阅读说明：本技术 超声波检测及成像的方法及装置、超声波成像系统 (Ultrasonic detection and imaging method and device and ultrasonic imaging system ) 是由 文荆江 于 2019-11-15 设计创作，主要内容包括：本发明提供一种超声波检测及成像的方法及装置、超声波成像系统,该检测方法包括：获取被测物的一幅或多幅初始超声振幅响应；将每幅初始超声振幅响应分解为多幅基元信束振幅响应的线性组合,其中每幅基元信束振幅响应是基元信束线性组合中相应基元信束独自在所述被测物上所产生的超声振幅响应；从分解出的多幅基元信束振幅响应中选择一幅或多幅基元信束振幅响应,重建出一幅或多幅所述被测物的最终超声振幅响应,使所述最终超声振幅响应的点扩散误差缩减为所选用的基元信束的点扩散误差。根据本发明的方法可以大幅度降低像斑对超声检测及成像的破坏性影响。(The invention provides a method and a device for ultrasonic detection and imaging and an ultrasonic imaging system, wherein the detection method comprises the following steps: acquiring one or more initial ultrasonic amplitude responses of a measured object; decomposing each initial ultrasonic amplitude response into a linear combination of a plurality of elementary beam amplitude responses, wherein each elementary beam amplitude response is an ultrasonic amplitude response generated on the object to be measured by a corresponding elementary beam in the elementary beam linear combination; and selecting one or more elementary signal beam amplitude responses from the decomposed plurality of elementary signal beam amplitude responses, reconstructing one or more final ultrasonic amplitude responses of the object to be measured, and reducing the point diffusion error of the final ultrasonic amplitude response into the point diffusion error of the selected elementary signal beam. The method can greatly reduce the destructive influence of the image spots on the ultrasonic detection and imaging.)

1. An ultrasonic testing method comprising the steps of:

acquiring one or more initial ultrasonic amplitude responses of a measured object;

decomposing each initial ultrasonic amplitude response into a linear combination of a plurality of elementary beam amplitude responses, wherein each elementary beam amplitude response is an ultrasonic amplitude response generated on the object to be measured by a corresponding elementary beam in the elementary beam linear combination;

and selecting one or more elementary signal beam amplitude responses from the decomposed plurality of elementary signal beam amplitude responses, reconstructing one or more final ultrasonic amplitude responses of the object to be measured, and reducing the point diffusion error of the final ultrasonic amplitude response into the point diffusion error of the selected elementary signal beam.

2. An ultrasonic testing method according to claim 1 wherein the elementary beamline linear combination equivalents represent the ultrasonic signal field from which the initial ultrasonic amplitude response is generated.

3. The ultrasonic testing method of claim 1, wherein said elementary beams are selected from the group consisting of the gaussian beam family, the modified gaussian beam family, and the beam function family based on field functions.

4. An ultrasonic detection method according to any one of claims 1 to 3, further characterized in that the primitive beamline linear combinations are obtained in advance as follows: and calculating parameters and combination coefficients of each elementary signal beam in the elementary signal beam linear combination by using the actually measured sound field distribution and the actually measured signal waveform of the ultrasonic signal field as references through a computer optimization algorithm, so that the field distribution and the signal waveform of the elementary signal beam linear combination are effectively matched with the actually measured field distribution and the actually measured signal waveform.

5. The ultrasonic testing method of claim 1, further comprising pre-computing sets of elementary beamline combinations for the same ultrasonic probe using multiple acoustic models of different acoustic media; and switching to adopt primitive signal line linear combination of corresponding acoustic media according to the acoustic characteristics of the object to be measured.

6. An ultrasonic testing method according to claim 1, wherein sets of elementary beam linear combinations for different fields are calculated using the same acoustic model for the ultrasonic signal fields of the same testing system, and the elementary beam linear combinations of the corresponding fields are switched for the different fields in the application, the different fields comprising: near field, mid field, far field, paraxial region, and abaxial region.

7. The ultrasonic testing method of claim 1, wherein the primitive beam amplitude response is in the mathematical form:

where σ and ε are the signal waveform parameters, z_BIs the Z coordinate of the reflector, i is an imaginary unit, k is a wave number, f₁(z_B) And f₂(z_B) The waveform of the signal with the propagation distance z is described, and C is a real or complex combined coefficient of a Gaussian signal or a modified Gaussian signal.

8. An ultrasonic imaging method comprising the steps of:

acquiring an initial ultrasonic image of an imaging target;

decomposing the initial ultrasonic image into a linear combination of a plurality of elementary beaming images, wherein each elementary beaming image is an ultrasonic image generated on the imaging target by a corresponding elementary beaming in the elementary beaming linear combination;

one or more primitive information beam images are selected from the decomposed primitive information beam images, one or more final ultrasonic images are reconstructed, and the image spot error of the final ultrasonic image is reduced to the image spot error of the selected primitive information beam image.

