An ultrasonic probe based on thermoacoustic effect

Abstract

The application relates to the technical field of ultrasonic detection, and discloses an ultrasonic probe based on a thermoacoustic effect, which comprises a thermoacoustic sound generator, a driving device and a sound film, the thermoacoustic sound generator is configured to generate input excitation signals of different frequencies through the driving device, and to drive the sound film to generate ultrasonic signals and propagate to a region to be detected according to the input excitation signals, wherein the frequency of the ultrasonic signals corresponds to the frequency of the input excitation signals; and an ultrasonic sensor, the ultrasonic sensor comprises an imaging device and a sound receiving film, the sound receiving film is configured to receive echo signals from the region to be detected, and the imaging device is configured to analyze the amplitude characteristics, time characteristics and spectral response characteristics of the echo signals to generate a detection image of the region to be detected according to the analysis results. The application can significantly improve the sound frequency adjustment capability of the ultrasonic probe, greatly simplify the operation process of ultrasonic imaging, and meet the imaging requirements of different organs from low frequency to high frequency.

Description

TECHNICAL FIELD

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

[0002] Ultrasonic technology is widely used to obtain image information of internal tissue structure of human body, mainly using the acoustic impedance difference and reflection characteristics of ultrasonic wave in the tissue when propagating, transmitting ultrasonic wave through the probe and receiving echo, and using the propagation characteristics of the acoustic wave to obtain image information of the tissue structure.

[0003] In medical imaging applications, different organ tissues have different acoustic characteristics and depths from the skin, so different probes need to be used in different frequency ranges for imaging. However, in the related art, the frequency range of the ultrasonic probe is limited by the manufacturing material and process, and can only work at a fixed frequency, which cannot be flexibly adjusted to meet the frequency requirements of different organ tissue medical imaging, resulting in the need to use multiple probes of different frequencies to complete multi-organ tissue imaging, increasing the complexity and cost of the imaging process. SUMMARY

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

[0005] In order to achieve the above purpose, the main technical scheme adopted by the present application includes:

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

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

[0008] An ultrasonic sensor comprises an imaging device and a receiving diaphragm configured to receive echo signals of the region to be detected in response to ultrasonic signals of different frequencies, and the imaging device is configured to perform swept-frequency analysis on the region to be detected according to amplitude characteristics, time characteristics and spectral response characteristics of the echo signals, so as to generate a detection image of the region to be detected according to an analysis result.

[0009] The ultrasonic probe provided in the embodiments of the present application adopts a transceiving integrated design, and the driving device is configured to output input excitation signals of different frequencies to drive the sound generating diaphragm to correspondingly generate ultrasonic signals of different frequencies, so that the sound generating diaphragm can work flexibly in different frequency ranges. Therefore, the ultrasonic probe provided in the embodiments of the present application can significantly improve the sound frequency adjustment capability of the ultrasonic probe, so that a single ultrasonic probe can replace multiple piezoelectric transducers, realize frequency adjustment of the ultrasonic probe, and further enable the single ultrasonic probe to adjust the ultrasonic frequency in a wide frequency spectrum, so that the single ultrasonic probe can cover the frequency spectrum range of multiple piezoelectric transducers to complete imaging of different organs. This not only improves the universality of the probe, solves the problem of frequent replacement of the probe, greatly simplifies the operation process of ultrasonic imaging and reduces the medical cost, but also meets different imaging requirements from low frequency to high frequency, significantly enhances the imaging capability of the ultrasonic probe, improves the imaging quality and precision, and further reduces energy loss or signal attenuation caused by frequency mismatch to a great extent, so that the single ultrasonic probe can be used in a wider application scenario.

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

[0011] In the embodiments of the present application, the preset frequency spectrum range can be determined according to the tissue type and the tissue depth of the region to be detected, and then the driving device is configured to generate the input excitation signal of the corresponding frequency in the adaptive preset frequency spectrum range, so as to realize dynamic adjustment of the frequency, ensure that the ultrasonic signal generated by the sound generating diaphragm can more accurately adapt to the tissue characteristics of the region to be detected, and thus be beneficial to improving the imaging quality.

[0012] Optionally, in some embodiments of the present application, the imaging device comprises a band-pass filter 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.

