Ultrasonic treatment head driving circuit capable of automatically sweeping and tracking frequency

Abstract

The utility model discloses an ultrasonic treatment head driving circuit capable of automatically sweeping and tracking frequency, which comprises a power supply module, a voltage conversion module, an ultrasonic driving circuit, an ultrasonic transducer and a frequency sweeping and tracking circuit board, and the frequency sweeping and tracking circuit board consists of a voltage sampling module, a signal processing module and an MCU (Microprogrammed Control Unit) chip. The voltage sampling module carries out voltage acquisition on the ultrasonic transducer, the voltage is transmitted to the MCU chip through the signal processing module, and the pulse signal output end of the MCU chip is communicated with the signal input end of the ultrasonic driving circuit. Compared with the prior art, through a voltage feedback mode, no time delay exists, the reaction is quicker, tiny changes of ultrasonic signals can be more accurately captured, the system can automatically sweep and track frequency to enable the fundamental frequency to be consistent with the maximum resonant frequency of the ultrasonic transducer, the ultrasonic transducer outputs at the highest frequency, and the ultrasonic transducer outputs at the highest frequency. The treatment effect of the ultrasonic treatment head is effectively improved, repeated debugging is not needed during installation and manufacturing, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of printed circuits of ultrasonic therapeutic apparatuses, in particular to an automatic frequency sweeping and tracking ultrasonic therapeutic head driving circuit. Background Art

[0002] Ultrasonic pulse conductivity therapy technology is a new dosage form and pharmaceutical method that uses physical power as a driving force to allow drugs to pass through intact skin and then enter the human circulation and diseased tissues to exert drug therapeutic effects. This medical technology that achieves targeted drug transmission and precise drug administration has many advantages over oral and injection methods. The ultrasonic conductivity meter transmits the generated pulse force to the metal electrode sheet through the piezoelectric ceramic ultrasonic transducer in the ultrasonic treatment head, allowing the drug in the foam cotton to penetrate the skin and enter the body, promoting drug absorption on the human body surface.

[0003] Since the piezoelectric ceramic ultrasonic transducer is affected by factors such as ceramic material, structure and packaging, the resonant frequency range of each piezoelectric ceramic ultrasonic transducer is inconsistent. Each time the ultrasonic treatment head is assembled, it is necessary to constantly change the fundamental wave frequency generated by the ultrasonic drive circuit of the treatment head to ensure that the ultrasonic drive circuit can drive the piezoelectric ceramic ultrasonic transducer to work normally. The work is cumbersome and inefficient. Moreover, there is a maximum resonant frequency point within the resonant frequency range of each piezoelectric ceramic ultrasonic transducer. If the fundamental wave frequency of the ultrasonic drive circuit can be made consistent with the maximum resonant frequency point of the piezoelectric ceramic ultrasonic transducer, the amplitude of the piezoelectric ceramic ultrasonic transducer will be much higher than the non-maximum resonant frequency point, which greatly improves the therapeutic effect of the ultrasonic treatment head. Even if the fundamental wave frequency is adjusted to be consistent with the maximum resonant frequency point of the piezoelectric ceramic ultrasonic transducer during production, the maximum resonant frequency point of the piezoelectric ceramic ultrasonic transducer may change with the daily use of the ultrasonic treatment head, as well as the ambient temperature and service life. This is also one of the reasons why the ultrasonic therapeutic device cannot maintain the best therapeutic effect.

[0004] Therefore, our company considered improving and innovating the existing driving circuit of the ultrasonic therapy head, and thus designed a method that can automatically scan and detect the maximum resonant frequency of the ultrasonic transducer every time the ultrasonic therapy instrument is started, and adjust the output of the ultrasonic therapy head driving circuit to make it consistent with the maximum resonant frequency of the ultrasonic transducer, thereby greatly improving the ultrasonic therapy effect of the ultrasonic therapy head, and each time it is installed and manufactured, there is no need to repeatedly debug the fundamental frequency of the ultrasonic transducer driving circuit, which greatly improves production efficiency. The existing resonant frequency tracking and scanning methods of ultrasonic transducers basically use current detection, which may have a certain time delay and requires signal processing and calculation, so the response speed is relatively slow. The current data of current detection cannot achieve the accuracy of voltage changes, and can usually only provide overall current information, and cannot obtain the specific changes of the ultrasonic signal at each point. Utility Model Content

