Ultrasonic probe based on thermoacoustic effect

Abstract

The invention relates to the technical field of ultrasonic detection, and discloses an ultrasonic probe based on a thermoacoustic effect, comprising: a thermoacoustic generator comprising a driving device and a sounding film, the thermoacoustic generator being configured to generate input excitation signals of different frequencies through the driving device, the sound production film is driven to generate an ultrasonic signal according to the input excitation signal, the ultrasonic signal is transmitted to the to-be-detected area, and the frequency of the ultrasonic signal corresponds to the frequency of the input excitation signal; the ultrasonic sensor comprises an imaging device and a sound receiving film, the sound receiving film is configured to receive an echo signal from the to-be-detected area, and the imaging device is configured to analyze an amplitude characteristic, a time characteristic and a spectrum response characteristic of the echo signal so as to generate a detection image of the to-be-detected area according to an analysis result. The sound production frequency adjusting capability of the ultrasonic probe can be remarkably improved, the operation process of ultrasonic imaging is greatly simplified, and the imaging requirements of different organs from low frequency to high frequency are met.

Description

Technical Field

[0001] The present application relates to the field of ultrasonic detection technology, and in particular to an ultrasonic probe based on the thermoacoustic effect. Background Art

[0002] Ultrasonic technology is widely used to obtain image information of the internal tissue structure of the human body. It mainly uses the acoustic impedance difference and reflection characteristics of ultrasound when it propagates in tissues. The probe transmits ultrasound and receives echoes, and uses the propagation characteristics of sound waves to obtain image information of tissue structures.

[0003] In medical imaging applications, different organs and tissues have different acoustic properties and depths from the skin, so different probes need to be used for imaging in different frequency ranges. However, in related technologies, the frequency range of ultrasound probes is limited by manufacturing materials and processes, and can only work at one fixed frequency, and cannot be flexibly adjusted to meet the frequency requirements of medical imaging of different organs and tissues, resulting in the need to use multiple probes of different frequencies to complete multi-tissue organ imaging, which increases the complexity and cost of the imaging process. Summary of the invention

[0004] The present application provides an ultrasonic probe based on the thermoacoustic effect, which solves the technical problems of the current ultrasonic probes that are difficult to adjust the frequency and cannot adapt to different tissues and organs. The present application forms an ultrasonic probe with an integrated transmitter and receiver through a thermoacoustic generator and an ultrasonic sensor, and generates wide-spectrum ultrasound based on the thermoacoustic effect, thereby achieving adjustable ultrasonic frequency and improving the adaptability to tissues and organs with different surface curvatures and different depths.

[0005] In order to achieve the above objectives, the main technical solutions adopted in this application include:

[0006] In a first aspect, an embodiment of the present application provides an ultrasonic probe based on the thermoacoustic effect, characterized in that the ultrasonic probe comprises:

[0007] A thermoacoustic generator, the thermoacoustic generator comprising a driving device and a sound-generating film, the thermoacoustic generator being configured to generate input excitation signals of different frequencies through the driving device, and to drive the sound-generating film to generate ultrasonic signals of different frequencies according to the input excitation signals and propagate them to the area to be detected, wherein the frequency of the ultrasonic signal corresponds to the frequency of the input excitation signal;

[0008] An ultrasonic sensor, wherein the ultrasonic sensor includes an imaging device and a sound-receiving film, wherein the sound-receiving film is configured to receive echo signals of the area to be detected in response to ultrasonic signals of different frequencies, and the imaging device is configured to perform a frequency sweep analysis on the area to be detected according to the amplitude characteristics, time characteristics and spectrum response characteristics of the echo signals, so as to generate a detection image of the area to be detected according to the analysis results.

[0009] The ultrasonic probe proposed in the embodiment of the present application adopts an integrated design of transmitting and receiving, and the driving device is set to output input excitation signals of different frequencies to drive the sounding film to generate ultrasonic signals of different frequencies, so that the sounding film can work flexibly in different frequency ranges. Therefore, the ultrasonic probe proposed in the embodiment of the present application can significantly improve the sound frequency adjustment ability of the ultrasonic probe, so that a single ultrasonic probe can replace multiple piezoelectric transducers, realize the adjustable frequency of the ultrasonic probe, and then enable the single ultrasonic probe to sweep the ultrasonic frequency under a wide spectrum (swept-frequency) adjustment, so that a single ultrasonic probe can cover the spectrum range of multiple piezoelectric transducers to complete the imaging of different organs. This not only improves the versatility of the probe, solves the problem of frequent replacement of probes at present, greatly simplifies the operation process of ultrasonic imaging and reduces medical costs, but also meets different imaging requirements from low frequency to high frequency, not only significantly enhances the imaging ability of the ultrasonic probe, and improves the imaging quality and accuracy, but also can reduce the energy loss or signal attenuation caused by frequency mismatch to a large extent, so that a single ultrasonic probe can be competent for a wider range of application scenarios.

[0010] Optionally, in some embodiments of the present application, the driving device is configured to determine a preset spectrum range corresponding to the area to be detected according to the tissue type and tissue depth of the area to be detected, so as to generate the input excitation signal within the preset spectrum range.