9. An ultrasonic imaging method according to claim 8, wherein the elementary beamline linear combination equivalents represent an ultrasonic signal field from which the initial ultrasonic image is derived.

10. An ultrasound imaging method according to claim 8, wherein said primitive beams are selected from the group consisting of the gaussian beam family, the modified gaussian beam family, and the beam function family based on field functions.

11. An ultrasonic imaging method according to claim 8, wherein the initial ultrasonic image is a B-mode medical image.

12. An ultrasound imaging method according to claim 8, wherein the initial ultrasound image is a one-, two-or three-dimensional dynamic ultrasound image.

13. An ultrasonic imaging method according to claim 8, further comprising previously obtaining the element beam combination in such a manner that: and taking the ultrasonic image of the target array or the acoustic model with known geometric distribution and acoustic characteristics as a calculation reference, and calculating parameters and combination coefficients of all elementary signal beams by using a computer optimization algorithm, so that the ultrasonic image generated by linearly combining the elementary signal beams on the target array or the acoustic model with known geometric distribution and acoustic characteristics is effectively matched with the calculation reference.

14. The ultrasonic imaging method according to claim 8, further comprising pre-calculating a plurality of sets of primitive beam combinations for different acoustic media using acoustic models of a plurality of different acoustic media for the same ultrasonic probe, and switching the primitive beam combinations using the respective acoustic media according to acoustic characteristics of an imaging target.

15. A method according to any of claims 8-14, characterized by calculating sets of elementary beam combinations for different fields using the same acoustic model for the ultrasound signal field of the imaging system, the elementary beam combinations of the respective fields being used for different field switching in the application, the different fields comprising: near field, mid field, far field, paraxial region, and abaxial region.

16. An ultrasonic imaging method according to claim 8, wherein the gaussian beam method of the two-dimensional ultrasonic image is expressed as:

in the formulaIs located within the range of the probe signal fieldI is the total number of reflection points within the probe beam,and g_nm() Respectively the square sum signal waveform of the field distribution of the elementary beam, C_nmAre the combining coefficients.

17. An ultrasonic testing device comprising:

a memory for storing a combination of elementary beams of ultrasound signal fields that have been obtained in advance and computer instructions; and

a processor for executing the computer instructions to implement the method of any one of claims 1-7.

18. An ultrasonic imaging apparatus comprising:

a memory for storing a combination of elementary beams of ultrasound signal fields that have been obtained in advance and computer instructions; and

a processor for executing the computer instructions to implement the method of any one of claims 8-16.

19. A computer-readable medium having stored thereon computer program code which, when executed by a processor, implements the method of any of claims 1-16.

20. An ultrasonic inspection system comprising:

an ultrasonic probe adapted to generate an ultrasonic signal field and to acquire one or more initial ultrasonic amplitude responses of a subject;

a memory for storing a combination of elementary beams of ultrasound signal fields that have been obtained in advance and computer instructions; and

a processor for executing the computer instructions to implement the method of any one of claims 1-7.

21. An ultrasound imaging system comprising:

an ultrasonic probe adapted to generate an ultrasonic signal field and to acquire an initial ultrasonic image of an imaging target;

a memory for storing a combination of elementary beams of ultrasound signal fields that have been obtained in advance and computer instructions; and

a processor for executing the computer instructions to implement the method of any one of claims 8-16.

Technical Field

The invention relates to the field of ultrasonic detection and imaging, in particular to an ultrasonic detection and imaging technology based on element information beams.

Background

The ultrasonic wave refers to the sound wave with the frequency higher than 20kHz, and has the advantages of good directivity, strong penetrating power and the like. With the gradual development of ultrasonic technology research, ultrasonic detection and imaging are widely applied to the fields of industrial detection, medical diagnosis and the like due to the advantages of safety, reliability, low cost and the like. However, compared with some detection and imaging technologies with higher precision, the ultrasonic detection and imaging has relatively lower resolution, poor precision and serious distortion of image detail. The main cause of these problems is point spread error, or speckle error, generated in the ultrasonic inspection.

Taking ultrasound imaging as an example, when performing ultrasound imaging, an ultrasound beam may be emitted to a measured object in an object domain, and an image corresponding to the measured object may be generated in an image domain. In general, a geometric point on a measured object in an object domain is referred to as an object point, and a geometric point on an image in an image domain is referred to as an image point. Ideally, a single image point should be generated at the corresponding image field position after imaging the independent object point, but actually, an image spot with a complicated shape, uneven brightness and an expanded space distribution of tens of times is generated. FIG. 1A is a schematic representation of a simulated object composed of open space discrete object points. FIG. 1B is an exemplary illustration of an acoustic simulation of the simulated subject of FIG. 1A after B-ultrasound imaging to produce an ultrasound image patch. The dots arranged in an array in fig. 1A are independent object points in an object domain, and should be unit pixel geometric dots, and since the unit pixel geometric dots are difficult to be visually recognized, the unit pixel geometric dots are enlarged to be visually recognizable dots. The different areas of the dots represent the difference in the reflection coefficient of the object points.

