WO2021036302A1 - Ultrasonic scalpel center frequency dynamic adjustment method, and ultrasonic scalpel - Google Patents

Abstract

An ultrasonic scalpel center frequency dynamic adjustment method, and an ultrasonic scalpel. The method comprises the following steps: S1, when power-on, presetting a bandwidth and a center frequency according to the properties of an ultrasonic scalpel handle vibration system, and calculating a sweep frequency range; S2, performing frequency sweep to obtain the start resonance frequency of the ultrasonic scalpel handle vibration system; S3, setting the start resonance frequency as a new center frequency, and obtaining a new resonance frequency range; and S4, starting to work from the new center frequency, and performing resonance frequency tracking. According to the method, the optimal resonance frequencies of inserted shafts is allowed to be inconsistent, the optimal frequency swept by the ultrasonic scalpel can be used as the working frequency, shafts of different types and designs can be replaced during use, and each type of shaft is allowed to produce a better effect. In addition, the method enhances the adaptability of an ultrasonic scalpel, and solves the problems of complicated frequency sweep operation and unreasonable frequency sweep design, for example, occurrence of shaft bending and breaking.

Description

Method for dynamically adjusting center frequency of ultrasonic knife and ultrasonic knife Technical field

The invention relates to the field of medical equipment and medical technology, in particular to a method for dynamically adjusting the center frequency of an ultrasonic knife and an ultrasonic knife.

Background technique

Ultrasonic scalpels with frequency tracking are more and more widely used in surgical operations. However, during use, if the vertical pressure applied to the jaws or the longitudinal pressure applied to the bone blade is too large, it will cause the blade The vibration damping is too large, so that the resonance frequency rises. When the resonance frequency exceeds the frequency bandwidth of the transducer, the machine will alarm and stop working; if you need to start the work again, you need to sweep the frequency again and lock the frequency.

When the ultrasonic knife head is stuck in the tissue, the external load impedance changes, there will be an alarm that the frequency is out of range or the frequency is lost and stops working. At this time, to start the ultrasonic knife work, the frequency must be re-swept, and the frequency scan needs to be in the no-load state to produce an accurate resonance frequency; at this time, the knife is stuck in the tissue and cannot be pulled out, so it can only be pulled out. In this way, it is very easy to damage the tool bar, causing bending or breaking.

At present, the center frequency of the sweep frequency of the mainstream ultrasonic knife on the market is fixed and is set in advance. Due to the deviation of the design, shape, material and machining accuracy of the tool holder, its resonance frequency is inconsistent. Often in the process of surgery, not only a knife bar is used, but also a lot of knife bars of different shapes are needed. In this way, the inconsistency of each cutter bar leads to inconsistent resonance frequencies. In this way, if the vertical pressure applied to the jaws or the longitudinal pressure applied to the bone cutter head is too large, the vibration damping of the cutter head is too large, or the vibrator temperature is too high, it is easy to be out of frequency and cause failure to work normally. .

In summary, when the frequency-locked ultrasonic knife is working, changes in temperature, changes in external load impedance, and the user's longitudinal pressure will cause the resonance frequency point of the ultrasonic knife handle vibration system to shift, or even Will exceed its bandwidth range.

Summary of the invention

The purpose of the present invention is to provide a method for dynamically adjusting the center frequency of an ultrasonic knife and an ultrasonic knife, so as to solve the defects of the existing ultrasonic knife that the frequency is lost, the damage to the tool bar caused by the deviation from the frequency range, the complicated operation, and the inability to work normally are solved. The adaptability of the knife to a variety of tool holders overcomes the problem of inconsistent resonance frequency and excessive vertical pressure applied to the jaws/longitudinal pressure applied to the bone cutter head during work. The vibration damping of the cutter head is too large.

In order to achieve the above objective, the technical solution of the present invention is achieved as follows:

A method for dynamically adjusting the center frequency of an ultrasonic knife includes the following steps:

S1. Start up according to the properties of the ultrasonic knife handle vibration system, preset the frequency width and center frequency, and calculate the sweep frequency range;

S2: Sweep frequency to obtain the initial resonance frequency of the ultrasonic knife handle vibration system;

S3. Set the initial resonance frequency to the new center frequency to obtain a new resonance frequency range;

S4. Start working from the new center frequency and track the resonant frequency.