[0011] In an embodiment of the present application, an adapted preset spectrum range can be determined according to the tissue type and tissue depth of the area to be detected, and then the driving device is configured to generate an input excitation signal of a corresponding frequency within the adapted preset spectrum range, thereby realizing dynamic adjustment of the frequency and ensuring that the ultrasonic signal subsequently generated by the sound-emitting film can more accurately adapt to the tissue characteristics of the area to be detected, thereby facilitating improving the imaging quality.

[0012] Optionally, in some embodiments of the present application, the imaging device includes a bandpass filter, and the bandpass filter is configured to filter the echo signal, wherein the frequency of the filtered echo signal matches the operating frequency of the ultrasonic probe.

[0013] The embodiment of the present application uses a bandpass filter to remove low-frequency and high-frequency noise in the echo signal received by the sound-receiving film, thereby retaining the echo signal that matches the operating frequency of the probe, ensuring the accuracy of subsequent processing, and thus facilitating improved imaging quality.

[0014] Optionally, in some embodiments of the present application, a plurality of the sound collecting films are provided on the ultrasonic sensor, and the sound collecting films and the sound emitting films are arranged in an array.

[0015] Optionally, in some embodiments of the present application, the imaging device further includes an imaging processor, and the imaging processor is configured to:

[0016] According to the amplitude characteristics and time characteristics of the echo signals received by each of the sound collecting films, combined with the ultrasonic wave propagation speed and the acoustic impedance of the area to be detected, the position of the reflection interface on the ultrasonic wave propagation path is determined based on the inversion algorithm;

[0017] Performing time delay compensation and coherent superposition processing on the reflection interface positions corresponding to the plurality of sound collecting films to determine the reflection points of the area to be detected;

[0018] Determine the tissue property corresponding to the reflection point according to the spectrum response characteristics of the echo signal received by each sound collecting film;

[0019] A detection image of the area to be detected is generated according to the reflection points and the tissue properties.

[0020] The embodiment of the present application receives echo signals through multiple sound-collecting membranes arranged in an array, and uses an inversion algorithm to combine amplitude characteristics, time characteristics, spectral response characteristics and acoustic parameters for the echo signals corresponding to each sound-collecting membrane to determine the reflection interface encountered by the ultrasonic signal on the propagation path. At the same time, the inversion calculation results corresponding to the multiple sound-collecting membranes are combined, and time error between the multiple sound-collecting membranes is eliminated by time delay compensation. The signal strength is enhanced through coherent superposition, so as to accurately determine the reflection point and its corresponding tissue properties, which is conducive to generating accurate and comprehensive detection images.

[0021] Optionally, in some embodiments of the present application, the imaging processor is further configured to: perform time calibration and space calibration on the reflection points based on a preset scanning method, and perform continuous smoothing on the detection image according to the calibrated reflection points corresponding to the adjacent sound collecting films in the array position.

[0022] The embodiment of the present application performs time calibration and space calibration on the reflection points based on a preset scanning method, ensuring the consistency of the reflected signals received by different sound-collecting films in the time and space dimensions, and at the same time performs continuous smoothing processing on the adjacent sound-collecting film reflection points in the array to eliminate the discreteness and discontinuity that may be generated in the signal processing process, so that the generated detection image has a more natural boundary and a more coherent detail expression, further improving the clarity and accuracy of the detection image, thereby providing a high-quality image with rich details and low noise, and realizing an accurate description of the internal structure of the area to be detected.

[0023] Optionally, in some embodiments of the present application, the preset scanning mode includes at least one of line-by-line scanning, sector scanning, curve array scanning, point-by-point scanning, circular scanning, volume scanning, dynamic real-time scanning and phased array scanning.

[0024] Optionally, in some embodiments of the present application, the driving device and the imaging device are arranged on a flexible circuit board, and the driving device is electrically connected to the sound-emitting film, and the imaging device is electrically connected to the sound-collecting film.

[0025] The embodiment of the present application uses flexible materials to prepare the sound-emitting film and ultrasonic sensor, so that it can better adapt to the surface curvature and special tissues of different areas to be detected. Especially for curved or non-planar areas to be detected, compared with rigid materials, the use of flexible materials can not only better adapt to different tissue surfaces, but also further enhance the comfort of the probe. In addition, due to the soft morphology of the flexible material, the use of impedance coupling agents can be avoided to a certain extent, while improving the stability and accuracy of imaging. In addition, setting the driving device and the imaging device on the flexible circuit board is conducive to realizing the wearability of the ultrasonic probe, so that the status of each organ can be continuously monitored in real time, which helps to improve the efficiency and accuracy of medical detection.

[0026] Optionally, in some embodiments of the present application, the sound-emitting film is a conductive film based on the thermoacoustic effect.

[0027] The embodiment of the present application uses a conductive film based on the thermoacoustic effect, which enables it to work efficiently in a wide frequency range, thereby achieving flexible frequency adjustment to adapt to the tissue characteristics and imaging frequency requirements of different areas to be detected. At the same time, the sound-emitting film is designed with a flexible material, so that it can not only respond quickly to the driving signal, but also fit closely to the surface of the target area, effectively improving the transmission efficiency and signal quality of ultrasound.

