A method, system, device, medium, and product for magnetoacoustic tomography

Abstract

The application discloses a kind of magnetoacoustic electric imaging method, system, equipment, medium and product, it is related to magnetoacoustic electric imaging field, the method comprises: according to the number of array elements of annular array probe Randomly generate multiple sets of space delay coding;Space delay coding is set on the annular array probe, and the corresponding ultrasonic wave of space delay coding is emitted by annular array probe;The delay of each array element is different, and the ultrasonic wave waveform emitted by each array element is identical;While array element emits ultrasonic wave, the magnetoacoustic electric signal excited by space delay coding is collected by electrode, and the ultrasonic wave emission of each set of space delay coding corresponds to the collection of one magnetoacoustic electric signal;According to each set of space delay coding, corresponding acoustic vibration velocity field is simulated and generated;According to the acoustic vibration velocity field corresponding to all space delay coding, system matrix is determined;According to system matrix and magnetoacoustic electric signal, reconstruct conductivity image, realize magnetoacoustic electric imaging, and the application improves spatial resolution and improves imaging effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of magnetic acoustic electric imaging, and in particular, to a magnetic acoustic electric imaging method, system, device, medium and product. BACKGROUND

[0002] Magnetic Acoustic Electrical Tomography (MAET) is an emerging functional imaging technique used to probe the electrical conductivity properties of soft tissues, which are closely related to the physiological and pathological states of the tissues. The imaging process of MAET generally includes three main steps. First, ultrasonic waves are generated in a static magnetic field using ultrasonic sensors, which are used for imaging within the sample. Then, while the ultrasonic waves propagate within the sample, the Magnetic Acoustic Electric Effect (MAE) signals related to tissue electrical conductivity are measured using surrounding electrodes. Next, the ultrasonic transducer is moved to different positions by mechanical or electronic means to collect a series of MAE signals. Finally, by processing these MAE signals, images containing spatial conductivity information, known as MAET images, can be generated. These images provide valuable information to researchers about tissue electrical conductivity and other physiological properties.

[0003] Scanning modes play a crucial role in MAET imaging, as they determine the choice of reconstruction algorithms that follow. Generally, there are two main scanning modes for MAET: linear scanning and rotational scanning.

[0004] Linear scanning is relatively simple, as for single-element transducers, only mechanical movement along a line is required; for array transducers, only electrical movement is needed. The related reconstruction method adopts a linear translation technique similar to B-mode ultrasonography.

[0005] However, due to the limitations of MAET principles, linear scanning has difficulty effectively presenting targets with irregular conductivity distributions. Recent studies have successfully overcome this drawback by using rotational scanning modes. In addition, based on this rotational scanning mode, MAET shares technical similarities with Computed tomography (CT), and it has been proven that CT reconstruction algorithms can be successfully applied to MAET. Therefore, this rotational scanning mode, used for MAET, is called MAE-CT. This innovative scanning method provides new prospects for the development and application of MAET technology.

[0006] However, traditional MAET methods rely on linear scanning, but this scanning method can only image regular-shaped target bodies and cannot image irregular-shaped target bodies.

[0007] The traditional rotating scanning method can solve the disadvantage that the linear scanning cannot image the irregularly shaped target object, but relies on the mechanical rotating scanning of the ultrasonic transducer, which leads to a long and time-consuming signal acquisition time, low rotating accuracy, and the traditional mechanical rotating scanning can only rotate a fixed angle, so the number of angles collected is very limited, resulting in low spatial resolution and poor imaging effect. SUMMARY

[0008] The purpose of the present application is to provide a magnetic acoustic electric imaging method, system, device, medium and product to solve the problems of low spatial resolution and poor imaging effect.

[0009] To achieve the above purpose, the present application provides the following solutions.

[0010] In a first aspect, the present application provides a magnetic acoustic electric imaging method, comprising the following steps.

