Low-intensity focused ultrasound prostate physiotherapy instrument and physiotherapy head thereof

Abstract

The invention relates to low-intensity focused ultrasound prostate physiotherapy equipment and a physiotherapy head thereof, and belongs to the field of focused ultrasound therapy. The device is characterized in that the ultrasonic control circuit can generate driving signals of various waveforms according to treatment requirements, the LCC power resonant inverter is adopted to realize power amplification, the problems of switching loss and signal distortion are solved, and a PDM modulation method is introduced to realize adjustability of output power. A phase difference detection method is adopted to calculate the propagation time of ultrasonic waves in a heated biological tissue, and an automatic frequency tracking function is introduced to ensure that the transducer is always in an optimal resonance state and is accurately focused on a target treatment area. Simultaneously acquiring a voltage effective value and a current effective value of the current state of the ultrasonic physiotherapy head; determining the current impedance of a transducer of the ultrasonic physiotherapy head according to the voltage effective value and the current effective value of the current state of the ultrasonic physiotherapy head, and judging whether the ultrasonic physiotherapy head enters an acoustic coupling state or not according to the current impedance; and when the ultrasonic physiotherapy head does not enter the acoustic coupling state, the ultrasonic excitation module is controlled to stop power output.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a low-intensity focused prostate therapy device and a therapy head thereof. Background Art

[0002] Prostate disease is a male urinary and reproductive system disease caused by factors such as prostate hyperplasia, inflammation or cancer. The main causes include aging, changes in hormone levels, genetic factors, bad living habits (such as sitting for a long time, improper diet) and chronic inflammation. The harm of prostate disease includes urinary system symptoms such as frequent urination, urgency, dysuria, and increased nocturia, as well as possible sexual dysfunction, bladder damage and renal dysfunction. It is characterized by worsening lower urinary tract symptoms (such as weak urine flow, urine retention), recurrent prostatitis symptoms, and possible pain and discomfort in the pelvic area.

[0003] There is a close relationship between prostate disease and local inflammatory response and tissue hyperplasia, which is a key mechanism for the progression of the disease. The process mainly involves the hyperplasia and fibrosis of prostate tissue, that is, the abnormal proliferation of prostate glandular tissue under inflammatory stimulation or hormone action, leading to urethral compression and dysuria. This process is crucial to the development of prostate disease. The hyperplasia and inflammatory response of prostate tissue can cause damage to local tissue structure and function and accelerate the progression of the disease. Prostate disease can be regarded as a clinical manifestation of worsening local inflammation and tissue hyperplasia. With the continuous progression of prostate hyperplasia, urinary function is more severely impaired, and a series of clinical symptoms such as dysuria and urinary retention appear, which may eventually lead to bladder dysfunction and chronic renal failure, and even require surgical intervention.

[0004] Low-intensity focused ultrasound (LIFU) is a new type of ultrasound therapy technology, which is characterized by a fixed frequency and an amplitude intensity usually ranging from 0.125 to 3 W / cm 2 LIFU uses the penetration and energy deposition characteristics of ultrasound into biological tissues to accurately project low-intensity sound energy to target tissues or cells. This technology promotes local friction and forms microflows by causing a series of ultrasonic biological effects, such as the vibration, contraction and expansion of microbubbles and the vibration of liquid particles, accelerating molecular diffusion and material exchange. In addition, LIFU can also regulate the permeability of prostate cell membranes and activate ion channels and receptor functions through diffusion, thixotropic changes, and polymerization and depolymerization of proteins, thereby improving prostate cell metabolism, enhancing enzyme activity, and increasing protein synthesis efficiency. This technology also helps to optimize the pH value in tissues, promote blood flow, and accelerate the metabolism of tissue cells.