[0028] Optionally, in some embodiments of the present application, the sound collecting film is a pressure sensor based on piezoresistive effect or resistive strain effect.

[0029] The sound-absorbing film in the embodiment of the present application adopts a pressure sensor design based on the piezoresistive effect or the resistive strain effect, which can effectively capture the time and amplitude characteristics of ultrasonic waves. The sound-absorbing film is designed with a flexible material, which can provide an accurate and stable signal basis for the subsequent imaging process of the detection image. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 A schematic diagram of the structure of an ultrasonic probe based on the thermoacoustic effect proposed in an embodiment of the present application;

[0032] Figure 2 A schematic diagram of the signal transmission and reception process between the sound-emitting film and the sound-receiving film in an embodiment of the present application;

[0033] Figure 3 A schematic diagram of the structure of the flexible probe and the circuit board proposed in the embodiment of the present application;

[0034] Figure 4 This is a schematic diagram of the structure of the imaging device proposed in an embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0036] In the field of medical imaging, ultrasonic technology is widely used to obtain image information of the internal tissue structure of the human body. Among them, piezoelectric ultrasonic probe is a common ultrasonic detection equipment. The manufacturing materials of piezoelectric ultrasonic probe mainly include piezoelectric crystals, metal electrodes, insulating materials, etc. It uses the piezoelectric effect to convert electrical energy into mechanical vibration through piezoelectric crystals to generate ultrasonic waves. At the same time, it can also convert the received ultrasonic waves into electrical signals to realize the transmission and reception functions of sound waves.

[0037] In some application scenarios, different organs and tissues have different acoustic characteristics such as distance from the surface and impedance, and have different requirements for the frequency of ultrasound, so different probes need to be used for imaging in different frequency ranges. For example, deep tissues such as the heart and liver require lower frequencies, usually between tens of kilohertz (KHz) and hundreds of kilohertz (KHz), while superficial tissues such as the thyroid and breast have higher imaging frequencies, generally between 5 megahertz (MHz) and 12 megahertz (MHz), and some special tissues such as the eyeball, blood vessels and skin may require a higher frequency range for imaging to obtain clearer images.

[0038] However, the frequency range of ultrasonic probes in related technologies is limited by manufacturing materials and processes, and they can usually only work at a fixed frequency, resulting in the need to use multiple probes with different frequencies to complete imaging, which increases the complexity and cost of the imaging process. Therefore, it is impossible to flexibly adjust the frequency to meet the frequency requirements of medical imaging of different organs and tissues. In particular, in imaging tissues of different depths and components or detecting specific lesions, fixed-frequency ultrasonic probes are difficult to provide high-quality imaging effects.

[0039] In addition, piezoelectric ultrasonic probes are usually made of rigid materials. This rigid structure limits its adaptability to surface curvatures and special areas. For example, when it is necessary to fit a curved surface or enter hard-to-reach areas such as joints and breasts, the rigid probe may not be able to fully adapt, resulting in blind spots or poor imaging quality during imaging.

[0040] The ultrasonic probe provided in this manual can be used in a variety of applications that require high-resolution imaging and dynamic monitoring, as well as wearable ultrasonic detection equipment. Users can place the ultrasonic probe on the skin surface at the area to be detected, and adjust the ultrasonic frequency through the driving device to achieve high-quality ultrasonic imaging.

[0041] In the embodiment of the present application, an ultrasonic probe 10 based on the thermoacoustic effect is provided, such as Figure 1 As shown, the ultrasonic probe 10 includes a thermoacoustic generator 11 and an ultrasonic sensor 12;

[0042] The thermoacoustic generator 11 includes a driving device 111 and a sound-generating film 112. The thermoacoustic generator 11 is configured to generate input excitation signals of different frequencies through the driving device 111, and drive the sound-generating film 112 to generate ultrasonic signals of different frequencies according to the input excitation signals and propagate them to the area to be detected, wherein the frequency of the ultrasonic signal corresponds to the frequency of the input excitation signal;

[0043] In some embodiments of the present application, the above-mentioned sound-generating film 112 is a conductive film based on the thermoacoustic effect. The user can control the driving device 111 to generate input excitation signals of different frequencies through external input instructions, wherein the input excitation signal is a DC bias signal superimposed on an AC signal, and the signal frequency is in the ultrasonic frequency band. When the input excitation signal passes through the sound-generating film 112, the surface temperature of the sound-generating film 112 rises and falls periodically with the AC signal, and the air molecules on the surface of the sound-generating film 112 will continue to expand and compress, thereby generating an ultrasonic signal corresponding to the frequency of the input excitation signal.

[0044] The ultrasonic sensor 12 includes an imaging device 121 and a sound-receiving film 122. The sound-receiving film 122 is configured to receive echo signals of the area to be detected in response to ultrasonic signals of different frequencies. The imaging device 121 is configured to perform a frequency sweep analysis on the area to be detected according to the amplitude characteristics, time characteristics and spectrum response characteristics of the echo signal, so as to generate a detection image of the area to be detected according to the analysis results.