As is customary for ultrasound images, the X-axis (horizontal axis) in FIGS. 1A and 1B points to the right, the Z-axis (vertical axis) points to the bottom, and the Y-axis (not shown) points out of the vertical image plane. The Z axis represents the distance from the object point or image point to the probe surface from the near to the far from the top. The upper box of fig. 1A and 1B is used to represent the surface of the ultrasound probe. When ultrasonic imaging is performed, an ultrasonic signal emits a beam-like acoustic wave, called an acoustic beam, downward (Z direction) from the probe surface. It is customary to represent the beam by its central axis, called the sound ray. The ultrasound probe scans along the X-axis, forming a sound line at each X-position. When the sound beam meets an interface of two different materials in the process of propagation, an echo signal is generated. In fig. 1A, each independent object point forms an interface where the acoustic beam is reflected to generate an echo signal, so that the independent object point is a reflector. The change in echo signal amplitude over time is referred to as the amplitude response. Since the time at which the echo is generated is proportional to the longitudinal distance Z traversed by the beam along the Z-axis, the amplitude response is also the change in echo amplitude with the longitudinal distance Z. Each of the longitudinally aligned intensity plots of fig. 1B represents the amplitude response of echoes produced by all reflectors in the path of the sound beam, referred to as the a (amplitude) line. As shown in fig. 1B, a distinct image spot is produced in the imaging result of fig. 1B for each individual object point in fig. 1A. Obviously, the imaging results are severely distorted. Both theory and actual measurement prove that the shape, size, brightness distribution and the like of the image spot are obviously different along with the geometric position of an object point relative to the ultrasonic probe, and are closely related to the sound field distribution and the sound signal waveform of the ultrasonic probe.

The image spot is also called a Point Spread Function (PSF) of a field Point where the object Point is located. The PSF may be used to quantify the degree of image distortion of the imaging system. When the PSF of all field points in the object field of an imaging system is 1, it indicates that all image points truly reproduce the corresponding object points, no point spread occurs in the image, and the distortion is zero. This ideal imaging effect requires an ideal ultrasound probe to achieve.

Theoretical analysis and acoustic simulation show that if the sound field of the ultrasonic probe is thin and straight without dispersion like a long needle, and the acoustic signal waveform also steeply rises and falls like a straight needle without a front wave tail wave, all image spots shrink into ideal image points, and distortion becomes zero. Referring to fig. 1A and 1B, the axial direction (Z direction) of the probe, i.e., the main direction of acoustic signal propagation, is the longitudinal direction of the image; the direction of the probe scanning motion (X direction) is transverse to the image. The pin-like acoustic signal waveform is a condition for longitudinal optimization of the PSF, and the pin-like sound field distribution is a condition for lateral optimization of the PSF. However, there is still a fundamental gap that is difficult to span between a real ultrasound probe and an ideal ultrasound probe that can generate needle-shaped signal waveforms and needle-shaped sound field distributions. In order to solve the problem of image spots in ultrasonic detection and imaging and improve the precision of ultrasonic detection and imaging, other solutions need to be found.

Disclosure of Invention

The invention aims to greatly reduce the destructive influence of point diffusion errors or image spot distortion on ultrasonic detection and imaging precision caused by the limitation of transverse and axial spatial resolution of a real probe.

The invention provides an ultrasonic detection method for solving the technical problems, which comprises the following steps: acquiring one or more initial ultrasonic amplitude responses of a measured object; decomposing each initial ultrasonic amplitude response into a linear combination of a plurality of elementary beam amplitude responses, wherein each elementary beam amplitude response is an ultrasonic amplitude response generated on the object to be measured by a corresponding elementary beam in the elementary beam linear combination; and selecting one or more elementary signal beam amplitude responses from the decomposed plurality of elementary signal beam amplitude responses, reconstructing one or more final ultrasonic amplitude responses of the object to be measured, and reducing the point diffusion error of the final ultrasonic amplitude response into the point diffusion error of the selected elementary signal beam.

In an embodiment of the invention, the elementary signal linear combination equivalently represents an ultrasound signal field upon which the initial ultrasound amplitude response is generated.

In one embodiment of the invention, the primitive bundles are selected from the group consisting of the gaussian bundle family, the modified gaussian bundle family, and the bundle function family based on field functions.