[0005] Studies have shown that low-intensity focused ultrasound can significantly treat symptoms caused by prostate hyperplasia and chronic prostatitis by improving the local microenvironment of the prostate, reducing inflammatory responses, and reducing the size of the prostate. After low-intensity focused ultrasound treatment, symptoms such as dysuria and frequent urination can be relieved by promoting blood circulation and cell metabolism in prostate tissue. This may provide a new non-invasive treatment option for prostate disease. Therefore, further research is needed on the effect of ultrasound therapy in alleviating the symptoms of prostate disease and its mechanism of action, in order to provide patients with more effective treatment methods. Summary of the invention

[0006] In view of the advantages of low-intensity focused ultrasound for prostate treatment, the purpose of the present invention is to provide a focused ultrasound therapy device and a therapy head thereof to solve the problems of large energy loss and inability to focus on the treatment area in existing ultrasound therapy devices.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A focused ultrasound therapy device and a therapy head thereof;

[0009] The focused ultrasound therapy instrument comprises an ultrasonic drive circuit board, a phase detection circuit, an LCC power resonance inverter, a PDM modulation module, and a therapy head;

[0010] The ultrasonic driving circuit board includes a main control circuit, a transmitting circuit, a power supply circuit and a peripheral circuit;

[0011] The transmitting circuit includes a DDS module to perform current-voltage conversion and voltage amplification on the transmitting signal, and output it to the physiotherapy head to convert it into ultrasonic waves and transmit it;

[0012] The DDS module uses direct digital synthesis technology to generate a precise and controllable sine wave signal to ensure the stability and accuracy of the transmission signal.

[0013] The LCC power resonant inverter module adopts resonant inversion technology to convert direct current into high-frequency alternating current to efficiently drive the ultrasonic transducer and reduce energy loss.

[0014] The PDM modulation module is used to adjust the output power. The average output power is adjusted by changing the number of switching signals per unit time (i.e., pulse density). The transducer is driven under a discontinuous voltage waveform to avoid the current discontinuity problem that may occur in the traditional PWM method, and three different preset output power levels can be provided to meet the needs of different treatment scenarios.

[0015] The power supply circuit converts the input 24V direct current into several voltages required for the operation of the main control circuit and the transmitting circuit. The ultrasonic drive circuit can generate a transmitting signal of a corresponding waveform according to the demand.

[0016] The ultrasonic driving circuit board adopts a phase difference detection method to calculate the propagation time of ultrasonic waves in the prostate tissue, and introduces a frequency self-tracking function to address the drift of the resonant frequency of the physiotherapy transducer itself, so that the transducer is always in a resonant state and focused on the target treatment area.

[0017] The phase difference detection method refers to determining whether the transducer is in a resonant state by determining whether the voltage and current signals at both ends of the transducer are in the same direction through a zero-crossing comparison method, that is, determining the power supply output frequency through the phase difference between the voltage and current signals at both ends of the transducer.

[0018] The zero-crossing comparison method refers to using the digital phase detector inside the main control chip to achieve phase difference measurement, and using the pulse counting method to measure the time difference ΔT of the zero-crossing points of two same-frequency signals. At the same time, if the frequency of the same-frequency signal is known to be f, the phase difference can be obtained.

[0019] The pulse counting method refers to converting two sinusoidal signals of the same frequency into square waves, and using these two square wave signals to control the phase detector to count the time base pulses. If the number of time base pulses counted by the counter is n, and the period of the time base pulse is τ, then ΔT=nτ is obtained.

[0020] The frequency self-tracking function refers to a frequency control module composed of a matching network, a voltage and current sampling circuit, a phase detection circuit, and a main control chip. After the ultrasonic drive voltage signal passes through the matching network, it is connected to both ends of the transducer. By adding sampling resistors at both ends of the transducer, the voltage signal and current signal at both ends of the transducer can be sampled. The sampling signal is processed by the digital phase detection circuit to obtain a phase difference, which is then fed back to the waveform generator chip after being processed by the frequency control algorithm to adjust the frequency of the PWM wave signal output by it, thereby changing the frequency of the output signal of the switching network, so that the transducer is in a resonant state again and maintains the best focusing effect.