[0011] A plurality of sets of spatial delay codes are randomly generated according to the number of array elements of the annular array probe.

[0012] The spatial delay codes are arranged on the annular array probe, and the annular array probe emits ultrasonic waves corresponding to the spatial delay codes; the delay of each array element is different, and the ultrasonic waveforms emitted by each array element are the same; at the same time that the array elements emit ultrasonic waves, the magnetic acoustic electric signals excited by the spatial delay codes are collected by the electrodes, and the emission of ultrasonic waves by each set of spatial delay codes corresponds to the collection of a magnetic acoustic electric signal.

[0013] According to each set of spatial delay codes, a corresponding acoustic vibration velocity field is simulated and generated; the acoustic vibration velocity field is used to represent the magnetic acoustic electric signals of different delays emitted by each array element.

[0014] According to the acoustic vibration velocity fields corresponding to all spatial delay codes, a system matrix is determined.

[0015] According to the system matrix and the magnetic acoustic electric signals, an electrical conductivity image is reconstructed to realize magnetic acoustic electric imaging.

[0016] In a second aspect, the present application provides a magnetic acoustic electric imaging system, comprising the following modules.

[0017] A spatial delay code generation module is configured to randomly generate a plurality of sets of spatial delay codes according to the number of array elements of the annular array probe.

[0018] An ultrasonic wave generating module is configured to set the spatially time-delayed codes on the annular array probe and emit corresponding ultrasonic waves from the annular array probe; the time delay of each array element is different, and the ultrasonic waveforms emitted by each array element are the same; while the array elements emit ultrasonic waves, the magnetic-acoustic-electric signals excited by the spatially time-delayed codes are collected by the electrodes, and the emission of ultrasonic waves of each set of spatially time-delayed codes corresponds to the collection of one magnetic-acoustic-electric signal.

[0019] An acoustic vibration velocity field generating module is configured to simulate and generate corresponding acoustic vibration velocity fields according to each set of spatially time-delayed codes; the acoustic vibration velocity fields are used to represent the magnetic-acoustic-electric signals emitted by each array element with different time delays.

[0020] A system matrix determining module is configured to determine a system matrix according to the acoustic vibration velocity fields corresponding to all spatially time-delayed codes.

[0021] An electrical conductivity image reconstructing module is configured to reconstruct an electrical conductivity image according to the system matrix and the magnetic-acoustic-electric signals, so as to realize magnetic-acoustic-electric imaging.

[0022] In a third aspect, the present application provides a computer device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the magnetic-acoustic-electric imaging method described above.

[0023] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the magnetic-acoustic-electric imaging method described above.

[0024] In a fifth aspect, the present application provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the magnetic-acoustic-electric imaging method described above.

[0025] According to the specific embodiments provided in the present application, the present application has the following technical effects.

[0026] The application sets spatial delay coding on a ring array probe to emit spatial delay coding corresponding ultrasonic waves, since the ring array probe is adopted, ultrasonic waves can be emitted from various angles, so that an irregularly shaped target body can be imaged; and a corresponding acoustic vibration velocity field is generated according to the spatial delay coding, so that different delay ultrasonic waves are emitted by each array element, the spatial delay coding technology does not need to be electronically rotated, the array element only needs to emit different delay ultrasonic waves according to the spatial delay coding, in a set of spatial delay coding emission, all array elements participate in the emission work, which greatly improves the power of acoustic excitation and the signal-to-noise ratio of the magnetoacoustic electric signal, in theory, there are countless combinations of delay coding, which is equivalent to countless 'rotation angles', which greatly improves the signal-to-noise ratio and spatial resolution of the reconstructed image in the final reconstruction process, the conductivity image is reconstructed through the application, and the imaging effect of magnetoacoustic electric imaging is realized. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0028] Figure 1 A flowchart of a magnetoacoustic electric imaging method provided by an embodiment of the application.