In an embodiment of the present invention, the primitive beamline linear combination is obtained in advance as follows: and calculating parameters and combination coefficients of each elementary signal beam in the elementary signal beam linear combination by using the actually measured sound field distribution and the actually measured signal waveform of the ultrasonic signal field as references through a computer optimization algorithm, so that the field distribution and the signal waveform of the elementary signal beam linear combination are effectively matched with the actually measured field distribution and the actually measured signal waveform.

In an embodiment of the invention, the method further comprises the steps of pre-calculating linear combinations of a plurality of groups of elementary signal lines by using a plurality of acoustic models of different acoustic media for the same ultrasonic probe; and switching to adopt primitive signal line linear combination of corresponding acoustic media according to the acoustic characteristics of the object to be measured.

In an embodiment of the present invention, a plurality of sets of primitive electrical beam linear combinations for different fields are calculated using the same acoustic model for the same ultrasonic signal field of the same detection system, and the primitive electrical beam linear combinations of the corresponding fields are adopted for different field switching in the application, wherein the different fields include: near field, mid field, far field, paraxial region, and abaxial region.

In an embodiment of the present invention, the mathematical form of the primitive beam amplitude response is:

where σ and ε are the signal waveform parameters, z_BIs the Z coordinate of the reflector, i is an imaginary unit, k is a wave number, f₁(z_B) And f₂(z_B) The waveform of the signal with the propagation distance z is described, and C is a real or complex combined coefficient of a Gaussian signal or a modified Gaussian signal.

The invention also provides an ultrasonic imaging method for solving the technical problems, which comprises the following steps: acquiring an initial ultrasonic image of an imaging target; decomposing the initial ultrasonic image into a linear combination of a plurality of elementary beaming images, wherein each elementary beaming image is an ultrasonic image generated on the imaging target by a corresponding elementary beaming in the elementary beaming linear combination; one or more primitive information beam images are selected from the decomposed primitive information beam images, one or more final ultrasonic images are reconstructed, and the image spot error of the final ultrasonic image is reduced to the image spot error of the selected primitive information beam image.

In an embodiment of the invention, the elementary beamline linear combination equivalently represents an ultrasound signal field from which the initial ultrasound image is generated.

In one embodiment of the invention, the primitive bundles are selected from the group consisting of the gaussian bundle family, the modified gaussian bundle family, and the bundle function family based on field functions.

In an embodiment of the present invention, the initial ultrasound image is a B-mode ultrasound image.

In an embodiment of the present invention, the initial ultrasound image is a one-dimensional, two-dimensional or three-dimensional dynamic ultrasound image.

In an embodiment of the present invention, the method further includes obtaining the primitive bundle combination in advance as follows: and taking the ultrasonic image of the target array or the acoustic model with known geometric distribution and acoustic characteristics as a calculation reference, and calculating parameters and combination coefficients of all elementary signal beams by using a computer optimization algorithm, so that the ultrasonic image generated by linearly combining the elementary signal beams on the target array or the acoustic model with known geometric distribution and acoustic characteristics is effectively matched with the calculation reference.

In an embodiment of the present invention, the method further includes pre-calculating multiple sets of primitive beam combinations for different acoustic media by using acoustic models of multiple different acoustic media for the same ultrasonic probe, and switching the primitive beam combinations using corresponding acoustic media according to the acoustic characteristics of the imaging target.

In an embodiment of the present invention, a same acoustic model is used to calculate multiple groups of primitive beam combinations for different fields of an ultrasound signal field of an imaging system, and primitive beam combinations of corresponding fields are switched for different fields of the application, wherein the different fields include: near field, mid field, far field, paraxial region, and abaxial region.

In an embodiment of the present invention, the gaussian beam method of the two-dimensional ultrasound image is expressed as:

in the formulaIs located within the range of the probe signal fieldI is the total number of reflection points within the probe beam,and g_nm() Respectively the square sum signal waveform of the field distribution of the elementary beam, C_nmAre the combining coefficients.

The present invention further provides an ultrasonic detection apparatus for solving the above technical problems, including: a memory for storing a combination of elementary beams of ultrasound signal fields that have been obtained in advance and computer instructions; and a processor for executing the computer instructions to implement the method as described above.

The present invention further provides an ultrasonic imaging apparatus for solving the above-mentioned problems, comprising: a memory for storing a combination of elementary beams of ultrasound signal fields that have been obtained in advance and computer instructions; and a processor for executing the computer instructions to implement the method as described above.

The present invention also proposes a computer readable medium storing computer program code, which when executed by a processor implements the method as described above.