[0013] The echo signal received by the sound receiving film is filtered by the band-pass filter to remove low-frequency and high-frequency noise, so that the echo signal matched with the working frequency of the probe is reserved, the accuracy of subsequent processing is ensured, and the imaging quality is improved.

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

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

[0016] According to the amplitude characteristics and time characteristics of the echo signals received by each sound receiving film respectively, and in combination with the ultrasonic wave propagation speed and the acoustic impedance of the to-be-detected region, the position of the reflection interface on the ultrasonic wave propagation path is determined based on an inversion algorithm;

[0017] The reflection interface positions corresponding to the plurality of sound receiving films are subjected to time delay compensation and coherent superposition processing to determine the reflection points of the to-be-detected region;

[0018] The tissue properties corresponding to the reflection points are determined according to the frequency spectrum response characteristics of the echo signals received by each sound receiving film;

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

[0020] In the embodiments of the present application, the echo signals are received by the plurality of sound receiving films arranged in an array, and the echo signals corresponding to each sound receiving film are processed respectively, the reflection interface encountered by the ultrasonic wave signal on the propagation path is determined by using the inversion algorithm in combination with the amplitude characteristics, time characteristics, frequency spectrum response characteristics and acoustic parameters, the time errors between the plurality of sound receiving films are eliminated by using time delay compensation, and the signal strength is enhanced by coherent superposition, so that the reflection points and the corresponding tissue properties are accurately determined, and a precise and comprehensive detection image is generated.

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

[0022] The embodiment of the present application performs time calibration and space calibration on the reflection points based on a preset scanning mode, ensures consistency of reflection signals received by different receiving films in time and space dimensions, and performs continuous smoothing processing on reflection points of receiving films adjacent in position in the array, so as to eliminate discreteness and discontinuity possibly generated in the signal processing process, make the generated detection image have more natural boundaries and more coherent detail performance, further improve the definition and accuracy of the detection image, thereby providing a high-quality image with rich details and low noise, and realizing accurate description of internal structures of the region to be detected.

[0023] Optionally, in some embodiments of the present application, the preset scanning mode includes at least one of a line-by-line scanning mode, a fan scanning, a curve array scanning, a point-by-point scanning, a ring scanning, a volume scanning, a dynamic real-time scanning, and a 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 with the sound emitting film, and the imaging device is electrically connected with the sound receiving film.

[0025] The embodiment of the present application uses flexible materials to prepare the sound emitting film and the ultrasonic sensor, so that it can better adapt to the surface curvature and special tissues of different regions to be detected. Especially for the curved or non-planar region 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. And because of the soft characteristics of the flexible materials, the use of impedance coupling agent can be avoided to some extent, while the stability and accuracy of imaging are improved. In addition, arranging the driving device and the imaging device on the flexible circuit board is conducive to realizing the wearability of the ultrasonic probe, so that real-time and continuous monitoring of the state of each organ can be realized, 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, so that it can work efficiently in a wide frequency range, thereby realizing flexible adjustment of the frequency and adapting to the tissue characteristics and imaging frequency requirements of different regions to be detected. At the same time, the sound emitting film is designed with flexible materials, so that it can not only respond quickly to the driving signal, but also closely fit the surface of the target region, effectively improving the transmission efficiency of ultrasonic waves and the signal quality.

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

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

[0030] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed in the description of the specific embodiments or prior art will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

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

[0032] Figure 2 A signal transceiving process schematic diagram between the sound emitting film and the sound receiving film in the embodiment of the present application.

[0033] Figure 3 A structure schematic diagram of a flexible probe and a circuit board is proposed for the embodiment of the present application.

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

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor 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 internal tissue structure of human body. Among them, the piezoelectric ultrasonic probe is a common ultrasonic detection device. The manufacturing materials of piezoelectric ultrasonic probe mainly include piezoelectric crystal, metal electrode, insulating material, etc. It utilizes piezoelectric effect to convert electrical energy into mechanical vibration through piezoelectric crystal, so as to generate ultrasonic waves. At the same time, it can also convert the received ultrasonic waves into electrical signals to realize the functions of ultrasonic emission and reception.