[0029] Figure 2 A schematic diagram of an acoustic vibration velocity field generated when COMSOL simulation is run, provided by an embodiment of the application.

[0030] Figure 3 An acoustic field simulation diagram of MATLAB.

[0031] Figure 4 A schematic diagram of part 1 of the MATLAB code for generating an acoustic vibration velocity field, provided by an embodiment of the application.

[0032] Figure 5 A schematic diagram of part 2 of the MATLAB code for generating an acoustic vibration velocity field, provided by an embodiment of the application.

[0033] Figure 6 A schematic diagram of part 3 of the MATLAB code for generating an acoustic vibration velocity field, provided by an embodiment of the application.

[0034] Figure 7 A schematic diagram of part 4 of the MATLAB code for generating an acoustic vibration velocity field, provided by an embodiment of the application. DETAILED DESCRIPTION

[0035] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described, obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0036] In order to make the purposes, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0037] As shown in the drawings, Figure 1 The embodiments of the present application provide a magnetic-acoustic-electric imaging method, comprising the following steps.

[0038] S1: randomly generating multiple sets of spatial delay codes according to the number of elements of a ring array probe.

[0039] S2: setting the spatial delay codes on the ring array probe, and transmitting ultrasonic waves corresponding to the spatial delay codes by the ring array probe; the delay of each element is different, and the ultrasonic waveforms transmitted by each element are the same; at the same time when the elements transmit the ultrasonic waves, a magnetic-acoustic-electric signal excited by the spatial delay codes is collected by an electrode, and the transmission of the ultrasonic waves of each set of spatial delay codes corresponds to the collection of one magnetic-acoustic-electric signal.

[0040] S3: simulating and generating a corresponding acoustic vibration velocity field according to each set of spatial delay codes; the acoustic vibration velocity field is used to represent the magnetic-acoustic-electric signals of different delays emitted by each element.

[0041] S4: determining a system matrix according to the acoustic vibration velocity fields corresponding to all the spatial delay codes.

[0042] S5: reconstructing an electrical conductivity image according to the system matrix and the magnetic-acoustic-electric signal, and realizing magnetic-acoustic-electric imaging.

[0043] In actual application, multiple sets of spatial delay codes are designed according to the number of elements of the ring array probe, one set of delay codes is set before ultrasonic transmission, and the ring array transducer transmits ultrasonic waves according to the set spatial delay codes, and the electrode collects magnetic-acoustic-electric signals at the same time.

[0044] After the ultrasonic waves of multiple sets of spatial delay codes are transmitted, the corresponding magnetic-acoustic-electric signals are collected by the electrode, and all the magnetic-acoustic-electric signals are processed correspondingly to reconstruct an electrical conductivity image.

[0045] In an exemplary embodiment, the number of elements is equal to the number of codes of each set of spatial delay codes; the delay time of each element is equal to the product of the code value of the spatial delay code and the unit time of delay.

[0046] In practical applications, each set of spatially delayed encoding is set to the annular array probe respectively, the probe transmits the corresponding spatially delayed encoding ultrasonic wave, and the electrode collects the corresponding magnetoacoustic electric signal. The ultrasonic transmission of each set of spatially delayed encoding corresponds to the collection of a magnetoacoustic electric signal, wherein the delay of each array element is different, and the delay is determined according to the encoding value of the spatially delayed encoding. The delay time is equal to the encoding value multiplied by the unit delay time t_Deday. Each array element transmits the same waveform, but the delay time of each array element is different.

[0047] The delay time of each array element is illustrated as follows: first, set the excitation signal, and the excitation signal is a 1MHz 3Cycle sine wave. It is assumed that the annular array transducer has 39 array elements, and 39 spatially delayed encodings are randomly generated, each encoding value is 0~9, for example [1, 4, 3, 9, 2,...], and there are a total of 39 codes. Each encoding value needs to be multiplied by the unit time t_Deday of the delay, and t_Deday can be set to 3μs. Therefore, the delay time of each array element is [1, 4, 3, 9, 2,...]×t_Deday, and the delay time of each array element in the annular array probe is set by this method.