[0045] In some embodiments of the present application, the sound collecting film 122 is a pressure sensor based on piezoresistive effect or resistive strain effect. Figure 2 As shown, when the ultrasonic wave emitted by the sound-emitting film 112 passes through the human body surface and meets the interface or structure in the human tissue and organ, a part of the energy is reflected back as an echo signal and received by the sound-receiving film 122. Based on the piezoresistive effect, the sound-receiving film 122 converts the received echo signal into an electrical signal representing the change in resistance value and feeds it back to the imaging device 121, and then the imaging device 121 reconstructs the detection image according to the characteristics of the electrical signal.

[0046] Therefore, the ultrasonic probe 10 proposed in the embodiment of the present application adopts an integrated transceiver design, and the driving device 111 is set to output input excitation signals of different frequencies to drive the sound-emitting film 112 to generate ultrasonic signals of different frequencies, so that the sound-emitting film 112 can work flexibly within different frequency ranges. Therefore, the ultrasonic probe 10 proposed in the embodiment of the present application can significantly improve the sound frequency adjustment capability of the ultrasonic probe 10, so that a single ultrasonic probe 10 can image different organs, which not only improves the versatility of the probe, greatly simplifies the operation process of ultrasonic imaging and reduces medical costs, but also meets different imaging requirements from low frequency to high frequency, which is not only conducive to improving the clarity of imaging, but also can reduce the energy loss or signal attenuation caused by frequency mismatch to a large extent, so that a single ultrasonic probe 10 can be competent for a wider range of application scenarios.

[0047] In addition, the bandwidth of existing ultrasonic probes is only at the KHz level, while the embodiment of the present application uses a sound-generating film 112 based on the thermoacoustic effect, and the bandwidth of the ultrasound generated by it can reach tens of MHz, which can meet the high-performance requirements of medical imaging frequency, and through the combined use with the driving device, it can work efficiently in a wide frequency range, realizing flexible frequency adjustment, thereby adapting to the tissue characteristics and imaging frequency requirements of different areas to be detected. At the same time, the sound-collecting film 122 in the embodiment of the present application adopts a pressure sensor design based on the piezoresistive effect, which can effectively capture the time and amplitude characteristics of ultrasound.

[0048] It should be noted that in some embodiments of the present application, the above-mentioned sound-emitting film 112 and the sound-receiving film 122 and their packaging materials are all flexible materials, so they can better fit the surface of the human body, improve the adaptability to surface curvature and special areas, and can provide an accurate and stable signal basis for the subsequent imaging process of the detection image, which is beneficial to improve the quality of the detection image.

[0049] In some embodiments of the present application, the driving device 111 is configured to determine a preset frequency spectrum range corresponding to the area to be detected, so as to generate an input excitation signal within the preset frequency spectrum range.

[0050] Specifically, the user can select a preset frequency spectrum range corresponding to the input area to be detected at the driving device 111 end, so that the sound-emitting film 112 can generate an ultrasonic signal corresponding to the frequency of the input excitation signal, thereby enabling the thermoacoustic generator 11 to perform frequency scanning within a wide frequency spectrum, thereby realizing ultrasonic monitoring of different frequencies for different areas to be detected by one ultrasonic probe.

[0051] For example, in deep tissue imaging, for areas to be detected such as the heart and liver with a large tissue depth and a low absorption coefficient, ultrasound needs to have good penetration ability to ensure that the signal can reach deep targets and generate effective echoes. In this regard, the driving device 111 can choose to generate a swept frequency input excitation signal within a preset spectrum range of tens of kHz to hundreds of kHz, and then drive the sound-emitting film 112 to generate a swept frequency ultrasonic signal. This low-frequency ultrasonic wave has strong penetration ability and can effectively reduce signal attenuation, ensuring that the structure of deep tissue is clearly presented. For example, in cardiac imaging, low-frequency ultrasound can not only display the dynamics of the heart chambers and valves, but also penetrate the myocardium to observe deeper tissues.

[0052] In superficial tissue imaging, for superficial tissues such as the thyroid gland and breast, since they are close to the surface and require higher resolution to observe details, the driving device 111 can generate a swept frequency input excitation signal within a preset frequency spectrum range of 5MHz to 12MHz, thereby driving the sound-generating film 112 to generate a swept frequency ultrasonic signal. High-frequency ultrasonic waves have a higher resolution and can clearly display the fine structure of superficial tissues, thus further enhancing the imaging resolution.