[0021] The physiotherapy head is connected to the peripheral circuit, and when the physiotherapy head is in the energy output state, the voltage effective value and current effective value of the current state of the ultrasonic physiotherapy head are obtained; according to the voltage effective value and current effective value of the current state of the ultrasonic physiotherapy head, the current impedance of the transducer of the ultrasonic physiotherapy head is determined, and according to the current impedance of the transducer of the ultrasonic physiotherapy head, whether the ultrasonic physiotherapy head enters the preset state of acoustic coupling is judged; when the ultrasonic physiotherapy head does not enter the preset state of acoustic coupling, the ultrasonic excitation module is controlled to stop power output. The physiotherapy head has a concave arc surface, and different buttons can be adjusted to focus on different treatment points, and with efficient heat dissipation design, a comfortable treatment experience is ensured.

[0022] The concave arc surface achieves focusing of ultrasound through its special geometric shape and two-way modulated signals emitted by the transmitting circuit. The specific process is as follows:

[0023] Concave arc design: provides an adsorption-type application in the form of low negative pressure. It uses the acoustic coupling function to determine whether the therapy head is in the acoustic coupling preset state, and changes the focal point of the ultrasonic wave by adjusting the phase of the transmitted signal.

[0024] Ultrasonic emission: When ultrasonic waves are generated by the transmitting circuit and transmitted to the therapy head, the concave curved surface causes these waves to gather. Due to the curved design, the ultrasonic waves are reflected and focused to a point when passing through the concave surface.

[0025] Focus adjustment: By adjusting the phase of the transmitted signal, the convergence point of the ultrasound can be changed so that it can be focused at different depths and positions. The key control function of the physiotherapy device can adjust the transmission parameters of the ultrasound. These adjustments enable the ultrasound to be focused at different depths and positions to meet different physiotherapy needs.

[0026] Frequency self-tracking function: This function ensures that the transducer of the therapy head is always in a resonant state, and can maintain the best focusing effect even when the propagation path and speed of the ultrasound in the prostate tissue change.

[0027] Through the above mechanism, the arc-shaped concave ultrasound head can accurately focus the ultrasound energy on a specific treatment area, providing effective treatment effects for prostate diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a schematic flow chart of the treatment method of the low-intensity focused ultrasound prostate therapy apparatus provided by the present invention;

[0030] Figure 2 It is a structural schematic diagram of the low-intensity focused ultrasound prostate therapy device provided by the present invention;

[0031] Figure 3 It is a schematic diagram of the frequency control structure of the low-intensity focused ultrasound prostate therapy device provided by the present invention.

[0032] Figure 4 It is a schematic diagram of a phase difference detection method of a low-intensity focused ultrasound prostate therapy apparatus provided by the present invention.

[0033] Figure 5 It is a schematic diagram of the frequency self-tracking method of the low-intensity focused ultrasound prostate therapy device provided by the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] According to an embodiment of the first aspect of the present application, Figure 1 As shown, first, the initialization and frequency self-tracking main control system initializes the ultrasound treatment intensity and focus position. The frequency self-tracking function is started to ensure that the transducer is always in a resonant state. The phase difference detection phase detector circuit measures the phase difference between the transmitted signal and the received signal through the zero-crossing comparison method. The digital phase detector processes this phase difference information and feeds it back to the main control system. Data preprocessing and fuzzy control The main control system preprocesses the collected data.

[0036] The phase difference is converted into the membership degree in the fuzzy set using the fuzzification method, and the fuzzy rule base is applied to evaluate the degree of deviation of the working state. The frequency adjustment instruction is generated to determine the new target frequency based on the fuzzy reasoning results. The frequency adjustment instruction is output to the DDS signal generator to change the PWM waveform frequency. Power amplification and load matching The LCC power resonant inverter module realizes power amplification under soft switching control and dynamically adjusts the inductance L S , capacitor C S and C P The matching network adjusts the impedance matching between the output signal and the transducer to maximize the energy transmission efficiency.