[0037] In some application scenarios, different organ tissues have different acoustic characteristics such as different distance from the surface and impedance, and the frequency requirements of ultrasonic waves are also different, 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 the imaging frequency of superficial tissues such as the thyroid and breast is higher, generally between 5 megahertz (MHz) and 12 megahertz (MHz), and certain 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 the ultrasonic probe in the related art is limited by the manufacturing materials and processes, and can usually only work at a fixed frequency, resulting in the need to use multiple probes of different frequencies to complete imaging, increasing the complexity and cost of the imaging process, and thus the frequency cannot be flexibly adjusted to meet the frequency requirements of different organ tissue medical imaging. Especially in the imaging of tissues of different depths and different components or the detection of specific lesions, the ultrasonic probe with a fixed frequency is difficult to provide high-quality imaging results.

[0039] In addition, piezoelectric ultrasonic probes are usually made of rigid materials, and such rigid structures limit their adaptability to surface curvature and special areas. For example, when it is necessary to fit a curved surface or enter a difficult-to-reach area such as a joint or a breast, a rigid probe may not be able to fully adapt to the fit, resulting in dead angles or poor imaging quality during imaging.

[0040] The ultrasonic probe provided in the present specification can be applied to various wearable ultrasonic detection devices that require high-resolution imaging and dynamic monitoring. The user can place the ultrasonic probe on the skin surface at the detection area and adjust the ultrasonic frequency through the driving device to achieve high-quality ultrasonic imaging.

[0041] An ultrasonic probe 10 based on the thermoacoustic effect is provided in the embodiments of the present application, as shown in Figure 1 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 film 112. The thermoacoustic generator 11 is configured to generate an input excitation signal of different frequencies through the driving device 111, and drive the sound film 112 to generate ultrasonic signals of different frequencies according to the input excitation signal and propagate them to the detection area, 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 sound generating film 112 is a conductive film based on the thermoacoustic effect. A user can control the driving device 111 to generate input excitation signals of different frequencies through external input instructions, wherein the input excitation signals are direct current bias signals superimposed with alternating current signals, and the signal frequency is in the ultrasonic frequency band. In the case of input excitation signals passing through the sound generating film 112, the surface temperature of the sound generating film 112 rises and falls periodically with the alternating current signal, and the air molecules on the surface of the sound generating film 112 are constantly expanded and compressed, thereby generating ultrasonic signals corresponding to the frequency of the input excitation signals.

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

[0045] In some embodiments of the present application, the receiving film 122 is a pressure sensor based on the piezoresistive effect or the resistive strain effect. As shown in FIG. 2, when the ultrasonic waves emitted by the sound generating film 112 pass through the surface of the human body and meet the interfaces or structures in the human tissue and organs, a part of the energy is reflected back as echo signals received by the receiving film 122. The receiving film 122 converts the received echo signals into an electrical signal representing the change in resistance value based on the piezoresistive effect, and feeds back to the imaging device 121, and then reconstructs the detection image according to the characteristics of the electrical signal through the imaging device 121. Figure 2

[0046] Therefore, the ultrasonic probe 10 proposed in the embodiments of the present application adopts a transceiving integrated design, and different frequency input excitation signals are output by the driving device 111 to drive the sound generating film 112 to correspondingly generate ultrasonic signals of different frequencies, so that the sound generating film 112 can work flexibly in different frequency ranges. Therefore, the ultrasonic probe 10 proposed in the embodiments of the present application can significantly improve the sound generating frequency adjustment capability of the ultrasonic probe 10, so that a single ultrasonic probe 10 can image different organs, not only improving the versatility of the probe, greatly simplifying the operation process of ultrasonic imaging and reducing the medical cost, but also meeting different imaging needs from low frequency to high frequency, which is not only conducive to improving the clarity of imaging, but also can greatly reduce the energy loss or signal attenuation caused by frequency mismatch, so that a single ultrasonic probe 10 can be used in a wider application scenario.

[0047] ​In addition, the bandwidth of the existing ultrasonic probe is only KHz level, while the sound generating film 112 based on the thermoacoustic effect is used in the embodiment of the present application, the bandwidth of the generated ultrasonic wave can reach tens of MHz level, which can meet the high performance requirements of medical imaging frequency, and through the combination with the driving device, it can work efficiently in a wide frequency range, realize flexible adjustment of frequency, and further adapt to the tissue characteristics and imaging frequency requirements of different to-be-detected regions. At the same time, the sound receiving film 122 in the embodiment of the present application is designed based on the piezoresistive effect, which can effectively capture the time and amplitude characteristics of the ultrasonic wave.