[0005] The purpose of the utility model is to provide an automatic frequency sweeping and tracking ultrasonic treatment head driving circuit which can effectively improve the conductivity of the electrode patch, thereby improving the treatment effect, and can make the patch adhere to the human body surface well, while avoiding the problem of liquid medicine leakage during the treatment process.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: an automatic frequency sweeping and tracking ultrasonic therapy head driving circuit, including a power supply module, a voltage conversion module, an ultrasonic driving circuit, an ultrasonic transducer and a frequency sweeping and tracking circuit board, the frequency sweeping and tracking circuit board is composed of a voltage sampling module, a signal processing module and an MCU chip, the voltage sampling module collects the voltage of the ultrasonic transducer and transmits it to the MCU chip through the signal processing module, the pulse signal output end of the MCU chip is connected to the signal input end of the driving ultrasonic driving circuit, and the power supply module supplies power to the ultrasonic driving circuit, the ultrasonic transducer and the MCU chip through the voltage conversion module.

[0007] Preferably, the model of the MCU chip is STM32F103RCT6, and the main oscillation frequency of the chip is 72 MHz.

[0008] Preferably, the MCU chip generates a 300ms square wave with an adjustable duty cycle, and drives four MOS tubes to form an H-bridge circuit through two MOS tube driver chips in the ultrasonic drive circuit to generate positive and negative square waves, which are amplified by a transformer to form a sine wave to drive the ultrasonic transducer to oscillate.

[0009] Preferably, the voltage sampling module adopts a bias voltage acquisition circuit, and the voltage sampling module acquires voltages at different frequency points of the ultrasonic transducer.

[0010] Preferably, the power module, voltage conversion module, ultrasonic drive circuit, ultrasonic transducer and frequency sweeping and tracking circuit board are installed in the ultrasonic therapy head.

[0011] Preferably, the method for the MCU chip to perform frequency sweeping and frequency tracking is as follows:

[0012] Step 1: The MCU chip generates an ultrasonic waveform within the basic waveform frequency range, so that the ultrasonic transducer can output effectively;

[0013] Step 2: Automatically sweep the frequency through the voltage acquisition circuit to collect 10 voltage data outputted by this frequency feedback, and use the analogy method to extract the voltage data with the most occurrences of this frequency, and record it as the voltage data of this frequency feedback;

[0014] Step 3: automatically switch to the next frequency and collect voltage data in the same way; collect 15 groups of fundamental wave feedback voltage data respectively, and record each group of fundamental wave feedback voltage data;

[0015] Step 4, when frequency tracking, find the feedback voltage with the smallest feedback voltage value among the 15 sets of data, use the fundamental frequency used by the feedback voltage value as the resonant frequency point, and output the resonant frequency to the ultrasonic driving circuit, thereby achieving frequency tracking.

[0016] Preferably, in step 4, the compared resonant frequency point is calculated in combination with the waveform deviation factor to calculate the optimal resonant frequency point that enables the transducer to generate maximum power.

[0017] Compared with the prior art, the advantages of the utility model are:

[0018] (1) The utility model realizes the automatic frequency tracking and sweeping functions of the ultrasonic transducer through circuit feedback voltage. Compared with the existing frequency sweeping and tracking method of current detection, there is no time delay, no need for complex signal processing and calculation, and the response is faster. By monitoring through voltage feedback, it can more accurately capture the slight changes of the ultrasonic signal, and perform corresponding processing and analysis on the data changes between point-to-point, so as to monitor the vibration frequency and amplitude changes of the ultrasonic wave in real time.

