Ultrasonic focusing device
By using a piezoelectric transducer with uneven thickness and a dynamically controlled excitation circuit, the problem of multi-frequency coordinated application in existing ultrasonic focusing devices has been solved, realizing multi-frequency excitation and sound wave focusing, simplifying the circuit structure and improving the system's flexibility and safety.
Patent Information
- Application Number
- CN202510903297.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-01
- Publication Date
- 2025-11-07
AI Technical Summary
Existing ultrasound focusing devices are difficult to implement multi-frequency collaborative applications, resulting in high circuit system complexity, increased power consumption and cost, and difficulty in multi-channel synchronous control, which cannot meet different imaging needs.
The system employs a multi-frequency focusing design based on piezoelectric transducers. Through a curved planar structure with uneven thickness and a dynamically controlled excitation circuit, it achieves multi-frequency excitation and acoustic wave focusing. Combined with an automatic safety protection module, it ensures the safe operation of the system.
It achieves multi-frequency resonance characteristics, simplifies the excitation circuit structure, has single-region selective excitation or multi-region synergistic excitation modes, dynamically reconstructs the focal position and energy distribution of the sound field, and improves the system's flexibility and safety.
Smart Images
Figure CN120900930A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of ultrasonic focusing, and particularly relates to an ultrasonic focusing device capable of realizing precise control and efficient operation. BACKGROUND
[0002] The ultrasonic focusing device is a core device in the fields of medical imaging and industrial nondestructive testing. The ultrasonic transducer widely used in the ultrasonic focusing device has a resonant frequency determined by physical parameters such as material thickness and electrode structure, so that a single transducer can only work efficiently in a narrow frequency band, and it is difficult to meet the demand of multi-frequency collaborative application. For example, in medical ultrasound, deep tissue needs low frequency to obtain sufficient penetration, and shallow structure needs high frequency to realize high-resolution imaging. The existing system usually switches multiple transducer arrays with different frequencies to adapt to different imaging needs, which not only has a slow response, but also is difficult to realize multi-frequency synchronous excitation. In addition, in order to realize multi-frequency driving, the traditional method needs to configure an independent driving circuit (including a high-voltage pulse source and an impedance matching network) for each working frequency, which leads to an exponential increase in circuit system complexity, a significant increase in power consumption and cost, and an increase in difficulty of multi-channel synchronous control, which becomes a key bottleneck restricting the development of multi-frequency ultrasonic systems. SUMMARY
[0003] In view of the deficiencies in the prior art, the application provides an ultrasonic focusing device.
[0004] To achieve the above-mentioned purpose, the application provides an ultrasonic focusing device, which comprises a device shell, a master control unit (MCU), an automatic safety protection module, an excitation circuit, a power module and a piezoelectric transducer.
[0005] The piezoelectric transducer is arranged at the front end of the device shell.
[0006] The master control unit (MCU) is connected with the automatic safety protection module and the excitation circuit, receives real-time data of the automatic safety protection module, and dynamically regulates and controls output parameters (such as frequency and amplitude) of the excitation circuit; the excitation circuit is connected with the piezoelectric transducer, and drives the piezoelectric transducer to generate a multi-frequency focusing sound field according to the instruction of the MCU. The power module is connected with other modules to supply power for other modules.
[0007] The automatic safety protection module and the MCU are bidirectionally linked, and rapid shutdown or power degradation protection is triggered based on the detected risk.
[0008] The piezoelectric transducer comprises a base body and a piezoelectric material layer attached to the upper and lower surfaces of the base body, and has a whole curved planar structure. The thickness of the planar surface is not uniform in the direction of sound wave excitation, that is, the thickness is different at different positions of the planar surface, so as to realize multi-frequency excitation and sound wave focusing.
[0009] In a possible implementation, the thickness of the piezoelectric transducer depends on the matching relationship between the selected frequency and the speed of sound of the material.
[0010] In a possible implementation, the planar curvature of the transducer is controlled by a circular arc opening angle, which ranges from 3° to 160°. The larger the opening angle, the closer the focal point. The smaller the opening angle, the farther the focal point, so as to achieve precise focusing of ultrasonic energy.
[0011] In a possible implementation, the piezoelectric transducer adopts a linearly tapered thickness structure, that is, gradually transitions from the thickest part to the thinnest part along a straight line to form a continuous wedge-shaped profile, and the target area is divided according to the frequency as needed.