The present invention further provides an ultrasonic detection system for solving the above technical problems, comprising: an ultrasonic probe adapted to generate an ultrasonic signal field and to acquire one or more initial ultrasonic amplitude responses of a subject; a memory for storing a combination of elementary beams of ultrasound signal fields that have been obtained in advance and computer instructions; and a processor for executing the computer instructions to implement the method as described above.

The present invention further provides an ultrasonic imaging system for solving the above technical problems, comprising: an ultrasonic probe adapted to generate an ultrasonic signal field and to acquire an initial ultrasonic image of an imaging target; a memory for storing a combination of elementary beams of ultrasound signal fields that have been obtained in advance and computer instructions; and a processor for executing the computer instructions to implement the method as described above.

According to the technical scheme, an ultrasonic signal field of a common probe is decomposed into linear combination of a plurality of elementary signal beams, in an ultrasonic signal or an image formed by each elementary signal beam, the form of an image spot is greatly simplified, the size of the image spot is greatly reduced, the distortion of the image spot is greatly reduced, and the destructive influence of the image spot is radically reduced in the ultrasonic amplitude response or the image reconstructed according to the amplitude response or the image of the elementary signal beams. Therefore, the invention greatly reduces the destructive influence of the image spot on the ultrasonic detection and imaging on the premise of not changing the probe and the excitation, control and signal receiving of the probe.

Drawings

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below, wherein:

FIG. 1A is a schematic view of a simulated object composed of open space discrete object points;

FIG. 1B is an exemplary diagram of an acoustic simulation of the simulated subject of FIG. 1A after B-ultrasonic imaging to generate an ultrasonic image patch;

FIG. 2 is a schematic flow diagram of an exemplary ultrasonic testing method in accordance with an embodiment of the present invention;

FIG. 3 is a signal waveform diagram of a typical ultrasound probe;

FIGS. 4A-4C are graphs comparing the results of the ultrasonic testing method according to the present invention with the results of a general B-mode ultrasonic test;

FIG. 5 is an exemplary flow diagram of an ultrasound imaging method of an embodiment of the present invention;

FIGS. 6A-6C are contrast images of an ultrasound imaging method according to the present invention and a conventional B-mode ultrasound image;

fig. 7A-7C are schematic block diagrams of three embodiments of an ultrasound inspection device and system, an ultrasound imaging device and system, and an ultrasound imaging system of the present invention.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only examples or embodiments of the invention, from which it is possible for a person skilled in the art to apply the invention to other similar contexts without inventive work. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

As used in this disclosure and in the claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are inclusive in the plural, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Also, the present invention has been described using specific terms to describe embodiments of the invention. Such as "one embodiment," "an embodiment," and/or "some embodiments" means a feature, structure, or characteristic described in connection with at least one embodiment of the invention. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some of the features, structures, or characteristics of one or more embodiments of the present invention may be combined as suitable.

Fig. 2 is an exemplary flow chart of an ultrasonic testing method according to an embodiment of the present invention. Referring to fig. 2, the ultrasonic testing method of this embodiment includes the following steps:

step 210, one or more initial ultrasound amplitude responses of the object under test are acquired.

In this step, the object to be measured is an object to be detected by the ultrasonic detection method of the present embodiment, and the object to be measured in this step includes a model for testing and a real detection object, corresponding to fig. 1A. The initial ultrasound amplitude response is the raw signal obtained by detecting the object under test with a normal ultrasound probe, corresponding to fig. 1B, i.e. the unprocessed two-dimensional image containing the image patch. The one or more initial ultrasonic amplitude responses may be acquired by probing the object under test with an ultrasonic probe. The one or more initial ultrasound amplitude responses may be stored in the form of digital signals or may be stored as images.

In some embodiments, a normal B-mode ultrasound probe may be used to obtain the initial ultrasound amplitude response in this step. An initial ultrasonic amplitude response corresponds to a longitudinal plot of the B-mode ultrasonic probe taken from the object at some X-coordinate point. The plurality of initial ultrasonic amplitude responses correspond to the whole two-dimensional image obtained after the same B ultrasonic probe scans the same measured object along the X axis for one time. The two-dimensional image is a two-dimensional space image with the axial direction of the ultrasonic probe as the longitudinal direction and the long axis of the surface of the probe as the transverse direction.

In other embodiments, an initial ultrasound amplitude response corresponds to a two-dimensional image obtained after a scan of the object at a fixed location using a B-mode ultrasound probe. The two-dimensional image is a signal image with time or the depth of a measured object as a horizontal axis and the amplitude of a reflected signal as a vertical axis.

In step 220, each initial ultrasonic amplitude response is decomposed into a linear combination of a plurality of elementary beam amplitude responses, wherein each elementary beam amplitude response is an ultrasonic amplitude response generated by a corresponding elementary beam in the elementary beam linear combination on the measured object independently.