[0048] It should be noted that in some embodiments of the present application, the sound generating film 112 and the sound receiving film 122 and their packaging materials are flexible materials, which can better fit the surface of the human body, improve the adaptability to the surface curvature and special areas, and provide accurate and stable signal basis for the subsequent imaging process of the detection image, thereby improving 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 to-be-detected region, so as to generate an input excitation signal in the preset frequency spectrum range.

[0050] Specifically, the user can select the input preset frequency spectrum range corresponding to the to-be-detected region at the driving device 111, so that the sound generating film 112 can generate an ultrasonic wave signal corresponding to the frequency of the input excitation signal, so that the thermoacoustic sound generator 11 can work in a wide frequency spectrum range, realizing different frequency ultrasonic monitoring of different to-be-detected regions by one ultrasonic probe.

[0051] For example, in deep tissue imaging, for the to-be-detected region of the heart, liver and other tissues with large depth and low absorption coefficient, the ultrasonic wave needs to have good penetration ability to ensure that the signal can reach the deep target and produce effective echo. To this end, the driving device 111 can select to generate a sweep-adjusted input excitation signal in a preset frequency spectrum range of tens of KHz to hundreds of KHz, and then drive the sound generating film 112 to generate a sweep-adjusted ultrasonic wave 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 ultrasonic waves not only can display the dynamic of heart cavity and valve, but also can penetrate the myocardial layer to observe deeper tissues.

[0052] In the superficial tissue imaging, for the superficial tissue such as thyroid and breast, the driving device 111 can select the preset frequency spectrum range of 5-12 MHz to generate the sweep-adjusted input excitation signal, and then drive the sound-emitting membrane 112 to generate the sweep-adjusted ultrasonic wave signal, because the superficial tissue is close to the surface and needs higher resolution to observe details.

[0053] In the related art, the ultrasonic wave probe can only work in a certain fixed frequency range due to the limited frequency, and cannot adapt to the imaging requirements of different depths and different tissues. Therefore, in the embodiments of the present application, the frequency of the ultrasonic wave is dynamically adjusted by the sweep mode, which can automatically or according to the requirements adjust the frequency to adapt to the imaging requirements of the superficial tissue and the deep tissue, so that the ultrasonic wave probe can cover a wide frequency spectrum from low frequency to high frequency. Not only can it realize the requirements of different tissue imaging by taking advantage of the wide frequency spectrum of a single probe, solving the problem of frequent replacement of the probe, but also can solve the problem of frequency mismatch between the ultrasonic wave probe and the to-be-detected region. Through the cooperation of the sound-emitting membrane 112 and the driving device 111 based on the thermoacoustic effect, the ultrasonic wave probe can select the best frequency according to the tissue characteristics of the to-be-detected region, ensure that the ultrasonic wave signal can be effectively transmitted and reduce unnecessary energy loss, thereby significantly enhancing the imaging capability of the ultrasonic wave 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 can also flexibly adjust the adaptive preset frequency spectrum range according to the characteristics of the to-be-detected region, and then configure the driving device 111 to generate the input excitation signal of the corresponding frequency in the adaptive preset frequency spectrum range, realize the dynamic adjustment of the frequency, and ensure that the ultrasonic wave signal generated by the sound-emitting membrane can more accurately adapt to the tissue characteristics of the to-be-detected region, thereby facilitating the improvement of the imaging flexibility. In some embodiments of the present application, as shown in Figure 3 The ultrasonic sensor 12 is provided with a plurality of sound-receiving membranes 122, and the sound-receiving membranes 122 and the sound-emitting membrane 112 are arranged in an array.

[0054] The sound-emitting membrane 112 and the sound-receiving membrane 122 in the embodiments of the present application are arranged in an array to form a membrane array, which can cover a larger detection area, so it can receive ultrasonic wave echo signals from multiple directions at the same time. Compared with a single receiver, the array design can capture more reflection information, especially in complex tissues or irregular areas, ensuring the comprehensiveness of signal acquisition. Through the cooperative work of each membrane in the array, the imaging details of the target area can be refined.