[0012] In a possible implementation, the piezoelectric transducer adopts a gradient thickness structure, that is, the thickness gradually decreases through multiple thickness steps, showing an approximate piecewise linear change. Similarly, the target area is divided as needed, and the thickness of each region decreases uniformly. The thickness difference of each region is the thickness difference of the two ends divided by the number of partitions.
[0013] In a possible implementation, the piezoelectric transducer is connected with an excitation circuit, and the excitation circuit selectively excites a single or multiple target areas on the piezoelectric transducer. In the single-area excitation mode, the excitation circuit applies a pulse signal of a single frequency to the piezoelectric transducer. In the multi-area excitation mode, the excitation circuit applies a composite waveform with adjustable phase difference to the piezoelectric transducer to synthesize an acoustic field.
[0014] In a possible implementation, the excitation circuit includes a multiplexer, a high-amplitude pulse generator, a medium-amplitude pulse generator, and a low-amplitude pulse generator. The multiplexer is used to control the high-amplitude pulse generator, the medium-amplitude pulse generator, and the low-amplitude pulse generator to generate pulse signals. By adjusting the channel selection and switching frequency of the multiplexer, the order of appearance of pulse signals of different amplitudes on the time axis is different, and different composite waveforms on the time axis are combined.
[0015] In a possible implementation, the automatic safety protection module includes an emergency stop button and an abnormality detection sensor. The emergency stop button is installed outside the device shell and directly connected to the master control unit (MCU) through a GPIO interface to form a hardware-level interrupt trigger link. The abnormality detection sensor includes a temperature sensor and an impedance detection unit, which collect and transmit the temperature of the focal point and the electrical impedance data of the piezoelectric transducer to the MCU in real time. When the emergency stop button is pressed or the abnormality detection sensor detects an abnormality, the hardware contact directly disconnects the power supply circuit of the excitation circuit and triggers the emergency interrupt service program of the MCU, thereby double-protecting the instantaneous shutdown of the system.
[0016] In a possible implementation, the piezoelectric material layer of the piezoelectric transducer, adopting lead zirconate titanate (PZT) or quartz crystal, converts an electric signal into an ultrasonic wave through the inverse piezoelectric effect.
[0017] In a possible implementation, the ultrasonic focusing device further comprises a liquid crystal display screen arranged on the device housing and connected to the master control unit MCU, serving as a man-machine interactive interface, calling data from the MCU and displaying working states and safety alarm information.
[0018] The present application has the following advantages: The device has the multi-frequency resonance characteristic, can realize the single-region selective excitation or multi-region collaborative excitation mode, and can realize the dynamic reconstruction of the sound field focal point position, action depth and energy distribution.
[0019] The present application proposes an innovative design of a piezoelectric transducer based on a thin-thick gradient distribution, simplifies a composite signal excitation circuit, and excites different thickness regions of the transducer through a single composite signal, so that the transducer has the multi-frequency resonance characteristic, can realize the single-region selective excitation or multi-region collaborative excitation mode, and can realize the dynamic reconstruction of the sound field focal point position, action depth and energy distribution. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 It is a structural schematic diagram of the ultrasonic focusing device of the embodiment of the present application.
[0021] Figure 2 It is a target region schematic diagram of the piezoelectric transducer with a linearly gradually changing thickness structure of the embodiment of the present application.
[0022] Figure 3 It is a target region schematic diagram of the piezoelectric transducer with a gradient changing thickness structure of the embodiment of the present application.
[0023] Figure 4 It is a schematic diagram of the excitation circuit structure of the embodiment of the present application.
[0024] Figure 5 It is a time domain superposition schematic diagram of the multi-frequency wave of the embodiment of the present application.
[0025] Figure 6 It is a multi-frequency component schematic diagram of the composite wave of the embodiment of the present application.
[0026] Figure 7 It is a combined composite waveform diagram of the embodiment of the present application.
[0027] Wherein, 1 - transparent protective cover, 2 - piezoelectric transducer, 3 - temperature sensor, 4 - emergency stop button, 5 - control button, 6 - master control unit (MCU), 7 - LCD. DETAILED DESCRIPTION
[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.