[0037] Power regulation and safety monitoring, PDM modulation controls the working state of the switch network through pulse density modulation and adjusts the output power. The voltage and current sampling circuit continuously monitors the working state of the transducer to ensure the safety and effectiveness of the treatment process. Acoustic coupling state judgment, the physiotherapy head determines the transducer impedance based on the current voltage RMS value and current RMS value. Determine whether to enter the acoustic coupling preset state; if not, stop the power output to ensure safety.

[0038] The characteristic information acquisition unit reads key parameters from the therapy head to control the frequency and excitation voltage to ensure the output of a sinusoidal ultrasonic excitation signal with a set power.

[0039] According to the low-intensity focused ultrasound prostate therapy device of the embodiment of the present application, an ultrasonic drive circuit board is integrated inside the therapy device, and the drive circuit board includes a main control circuit, a transmitting circuit and a power supply circuit. The main control circuit adopts a high-performance microprocessor, which is responsible for the overall control logic, the transmitting circuit is responsible for converting the signal generated by the main control circuit into a high-voltage pulse signal, and the power supply circuit is responsible for converting 24V DC into the working voltage required by the main control circuit and the transmitting circuit.

[0040] According to the low-intensity focused ultrasound prostate therapy apparatus of the present application, Figure 2 As shown, in order to ensure that the transducer is always in a resonant state, this embodiment adopts a frequency self-tracking function. This function obtains voltage and current signals by installing sampling resistors at both ends of the transducer. After the signal is processed by the digital phase detector, the phase difference information is fed back to the main control chip, and then the frequency of the PWM wave signal is adjusted to keep the transducer at the optimal operating frequency.

[0041] In the specific implementation process, it is assumed that the power supply in the circuit and the inductor and capacitor in the resonant network are ideal components. Using the Thevenin theorem, the equivalent impedance of the power supply is:

[0042]

[0043] Where ω s is the operating frequency of the inverter switch. The Thevenin equivalent voltage of the circuit is:

[0044]

[0045] When the inverter operating frequency meets When , its admittance is zero, and the entire circuit appears to be a constant current source, and the current expression is:

[0046]

[0047] in I depends only on the input voltage and the series-parallel resonant network parameters, but the output voltage will vary with the load impedance. When the load is open circuit, the resonant network parameters are in series. Circuit series resonance, C P The end has a very high voltage output, and its value is equal to k=C P / C s The known conditions for circuit calculation are V in ,I,ω s In the actual circuit, it is the current flowing through the load. Since the resonant network has a filtering function, the fundamental wave analysis method can be used to calculate the parameters in the circuit. th Available Instead, we get:

[0048]

[0049] Further deduction can get the output voltage:

[0050]

[0051] Output Current:

[0052]

[0053] Further we can get:

[0054]

[0055] Near the resonant frequency point, the smaller the quality factor Q value, the greater the output voltage gain. Within a certain frequency range, the series-parallel resonant network has good voltage regulation characteristics, but as the quality factor Q value decreases, its voltage regulation characteristics will also deteriorate accordingly. At the resonant frequency point, the output voltage of the series-parallel resonant network can reach the maximum value, and when the frequency shifts from the resonant frequency point, the output voltage decreases sharply, and the series-parallel resonant network has good filtering performance. Under light load conditions, it automatically adjusts to characteristics close to the parallel resonant network, and under heavy load conditions, it converts to characteristics close to the series resonant network, ensuring the stability and efficiency of the system.

[0056] like Figure 3 As shown in the figure, the frequency tracking of ultrasonic signals is achieved by collecting the voltage and current signals at both ends of the transducer. After the signal is processed by the digital phase detector, the phase difference information of the voltage and current can be obtained. According to the phase difference information, the main control chip can dynamically adjust the frequency of the PWM signal so that the transducer always maintains the best resonant state during operation.