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

[0056] Further, as shown in Figure 3 the driving device 111 and the imaging device 121 are arranged on a flexible circuit board, and the driving device 111 is electrically connected with the sound emitting film 112, and the imaging device 121 is electrically connected with the sound receiving film 122.

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

[0058] The embodiments of the present application fully consider the actual application environment of the ultrasonic probe 10, encapsulate the driving device 111 and the imaging device 121 with flexible materials, so that they can better adapt to the surface curvature and special tissues of different to-be-detected regions, to ensure perfect fitting with the human body surface. And because of the soft characteristics of the flexible material, the use of impedance coupling agent can be avoided to some extent, while the stability and accuracy of imaging are improved.

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

[0060] Further, in some embodiments of the present application, the driving device 111, the sound emitting film 112, and the sound receiving film 122 are all 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 has the characteristics of lightness and thinness, reducing the volume and weight of the ultrasonic probe 10, which is conducive to realizing the wearability of the ultrasonic probe 10, reducing the burden on the carrier, thus 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 to-be-detected region, which is particularly important for special application scenarios such as timely monitoring of organ state during surgery or patient care, and has important significance for real-time observation in the process of medical diagnosis and treatment, which helps to improve medical efficiency and accuracy.

[0061] In some embodiments of the present application, as shown in 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 ultrasonic probe 10.

[0062] In some embodiments of this application, filtering is used to remove noise and irrelevant frequency components from 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. Therefore, the filtered echo signal mainly retains the ultrasonic signal that matches the probe's operating frequency, thereby ensuring the accuracy of subsequent signal processing and thus improving imaging quality.

[0063] In some embodiments of this application, such as Figure 4 As shown, the imaging device 121 also includes an imaging processor 1212, which is configured to:

[0064] Based on the amplitude and time characteristics of the echo signal received by each receiving diaphragm 122, combined with the ultrasonic propagation speed and the acoustic impedance of the area to be detected, the position of the reflection interface on the ultrasonic propagation path is determined by an inversion algorithm.

[0065] Time delay compensation and coherent superposition processing are performed on the reflective interface positions corresponding to multiple sound-receiving films 122 to determine the reflection point of the area to be detected.

[0066] The tissue properties corresponding to the reflection point are determined based on the spectral response characteristics of the echo signal received by each sound-receiving diaphragm 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 receiving diaphragm 122 contains information about the reflecting interface within the area to be detected. The amplitude characteristics of the echo signal reflect the intensity of the ultrasonic wave as it travels through the reflecting interface in its propagation path. The amplitude characteristics of the echo signal are closely related to the acoustic impedance difference between the media on either side of the reflecting interface. When an ultrasonic signal propagates from one medium to another with a large acoustic impedance difference, a stronger echo signal is generated, resulting in a larger amplitude. For example, the interface between bone and soft tissue produces a high-amplitude reflection signal. Conversely, if the acoustic impedance difference between the media is small, the amplitude of the reflection signal will be weaker. The time characteristic of the echo signal refers to the propagation time from the emission of the ultrasonic signal from the emitting diaphragm to its reflection back to the target interface in the area to be detected. The propagation time is related to the path length of the ultrasonic wave, and the signal propagation distance can be calculated using the ultrasonic wave propagation time characterized by the time characteristic and the ultrasonic wave propagation speed.

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

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

[0071] In the formula, v is the speed of ultrasonic wave propagation, d is the signal propagation distance, and t is the propagation time.

[0072] The propagation speed of ultrasound is affected by the density and elastic modulus of human tissue. The propagation speed of ultrasound is expressed by the following formula (2):

[0073]

[0074] Where v is the speed of ultrasound propagation, E is the elastic modulus of human tissue, and ρ is the density of human tissue.

[0075] Because higher density increases the energy required for wave propagation, the density of organ tissues affects the speed of ultrasound propagation: the higher the density, the slower the ultrasound propagation. For example, the density of adipose tissue is approximately 900 kg / m³. 3 The speed of ultrasound propagation is 1450-1470 m / s, and the density of bone tissue is approximately 1900 kg / m³. 3 The speed of ultrasonic wave propagation is 3000-4300m / s.