[0029] The present application provides an ultrasonic focusing device, as shown in Figure 1 The device housing is provided with a piezoelectric transducer 2 at the front end; the device housing is internally provided with a master control unit (MCU) 6, an excitation circuit and a power module.
[0030] The device housing is provided with a piezoelectric transducer 2 at the front end; the device housing is internally provided with a master control unit (MCU) 6, an excitation circuit and a power module.
[0031] The master control unit (MCU) 6 is connected to the automatic safety protection module and the excitation circuit, receives real-time data of the automatic safety protection module, and dynamically controls the output parameters (such as frequency and amplitude) of the excitation circuit; the excitation circuit is connected to the piezoelectric transducer 2, and drives the piezoelectric transducer 2 to generate a multi-frequency focused sound field according to the instructions of the master control unit (MCU) 6. The power module is connected to other modules to supply power to other modules.
[0032] The automatic safety protection module and the MCU are bidirectionally linked, based on the detected impedance abnormalities, temperature overruns or power fluctuations and other risks, triggering rapid shutdown or power degradation protection.
[0033] The piezoelectric transducer 2 is a bending plane structure, the plane is in the direction of sound wave excitation (generally the thickness direction of the plane), which is not uniform. That is, in the thickness direction, the thickness is different at different positions of the plane, thereby realizing multi-frequency excitation and sound wave focusing.
[0034] According to the principle of acoustics, the sound wave excited by the piezoelectric transducer 2 in the thickness direction has a working wavelength which is usually an integer multiple of the thickness of the transducer, and a half-wavelength structure is commonly used. Since the sound speed in the piezoelectric material is constant, different thicknesses correspond to different wavelengths, thereby generating sound wave signals of different frequencies. Therefore, different frequency electric signals can be applied to excite corresponding thickness regions, achieving the effect of a transducer exciting multiple frequency ultrasonic signals.
[0035] In one possible implementation, the power module is composed of three direct current modules, which output high voltage, medium voltage and low voltage through three independent direct current to supply power to other modules, ensuring hierarchical energy supply of the system.
[0036] In a possible implementation, the piezoelectric transducer 2 is provided with a transparent protective cover 1 on the outside.
[0037] In a possible implementation, the ultrasonic focusing device further comprises a liquid crystal display screen 7 provided on the device shell, connected to the master control unit (MCU) 6, serving as a man-machine interface, and called by the MCU to display working status and safety alarm information.
[0038] In a possible implementation, the ultrasonic focusing device further comprises a control button 5 provided on the device shell, connected to the master control unit (MCU) 6, for regulating the master control unit (MCU) 6, including the issuance of instructions of the master control unit (MCU) 6.
[0039] In a possible implementation, the piezoelectric transducer 2 can adopt a rectangular, triangular, circular or elliptical plane.
[0040] In a possible implementation, since the thickness of the piezoelectric transducer 2 is about half of its working wavelength, and the sound speed in common piezoelectric materials is about 3000-4000 m / s, under the condition of designing a frequency range of 100 KHz to 15 MHz, the thickness of the thickest end of the transducer unit can reach about 3 mm, and the thickness of the thinnest end can be as low as about 0.1 mm. The specific thickness depends on the matching relationship between the selected frequency and the material sound speed.
[0041] In a possible implementation, to realize the spatial focusing function, the piezoelectric transducer 2 is a curved structure, and the curvature is controlled by the circular arc opening angle, which is generally in the range of 3°-160°. The larger the opening angle, the closer the focal point; the smaller the opening angle, the farther the focal point, so as to realize precise focusing of ultrasonic energy.
[0042] In a possible implementation, the thickness of the piezoelectric transducer 2 is designed in two transition modes: one is a linearly tapered thickness structure (such as Figure 2 ), which gradually transitions from the thickest part to the thinnest part along a straight line, forming a continuous wedge-shaped profile, and the target area is divided by frequency as needed. The other is a gradient thickness structure (such as Figure 3 ), which gradually decreases in thickness by multiple steps, showing an approximate piecewise linear change. Similarly, the target area is divided as needed, and the thickness of each region decreases uniformly, and the thickness difference of each region is the thickness difference of the two ends divided by the number of partitions.
[0043] In a possible implementation, the thickness distribution of the upper and lower surfaces of the piezoelectric transducer 2 can be a symmetrical structure, or can be designed as an asymmetrical structure according to actual application requirements, to further improve the flexibility and focusing accuracy of the sound field control. The number of target regions is preferably 10 to 200.