In the embodiment of the invention, the ultrasonic signal field generated by the common probe is expressed as a signal field generated by a plurality of elementary signal beams together, and each elementary signal beam has the same mathematical form but different beam parameters and signal parameters. The elementary signal beam amplitude response refers to the ultrasonic amplitude response generated by a certain elementary signal beam on the measured object alone. The invention considers that the amplitude response (called initial ultrasonic amplitude response) generated by the ultrasonic signal field of the common probe on the measured object is equivalent to the linear combination of the amplitude responses of a plurality of elementary signal beams respectively generated by the plurality of elementary signal beams on the same measured object. Thus, after obtaining one or more initial ultrasound amplitude responses at step 210, each initial ultrasound amplitude response may be decomposed into a linear combination of a plurality of elementary beam amplitude responses.

A metaphor is used here to illustrate the objective basis for decomposition in this step. It is well known that superimposing multiple identical sharp images together with slight misalignment creates a blurred image. It is to be understood conversely that a blurred image may be a superposition, i.e. a linear combination, of a plurality of sharp images. By such a ratio, the blurred image is an initial ultrasonic amplitude response seriously blurred by the image spots, and a plurality of images are mutually superposed to form a plurality of primitive beam amplitude responses which are decomposed after the initial ultrasonic amplitude response is formed. Here, the decomposed elementary signal amplitude responses are not necessarily clear per frame or in all regions, but the final ultrasonic amplitude response reflecting the measured object more clearly and accurately can be reconstructed by one or more elementary signal amplitude responses selected in step 230.

In all embodiments, the building criteria for the linear combination of primitive signal lines is to equivalently represent the ultrasound signal field from which the initial ultrasound amplitude response is generated. That is, the signal field characterized by the linear combination of elementary signal lines is equivalent to the ultrasound signal field used to acquire the initial ultrasound amplitude response or responses of the object under test. Only then is the amplitude response produced by the signal field characterized by the linear combination of the elementary signal lines likely to be equivalent to the initial ultrasound amplitude response obtained with the ultrasound signal field of a normal ultrasound probe.

Step 230, selecting one or more elementary signal beam amplitude responses from the decomposed plurality of elementary signal beam amplitude responses, and reconstructing a final ultrasonic amplitude response of one or more measured objects, so that the point diffusion error of the final ultrasonic amplitude response is reduced to the point diffusion error of the selected elementary signal beam. The selection criteria of the primitive beams are that point diffusion errors are small on the whole or in a certain local area, and basic materials are provided for reconstructing a final amplitude response or a final image.

Error of point spreadThe difference is used to characterize the degree of image distortion for all field points within the object field of an imaging system. The larger the point spread error, the higher the degree of image distortion. Image speckle is just a clear manifestation of the initial ultrasound amplitude response with severe diffusion errors. According to the invention, by decomposing the initial ultrasonic amplitude response, not every one of the decomposed multiple elementary signal beam amplitude responses has a desired point spread error in all regions. Therefore, one or more primitive signal beam amplitude responses are required to be screened out from the multiple primitive signal beam amplitude responses to reconstruct the final ultrasonic amplitude response of the measured object, so that the point diffusion error of the final ultrasonic amplitude response is reduced to the point diffusion error of the optimal combination of the selected primitive signal beams, thereby generally reducing the destructive influence of the image spot on the initial ultrasonic amplitude response and improving the accuracy of the ultrasonic amplitude response for reflecting the measured object. For example, the following method can be adopted to reconstruct the final ultrasonic amplitude response of the measured object according to the amplitude responses of the plurality of elementary signal beams: suppose the waist centers of the first, second and third beams are located at (x)₁,z₁)、(x₂,z₂) And (x)₃,z₃) The reconstructed image or amplitude response is in (x)₁,z₁) The nearby area is mainly the beam A and is in (x)₂,z₂) The nearby area is mainly the beam B and is in (x)₂,z₂)、(x₃,z₃) The area between the two channels is mainly the signal beam B and the signal beam C. In the area near the waist of the plurality of bundles, the reconstruction is mainly performed on the bundles with small waist width. In the area far away from all waist positions, the reconstruction is mainly based on the signal beam with large waist width.

The elementary bundles involved in steps 220 and 230 and the method of obtaining elementary bundles are further explained below.

In some embodiments, the primitive bundles in step 220 are selected from the group consisting of a family of Gaussian bundles, a family of variant Gaussian bundles, and a family of bundle functions based on field functions. In a preferred embodiment of the invention, the elementary bundles are selected from the gaussian bundle family. The ultrasonic detection method of the present invention will be described below by taking a gaussian signal beam as an example.