[0019] (2) After adopting the frequency sweeping and tracking circuit board of the utility model, each time the equipment is started, the maximum resonant frequency of the ultrasonic transducer can be automatically swept and detected, and the output of the ultrasonic treatment head driving circuit can be adjusted by frequency tracking, so that the output is the fundamental frequency consistent with the maximum resonant frequency of the ultrasonic transducer, so that the ultrasonic transducer outputs at the highest frequency, effectively improving the ultrasonic treatment effect of the ultrasonic treatment head. Moreover, during installation and manufacturing, there is no need to repeatedly adjust the fundamental frequency of the ultrasonic transducer driving circuit, and the system will automatically sweep and track the frequency, which greatly improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the structural principle diagram of the utility model;

[0021] Figure 2 This is the pin interface diagram of the MCU chip of the utility model;

[0022] Figure 3 This is a circuit schematic diagram of the driving circuit of the ultrasonic therapy head of the utility model;

[0023] Figure 4 It is a curve chart of the output data of the utility model. DETAILED DESCRIPTION

[0024] The utility model will be further described below.

[0025] The utility model realizes the automatic frequency tracking and frequency sweeping functions of the ultrasonic transducer through the circuit feedback voltage. After turning on the ultrasonic treatment head, the system will automatically scan within a specific frequency range. In this embodiment, the actual resonant frequency measured by the scanned transducer is 608kHz, and the scanned frequency range is 585kHz to 760kHz. The microcontroller unit (MCU) used in this product is STM32F103RCT6, and the main oscillation frequency of the chip is 72MHz. Through this system design, the frequency changes of ultrasound waves can be tracked more accurately, and the application requirements of different frequency ranges can be flexibly adapted.

[0026] Embodiment: An automatic frequency sweeping and tracking ultrasonic therapy head driving circuit, the circuit schematic diagram of which is shown in FIG. Figures 1 to 3 , including a power module, a voltage conversion module, an ultrasonic driving circuit, an ultrasonic transducer and a frequency sweeping and tracking circuit board. The frequency sweeping and tracking circuit board is composed of a voltage sampling module, a signal processing module and a microcontroller unit MCU chip. The voltage sampling module adopts a bias voltage acquisition circuit. The voltage sampling module collects voltages at different frequency points of the ultrasonic transducer and transmits them to the MCU chip through the signal processing module. The pulse signal output end of the MCU chip is connected to the signal input end of the ultrasonic driving circuit. The power module supplies power to the ultrasonic driving circuit, the ultrasonic transducer and the MCU chip through the voltage conversion module.

[0027] The model of the MCU chip is STM32F103RCT6, and the main oscillation frequency of the chip is 72MHz. Through this system design, it can track the frequency changes of ultrasound more accurately and flexibly adapt to application requirements in different frequency ranges. The chip has ADC detection function and the use of timer. At the same time, the complementary PWM waveform of the chip is used to drive the ultrasonic drive circuit, so that the fundamental wave frequency emitted by the ultrasonic drive circuit is consistent with the maximum resonant frequency of the ultrasonic transducer, so that the ultrasonic transducer can reach the maximum output power.

[0028] The signal processing module performs rectification, voltage division and operational amplifier processing to form an ADC signal having a ratio of 144:1 to the actual voltage.

[0029] The power module, voltage conversion module, ultrasonic drive circuit, ultrasonic transducer and sweep frequency tracking circuit board are installed in the ultrasonic therapy head. Each time the ultrasonic therapy device is used, the power module of the ultrasonic therapy head is powered on, and the sweep frequency tracking circuit board automatically detects the ultrasonic transducer to determine its maximum resonant frequency point, and drives the ultrasonic drive circuit to be consistent with the maximum resonant frequency of the ultrasonic transducer.

[0030] When working, the MCU chip generates a 300ms square wave with an adjustable duty cycle, and drives 4 MOS tubes to form an H-bridge circuit through the two MOS tube driver chips in the ultrasonic drive circuit, generating positive and negative square waves, which are amplified by the transformer to form a sine wave, driving the ultrasonic transducer to oscillate. The drive signal is amplified by the transformer, and the voltage is AC100-AC300V. When the resonant frequency point of the ultrasonic transducer is consistent with the drive signal, the voltage collected by the voltage acquisition module is the highest value. When the resonant frequency point of the transducer is inconsistent with the drive signal, the voltage is reduced. After the voltage acquisition module passes through the rectifier bridge, it passes through the voltage divider circuit and is processed by the operational amplifier to form an ADC signal with a ratio of 144:1 to the actual voltage, and then the ADC signal is provided to the MCU for voltage comparison. The MCU uses the highest voltage frequency point to the drive circuit to achieve automatic adaptation of the transducer with errors, so that the fundamental wave frequency of the ultrasonic drive circuit at this time is consistent with the maximum resonant frequency point of the ultrasonic transducer, and the ultrasonic transducer achieves maximum power operation.