[0044] In a possible implementation, the piezoelectric transducer 2 is connected with an excitation circuit, and the excitation circuit selectively excites a single or multiple target regions on the piezoelectric transducer 2 by configuration. In the single-region excitation mode, the excitation circuit applies a pulse signal of a single frequency to the piezoelectric transducer 2. In the multi-region excitation mode, the excitation circuit applies a composite waveform with adjustable phase difference to the piezoelectric transducer 2 to synthesize a sound field.
[0045] In a possible implementation, the excitation circuit includes a multiplexer, a high-amplitude pulse generator, a medium-amplitude pulse generator, and a low-amplitude pulse generator, as shown in Figure 4 The multiplexer is used to control the high-amplitude pulse generator, the medium-amplitude pulse generator, and the low-amplitude pulse generator to generate pulse signals. By adjusting the channel selection and switching frequency of the multiplexer, the order of appearance of pulse signals with different amplitudes on the time axis is different, and different composite waveforms on the time axis are combined. Through Fourier transform analysis, these composite waveforms can be decomposed into the superposition of multiple sinusoidal components with different frequencies, amplitudes, and phases, indicating that there is a clear corresponding relationship between the pulse signals and the sinusoidal signals in the frequency domain.
[0046] For the composite waveform as shown in Figure 5 , which is obtained by superimposing three sinusoidal signals f1, f2, and f3 with different frequencies, the state in the time domain is a complex non-sine. However, in the frequency domain, the superimposed signals retain the original frequency components, so when the composite waveform is applied to the piezoelectric transducer 2 by the excitation circuit, different regions of the piezoelectric transducer 2 will correspond to different frequency components, thereby exciting corresponding ultrasonic signals. Figure 6 is a schematic diagram of the composite wave multi-frequency components. Figure 7 is a combined composite waveform diagram.
[0047] In a possible implementation, the automatic safety protection module includes an emergency stop button 4 and an abnormality detection sensor. The emergency stop button 4 is installed outside the device shell and directly connected to the main control unit MCU through a GPIO interface, forming a hardware-level interrupt triggering link. The abnormality detection sensor includes a temperature sensor 3 and an impedance detection unit, which collects and transmits the focusing point temperature and the electrical impedance data of the piezoelectric transducer 2 to the MCU in real time. When the user actively presses the button or the abnormality detection sensor detects an abnormality, the hardware contact directly disconnects the power supply circuit of the excitation circuit and triggers the emergency interrupt service program of the MCU, to double-protect the system from instantaneous shutdown.
[0048] In a possible implementation, the impedance detection unit is integrated in the excitation circuit, and the running state of the piezoelectric transducer 2 is determined by monitoring the electrical impedance change of the piezoelectric transducer 2 in the working process in real time. The impedance detection unit acquires the excitation voltage and current signals, calculates the impedance parameters, and compares them with the preset normal working characteristics to realize abnormal identification (such as impedance mismatch, component aging, connection failure, etc.). The detection result is processed and fed back to the main control unit (MCU) in real time, which is used for dynamically adjusting the driving parameters of the excitation circuit or issuing a fault warning, thereby improving the stability and reliability of the system operation.
[0049] The temperature sensor 3 is attached to the outer surface of the piezoelectric transducer 2, and is used to monitor the focus point temperature in real time and feed back to the main control unit (MCU) in real time, which is used for dynamically adjusting the driving parameters of the excitation circuit or issuing a fault warning, thereby improving the stability and reliability of the system operation.
[0050] The piezoelectric material layer of the piezoelectric transducer 2 adopts lead zirconate titanate (PZT) or quartz crystal, which converts electrical signals into ultrasonic waves through the inverse piezoelectric effect.
[0051] It should be noted that the relational terms herein, such as first and second, are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device including the element.
[0052] Each embodiment in the specification is described in a related manner, and each embodiment focuses on the difference from other embodiments. The same and similar parts between each embodiment can be referred to each other.