[0057] According to the embodiment of the present application, the zero-crossing comparison method is used for phase difference detection. By measuring the time difference ΔT of the zero-crossing points of the two same-frequency signals, and knowing that the frequency of the same-frequency signal is f, it can be obtained The corresponding waveform relationship is as follows Figure 4 As shown. According to the embodiment of the present application, the digital phase detector inside the main control chip is used to measure the phase difference. The two sinusoidal signals of the same frequency are converted into square waves according to the pulse counting method of the digital phase detector. The two square wave signals are used to control the phase detector to count the time base pulses. If the number of time base pulses counted by the counter is n, and the period of the time base pulse is τ, then ΔT≈nτ is obtained. When the time is measured in s, the resolution of the measuring device is about 10 -4 πτ. According to the embodiment of the present application, in order to make the measurement accuracy high enough, the period of the time base pulse should be small enough. Its advantages are high measurement resolution, good linearity, easy digitization, low cost, simple circuit and easy implementation.

[0058] According to the embodiments of the present application, frequency tracking is performed by using a traversal search algorithm through a variable step length frequency point search method. Within a certain frequency range, a suitable step length is selected to change the driving frequency according to the voltage and current phase difference and the current effective value fed back from both ends of the transducer. The frequency that minimizes the voltage and current phase difference or maximizes the current effective value within this frequency range is taken as the resonant frequency point of the transducer. There must be a frequency point within this frequency range that minimizes the phase difference and maximizes the current effective value, but this frequency point can only be a local optimum. A variable step length frequency tracking method is introduced as a frequency tracking algorithm. The principle is as follows: Figure 5 As shown. In this way, the resonant state of the therapy transducer probe is maintained, and the resonant frequency is calculated to replace the resonant frequency measured by the impedance analyzer, ensuring that the therapy transducer probe is infinitely close to the resonant state. The feedback network of the driving power supply feeds back the voltage and current signals and the effective current value at both ends of the therapy transducer probe in real time, and the main control chip calculates the phase difference based on the feedback data. When the current leads the voltage, the phase difference θ is greater than the given value When f'=f+400, the phase difference θ is less than the given value When f'=f+100, on the contrary, the voltage leads and the phase difference θ is greater than the given value When f=f-400, the phase difference θ is less than the given value When f'=f-100, f' is the updated drive frequency, f is the current drive frequency, and the unit is Hz. The search with a step length of 400Hz is a coarse search, and the search with a step length of 100Hz is a fine search. After obtaining the new frequency, the output PWM wave of the DDS chip can be changed.

[0059] According to the embodiment of the present application, the fuzzy controller is applied to the frequency self-tracking of the transducer. First, the fuzzification is to convert the digital input value of the fuzzy controller into a fuzzy set represented by a language value, that is, the precise quantity is converted into a fuzzy quantity. At the same time, the input quantity of the controller is processed to meet the requirements of the fuzzy controller, and then the scale is transformed to transform it into the selected domain range. A two-dimensional fuzzy controller is used, that is, the controller has two input quantities, namely the current difference and the difference change rate. Take the quantization factor k e=0.1, the domain of the fuzzy quantity E can be {0,1,2,3,4,5,6}. The basic domain of the rate of change of the current difference relative to the frequency is [-10,10], then the domain of the fuzzy quantity EC is {6,5,4,3,2,1,0,1,2,3,4,5,6}. The basic domain of the output frequency change dF of the fuzzy controller is [-600,600], and its fuzzy domain is the same as EC. Then the sign of the output quantity dF is determined by fuzzy reasoning. When the deviation E between the maximum current effective value and the current effective value collected and fed back in real time and its rate of change EC to the frequency are positive, dF is a positive value, and then the degree of change of dF is determined according to the size of E and EC. When EC is zero, regardless of the size of E, the output frequency change rate is always zero.