[0053] In the related art, the ultrasonic probe is usually limited in frequency and can only work within a fixed frequency range, and cannot adapt to the imaging requirements of different depths and different tissues. Therefore, in the embodiment of the present application, the ultrasonic frequency is dynamically adjusted by frequency sweeping, and the frequency can be adjusted automatically or according to demand to adapt to the imaging requirements of superficial tissues and deep tissues, so that the ultrasonic probe can cover a wide spectrum from low frequency to high frequency, which can not only utilize the wide spectrum advantage of a single probe to meet the imaging requirements of different tissues at the same time, solve the current problem of frequent probe replacement, but also solve the problem of frequency mismatch between the ultrasonic probe and the area to be detected. Through the mutual cooperation of the sound-emitting film 112 based on the thermoacoustic effect and the driving device 111, the ultrasonic probe can select the optimal frequency according to the tissue characteristics of the area to be detected, ensure that the ultrasonic signal can be effectively transmitted and reduce unnecessary energy loss, thereby significantly enhancing the imaging capability of the ultrasonic probe, and improving the imaging quality and accuracy, especially in the high-frequency part, it can provide higher spatial resolution to obtain more detailed tissue structure information. It is also possible to flexibly adjust the preset frequency spectrum range according to the characteristics of the area to be detected, and then configure the driving device 111 to generate an input excitation signal of the corresponding frequency within the preset frequency spectrum range, thereby realizing dynamic frequency adjustment and ensuring that the ultrasonic signal generated by the subsequent sounding film can more accurately adapt to the tissue characteristics of the area to be detected, thereby facilitating improved imaging flexibility. In some embodiments of the present application, such as Figure 3 As shown, a plurality of the sound collecting films 122 are disposed on the ultrasonic sensor 12 , and the sound collecting films 122 and the sound emitting films 112 are arranged in an array.

[0054] The sound-emitting film 112 and the sound-receiving film 122 in the embodiment of the present application are arranged in an array to form a film array, which can cover a larger detection area, so that ultrasonic echo signals from multiple directions can be received simultaneously. Compared with a single receiving device, the array design can capture more reflection information, especially in complex tissues or irregular areas, ensuring the comprehensiveness of signal acquisition. Through the coordinated work of each film in the array, the imaging details of the target area can be refined.

[0055] It should be noted that, in the embodiment of the present application, the driving device 111 and the imaging device 121 may be arranged on a rigid circuit board or on a flexible circuit board.

[0056] Furthermore, if Figure 3 As shown, the driving device 111 and the imaging device 121 are arranged on a flexible circuit board, and the driving device 111 is electrically connected to the sound emitting film 112 , and the imaging device 121 is electrically connected to the sound collecting film 122 .

[0057] Optionally, the flexible circuit board is mainly composed of a flexible substrate and a conductive material, and has excellent flexibility and stretchability. Its flexible characteristics ensure that even under deformation conditions such as bending and stretching, the circuit can still maintain a stable structure and function and is not affected by external deformation.

[0058] The embodiment of the present application fully considers the actual application environment of the ultrasonic probe 10, and uses flexible materials to encapsulate the driving device 111 and the imaging device 121, so that they can better adapt to the surface curvature and special tissues of different areas to be detected, so as to ensure perfect fit with the human body surface. In addition, due to the soft morphology of the flexible material, the use of impedance coupling agents can be avoided to a certain extent, while improving the stability and accuracy of imaging.

[0059] In addition, the circuit board is also provided with a communication module 13 such as Bluetooth and WIFI for data communication with external devices. For example, a user can use an external device to send a frequency adjustment control instruction to the driving device 111 through a module such as Bluetooth and WIFI. The circuit board is also provided with a battery 14 for powering the driving device 111 and the imaging device 121.

[0060] Furthermore, in some embodiments of the present application, the driving device 111, the sound-emitting film 112, and the sound-receiving film 122 are all made of flexible materials, and the driving device 111 and the imaging device 121 can be arranged on a flexible circuit board, and the flexible circuit board is light and thin, which reduces the volume and weight of the ultrasonic probe 10, is conducive to realizing the wearability of the ultrasonic probe 10, and reduces the burden on the carrier, thereby not only improving the stability and reliability of ultrasonic imaging, but also bringing a more comfortable use experience to the carrier. In addition, the wearability of the ultrasonic probe 10 is also conducive to realizing real-time continuous monitoring of the area to be detected, which is particularly important for special application scenarios such as timely monitoring of organ status during surgery or patient monitoring, and is of great significance to real-time observation during medical diagnosis and treatment, and helps to improve medical efficiency and accuracy.

[0061] In some embodiments of the present application, Figure 4As shown, the imaging device 121 includes a bandpass filter 1211 , which is configured to filter the echo signal, wherein the frequency of the filtered echo signal matches the operating frequency of the ultrasound probe 10 .

[0062] In some embodiments of the present application, filtering is used to remove noise and irrelevant frequency components in the received echo signal. The bandpass filter 1211 can retain the echo signal within a specific frequency range and remove low-frequency and high-frequency noise, so the filtered echo signal mainly retains the ultrasonic signal that matches the probe operating frequency, thereby ensuring the accuracy of subsequent signal processing, which is beneficial to improving the imaging quality.

[0063] In some embodiments of the present application, Figure 4 As shown, the imaging device 121 further includes an imaging processor 1212, and the imaging processor 1212 is configured to:

[0064] According to the amplitude characteristics and time characteristics of the echo signals received by each sound collecting film 122, combined with the ultrasonic wave propagation speed and the acoustic impedance of the area to be detected, the position of the reflection interface on the ultrasonic wave propagation path is determined based on the inversion algorithm;

[0065] Performing time delay compensation and coherent superposition processing on the reflection interface positions corresponding to the multiple sound collecting films 122 to determine the reflection points of the area to be detected;

[0066] Determine the tissue property corresponding to the reflection point according to the spectrum response characteristics of the echo signal received by each sound collecting film 122;

[0067] A detection image of the area to be detected is generated based on the reflection points and tissue properties.

