Ultrasonic knife hemostasis apparatus and control method

Abstract

The application relates to the technical field of medical devices, in particular to an ultrasonic knife hemostasis device and a control method. The ultrasonic knife hemostasis device 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 power supply for the device; the power driving module is used for driving and amplifying the SPWM signal generated by the main controller; the matching network is used for filtering the signal output by the power driving module to generate a standard sine wave signal to drive a transducer; the voltage sampling part is used for collecting a driving voltage signal of the transducer; and the current sampling part is used for collecting a driving current signal of the transducer. The ultrasonic knife hemostasis device introduces an SPWM signal, an FFT signal processing and a dynamic detection algorithm, solves the problems of difficult heat dissipation and complex control of a traditional scheme, and has the advantages of improving system precision and reliability, facilitating miniaturization and high performance of the device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to an ultrasonic knife hemostasis device and a control method. BACKGROUND

[0002] An ultrasonic knife is a medical device widely used in surgical operations, which cuts and coagulates tissues by mechanical energy generated by high-frequency vibration. Figure 1 The conventional ultrasonic knife system shown in the figure is driven by a linear power amplifier, which uses two power tubes to generate positive and negative half cycles of sinusoidal driving voltage. However, this traditional scheme has the following problems: (1) large power tube loss, the power tube works in the linear amplification interval, most of the electric energy will be lost in the form of heat, which not only reduces the efficiency, but also causes the power amplifier to heat up seriously; in order to dissipate heat, large-area heat sinks and fans need to be added, which limits the reduction of the size of the device; (2) poor reliability, when cutting tissues, the impedance of the transducer may change suddenly, causing the power tube to be damaged by overvoltage and overcurrent, which limits the further improvement of the driving capability of the ultrasonic transducer; (3) low signal processing precision, in the traditional scheme, 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 requires high voltage and current signal amplitude and waveform, and the analog circuit processing of the two signals needs to be perfect, otherwise it will introduce test errors; (4) complex power control, the traditional scheme controls the current of the transducer by adjusting the bus power supply, which requires complex voltage and current feedback to realize power regulation; (5) matching inductance problem, the traditional scheme has a matching inductance in the power output stage to compensate for the static capacitance C0 of the transducer, but the heat of the transducer will cause C0 to drift, and the invariable matching inductance will cause the shift of the resonance point, further reducing the efficiency of the transducer and increasing the temperature rise. SUMMARY

[0003] The purpose of the present application is to provide an ultrasonic knife hemostasis device which is convenient for miniaturization, has high signal processing precision and good reliability.

[0004] To achieve the above object, the application adopts an ultrasonic knife hemostasis device, which comprises a main controller, a high-voltage direct-current power supply, a power drive module, a matching network, a voltage sampling part and a current sampling part. The main controller is used to generate a SPWM signal with adjustable frequency and amplitude, the high-voltage direct-current 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 part is used to collect the driving voltage signal of the transducer, and the current sampling part is used to collect the driving current signal of the transducer. The main controller processes the collected voltage and current signals through FFT operation, obtains 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 works near the resonance point and the current is stable at the preset gear.

[0005] The device of the application adopts SPWM signal driving, which can reduce power tube loss, reduce heat dissipation demand, select smaller heat dissipation fins and fans, and facilitate the miniaturization of the device volume. At the same time, the power drive module is directly controlled, avoiding complex bus power regulation and simplifying the control logic. At the same time, the SPWM signal driving mode makes the power tube work in switching mode instead of linear interval, avoiding overcurrent and overheating damage, thereby improving reliability.

[0006] The FFT signal processing method is more accurate than the traditional phase difference measurement, especially in the case of mistuning, which can further improve the signal processing accuracy. 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 loss of power in the transmission process, and improving the overall efficiency of the system. The matching network can adapt to these changes by dynamically adjusting parameters (such as dynamically compensating static capacitance by algorithm in the application), maintaining stable operation of the system.

[0007] The device of the application dynamically detects the transducer to realize dynamic adjustment of the resonance point, so that the matching inductance is not used, the hardware complexity and volume are reduced, and the resonance frequency is dynamically detected and adjusted in real time, which is more suitable for load and temperature changes.