[0060] After logical reasoning according to fuzzy rules, the output is a fuzzy set. The fuzzy quantity is converted into an accurate quantity through fuzzy judgment. The weighted average method is selected to set the membership function A(u) of the dF set A on the domain U. After assuming the weighted average method, the result of the fuzzy judgment is u x ,U={u1,u2,…u n} is a discrete domain, u j The degree of membership at is A(u j ), then u x It is obtained by the following formula:

[0061]

[0062] Correct the DDS output signal frequency in real time according to the following formula:

[0063] F′=F+dF

[0064] Where F is the resonant frequency of the transducer at the previous moment, that is, the signal frequency output by the current DDS, and F' is the resonant frequency of the current transducer, that is, the signal frequency output by the DDS at the next moment. This can make the transducer infinitely close to the resonant state.

[0065] According to an embodiment of the present application, the therapy head of the therapy device adopts an inwardly concave arc design and is made of medical-grade silicone.

[0066] During the specific implementation process, the concave arc design of the therapy head provides an adsorption-type application, which adopts the form of low negative pressure, and determines whether the therapy head is in the preset state of acoustic coupling through the acoustic coupling function, and adjusts the phase of the transmitted signal to change the focal point of the ultrasound. The depth and position of the focal point are adjusted by pressing buttons to adapt to different treatment needs. For different patients or different lesion sites, the focal depth of the ultrasound can be adjusted according to actual conditions so that it can act more accurately on the pain or lesion area, thereby achieving better treatment effects. The above specific implementation methods further explain the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above are only specific implementation methods of the present application, and are not used to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solution of the present application should be included in the scope of protection of the present application.

Claims

1. An ultrasonic focused therapy device and a therapy head thereof, characterized in that: include: S1, main control and its peripheral circuits: Initialize the ultrasound treatment intensity and focus position, and dynamically adjust the baseband signal frequency and phase according to the phase information fed back by the phase detection circuit and the voltage and current information of the ultrasonic transducer drive circuit. The main control circuit also has a frequency self-tracking function. Through frequency self-tracking, the transmitting circuit can automatically adjust the frequency of the transmitting signal to ensure that the transducer is always in a resonant state, thereby achieving continuous and stable ultrasonic output. S2, phase detection circuit: connected to the main control circuit, detecting the phase difference between the output signal of the transmitting circuit and the received signal of the transducer in the physiotherapy head. S3, ultrasonic transducer driving circuit: connected to the main control circuit, including a matching network and a voltage and current sampling circuit. It amplifies the baseband signal and drives the physiotherapy head to emit ultrasonic waves. It samples the voltage signal and current signal at both ends of the transducer. S4, LCC power resonant inverter: connected to the ultrasonic transducer drive circuit, using LCC resonant network structure to achieve power amplification function, by reasonably designing the inductor L S , capacitor C S and C P Parameters, providing good filtering effect without additional low-pass filter, and can show the characteristics of series or parallel resonant network according to the load conditions, so that it is close to the characteristics of parallel resonant network under light load and close to the characteristics of series resonant network under heavy load, and it has self-protection function and excellent filtering characteristics. S5. PDM modulation method: It is used to adjust the output power of the ultrasonic therapy device. By performing pulse density modulation (PDM) on the baseband signal, the working state of the switching network is controlled to ensure a high output power factor. It can switch between different power levels to achieve output power adjustability while avoiding probe overheating caused by continuous voltage waveform drive. S6. Therapy head: connected to the peripheral circuit, when the therapy head is in the energy output state, obtain the effective value of voltage and effective value of current of the current state of the ultrasonic therapy head; determine the current impedance of the transducer of the ultrasonic therapy head according to the effective value of voltage and effective value of current of the current state of the ultrasonic therapy head, and judge whether the ultrasonic therapy head enters the preset state of acoustic coupling according to the current impedance of the transducer of the ultrasonic therapy head; when the ultrasonic therapy head does not enter the preset state of acoustic coupling, control the ultrasonic excitation module to stop power output.

