the current value at the preset level.

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