[0031] The utility model scans through voltage feedback values, and has the following advantages compared to other methods based on current detection: First, voltage monitoring can monitor the vibration frequency and amplitude changes of ultrasonic waves in real time, and the response is faster. However, current detection may have a certain time delay, and signal processing and calculation are required, so the response speed is relatively slow. In addition, the current data cannot achieve the accuracy of voltage changes. When using voltage monitoring, because the voltage value directly reflects the amplitude and frequency of the ultrasonic signal, we can obtain point-to-point data changes. However, current detection can usually only provide overall current information, and cannot obtain the specific changes of the ultrasonic signal at each point.

[0032] Therefore, the utility model can more accurately capture the slight changes of ultrasonic signals by monitoring through voltage feedback, and perform corresponding processing and analysis on the data changes between points. This method is particularly important in ultrasonic monitoring applications that require higher accuracy and more real-time.

[0033] The experimental test is as follows: The utility model uses circuit feedback voltage to realize the automatic frequency tracking and frequency sweeping functions of the ultrasonic transducer. Through program control, it will automatically scan within a specific frequency range after turning on the ultrasound. In this experiment, the actual resonant frequency measured by the scanning transducer was 608kHz, and the scanning frequency range was 585kHz to 760kHz. We amplified the recorded values ​​100 times through the program. The amplification process not only highlights the difference between each frequency, but also enables us to extract the most suitable data by comparing the differences between each data. We then apply this data to our transducer frequency, thereby maximizing the transducer output function. In this way, we tested and obtained the output data as shown in Table 1:

[0034] Table 1:

[0035]

[0036] Table 1 shows the amplified data, which reflects the uniqueness and differences of each frequency and provides us with rich information. By comparing these data, we identified the most suitable frequency setting and successfully applied it to our ultrasonic transducer. This setting maximizes the output function of the transducer and provides us with better quality and more efficient output results.

[0037] Through the detailed records in the data table, we can clearly see that when the frequency automatically generated by the MCU is 666KHZ, the output power of our ultrasonic transducer reaches the maximum value, which is 2KHZ different from the actual measured resonant frequency. This is determined by the automatic generation frequency of the MCU, but by increasing the main oscillation frequency of the MCU, we can further improve the output accuracy. By observing the curve, such as Figure 4 , we can see this trend more intuitively and further understand the impact of this frequency setting on the output power. These data and charts provide us with valuable reference information, which can help us optimize the performance of the ultrasonic transducer and achieve more efficient output. In the curve chart, the utility model summarizes the law through the change trend of the transducer power and the change trend of our voltage feedback value, and finds that both downward and upward deviations will increase the output power of the program. The actual output power measured by the feedback data with downward deviation is generally greater than that of the upward deviation, which further improves the availability and effectiveness of the program and detection data.

[0038] The method for the MCU chip to perform frequency sweeping and frequency tracking is as follows:

[0039] Step 1: The MCU chip generates an ultrasonic waveform within the basic waveform frequency range, so that the ultrasonic transducer can output effectively;

[0040] Step 2: Automatically sweep the frequency through the voltage acquisition circuit to collect 10 voltage data outputted by this frequency feedback, and use the analogy method to extract the voltage data with the most occurrences of this frequency, and record it as the voltage data of this frequency feedback;

[0041] Step 3: automatically switch to the next frequency and collect voltage data in the same way; collect 15 groups of fundamental wave feedback voltage data respectively, and record each group of fundamental wave feedback voltage data;

[0042] Step 4: When frequency tracking, the fundamental frequency used by the feedback voltage value is used as the resonant frequency point, and the resonant frequency is output to the ultrasonic drive circuit to achieve frequency tracking. In actual use, some factors that affect the waveform deviation may occur. The compared resonant frequency point can be calculated by combining the waveform deviation factor through empirical formulas or correction formulas to obtain a more accurate optimal resonant frequency point of the maximum power of the ultrasonic transducer.