[0076] The elastic modulus affects the propagation speed of ultrasound waves; the higher the elastic modulus, the faster the ultrasound waves propagate. For example, the elastic modulus of muscle tissue is approximately 10 kPa, and the propagation speed of ultrasound waves is 1540-1580 m / s. The elastic modulus of bone tissue is approximately 15-20 GPa, and the propagation speed of ultrasound waves 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 the reflection interface corresponding to the echo signal received by each receiving diaphragm 122 can be obtained. Based on the amplitude characteristics of the echo signal and the acoustic impedance of the area to be detected, the organizational properties of the reflection interface can be determined.

[0078] This application embodiment analyzes the amplitude and time characteristics of the received echo signal using an inversion algorithm. Combined with known ultrasonic propagation speed and acoustic impedance, the location of the reflecting interface can be inferred. Furthermore, since physical models are typically complex and not directly invertible, solving the inverse problem relies on optimization or iterative methods. Therefore, during the training of 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 using optimization algorithms such as least squares and gradient descent until the error between the model output and the actual measurement results reaches a preset standard.

[0079] Further, due to the frequency-dependent attenuation and scattering properties of different tissues, certain tissues exhibit strong resonance or attenuation phenomena 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 frequency response characteristics of the to-be-detected region under different frequencies of the ultrasound signal, such as the main frequency, the spectral width, and the resonance frequency, by performing frequency domain analysis on the echo signal, determines the tissue properties corresponding to the reflection point according to the frequency response characteristics, and thus expresses the ultrasound diagnostic information such as the tissue type and the lesion in the generated detection image.

[0080] When multiple arrayed receiving films 122 are used, the echo signals received by each receiving film 122 can have a time delay because the propagation distances of the echo signals from the sound emitting film 112 to each receiving film 122 are different. In order to accurately extract the position of the reflection point from the signals received by different films, the embodiments of the present application calculate the time delay difference of the signal propagation and perform time delay compensation on the received signals, so that all echo signals are superimposed and processed under the same time reference. At the same time, the echo signals received by multiple receiving films 122 are coherently superimposed, which can effectively enhance the echo signals from the same reflection interface and suppress noise and other irrelevant signals. By this method, the accuracy of reflection point positioning and the signal-to-noise ratio of the signal can be improved. After time delay compensation and coherent superposition processing, the position of the intensity peak of the echo signal corresponds to the reflection point of the to-be-detected region.

[0081] By this method, the positions of the reflection interface and the reflection point in the to-be-detected region can be accurately determined, which helps to identify potential defects or structural features, and is widely used in the fields of non-destructive testing (NDT), medical imaging (such as ultrasonic imaging), etc.

[0082] Further, in some embodiments of the present application, in the case of ultrasonic detection applications involving blood flow analysis, the above imaging processor 1212 is further configured to perform Doppler shift analysis on the frequency characteristics of the echo signal, and determine the blood flow direction of the to-be-detected region according to the analysis result, so as to display the blood flow direction in the detection image.

[0083] The application of Doppler shift analysis in ultrasound detection is mainly reflected in the evaluation and measurement of blood flow dynamics. By emitting ultrasound waves and receiving the waves reflected back by moving objects such as red blood cells in the blood, the frequency change of the reflected waves, i.e. Doppler shift, can be analyzed to obtain the speed and direction information of the objects. 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 embodiments of the present application utilize the frequency characteristics of echo signals to realize ultrasound detection of blood flow direction, making the generated detection image contain more rich and comprehensive diagnostic information, and further improving the accuracy and comprehensiveness of ultrasound monitoring of the to-be-detected region.

[0084] Therefore, the embodiments of the present application receive echo signals through multiple receiving diaphragms arranged in an array, and respectively determine the reflection interfaces encountered by the ultrasound signals on the propagation path by using inversion algorithms combined with amplitude, time, frequency characteristics and acoustic parameters for the echo signals corresponding to each receiving diaphragm. Meanwhile, the inversion calculation results corresponding to multiple receiving diaphragms are combined, time errors between multiple receiving diaphragms are eliminated by time delay compensation, and signal strength is enhanced by coherent superposition, so as to provide a high-quality image with rich details and low noise, and realize accurate description of the internal structure of the to-be-detected region.