Further, each time the ultrasonic knife blade is replaced, the step S2 is repeated, and then the steps S3 and S4 are performed.

Further, in the step S1, the frequency bandwidth is set to 2.0KHz.

Further, the deviation range between the initial resonance frequency in step S2 and the center frequency in step S1 is within 2KHz, before the next step S3 can be performed.

Further, before the initial resonance frequency is set to the new center frequency in step S3, the ultrasonic knife will be activated according to the initial resonance frequency value locked after the ultrasonic knife is swept, or when the initial resonance frequency is greater than the initial resonance frequency. Starting from 0.1KHz to 0.1KHz less than the initial resonance frequency.

Further, the ultrasonic knife handle vibration system includes an ultrasonic knife handle and a knife shaft, and the ultrasonic knife handle includes an horn and a transducer.

An ultrasonic knife, using the above-mentioned method of dynamically adjusting the center frequency of the ultrasonic knife, including the operation interface, STM32, DSP, inverter circuit, vibrator, ultrasonic knife current sensor, ultrasonic knife voltage sensor, current and voltage phase difference sensor, foot Step, the operation interface implements serial communication with the STM32, the STM32 implements serial communication with the DSP, the pedal is connected to the STM32, the DSP is connected to the inverter circuit, and the inverter The circuit is connected to the vibrator, the vibrator is connected to the ultrasonic knife current sensor, the ultrasonic knife voltage sensor, the current-voltage phase difference sensor, the ultrasonic knife current sensor, the ultrasonic knife voltage sensor, the current and voltage The phase difference sensor is also connected to the DSP.

Further, the inverter circuit is a passive voltage type inverter circuit.

Further, the ultrasonic knife current sensor, the ultrasonic knife voltage sensor, and the current-voltage phase difference sensor feed back the collected data of the vibrator to the DSP, and the DSP performs calculation and realizes resonance frequency tracking.

Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

1. In the technical scheme of the present invention, since the optimal resonance point can be dynamically adjusted, the optimal resonance frequency of the inserting tool bar can be allowed to be inconsistent. As long as the resonance frequency is within the allowable deviation range (bandwidth 2KHz), the ultrasonic The best frequency from the knife sweep is used as the working frequency.

2. Since the ultrasonic knife device of the present invention can provide the best resonance frequency according to the inconsistency of the knife bar, the design accuracy and design requirements of the knife bar are reduced. During use, different types of toolholders can be replaced, and each type of toolholder can be used for better results; even if the same type of toolholder is used, the machine can adjust each tool according to the specific machining accuracy error of each toolholder. The best resonant frequency of the rod.

3. In this technical solution, the frequency bandwidth is set to 2.0KHz, and the frequency width range is large, and the phenomenon of frequency loss and frequency loss is not easy to occur, so the ultrasonic knife can work continuously for a long time.

4. The center frequency dynamic adjustment method of this technical solution enhances the adaptability of the ultrasonic knife, and solves the problems of complicated frequency sweeping operation and unreasonable frequency sweeping design (the tool bar will be bent or broken).

Description of the drawings

Figure 1 is a working flow chart of the method for dynamically adjusting the center frequency of an ultrasonic knife according to the present invention;

Figure 2 is a structural block diagram of the ultrasonic knife of the present invention;

In the figure: 1. Operation interface, 2. STM32, 3, DSP, 4. Inverter circuit, 5. Vibrator, 6. Ultrasonic knife current sensor, 7. Ultrasonic knife voltage sensor, 8. Current and voltage phase difference sensor, 9. , Pedal.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Example one:

A method for dynamically adjusting the center frequency of an ultrasonic knife includes the following steps:

S1. Start up according to the properties of the ultrasonic knife handle vibration system, preset the frequency width and center frequency, and calculate the sweep frequency range;

S2: Sweep frequency to obtain the initial resonance frequency of the ultrasonic knife handle vibration system;

S3. Set the initial resonance frequency to the new center frequency to obtain a new resonance frequency range;

S4. Start working from the new center frequency and track the resonant frequency.