[0053] The above description is only the preferred embodiment of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. An ultrasonic focusing device, characterized by, The application relates to a device for generating a multi-frequency focused sound field. The device comprises a device shell, a master control unit (MCU), an automatic safety protection module, an excitation circuit, a power module and a piezoelectric transducer. The piezoelectric transducer is arranged at the front end of the device shell; the device shell is internally provided with the master control unit (MCU), the excitation circuit and the power module. The master control unit (MCU) is connected to the automatic safety protection module and the excitation circuit, receives real-time data of the automatic safety protection module and dynamically controls the output parameters of the excitation circuit; the excitation circuit is connected to the piezoelectric transducer and drives the piezoelectric transducer to generate a multi-frequency focused sound field according to the instruction of the MCU. The power module is connected to other modules and supplies power to other modules. The automatic safety protection module is bidirectionally linked to the MCU and triggers quick shutdown or power degradation protection based on the detected risks. The piezoelectric transducer comprises a base body and a piezoelectric material layer attached to the upper and lower surfaces of the base body, and has a curved plane structure; the thickness of the plane is uneven in the direction of sound wave excitation, that is, the thickness is different at different positions of the plane, so that multi-frequency excitation and sound wave focusing are realized.
2. An ultrasonic focusing device according to claim 1, wherein The thickness of the piezoelectric transducer depends on the matching relationship between the selected frequency and the speed of sound of the material.
3. An ultrasonic focusing device according to claim 1, wherein The plane curvature of the transducer is controlled by the circular arc opening angle, and the opening angle ranges from 3 to 160 degrees; the greater the opening angle, the closer the focal point; the smaller the opening angle, the farther the focal point, so that the ultrasonic energy is accurately focused.
4. The ultrasonic focusing device of claim 1, wherein, The piezoelectric transducer adopts a linearly tapered thickness structure, that is, gradually transitions from the thickest part to the thinnest part along a straight line to form a continuous wedge-shaped profile, and simultaneously divides the target area by frequency as required.
5. The ultrasonic focusing device of claim 1, wherein, The piezoelectric transducer adopts a gradient thickness structure, that is, gradually decreases through multiple thickness steps to form an approximately segmented linear change; similarly, the target area is divided as required, and the thickness of each area decreases uniformly, and the thickness difference of each area is the thickness difference of the two ends divided by the number of partitions.
6. The ultrasonic focusing device of claim 1, wherein, The piezoelectric transducer is connected to the excitation circuit, and the excitation circuit selectively excites a single or multiple target areas on the piezoelectric transducer by configuration; in the single-area excitation mode, the excitation circuit applies a pulse signal of a single frequency to the piezoelectric transducer; In the multi-area excitation mode, the excitation circuit applies a composite waveform with adjustable phase difference to the piezoelectric transducer to synthesize a sound field.
7. The ultrasonic focusing device according to claim 1 or 6, wherein The excitation circuit comprises a multiplexer, a high-amplitude pulse generator, a medium-amplitude pulse generator and a low-amplitude pulse generator. The multiplexer is used to control the high-amplitude pulse generator, the medium-amplitude pulse generator and the low-amplitude pulse generator to generate pulse signals; by adjusting the channel selection and switching frequency of the multiplexer, the order of appearance of pulse signals with different amplitudes on the time axis is different, and different composite waveforms on the time axis are combined.
8. The ultrasonic focusing device of claim 1, wherein, The automatic safety protection module comprises an emergency stop button and an abnormality detection sensor, the emergency stop button is installed outside the equipment shell and directly connected to the master control unit (MCU) through a GPIO interface to form a hardware level interrupt trigger link; the abnormality detection sensor comprises a temperature sensor and an impedance detection unit, which collects the temperature of the focal point and the electrical impedance data of the piezoelectric transducer in real time and transmits them to the MCU; when the emergency stop button is pressed or the abnormality detection sensor detects an abnormality, the hardware contact directly disconnects the power supply loop of the excitation circuit and triggers the emergency interrupt service program of the MCU, thereby double-protecting the instantaneous shutdown of the system.
9. The ultrasonic focusing device of claim 1, wherein, The piezoelectric material layer of the piezoelectric transducer adopts lead zirconate titanate (PZT) or a quartz crystal, which converts an electrical signal into an ultrasonic wave through the inverse piezoelectric effect.
10. The ultrasonic focusing device of claim 1, wherein, The ultrasonic focusing device further comprises a liquid crystal display screen, which is arranged on the device shell, connected to the master control unit (MCU) and serves as a man-machine interaction interface, calls data from the MCU and displays the working state and safety alarm information.