[0048] The magnetoacoustic electric signal is recorded at the same time when the array element starts to transmit the ultrasonic wave, and the total recording time can be 100μs (at this time all waves completely pass through the target body).

[0049] The transmission of the second set of encodings is also similar to the above calculation method, 39 encodings are randomly generated, such as [2, 3, 1, 0, 9,...], and the delay time of each array element is obtained by multiplying the unit time t_Deday of the delay [2, 3, 1, 0, 9,...]×t_Deday.

[0050] Similarly, a plurality of different combinations of encodings can be generated, and the corresponding spatially delayed encoding excitation magnetoacoustic electric signal can also be obtained.

[0051] In an exemplary embodiment, S3 specifically includes: writing a sound field simulation code in MATLAB, such as Figures 3-7 As shown in the figure, the spatially delayed encoding is input, and the corresponding acoustic vibration velocity field (V x , V y , V x and V y are the x component and y component of the acoustic vibration velocity field respectively, and the acoustic vibration velocity field can be provided from COMSOL simulation. This is the acoustic velocity field at a certain time after transmission, as shown in Figure 2 It can be seen that each array element emits ultrasonic waves with different delays.

[0052] In one exemplary embodiment, the multiple sets of spatially delayed coded acoustic vibration velocity fields are combined into a system matrix A, and the multiple sets of magnetoacoustic electrical signals are arranged into a column vector b. The reciprocal current density, which is related to the electrical conductivity, is solved by an iterative optimization method. The electrical conductivity is solved again by an iterative optimization method according to the relationship between the reciprocal current density and the electrical conductivity.

[0053] In one exemplary embodiment, the magnetoacoustic electrical signals are collected

[0054]

[0055] wherein, is the acoustic vibration velocity field, r is an arbitrary point in the field space, and t is time; B is the vector representation of the static magnetic field strength; is the reciprocal current density; is the integration region.

[0056] The above equation is further derived as:

[0057]

[0058] Since the magnetic field B is a uniform field, it can be extracted from the integral, wherein v ⊥ represents the direction perpendicular to the vibration velocity v, and the vector v(r, t) can be represented in coordinate form Thus, the coordinate form of v ⊥ (r, t) is , is the x component of the acoustic vibration velocity, is the y component of the acoustic vibration velocity, and finally, the measurement equation of Jx

[0059]

[0060] wherein, is the x component of the reciprocal current density, is the y component of the reciprocal current density.

[0061] The discrete form of the measurement equation of Jx

[0062]

[0063] wherein, i is the point number in the x direction, j is the point number in the y direction, is the y component of the acoustic vibration velocity, is the x component of the reciprocal current density, is the x component of the acoustic vibration velocity, ​The y-component of the reciprocal current density. Let x be a infinitesimal element in the x-direction. Let be a small element in the y-direction.

[0064] therefore, The matrix form of the measurement formula is:

[0065]

[0066] Where v is the matrix form of acoustic vibration velocity; M is the magnetoacoustic signal. Matrix form; The sampling interval in the x-direction is a constant. y is the sampling interval in the y direction, a constant; J is the matrix form of the reciprocal current density, i.e., the current density matrix.

[0067] In one exemplary embodiment, based on The measurement formula is in matrix form, and the linear equations of the magnetoacoustic signal are as follows:

[0068]

[0069] Where A is the system matrix, , It is a column vector composed of multiple sets of magnetoacoustic and electrical signals. .

[0070] In one exemplary embodiment, S5 specifically includes the following steps.

[0071] S51: Based on the system matrix and the magnetoacoustic signal, the reciprocal current density is solved using the conjugate gradient method.

[0072] S52: Solve for the conductivity based on the reciprocal current density.

[0073] S53: Reconstruct the conductivity image based on the conductivity to achieve magnetoacoustic-electric imaging.