In step S1, the frequency bandwidth is set to 2.0KHz. In this embodiment, the preset center frequency is 39KHz. According to the frequency bandwidth, the sweep frequency range is 38KHz to 40KHz. Step S1 is essentially a preparatory work, and the value of the preset center frequency can be obtained by a person skilled in the art according to the conventional determination method of different ultrasonic knife holders. In steps S2 and S3, the sweep step is performed within the sweep frequency range, and the system will automatically sweep the frequency according to the different tool holders, and use the detected resonance frequency as the best center frequency. This means that as long as the resonant frequency of the tool holder can be locked, the resonant bandwidth of each tool holder with different resonant frequencies is the same, and only the first frequency sweep is required each time, and the new resonant frequency range obtained can be used as The working data support of the ultrasonic knife holder is used for monitoring and data comparison. In step S4, this step is an execution step, and the resonant frequency should be tracked.

It should be noted that each time the ultrasonic knife blade is replaced, the step S2 is repeated, and then the steps S3 and S4 will be performed, that is, the ultrasonic knife has performed the steps S1 to S4 to realize the working process. If the ultrasonic knife needs to be replaced After the tool bar is replaced, step S2 will be repeated. The method for dynamically adjusting the center frequency of the ultrasonic knife in this embodiment will omit step S2 and proceed directly to step S3 and S4 only when the ultrasonic knife is restarted without replacement. At the same time, in step S3, before the initial resonance frequency is set to the new center frequency, the ultrasonic knife will be activated according to the initial resonance frequency value locked after the ultrasonic knife sweeps or at a value greater than 0.1KHz to the initial resonance frequency. Start in the range of 0.1KHz less than the initial resonance frequency.

A limitation of this embodiment: the deviation range between the initial resonance frequency in step S2 and the center frequency in step S1 is within 2KHz, and then the next step S3 can be performed.

It should be understood that when the ultrasonic knife is working, an attribute of the ultrasonic knife is the working resonance frequency, but this attribute is not a fixed value. When the temperature changes or the tool shaft deforms, the working resonance frequency of the ultrasonic knife will occur. Change, when the temperature rise or fall causes the working resonance frequency to exceed the resonance frequency range, that is, the frequency loss phenomenon; the vertical pressure applied to the jaws or the longitudinal pressure applied to the bone cutter head is too large, so that the vibration of the cutter head is over damped If the pressure is too large, it will also cause the resonance frequency to increase. If the pressure is too high, the frequency will be lost. Even if the frequency loss alarm occurs in both cases, as long as it is restarted, there is no need to perform no-load frequency sweeping. No need to re-sweep means that the ultrasonic knife can be easily pulled out by directly starting when the knife is stuck.

In the technical scheme of the present invention, since the optimal resonance point can be dynamically adjusted, the optimal resonance frequency of the inserting tool bar can be allowed to be inconsistent. As long as the resonance frequency is within the allowable deviation range (bandwidth 2KHz), the ultrasonic knife can be swept The best frequency out of the frequency is used as the working frequency.

The frequency bandwidth is set to 2.0KHz, the frequency bandwidth is large, and it is not easy to lose frequency and frequency loss, so the ultrasonic knife can work continuously for a long time.

Embodiment two:

The first thing that needs to be introduced is that the ultrasonic knife includes an ultrasonic knife drive system and an ultrasonic knife handle vibration system. The ultrasonic knife handle vibration system is composed of a transducer, an horn and a cutter bar. The transducer and the horn are collectively called ultrasonic knife vibration The vibrator of the ultrasonic knife is fixed by the pre-tightening screw. The transducer converts the electrical energy of the power supply into the mechanical energy of vibration. The horn amplifies the displacement or speed of the mechanical vibration by concentrating the ultrasonic energy on a small area. The model and type, the sound energy of the knife head radiates; the shape of the jaw or the knife head is determined according to the surgical method and surgical requirements.

In the prior art ultrasonic knife, if the vertical pressure applied to the jaws or the longitudinal pressure applied to the bone cutter head is too large during use, the vibration damping of the cutter head will be too large, so that the resonance frequency will rise. When the frequency exceeds the frequency range of the transducer, the machine will alarm and stop working. If you need to start the work again, you need to sweep the frequency again and lock the frequency; when the ultrasonic cutter head is stuck in the tissue, the external load impedance changes, There will be an alarm that the frequency is out of range or the frequency is lost and stop working. At present, the center frequency of the sweep frequency of the mainstream ultrasonic knife on the market is fixed and is preset. Due to the deviation of the design, shape, material, and machining accuracy of the tool shaft, the resonance frequency is inconsistent. In this way, the inconsistency of each cutter bar leads to inconsistent resonance frequencies, which is extremely prone to problems.