[0068] Specifically, the echo signal received by each sound-receiving film 122 will contain information about the internal reflection interface of the area to be detected. Among them, the amplitude characteristics of the echo signal reflect the strength of the reflection interface that the ultrasonic wave passes through in the propagation path. The amplitude characteristics of the echo signal are closely related to the difference in acoustic impedance of the media on both sides of the reflection interface. When an ultrasonic signal propagates from one medium to another medium with a large difference in acoustic impedance, a stronger echo signal will be generated, so that the amplitude of the echo signal is larger. For example, the interface between bones and soft tissues will produce a high-amplitude reflection signal. Conversely, if the difference in acoustic impedance between the media is small, the amplitude of the reflection signal will be weakened. The time characteristic of the echo signal refers to the propagation time of the ultrasonic signal from the sound-emitting film to the reflection and reception by the target interface in the area to be detected. The propagation time is related to the length of the path that the ultrasonic wave passes through. The signal propagation distance can be calculated by the ultrasonic wave propagation time characterized by the time characteristic and the ultrasonic wave propagation speed.

[0069] The relationship between the propagation time, ultrasonic propagation speed, and propagation distance of the ultrasonic signal is expressed by the following formula (1):

[0070] v=d / t Formula (1)

[0071] Where v is the ultrasonic propagation velocity, d is the signal propagation distance, and t is the propagation time.

[0072] The ultrasonic wave propagation velocity is affected by the density and elastic modulus of human tissue. The ultrasonic wave propagation velocity is expressed according to the following formula (2):

[0073]

[0074] Among them, v is the propagation velocity of ultrasound, E is the elastic modulus of human tissue, and ρ is the density of human tissue.

[0075] Among them, because higher density increases the energy demand for wave propagation, the density of organ tissue affects the propagation speed of ultrasound: the higher the density, the slower the ultrasound propagation speed. For example, the density of fat tissue is about 900kg / m 3 The propagation speed of ultrasound is 1450-1470m / s, and the density of bone tissue is about 1900kg / m 3 , the propagation speed of ultrasonic wave is 3000-4300m / s.

[0076] The elastic modulus has an effect on the ultrasonic wave propagation speed: the larger the elastic modulus, the faster the ultrasonic wave propagation speed. For example, the elastic modulus of muscle tissue is about 10 kPa, and the ultrasonic wave propagation speed is 1540-1580 m / s; the elastic modulus of bone tissue is about 15-20 GPa, and the ultrasonic wave propagation speed is 3000-4300 m / s.

[0077] Therefore, based on the time characteristics of the echo signal and the ultrasonic propagation speed, the signal propagation distance can be determined, and then the reflection interface corresponding to the echo signal received by each sound-collecting film 122 can be obtained, and the tissue properties of the reflection interface can be determined based on the amplitude characteristics of the echo signal combined with the acoustic impedance of the area to be detected.

[0078] The embodiment of the present application analyzes the amplitude characteristics and time characteristics of the received echo signal through an inversion algorithm, and in combination with the known ultrasonic propagation speed and acoustic impedance, the position of the reflection interface can be inferred. In addition, because the physical model is usually complex and cannot be directly inverted, the solution to the inverse problem depends on optimization or iterative methods. Therefore, in the process of training the inversion algorithm, these parameters are usually inferred through an optimization process. For example, an inverse problem model is established, known historical data is input, and the model parameters are adjusted through the least squares method, gradient descent method, and optimization algorithm until the error between the model output result and the actual measurement result reaches a preset standard.

[0079] Furthermore, since the attenuation and scattering characteristics of ultrasound waves of different tissues vary with frequency, some tissues exhibit strong resonance or attenuation at specific frequencies, and different types of tissues can be further distinguished by frequency characteristics. Therefore, in some embodiments of the present application, the imaging processor 1212 extracts the spectrum response characteristics of the area to be detected under ultrasound signals of different frequencies, such as the main frequency, spectrum width, and resonance frequency, by performing frequency domain analysis on the echo signal, thereby determining the tissue properties corresponding to the reflection point according to the spectrum response characteristics, thereby expressing ultrasound diagnostic information such as tissue type and lesions in the generated detection image.

[0080] When using multiple array-arranged sound-collecting films 122, since the propagation distance of the echo signal from the sound-emitting film 112 to each sound-collecting film 122 is different, the echo signal received by each sound-collecting film 122 may have a time delay. In order to accurately extract the position of the reflection point from the signals received by different films, the embodiment of the present application calculates the delay difference of signal propagation and performs delay compensation on the received signal, so that all echo signals can be superimposed and processed under the same time reference. At the same time, the echo signals received by multiple sound-collecting films 122 are coherently superimposed. This process can effectively enhance the echo signal from the same reflection interface and suppress noise and other irrelevant signals. In this way, the accuracy of reflection point positioning and the signal-to-noise ratio of the signal can be improved. After delay compensation and coherent superposition processing, the peak position of the intensity of the echo signal corresponds to the reflection point of the area to be detected.