2. The ultrasonic focusing therapy device and the therapy head thereof according to claim 1, characterized in that: The S1, main control system comprises: S11, receiving effective value and phase information of voltage and current signals from the phase detection circuit; S12, preprocessing the collected data to remove noise interference, and using a fuzzification method to convert the actually measured phase difference into a membership degree in a fuzzy set; S13, using a predefined fuzzy rule base to evaluate the degree to which the current working state deviates from the ideal state, and determining a new target frequency based on the fuzzy reasoning result; S14, output frequency adjustment instructions to the DDS signal generator to change the frequency of the PWM waveform it generates, continuously monitor and iterate the above process to ensure the adaptability and stability of the system.

3. The ultrasonic focusing therapy device and the therapy head thereof according to claim 1, characterized in that: The S2 phase detection circuit comprises: S21, zero-crossing comparison module: used to measure the phase difference between the output signal of the transmitting circuit and the received signal of the transducer in the physiotherapy head. This method calculates the phase difference by detecting the time difference between the zero-crossing points of two signals of the same frequency. It has the characteristics of high resolution, good linearity and easy digital implementation. In order to ensure the measurement accuracy, this module will convert the original sine waveform into a square wave signal so that the time interval can be accurately determined using the pulse counting method. S22, digital phase detector: integrated in the main control chip STM32, responsible for processing the square wave signal from the zero-crossing comparison module and calculating the phase difference between the two signals. The digital phase detector can provide fast and accurate phase information feedback to the main control system to support the frequency tracking algorithm to adjust the output frequency, so that the transducer always remains in a resonant state.

4. The ultrasonic focusing therapy device and the therapy head thereof according to claim 1, characterized in that: The S3, ultrasonic transducer driving circuit comprises: S31, matching network: used to adjust the impedance matching between the output signal of the transmitting circuit and the transducer to ensure maximum energy transmission; S32. Voltage and current sampling circuit: used to sample the voltage signal and current signal at both ends of the transducer so as to monitor the working state of the transducer and ensure the safety and effectiveness of the treatment process.

5. An ultrasonic focusing therapy device and a therapy head thereof according to claim 1, characterized in that: The S4, LCC power resonant inverter comprises: S41, soft switch control module: used to switch the switching devices in the inverter under zero voltage or zero current conditions, thereby significantly reducing switching losses. This module precisely controls the switching moment so that the switching process occurs near the voltage or current zero point, reduces electromagnetic interference (EMI) generated by switching transients, improves system efficiency and reliability, and extends the service life of switching devices. S42, parameter adaptive adjustment module: connected to the main control system, real-time monitoring of load changes, and dynamic adjustment of the inductance L in the LCC resonant network S , capacitor C S and C P This module uses a built-in algorithm to analyze the current working status of output power and phase difference to ensure that the LCC resonant inverter can maintain optimal performance even when load conditions change.

6. An ultrasonic focusing therapy device and a therapy head thereof according to claim 1, characterized in that: The S5, PDM modulation method comprises: S51, Pulse Density Modulation (PDM) control module: used to adjust the output power. The average output power is adjusted by changing the number of switching signals per unit time (i.e., pulse density). The transducer is driven under a discontinuous voltage waveform to avoid the current discontinuity problem that may occur in the traditional PWM method, and three different preset output power levels are provided.

7. The ultrasonic focusing therapy device and the therapy head thereof according to claim 1, characterized in that: The S6, physiotherapy head also includes: S61, acoustic coupling state indication module: used to display in real time whether the ultrasonic therapy head has entered the acoustic coupling preset state. S62. Characteristic information acquisition unit: Before use, key characteristic information such as the working frequency, acoustic coupling impedance threshold, power coefficient or electromechanical conversion efficiency of the ultrasonic therapy head is obtained from the therapy head characteristic parameter module to control the ultrasonic frequency control module to generate the therapy head working frequency, and generate appropriate excitation voltage through the excitation voltage module, and finally output a sinusoidal ultrasonic excitation signal of a set power.

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