[0008] As a preferred embodiment, the main controller comprises at least one of a single-chip microcomputer, a SOC chip, a DSP (digital signal processor) or an FPGA (field programmable gate array).

[0009] As a preferred embodiment, 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.

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

[0011] The application also discloses a control method for the ultrasonic knife hemostasis device.

[0012] S1. Before starting work each time, the main controller generates a fixed SPWM signal away from the resonant frequency to drive the transducer;

[0013] S2. Synchronously collect the driving voltage and current signals of the transducer;

[0014] S3. Calculate the phase difference by FFT operation using the collected voltage and current signals , and combine the known output frequency, voltage and current phase and amplitude information to calculate the equivalent static capacitance C0 of the transducer.

[0015] As preferred, in step S2, the voltage and current signals of the transducer are collected according to the current SPWM signal driving.

[0016] As preferred, in step S3, the current flowing through the static capacitance is calculated using the collected voltage and current signals and the static capacitance C0, and the actual resonant current is obtained through vector calculation .

[0017] The phase difference and amplitude information of the transducer operation are calculated according to the resonant current;

[0018] The output frequency of the SPWM signal is adjusted to make the phase difference zero;

[0019] The output amplitude of the SPWM signal is adjusted through PID control according to the amplitude of the resonant current to keep the current of the dynamic branch at the current value of the preset gear.

[0020] The ultrasonic knife hemostasis device solves the problems of heat dissipation difficulty and complex control of the traditional scheme by introducing the SPWM signal, FFT signal processing and dynamic detection algorithm. It not only improves the precision and reliability of the system, but also simplifies the hardware design, and is convenient for miniaturization and high performance of the device. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of an existing ultrasonic knife system.

[0022] Figure 2 is a schematic diagram of an ultrasonic knife hemostasis device of the present application.

[0023] Figure 3 is a logic control diagram of the ultrasonic knife hemostasis device of the present application. DETAILED DESCRIPTION

[0024] The present application will be further described below according to the accompanying drawings and specific embodiments.

[0025] As shown in Figure 2 and Figure 3 , the embodiment discloses an ultrasonic knife hemostasis device, which comprises a main controller 100, a high-voltage direct-current 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 a SPWM signal with adjustable frequency and amplitude, the high-voltage direct-current power supply is used to provide power supply 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 a transducer 600, the voltage sampling part 400 is used to collect a driving voltage signal of the transducer 600, and the current sampling part 500 is used to collect a driving current signal of the transducer 600.

[0026] The main controller is further 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 a PID control algorithm, so that the transducer works near a resonance point and the current is stabilized at a preset gear. The device cancels the output stage matching inductance in the traditional scheme, and realizes dynamic adjustment of the resonance point by dynamically detecting the static capacitance C0 of the transducer.

[0027] The main controller processes the collected voltage and current signals through FFT operation. Compared with the traditional method of processing through a double-channel analog link of voltage and current and zero-crossing detection, the main controller can more accurately obtain the phase difference between the current and voltage signals, especially in the case of detuning, and can provide more accurate measurement results.

[0028] Wherein, the main controller of the embodiment can be implemented by FPGA, the high-voltage direct-current power supply provides 24V direct-current voltage, and the power driving module adopts 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 and current sensors. The main controller acquires 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, so as to ensure stable operation of the system.

[0029] Regarding the SPWM signal driving of the embodiment; the main controller generates a frequency and amplitude adjustable SPWM signal, which is amplified through the power driving module, filtered through the matching network to generate a standard sine wave signal, and drives the transducer.

[0030] Regarding the signal acquisition and FFT processing of the embodiment; the main controller synchronously samples the collected voltage and current signals through ADC, and acquires real-time voltage value, current value and phase difference information through FFT operation; the FFT method has higher precision than the traditional method, and can provide more accurate measurement results especially in the case of mistuning.

[0031] Regarding the dynamic detection of static capacitance C0 of the embodiment; before starting the device, the main controller generates a fixed SPWM signal far away from the resonance frequency to drive the transducer, and synchronously collects the voltage and current signals of the transducer; the phase difference is calculated by using the collected signals, and the equivalent static capacitance C0 of the transducer is dynamically detected by combining the known output frequency, voltage and current phase and amplitude information.