As described above, the acicular acoustic signal waveform and the acicular acoustic field distributionThis is an ideal condition for PSF, but it cannot be realized in reality. Delta-functions or "ideal impulse functions" are commonly used in mathematics and physics for the study of needle-like acoustic signal waveforms and needle-like sound field distributions. However, the delta-function distribution is not only far from the physical reality of ultrasound imaging, but also often becomes the root of calculating the divergent disfribution on computer operation. Gaussian function in comparison with delta-functionWhen the value of the Gaussian coefficient alpha is large enough, the Gaussian coefficient alpha has the similar wonderful effect with the delta-function in the aspects of steep rise and steep fall and no sidelobe wake waves, and can provide invaluable continuity, quick convergence and repeated integrability in theoretical analysis and computer operation. More importantly, the gaussian beam function is a general solution to the wave equation. Therefore, the embodiments of the present invention mainly use the gaussian beam as the primitive beam.

According to an embodiment of the invention, the ultrasound signal field of a common probe is expressed as a linear combination of multiple gaussian beams. The spatial distribution of each Gaussian beam is a single Gaussian beam, the amplitude waveform of the Gaussian beam is a single generalized Gaussian signal, and the mathematical expression of the single generalized Gaussian beam is the product of the Gaussian beam and the generalized Gaussian signal. Therefore, according to the corresponding combination parameters, the initial ultrasonic amplitude response or image which is obtained by the common probe and contains the image spot distortion can be decomposed into a plurality of elementary signal beam amplitude responses or images which are generated by a single Gaussian signal beam, the image spot form is greatly simplified, the image spot size is greatly reduced, and the image spot distortion is greatly reduced, so that the ultrasonic amplitude response or the ultrasonic image of the object to be detected with higher precision can be recombined from the elementary signal beam amplitude responses or the images.

A method using gaussian primitive beams is explained below.

First, a gaussian beam function and a gaussian beam method will be described.

The Gaussian Beam function (Gaussian Beam Functions) is a general solution of the wave field propagation equation helmholtz equation under Beam approximation. The beam approximation is also known as a parabolic approximation and is equivalent to a fresnel paraxial approximation. The wave motion fields related to optical, acoustic and electromagnetic wave detection technologies including ultrasonic imaging mostly fully meet the requirements of beam approximation. The mathematical form of the three-dimensional gaussian beam function is shown in the following formula (1):

wherein

In equations (1) and (2), x, y, and Z represent X, Y and Z coordinates of the gaussian beam in three dimensions of the stereo space, respectively. I in the formula is an imaginary number symbol,the wave number (ω ═ 2 π f is the frequency of the circle, f, c are the frequency and propagation velocity, respectively), w_x、w_yThe "Waist Width" (Width of Beam Water), μ, of the Gaussian Beam X-dimension and Y-dimension Waist (Beam Water, i.e., the narrowest point of the Beam), respectively_x、μ_yThe z coordinates of the X dimension and the Y dimension wave waist are respectively called waist positions. Two waist widths (w)_x、w_y) And two waist positions (mu)_x、μ_y) The four beam parameters of the Gaussian beam can be assigned to any real number or complex number to form a Gaussian beam family with different distribution forms and the same mathematical property. The gaussian beam function inherits the continuity, fast convergence, and repeatable integrability of the gaussian function.

For ultrasound inspection or ultrasound imaging, the Y-dimension distribution is often not needed or displayed. Therefore, let y in equation (1) be 0, and to express the beam introduction axis parameter θ in which the lateral positions of the axes are different, a two-dimensional gaussian beam function is obtained, whose mathematical form is shown in equation (3) below:

in the formula (3), a is a beam coefficient, and the meanings of the remaining parameters are the same as those in the formulas (1) and (2). It can be seen that the effect of the Y-dimension distribution on the axial wavefield is through P_y(z) is still present. Equation (3) is a Gaussian beam form commonly used in two-dimensional ultrasound image analysis processing, which includes a beam coefficient A and five beam parameters w_x、w_y、μ_x、μ_yAnd theta.

The beam-like wavefield is expressed as a combination of gaussian beams, referred to as the gaussian beam method in wavefield theory.

Traditional wave field theory uses flat waves (plane waves) or spherical waves (spherical waves) as basic units or basis functions for describing wave fields, for example, fourier optics expresses a light field as a combination of innumerable flat waves, and rayleigh sound field theory expresses a sound field as a combination of innumerable spherical waves. Similarly, the gaussian beam method uses gaussian beams as basic units for describing a wavefield, and expresses a beam-like wavefield as a combination of M gaussian beams, M being any integer greater than or equal to 1. The ultrasound beam emitted by the ultrasound probe is typically a beam-like wave field and can therefore be effectively expressed as a combination of M gaussian beams, typically M is between 4 and 10, using the gaussian beam method.