[0081] Through this method, the positions of reflection interfaces and reflection points within the area to be detected can be accurately determined, thereby helping to identify potential defects or structural features. It is widely used in non-destructive testing (NDT), medical imaging (such as ultrasonic imaging) and other fields.

[0082] Furthermore, in some embodiments of the present application, in the case of ultrasound detection applications involving blood flow analysis, the above-mentioned imaging processor 1212 is also configured to perform Doppler frequency shift analysis on the frequency characteristics of the echo signal, and determine the blood flow direction of the area to be detected based on the analysis results, so as to display the blood flow direction in the detection image.

[0083] The application of Doppler shift analysis in ultrasonic testing is mainly reflected in the evaluation and measurement of hemodynamics. By emitting ultrasonic waves and receiving waves reflected by moving objects (such as red blood cells in the blood), the frequency change of the reflected wave, that is, the Doppler shift, can be analyzed to obtain the speed and direction information of the object. This technology is particularly important in medical ultrasound, especially in the diagnosis of heart and vascular diseases, and can provide key information such as the origin, direction and speed of blood flow. The embodiment of the present application utilizes the frequency characteristics of the echo signal to realize ultrasonic detection of the direction of blood flow, so that the generated detection image contains richer and more comprehensive diagnostic information, further improving the accuracy and comprehensiveness of ultrasonic monitoring of the area to be detected.

[0084] Therefore, the embodiment of the present application receives echo signals through multiple sound-collecting membranes arranged in an array, and uses an inversion algorithm to combine the amplitude, time, frequency characteristics and acoustic parameters of the echo signals corresponding to each sound-collecting membrane to determine the reflection interface encountered by the ultrasonic signal on the propagation path. At the same time, the inversion calculation results corresponding to the multiple sound-collecting membranes are combined, and the time error between the multiple sound-collecting membranes is eliminated by using time delay compensation. The signal strength is enhanced through coherent superposition, thereby providing high-quality images with rich details and low noise, and realizing an accurate description of the internal structure of the area to be detected.

[0085] In some embodiments of the present application, the imaging processor 1212 is further configured to:

[0086] The reflection points are time-calibrated and space-calibrated based on the preset scanning mode, and the detection image is continuously smoothed according to the calibrated reflection points corresponding to the adjacent sound collecting films in the array position.

[0087] Specifically, the scanning algorithm is responsible for combining the signals obtained by the sound collecting films at different positions in the probe array to generate a complete two-dimensional or three-dimensional image. The embodiments of the present application use a scanning algorithm to read and process the signals of each sound collecting film according to a preset scanning method, wherein, in some embodiments of the present application, the preset scanning method includes at least one of linear scanning, sector scanning, curved array scanning, point-by-point scanning, circular scanning, volume scanning, dynamic real-time scanning, and phased array scanning.

[0088] Among them, line-by-line scanning is suitable for observing superficial tissues, such as blood vessels, tendons and skin; sector scanning is suitable for imaging deep organs, such as the heart and abdomen; curved array scanning is suitable for adapting to imaging needs of a wide area, such as abdominal, gynecological and obstetric imaging; point-by-point scanning is suitable for high-precision imaging, such as ophthalmic ultrasound or micro-ultrasound; annular scanning is suitable for imaging of specific parts, such as breast or joints; volume scanning is suitable for fetal examination, volume assessment of the heart and tumors; dynamic real-time scanning is suitable for observing dynamic changes of organs, such as the contraction and relaxation movements of the heart; and phased array scanning is suitable for imaging deep tissues or narrow spaces, such as cardiac imaging and neural ultrasound.

[0089] In some embodiments of the present application, film signals at different positions may have slight time errors due to scanning delays or reading timing differences, and calibration is required to ensure the timing consistency of image reconstruction. At the same time, there may be slight geometric deviations in the film array during the manufacturing or layout process, resulting in systematic errors in the spatial coordinates of the reflection points. Therefore, the reflection points corresponding to each sound-absorbing film 122 are calibrated in the time dimension and the space dimension.

[0090] In order to generate a continuous and smooth detection image, the imaging processor 1212 interpolates and filters the reflection points corresponding to all the sound-collecting films 122. The interpolation is used to fill the missing spatial data caused by the intervals of the array arrangement of the sound-collecting films 122, and the filtering is used to eliminate the residual noise to make the boundaries of the detection image more natural. Through the processing of the scanning algorithm, the film array of the ultrasonic probe can efficiently scan the area to be detected and integrate the signals of different films into a complete two-dimensional or three-dimensional image.

[0091] Therefore, the embodiment of the present application performs time calibration and space calibration on the reflection points based on a preset scanning method to ensure the consistency of the reflected signals received by different sound-collecting films in the time and space dimensions, and at the same time performs continuous smoothing on the adjacent sound-collecting film reflection points in the array to eliminate the discreteness and discontinuity that may occur in the signal processing process, so that the generated detection image has more natural boundaries and more coherent details, further improving the clarity and accuracy of the detection image.