[0074] In practical applications, the current density matrix J is solved by iterative optimization method (conjugate gradient method), and then the conductivity σ is solved. The relationship between reciprocal current density and conductivity is explained below.

[0075] The reciprocity process refers to removing the sound field and static magnetic field and adding them back into the code. and The measuring electrode at that location was changed to an excitation electrode, and the injection was performed. Ampere's direct current, ,in, For electrode a, For electrode b, Let i be the direct current, and i be the point number of the electrode location.N the number of points for the electrode position.

[0076] the injected current function

[0077]

[0078] wherein, and is the Dirac function, is any point in the field space, is the point of electrode a, is the point of electrode b.

[0079] Thus, the potential in the target body can be derived as ; wherein, is the gradient operator, is the gradient of the reciprocal potential, is the reciprocal potential, is the boundary condition of the reciprocal potential, is the boundary.

[0080] The corresponding reciprocal current density is:

[0081]

[0082] In practical applications, the problem of reconstructing the conductivity is to find the optimal combination so that the objective function is minimized, that is, to solve the following optimization problem.

[0083]

[0084] wherein, is the estimate of the conductivity, f is referred to as the objective function.

[0085] The matrix form of the objective function of the conductivity is:

[0086]

[0087] wherein, is the conductivity; E is the reciprocal electric field matrix, the reciprocal electric field is expressed as ; J is the matrix form of the reciprocal current density ; T is the transpose of the matrix.

[0088] The present application can obtain the conductivity from the matrix form of the reciprocal current density J by using the quasi-Newton method to iteratively solve the objective function.

[0089] ​In practical applications, magnetoacoustic electric imaging is an imaging method using ultrasonic excitation to obtain an electric signal curve (magnetoacoustic electric signal) and then reconstructing the electric conductivity through the electric signal. First, the application proposes a time-delayed encoding excitation instead of a traditional rotating scanning excitation. When each set of time-delayed encoding excitation is transmitted, a corresponding magnetoacoustic electric signal curve is obtained. Multiple sets of time-delayed encoding excitation can obtain multiple sets of magnetoacoustic electric signal curves. Then, image reconstruction is performed. In the reconstruction process, the multiple sets of magnetoacoustic electric signals are used to reconstruct the electric conductivity image.

[0090] Step 1: Transmit ultrasonic waves and obtain magnetoacoustic electric signals.

[0091] In the experiment, spatially time-delayed encoding ultrasonic excitation is transmitted to the imaging target body, and the electrodes attached to the two sides of the target body obtain magnetoacoustic electric signals.

[0092] Step 2: Reconstruct the electric conductivity image according to the magnetoacoustic electric signals.

[0093] The reconstruction process includes the following three steps.

[0094] (1) Simulate the velocity field to obtain the x and y components (V x and V y ) of the acoustic velocity field V, which are used in subsequent image reconstruction.

[0095] (2) According to the simulated acoustic velocity field Vx, Vy and the obtained magnetoacoustic electric signal M(t), the conjugate gradient method is used to reconstruct the intermediate quantity reciprocal current density J.

[0096] (3) According to the matrix form J of the reciprocal current density reconstructed in step (2), the final electric conductivity image σ is reconstructed.

[0097] The application also provides a magnetoacoustic electric imaging system, which includes the following modules.

[0098] A spatial time-delayed encoding generation module is configured to randomly generate multiple sets of spatial time-delayed encoding according to the number of elements of a ring array probe.

[0099] An ultrasonic wave generation module is configured to set the spatial time-delayed encoding on the ring array probe and transmit spatial time-delayed encoding corresponding ultrasonic waves from the ring array probe. The time delay of each element is different, and the ultrasonic waveforms emitted by each element are the same. The elements emit ultrasonic waves at the same time, and the electrodes collect magnetoacoustic electric signals excited by the spatial time-delayed encoding. Each set of spatial time-delayed encoding ultrasonic wave transmission corresponds to the collection of a magnetoacoustic electric signal.