This embodiment provides a detailed explanation of the solution to the above-mentioned problem. Refer to Figure 2, an ultrasonic knife that uses the above-mentioned method for dynamically adjusting the center frequency of the ultrasonic knife, including the operation interface 1, STM32 2, DSP 3, and reverse Variable circuit 4, vibrator 5, ultrasonic knife current sensor 6, ultrasonic knife voltage sensor 7, current and voltage phase difference sensor 8, foot pedal 9, the operation interface 1 and the STM32 2 realize serial communication, and the STM32 2 and The DSP 3 implements serial communication, the pedal 9 is connected to the STM32 2, the DSP 3 is connected to the inverter circuit 4, the inverter circuit 4 is connected to the vibrator 5, and the vibration Sub 5 is connected to the ultrasonic knife current sensor 6, the ultrasonic knife voltage sensor 7, the current and voltage phase difference sensor 8, the ultrasonic knife current sensor 6, the ultrasonic knife voltage sensor 7, the current voltage phase difference sensor 8 and Connect with the DSP 3.

The inverter circuit 4 is a passive voltage type inverter circuit. The ultrasonic blade current sensor 6, the ultrasonic blade voltage sensor 7, and the current-voltage phase difference sensor 8 feed back the collected data of the vibrator 5 to the DSP 3, and the DSP 3 performs calculations and realizes resonance frequency tracking.

When using the above-mentioned ultrasonic knife, the specific working process should be combined with the equipment composition and the aforementioned method of dynamic adjustment of the center frequency of the ultrasonic knife. The specific working process is:

Start the ultrasonic knife device through the pedal 9, preset the center frequency through the operation interface 1, and calculate the sweep frequency range based on the bandwidth and the preset center frequency. For example, the bandwidth is set to 2.0KHz, and the center frequency is preset in this embodiment According to the bandwidth, the sweep frequency range is 38KHz to 40KHz. After the sweep frequency range is obtained, control STM32 2 through the operation interface 1 to send a command to start the sweep to the DSP 3, and the DSP 3 will perform the operation on the ultrasonic knife. Sweep the frequency to obtain the initial resonance frequency of the ultrasonic knife handle vibration system.

Set the initial resonance frequency to the new center frequency through the operation interface 1, and calculate the new resonance frequency range. At this time, the preparation work is completed and you can enter the working state. Start the device through the pedal 9 and control the operation interface 1. STM32 2 sends a command to start work to DSP 3. DSP 3 starts to work from the new center frequency and outputs a sine wave of resonant frequency. DSP 3 outputs a PWM signal corresponding to the initial resonant frequency to inverter circuit 4, which corresponds to the output of inverter circuit 4 The frequency excitation driving signal drives the ultrasonic knife vibrator 5 to work. During the working process, the ultrasonic blade current sensor 6, the ultrasonic blade voltage sensor 7, and the current-voltage phase difference sensor 8 monitor the current, voltage, and current-voltage phase difference of the ultrasonic blade vibrator 5 in real time; DSP 3 analyzes the ultrasonic blade handle vibration system The current, voltage and phase difference of current and voltage are obtained to obtain the working resonance frequency of the ultrasonic knife handle vibration system, and control and frequency tracking are performed.

In this embodiment, it should be noted that when the deviation between the initial resonance frequency and the center frequency is within 2KHz, the third and fourth steps above can be performed "Set the initial resonance frequency to the new center frequency to obtain New resonant frequency range", "start working from the new center frequency and follow the resonant frequency" steps.