[0043] The utility model adopts voltage feedback data and combines the data actually tested by the ultrasonic power meter to regularize the data, thereby finding the most suitable resonant frequency for the transducer.

[0044] To prove the reliability of the above method, five sets of transducer equipment were tested:

[0045] After scanning the transducer through other equipment, the maximum resonance data of the five groups of transducers were measured to be 623KHZ, 610KHZ, 685KHZ, 702KHZ, and 652KHZ respectively. Therefore, the basic waveform frequency generated by the MCU chip is set to the fundamental wave between 560-750KHZ.

[0046] After the system is started, it first generates an ultrasonic waveform with a frequency of 550KHZ. The effective ultrasonic output is a 20ms ultrasonic waveform every 300ms period, that is, the effective ultrasonic output is 6%. At each effective ultrasonic output, the circuit will feed back a voltage to us; the system automatically turns on the control of the transducer connection end, and automatically collects the 10 data recorded in this output, and uses the analogy method to extract the data with the most occurrences of this frequency as the data for this frequency feedback. After recording the data, the program will automatically switch to the next frequency and use the same method to collect data. The collected frequency is 15 groups of fundamental wave feedback voltage data between 560-750KHZ.

[0047] In the process of comparing the data measured by the actual power meter with the actual circuit voltage data recorded by the MCU chip, it was found that both downward and upward biases of the voltage data fed back by the five sets of transducer device data would increase the output power of the program. The output power actually measured by the feedback data with downward deviation was generally greater than that of the upward deviation. Based on this, the MCU chip will memorize the minimum downward deviation data (that is, the data with the smallest feedback voltage value among the 15 sets of data) and use the fundamental frequency used by the voltage feedback value to realize the frequency tracking function of the transducer.

[0048] The above is a detailed introduction to an automatic frequency sweeping and tracking ultrasonic therapy head driving circuit provided by the utility model. This article uses specific examples to illustrate the principles and implementation methods of the utility model. The description of the above embodiments is only used to help understand the method and core idea of ​​the utility model; at the same time, for general technicians in this field, according to the idea of ​​the utility model, there will be changes in the specific implementation method and application scope. Changes and improvements to the utility model will be possible without exceeding the concept and scope specified in the attached claims. In summary, the content of this specification should not be understood as a limitation on the utility model.

Claims

1. An automatic frequency sweeping and frequency tracking ultrasonic therapy head driving circuit, characterized in that: It includes a power supply module, a voltage conversion module, an ultrasonic driving circuit, an ultrasonic transducer and a frequency sweeping and tracking circuit board. The frequency sweeping and tracking circuit board is composed of a voltage sampling module, a signal processing module and an MCU chip. The voltage sampling module collects voltage from the ultrasonic transducer and transmits it to the MCU chip through the signal processing module. The pulse signal output end of the MCU chip is connected to the signal input end of the ultrasonic driving circuit. The power supply module supplies power to the ultrasonic driving circuit, the ultrasonic transducer and the MCU chip through the voltage conversion module.

2. The automatic frequency sweeping and tracking ultrasonic therapy head driving circuit according to claim 1, characterized in that: The model of the MCU chip is STM32F103RCT6, and the main oscillation frequency of the chip is 72MHz.

3. The automatic frequency sweeping and tracking ultrasonic therapy head driving circuit according to claim 1, characterized in that: The MCU chip generates a 300ms square wave with an adjustable duty cycle, and drives four MOS tubes to form an H-bridge circuit to generate positive and negative square waves through two MOS tube driver chips in the ultrasonic drive circuit, which are amplified by a transformer to form a sine wave to drive the ultrasonic transducer to oscillate.

4. The automatic frequency sweeping and tracking ultrasonic therapy head driving circuit according to claim 1, characterized in that: The voltage sampling module adopts a bias voltage acquisition circuit, and the voltage sampling module acquires voltages at different frequency points of the ultrasonic transducer.

5. The automatic frequency sweeping and tracking ultrasonic therapy head driving circuit according to claim 1, characterized in that: The power module, the voltage conversion module, the ultrasonic driving circuit, the ultrasonic transducer and the frequency sweeping and tracking circuit board are installed in the ultrasonic treatment head.

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