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

[0086] The reflection points are time calibrated and spatially calibrated based on the preset scanning mode, and the detection image is continuously smoothed according to the calibrated reflection points corresponding to the receiving diaphragms adjacent in array position.

[0087] Specifically, the scanning algorithm is responsible for combining the signals obtained by the receiving diaphragms at different positions in the probe array to generate a complete two-dimensional or three-dimensional image. The embodiments of the present application adopt a scanning algorithm to perform signal reading and processing on each receiving diaphragm according to a preset scanning mode. In some embodiments of the present application, the preset scanning mode includes at least one of a line-by-line scanning mode (Linear Scanning), a sector scanning (Sector Scanning), a curved array scanning (Curved Array Scanning), a point-by-point scanning (Point-by-Point Scanning), a circular scanning (Circular Scanning), a volume scanning (Volume Scanning), a dynamic real-time scanning (Dynamic Real-Time Scanning), and a phased array scanning (Phased Array Scanning).

[0088] Among them, the line-by-line scanning is suitable for the observation of superficial tissues such as blood vessels, tendons and skin, the fan-shaped scanning is suitable for the imaging of deep organs such as heart and abdomen, the curved array scanning is suitable for the imaging of wide areas such as abdomen, gynecology and obstetrics, the point-by-point scanning is suitable for high-precision imaging such as ophthalmic ultrasound or microscopic ultrasound, the ring-shaped scanning is suitable for the imaging of specific parts such as breast or joint, the volume scanning is suitable for fetal examination, volume evaluation of heart and tumor, the dynamic real-time scanning is suitable for observing the dynamic changes of organs such as the contraction and relaxation of the heart, and the phased array scanning is suitable for imaging deep tissues or narrow spaces such as heart imaging and nerve ultrasound.

[0089] In some embodiments of the present application, the film signals at different positions may have slight time errors due to scanning delays or reading timing differences, and the timing consistency of image reconstruction needs to be ensured through calibration. Meanwhile, there may be slight geometric deviations in the manufacturing or arrangement of the film array, resulting in systematic errors in the spatial coordinates of the reflection points. Therefore, the reflection points corresponding to each receiving film 122 are calibrated in the time dimension and the spatial dimension.

[0090] In order to generate continuous and smooth detection images, the imaging processor 1212 performs interpolation and filtering processing on the reflection points corresponding to all receiving films 122. Among them, interpolation is used to fill in the missing spatial data caused by the interval of the array arrangement of the receiving films 122, and filtering is used to eliminate residual noise and make the boundaries of the detection images more natural. Through the processing of the scanning algorithm, the film array of the ultrasonic probe can efficiently scan the to-be-detected region and integrate the signals of different films into complete two-dimensional or three-dimensional images.

[0091] Therefore, the embodiments of the present application perform time calibration and spatial calibration on the reflection points based on the preset scanning mode, ensure the consistency of the reflection signals received by different receiving films in the time and spatial dimensions, and perform continuous and smooth processing on the reflection points of the receiving films adjacent in position in the array, so as to eliminate the discreteness and discontinuity that may be generated in the signal processing process, make the generated detection images have more natural boundaries and more coherent detail performance, and further improve the clarity and accuracy of the detection images.

[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 algorithm and scanning algorithm, etc. Finally, the detection image generated by the imaging device 121 is displayed on the screen of the ultrasonic imaging device for observation and diagnosis by doctors or technicians.

[0093] The embodiment of the present application combines the driving device 111, the sound emitting 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 to-be-detected area, adjusts the ultrasonic frequency matched with the to-be-detected area through the external driving device 111, and realizes ultrasonic imaging. Not only the integration of the functions of each part is realized, but also the overall performance of the ultrasonic probe 10 is significantly improved by combining the characteristics of flexible materials and thermoacoustic effect. Compared with the traditional rigid ultrasonic probe, the combination of the thermoacoustic sound emitter 11 and the ultrasonic sensor 12 significantly enhances the frequency adjustment capability and adaptability of the sound emitter. The application of flexible materials enables the ultrasonic probe 10 to closely fit the curvature of the human body surface, reduces signal distortion caused by poor contact, and ensures efficient transmission and reception of ultrasonic waves. At the same time, seamless integration is realized between the components in terms of physical structure and functional operation, avoiding mutual interference and obstruction, and ensuring the stability and imaging quality of the system in various complex tissue environments. Ultimately, this integrated design not only improves the imaging adaptability of the ultrasonic probe 10, but also enhances the imaging accuracy and reliability, fully meeting the real-time and diversified needs of the medical imaging field.