In addition, this technical solution has the following limitations: 1. The preset center frequency fails, the frequency sweep fails, and the S2 step is unsuccessful. Perform the preset center frequency process again or replace the ultrasonic knife handle vibration system near the preset center frequency; 2. Before proceeding to the “set the initial resonance frequency to the new center frequency” in step S3, the ultrasonic knife will be activated according to the initial resonance frequency value locked after the ultrasonic knife is swept, or if it is greater than the initial resonance frequency 0.1KHz Start within the numerical range of 0.1KHz less than the initial resonance frequency; 3. When restarting, there is no need to perform no-load frequency sweeping. For example: preset the center frequency according to the common sense of those skilled in the art, tentatively preset as 30KHz, calculate the sweep frequency range from 29KHz to 31KHz according to the bandwidth of 2KHz, sweep the frequency, at this time, if the frequency of this tool bar is not in the sweep In the frequency range, the frequency sweep will fail, and the operation interface indicates to restart the preset center frequency or replace the ultrasonic knife handle vibration system with a similar preset center frequency. After resetting the center frequency and sweeping the frequency to obtain the initial resonance frequency, for example, the initial resonance frequency is 38.7KHz, the ultrasonic knife will work from 38.7KHz or any value in the range of 38.6KHz to 38.8KHz. , And perform resonant frequency tracking. When the frequency is lost and stops working, there is no need to perform no-load sweep before restarting. No need to re-sweep means that when the knife is stuck, the ultrasonic cutter can be easily pulled out by directly starting.

The dynamic adjustment method of the ultrasonic knife center frequency of this technical solution allows the doctor to choose a more suitable knife bar according to different tissues or shapes during the operation, and always works at the best resonance frequency to ensure that different models and types of ultrasonic knife bars can perform at the highest level. The work efficiency is reduced, the heat of the transducer and the power supply is reduced, the service life of the equipment is improved, and the surgical error rate is reduced.

The above is a detailed description of the preferred implementation of the present invention, but the present invention is not limited to the described embodiments. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should not violate the spirit of the present invention. Various equivalent modifications or substitutions can be made under the premise, and equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims (9)

A method for dynamically adjusting the center frequency of an ultrasonic knife, which is characterized in that it comprises the following steps: S1. Start up according to the properties of the ultrasonic knife handle vibration system, preset the bandwidth and center frequency, and calculate the sweep frequency range; S2: Sweep frequency to obtain the initial resonance frequency of the ultrasonic knife handle vibration system; S3. Set the initial resonance frequency to the new center frequency to obtain a new resonance frequency range; S4. Start working from the new center frequency and track the resonant frequency. The method for dynamically adjusting the center frequency of an ultrasonic knife according to claim 1, wherein the step S2 is performed every time the ultrasonic knife blade is replaced, and then the steps S3 and S4 are performed. The method for dynamically adjusting the center frequency of an ultrasonic knife according to claim 1, wherein in the step S1, the frequency bandwidth is set to 2.0 KHz. The method for dynamically adjusting the center frequency of an ultrasonic knife according to claim 1, wherein the deviation range between the initial resonance frequency in step S2 and the center frequency in step S1 is within 2KHz before the next step can be performed. S3 step. The method for dynamically adjusting the center frequency of an ultrasonic knife according to claim 1, wherein, in step S3, before the initial resonance frequency is set to the new center frequency, the ultrasonic knife will be locked according to the lock after the ultrasonic knife is swept. The starting resonant frequency value is started or starting in the range of 0.1KHz greater than the starting resonant frequency to 0.1KHz smaller than the starting resonant frequency. The method for dynamically adjusting the center frequency of an ultrasonic knife according to claim 1, wherein the ultrasonic knife handle vibration system includes an ultrasonic knife handle and a knife shaft, and the ultrasonic knife handle includes an horn and a transducer. An ultrasonic knife, characterized in that the method for dynamically adjusting the center frequency of the ultrasonic knife according to any one of claims 1 to 6 is used, which includes an operation interface, STM32, DSP, an inverter circuit, a vibrator, an ultrasonic knife current sensor, and an ultrasonic knife. Knife voltage sensor, current and voltage phase difference sensor, foot pedal, the operation interface realizes serial communication with the STM32, the STM32 realizes serial communication with the DSP, the pedal connects with the STM32, and the DSP connects with the STM32. The inverter circuit is connected, the inverter circuit is connected to the vibrator, and the vibrator is connected to the ultrasonic knife current sensor, the ultrasonic knife voltage sensor, and the current-voltage phase difference sensor. The ultrasonic knife current sensor, The ultrasonic knife voltage sensor and the current and voltage phase difference sensor are also connected to the DSP. The ultrasonic knife according to claim 7, wherein the inverter circuit is a passive voltage type inverter circuit. The ultrasonic knife according to claim 7, wherein the ultrasonic knife current sensor, the ultrasonic knife voltage sensor, and the current and voltage phase difference sensor feed back the collected data of the vibrator to the DSP, and the DSP performs Calculate and realize resonant frequency tracking.

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