[0032] Regarding the resonance point frequency calculation of the 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 resonance current by using the calculated static capacitance C0, obtains the phase difference and amplitude information of the transducer working through vector calculation, adjusts the output frequency of the SPWM according to the phase difference so that the phase difference is 0, adjusts the output amplitude of the SPWM through the PID algorithm according to the calculated current amplitude, so that the current of the dynamic branch is maintained at the current value of the preset gear.

[0033] Embodiment 2

[0034] The control method for the ultrasonic knife hemostasis device of embodiment 1 comprises the following steps:

[0035] S1. Before starting to work each time, the main controller generates a fixed SPWM signal far away from the resonance frequency to drive the transducer;

[0036] S2. Synchronously collect the driving voltage and current signals of the transducer;

[0037] S3. Calculate the phase difference by FFT operation and current signal , and combine the known output frequency, voltage and current phase and amplitude information to calculate the equivalent static capacitance C0 of the transducer.

[0038] Where, according to the current SPWM signal driving, the voltage signal and current signal of the transducer are sampled; using the sampled voltage signal and current signal and the static capacitance C0, the current flowing through the static capacitance is calculated, and the actual resonant current is obtained by vector calculation; according to the resonant current, the phase difference and amplitude information of the transducer working are calculated; the output frequency of the SPWM signal is adjusted to make the phase difference zero; according to the amplitude of the resonant current , the output amplitude of the SPWM signal is adjusted by PID control to make the current of the dynamic branch keep at the preset current value of the gear.

[0039] This embodiment introduces SPWM signal, FFT signal processing and dynamic detection algorithm, solves the problems of heat dissipation difficulty and complex control of the traditional scheme. It not only improves the accuracy and reliability of the system, but also simplifies the hardware design, and is convenient for miniaturization and high performance of the equipment.

Claims

1. An ultrasonic knife hemostasis apparatus, characterized by, The ultrasonic knife hemostasis device comprises: a main controller for generating a frequency-adjustable and amplitude-adjustable SPWM signal and synchronously sampling drive voltage and current signals on a transducer by ADC; a high-voltage direct-current power supply connected with the main controller for providing a driving power supply; a power driving module connected with the main controller for amplifying the SPWM signal to drive the transducer; a matching network connected with the power driving module for filtering the SPWM signal to generate a standard sine wave signal; a voltage sampling part connected with the transducer for collecting a drive voltage signal of the transducer; a current sampling part connected with the transducer for collecting a drive current signal of the transducer; wherein the main controller processes the collected voltage and current signals by 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 a PID control algorithm, so that the transducer works near a resonance point and the current is stabilized at a preset gear; the specific steps are as follows: S1. Before starting work each time, the main controller generates a fixed SPWM signal away from the resonance frequency to drive the transducer; S2. Synchronously acquiring the driving voltage of the transducer and current signals ; according to the current SPWM signal driving, acquiring the voltage signal of the transducer and current signals ; S3. Utilize the acquired voltage signal and current signal The phase difference is calculated using FFT, and combined with the known output frequency, voltage and current phase and amplitude information, the equivalent static capacitance C0 of the transducer is calculated; the sampled voltage signal is then used. and current signal And the equivalent static capacitance C0, calculate the current flowing through the equivalent static capacitance C0. The actual resonant current is obtained through vector calculation. ; calculating the phase difference and amplitude information of the transducer working according to the resonance current; adjusting the output frequency of the SPWM signal to make the phase difference zero; According to the amplitude of the resonant current The output amplitude of the SPWM signal is adjusted by PID control according to the amplitude of the resonant current, so that the current of the dynamic branch is kept at the current value of the preset gear.

2. The ultrasonic knife hemostasis apparatus of claim 1, wherein: the main controller comprises at least one of a single-chip microcomputer, a SOC chip, a DSP or an FPGA.

3. The ultrasonic surgical tourniquet apparatus of claim 1, wherein: 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 surgical tourniquet apparatus of claim 1, wherein: The main controller obtains discrete data of voltage and current by synchronous ADC sampling, and performs FFT operation on the discrete data to obtain amplitude and phase difference information of the current and voltage signals.

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