[0100] The acoustic vibration velocity field generation module is configured to simulate and generate a corresponding acoustic vibration velocity field according to each set of spatial delay encoding, and the acoustic vibration velocity field is used to represent the magnetic-acoustic-electric signals of different time delays emitted by each array element.

[0101] The system matrix determination module is configured to determine a system matrix according to the acoustic vibration velocity field corresponding to all spatial delay encodings.

[0102] The conductivity image reconstruction module is configured to reconstruct a conductivity image according to the system matrix and the magnetic-acoustic-electric signals, and realize magnetic-acoustic-electric imaging.

[0103] Compared with the conventional linear scanning magnetic-acoustic-electric imaging method, the application can image an irregularly shaped target object.

[0104] Compared with the method of electronic rotation scanning of the annular array probe, the application also uses the annular array probe for scanning, but the scanning method is different from the rotation scanning. The rotation scanning only has one or part of the array elements participating in the emission work at each angle, which will cause the insufficient acoustic power of the ultrasound and result in the too low signal-to-noise ratio of the magnetic-acoustic-electric signals, and the number of rotation angles also has a limit. The spatial delay encoding technology of the application does not need to perform electronic rotation, and the array elements only need to emit different time delay ultrasonic waves according to the encoding. In the emission of one set of delay encoding, all the array elements participate in the emission work, which greatly improves the acoustic excitation power and the signal-to-noise ratio of the magnetic-acoustic-electric signals. In theory, there are countless combinations of delay encodings, which is equivalent to countless “rotation angles”. In the final reconstruction process, the signal-to-noise ratio and the spatial resolution of the reconstructed image will be greatly improved.

[0105] The application has the advantages of realizing fast rotation scanning, having dense rotation angles, and having high spatial resolution, and can accelerate the scanning speed and improve the spatial resolution, so that it becomes a clinical imaging method with better performance.

[0106] In an example embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, and the processor implementing the steps in the above method embodiments when executing the computer program. The computer device can be a server or a terminal. The computer device includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The database of the computer device is configured to store to-be-processed data. The input / output interface of the computer device is configured to exchange information between the processor and external devices. The communication interface of the computer device is configured to communicate with external terminals through a network connection. The computer program is executed by the processor to implement the above method.

[0107] In an example embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, and the processor implementing the steps in the above method embodiments when executing the computer program.

[0108] In an example embodiment, a computer readable storage medium is provided, storing a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0109] In an example embodiment, a computer program product is provided, including a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0110] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant regulations.

[0111] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by computer program instructions related to hardware, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments of each method. Among them, any reference to memory, database or other medium used in each embodiment provided by the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (Read-Only Memory, ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric memory (Ferroelectric Random Access Memory, FRAM), phase change memory (Phase Change Memory, PCM), graphene memory, etc. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc.

[0112] The database involved in each embodiment provided by the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on blockchain, etc., without being limited thereto. The processor involved in each embodiment provided by the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0113] Each technical feature of the above embodiments can be combined arbitrarily. In order to make the description simple, not all possible combinations of each technical feature in the above embodiments are described, however, as long as the combination of these technical features does not exist contradictory, it should be considered as the scope of the present application.