[0092] It should be noted that the imaging device 121 uses various signal processing algorithms and image reconstruction techniques, including but not limited to filtering, inversion algorithms and scanning algorithms, etc. Finally, the detection image generated by the imaging device 121 is displayed on the screen of the ultrasound imaging device for observation and diagnosis by doctors or technicians.

[0093] The embodiment of the present application combines the driving device 111, the sound-generating film 112, the imaging device 121 and the sound-receiving film 122. The user attaches the flexible ultrasonic probe to the skin corresponding to the area to be detected, and adjusts the ultrasonic frequency matching the area to be detected through the external driving device 111 to achieve ultrasonic imaging. This not only realizes the integration of the functions of each part, but also combines the characteristics of flexible materials and thermoacoustic effects to significantly improve the overall performance of the ultrasonic probe 10. Compared with the traditional rigid ultrasonic probe, the combination of the thermoacoustic generator 11 and the ultrasonic sensor 12 proposed in the embodiment of the present application significantly enhances the frequency adjustment ability and adaptability of the sound generator. The application of flexible materials enables the ultrasonic probe 10 to fit the curvature of the human body surface more closely, reduces signal distortion caused by poor contact, and ensures efficient transmission and reception of ultrasonic waves. At the same time, the components are seamlessly integrated in terms of physical structure and functional operation, avoiding mutual interference and obstruction, and ensuring the stability and imaging quality of the system in a variety of complex tissue environments. Ultimately, this integrated design not only improves the imaging adaptability of the ultrasonic probe 10, but also enhances the accuracy and reliability of imaging, fully meeting the real-time and diversified requirements in the field of medical imaging.

[0094] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0095] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0096] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0097] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

[0098] Although the embodiments of the present application have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An ultrasonic probe based on thermoacoustic effect, characterized in that: The ultrasonic probe comprises: A thermoacoustic generator, the thermoacoustic generator comprising a driving device and a sound-generating film, the thermoacoustic generator being configured to generate input excitation signals of different frequencies through the driving device, and to drive the sound-generating film to generate ultrasonic signals of different frequencies according to the input excitation signals and propagate them to the area to be detected, wherein the frequency of the ultrasonic signal corresponds to the frequency of the input excitation signal; An ultrasonic sensor, wherein the ultrasonic sensor includes an imaging device and a sound-receiving film, wherein the sound-receiving film is configured to receive echo signals of the area to be detected in response to ultrasonic signals of different frequencies, and the imaging device is configured to perform a frequency sweep analysis on the area to be detected according to the amplitude characteristics, time characteristics and spectrum response characteristics of the echo signals, so as to generate a detection image of the area to be detected according to the analysis results.

2. The ultrasonic probe according to claim 1, characterized in that: The driving device is configured to determine a preset frequency spectrum range corresponding to the area to be detected according to the tissue type and tissue depth of the area to be detected, so as to generate the input excitation signal within the preset frequency spectrum range.

3. The ultrasonic probe according to claim 1, characterized in that: The imaging device includes a bandpass filter, which is configured to perform filtering processing on the echo signal, wherein the frequency of the filtered echo signal matches the working frequency of the ultrasonic probe.

4. The ultrasonic probe according to claim 1, characterized in that: A plurality of the sound collecting films are arranged on the ultrasonic sensor, and the sound collecting films and the sound emitting films are arranged in an array.

5. The ultrasonic probe according to claim 4, characterized in that: The imaging device further comprises an imaging processor, wherein the imaging processor is configured to: According to the amplitude characteristics and time characteristics of the echo signals received by each of the sound collecting films, combined with the ultrasonic wave propagation speed and the acoustic impedance of the area to be detected, the position of the reflection interface on the ultrasonic wave propagation path is determined based on the inversion algorithm; Performing time delay compensation and coherent superposition processing on the reflection interface positions corresponding to the plurality of sound collecting films to determine the reflection points of the area to be detected; Determine the tissue property corresponding to the reflection point according to the spectrum response characteristics of the echo signal received by each sound collecting film; A detection image of the area to be detected is generated according to the reflection points and the tissue properties.

6. The ultrasonic probe according to claim 5, characterized in that: The imaging processor is further configured to: The reflection points are time-calibrated and space-calibrated based on a preset scanning method, and the detection image is continuously smoothed according to the calibrated reflection points corresponding to the adjacent sound collecting films at the array position.

7. The ultrasonic probe according to claim 6, characterized in that: The preset scanning mode includes at least one of line-by-line scanning, sector scanning, curve array scanning, point-by-point scanning, annular scanning, volume scanning, dynamic real-time scanning and phased array scanning.

8. The ultrasonic probe according to any one of claims 1 to 7, characterized in that: The driving device and the imaging device are arranged on a flexible circuit board, and the driving device is electrically connected to the sound emitting film, and the imaging device is electrically connected to the sound collecting film.

9. The ultrasonic probe according to any one of claims 1 to 7, characterized in that: The sound-generating film is a conductive film based on the thermoacoustic effect.

10. The ultrasonic probe according to any one of claims 1 to 7, characterized in that: The sound collecting film is a pressure sensor based on piezoresistive effect or resistive strain effect.

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