[0094] For the convenience of description, the above device is described as various units by function. Of course, the functions of each unit can be implemented in one or more software and / or hardware in the implementation of the present application.

[0095] It should also be noted that the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices that include a series of elements not only include those elements, but also include other elements not explicitly listed or inherent to such processes, methods, articles or devices. 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 that includes the element.

[0096] Each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other. Each embodiment focuses on the difference from other embodiments.

[0097] The above description is only an embodiment of the present application and is not intended to limit the present application. Those skilled in the art can make various changes and modifications to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

[0098] While embodiments of the application have been described in connection with the preferred embodiments of the various figures, those of ordinary skill in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the application, and that such modifications and changes fall within the scope of the appended claims.

Claims

1. An ultrasonic probe based on thermoacoustic effect, characterized in that, The ultrasonic probe comprises: a heat-induced sound generator comprising a driving device and a sound-emitting film, the heat-induced sound generator being configured to generate input excitation signals of different frequencies by the driving device, and to drive the sound-emitting film to generate and propagate ultrasonic signals of different frequencies to a region to be detected according to the input excitation signals, wherein the frequencies of the ultrasonic signals correspond to the frequencies of the input excitation signals; an ultrasonic sensor comprising an imaging device and a sound-receiving film, the sound-receiving film being configured to receive echo signals of the region to be detected in response to the ultrasonic signals of different frequencies, and the imaging device being configured to perform sweep analysis on the region to be detected according to amplitude characteristics, time characteristics and spectral response characteristics of the echo signals, to generate a detection image of the region to be detected according to analysis results; a plurality of sound-receiving films are arranged on the ultrasonic sensor in an array manner; the imaging device further comprises an imaging processor configured to: determine positions of reflection interfaces on ultrasonic propagation paths according to amplitude characteristics and time characteristics of echo signals received by each sound-receiving film, in combination with ultrasonic propagation speed and acoustic impedance of the region to be detected, based on an inversion algorithm; perform time delay compensation and coherent superposition processing on the positions of the reflection interfaces corresponding to the plurality of sound-receiving films, to determine reflection points of the region to be detected; determine tissue properties corresponding to the reflection points according to spectral response characteristics of the echo signals received by each sound-receiving film; generate the detection image of the region to be detected according to the reflection points and the tissue properties.

2. The ultrasonic probe according to claim 1, characterized by the driving device is configured to determine a preset frequency spectrum range corresponding to the region to be detected according to tissue types and tissue depths of the region to be detected, to generate the input excitation signals in the preset frequency spectrum range.

3. The ultrasonic probe of claim 1, wherein, the imaging device comprises a band-pass filter configured to perform filtering processing on the echo signals, wherein frequencies of the filtered echo signals match operating frequencies of the ultrasonic probe.

4. The ultrasonic probe of claim 1, wherein, the imaging processor is further configured to: perform time calibration and spatial calibration on the reflection points based on a preset scanning mode, and perform continuous smoothing processing on the detection image according to the calibrated reflection points corresponding to sound-receiving films adjacent in array positions.

5. The ultrasonic probe of claim 4, wherein, the preset scanning mode comprises at least one of a line-by-line scanning mode, a fan scanning, a curve array scanning, a point-by-point scanning, a ring scanning, a volume scanning, a dynamic real-time scanning and a phased array scanning.

6. The ultrasonic probe according to any one of claims 1 to 5, characterized in that, the driving device and the imaging device are arranged on a flexible circuit board, and the driving device is electrically connected with the sound-emitting film, and the imaging device is electrically connected with the sound-receiving film.

7. The ultrasonic probe according to any one of claims 1 to 5, characterized by the sound-emitting film is an electrically conductive film based on a thermoacoustic effect.

8. The ultrasonic probe according to any one of claims 1 to 5, characterized by the sound-receiving film is a pressure sensor based on a piezoresistive effect or an electrical resistance strain effect.

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