[0114] The principles and implementation modes of the present application are described by applying specific examples in this paper, and the above-mentioned examples are only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A magnetoacoustic-electroelectric imaging method, characterized in that, include: Multiple sets of spatial delay codes are randomly generated based on the number of array elements of the ring array probe; The spatial delay code is set on the ring array probe, and the ring array probe emits the ultrasonic wave corresponding to the spatial delay code; the delay of each array element is different, and the ultrasonic wave waveform emitted by each array element is the same; while the array element emits ultrasonic waves, the magnetoacoustic signal excited by the spatial delay code is collected by the electrode, and the ultrasonic wave emission of each set of spatial delay codes corresponds to the acquisition of one magnetoacoustic signal. Based on each set of spatial delay codes, a corresponding acoustic vibration velocity field is generated through simulation to obtain the ultrasonic waves emitted by each array element with different delays; the acoustic vibration velocity field is used to characterize the magnetoacoustic signals emitted by each array element with different delays; the array element only needs to emit ultrasonic waves with different delays according to the spatial delay codes, and in the transmission of a set of spatial delay codes, all array elements participate in the transmission work; The system matrix is ​​determined based on the acoustic vibration velocity fields corresponding to all spatial delay codes; Reconstructing a conductivity image based on the system matrix and the magnetoacoustic signal to achieve magnetoacoustic imaging specifically includes: Based on the system matrix and the magnetoacoustic signal, the reciprocal current density is solved using the conjugate gradient method. The conductivity is determined based on the reciprocal current density. Based on the conductivity, a conductivity image is reconstructed to achieve magnetoacoustic-electroelectric imaging.

2. The magnetoacoustic-electroelectric imaging method according to claim 1, characterized in that, The number of array elements is equal to the number of codes in each spatial delay code; The delay time of each array element is equal to the product of the encoded value of the spatial delay code and the unit delay time.

3. The magnetoacoustic-electroelectric imaging method according to claim 1, characterized in that, Collected magnetoacoustic signals for: in, Let r be the acoustic vibration velocity field, r be any point in the field space, and t be time; B is the vector representation of the static magnetic field strength. The reciprocal current density; This is the integration region.

4. The magnetoacoustic-electroelectric imaging method according to claim 3, characterized in that, The linear equations of the magnetoacoustic signal are as follows: Where A is the system matrix, , B The static magnetic field strength, Let x be a infinitesimal element in the x-direction. Let be a small element in the y-direction. v The velocity of sound vibration; It is a column vector composed of multiple sets of magnetoacoustic and electrical signals. M is the magnetoacoustic signal. In matrix form.

5. The magnetoacoustic-electroelectric imaging method according to claim 1, characterized in that, The objective function for the conductivity is: in, For conductivity estimation; E is the electrical conductivity; E is the reciprocal electric field matrix; J is the reciprocal AC density. The matrix form of ; T is the matrix transpose.

6. A magnetoacoustic-electroelectric imaging system, characterized in that, The magnetoacoustic-electroelectric imaging system performs the magnetoacoustic-electroelectric imaging method according to any one of claims 1-5, and the magnetoacoustic-electroelectric imaging system comprises: The spatial delay coding generation module is used to randomly generate multiple sets of spatial delay codes based on the number of array elements of the ring array probe; An ultrasonic wave generating module is used to set the spatial delay code on the ring array probe, and the ring array probe emits ultrasonic waves corresponding to the spatial delay code; the delay of each array element is different, and the ultrasonic wave waveform emitted by each array element is the same; while the array element emits ultrasonic waves, the magnetoacoustic signal excited by the spatial delay code is collected by electrodes, and the ultrasonic wave emission of each set of spatial delay codes corresponds to the acquisition of one magnetoacoustic signal. The acoustic vibration velocity field generation module is used to simulate and generate the corresponding acoustic vibration velocity field based on each set of spatial delay codes; the acoustic vibration velocity field is used to characterize the magnetoacoustic signals with different delays emitted by each array element. The system matrix determination module is used to determine the system matrix based on the acoustic vibration velocity fields corresponding to all spatial delay codes. The conductivity image reconstruction module is used to reconstruct the conductivity image based on the system matrix and the magnetoacoustic signal to achieve magnetoacoustic imaging.

7. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the magnetoacoustic-electroelectric imaging method according to any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the magnetoacoustic-electroelectric imaging method according to any one of claims 1-5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the magnetoacoustic-electroelectric imaging method according to any one of claims 1-5.

Images