Assume that a certain beam-like wave field can be represented by M gaussian beams shown in formula (3), whose mathematical expression is shown in the following formula (4):

in the formula (4), "≡" is "written". All beam parameters in equation (4) include A_m、θ_mCan be calculated by a computer according to the principle of minimizing the total square error according to theoretical values or measured values of known field points.

For ultrasonic detection and imaging, a Gaussian beam method is adopted, and sound fields of different ultrasonic probes are different only in beam parameters and are completely same in mathematical properties. Therefore, for the sound field formed by different ultrasonic probes, the sound field can be decomposed into linear combinations of M Gaussian beams by calculating Gaussian beam parameters. The linear combination here is in particular the summation of M gaussian beams according to a complex function operation rule.

The following illustrates a calculation method for calculating the combination parameters of the optimal gaussian beam combination by using a computer optimization algorithm.

Defining an error functionWherein y is_n＝y(x_n,z_n) Is a field point (x)_n,z_n) The target value (measured value or theoretical reference value) and N is the total number of target values. T is_nCombined at field point (x) for Gaussian beam_n,z_n) The values of (A):

T_nby M Gaussian beams G_mAt site (x)_n,z_n) Numerical composition of (A)_mBm, etc. represents beam coefficients or beam parameters, where M is 1, 2, …, M. Each beam parameter may be complex, with independent real and imaginary parts. For simplicity, all beam parameters are collectively referred to as combined parameters C_lThe total number of parameters L is typically an integer multiple of M. Thereby will T_nThe expression of (c) is simplified as:

writing each combined parameter to its initial valueAnd the correction value to be obtainedTo sum, i.e.T_nThe expression of (a) is further evolved to:

n₀indicating that each parameter takes an initial value during the iteration. In subsequent iterative computations, n₀Will be updated to n successively₁、n₂Up to n_kAnd k represents the number of iterations for obtaining the optimal solution by the iterative computation.

Let the error function Q be applied to all beam parameters C_lAll that can minimize Q is obtained when the partial derivatives of (A) are simultaneously zero

Is equivalent to

Or

Wherein

The matrix is expressed in the form of

Or

Thus obtaining a combined parameter C_lAll correction values ofThe correction value is calculatedAnd an initial valueAdding to obtain the first generation new combination parameter

Combining the first generation with the parametersSubstitution into T_nAnd Q expression to obtain a first new error value Q_new1If Q is_new1<Q is thenInstead of the formerRepeating the above process to obtain the second generation new combination parametersAnd the corresponding second generation new error value Q_new2If Q is_new2<Q_new1Then the above process continues to be repeated. Iterative calculation is carried out according to the method until the k-th generation new error value Q is finally obtained_newkNo longer reduced. According to the Gaussian beam combination parameters at the momentUltrasonic probeThe resulting sound field is decomposed into a combination of M gaussian beams with the smallest sum of the squared errors between all target values in the sound field and the wavefield values calculated with the gaussian beam combinations, i.e. the best gaussian beam combination.

The present specification has described a gaussian beam function and a gaussian beam method. In some embodiments, the primitive beams involved in steps 220 and 230 of the present invention include, but are not limited to, gaussian beams.

In other embodiments, the primitive bundles involved in steps 220 and 230 of the present invention also include gaussian signals. Therefore, a gaussian signal waveform, a gaussian signal method, and the like will be described below.

In order to improve the longitudinal resolution of ultrasonic detection and imaging, the ultrasonic signal should be as short as possible even if a needle-like waveform is not used. For ultrasonic detection and imaging, short bursts of acoustic vibrations are typically used to generate and transmit geometric and physical information of the object under test. The acoustic vibration is also referred to herein as an acoustic signal. The waveform of the acoustic signal, that is, the waveform of the change of the amplitude of the acoustic wave with time is not less important to acoustic imaging than the sound field distribution. Wave fields that carry and transmit short wave signals are referred to herein as signal fields.

Gaussian signal waveforms are the preferred practical waveforms for situations where ideal needle waveforms cannot be achieved, but are far from readily available. Narrow-lobe unimodal gaussian ultrasound signals in a strict sense cannot be realized so far, fortunately, multimodal ultrasound signals with gaussian envelope also have analytical and computational advantages of gaussian spectrum and gaussian function, and can be called generalized gaussian signals, and the mathematical form of the generalized gaussian signals is shown in the following formula (5):

in the formula (5), i is an imaginary number symbol, t is time, alpha, tau₀、β、τ₁Is a gaussian signal parameter. Alpha determines the width of the Gaussian envelope of the signal, beta is proportional to the center frequency, tau, of the acoustic signal₀、τ₁Then the time of the echo to the ultrasound probe is correlated. When beta is ═At 0, the formula (5) is simplified into a single-peak gaussian signal, i.e. a narrow-sense gaussian signal, which can be achieved only by an electric signal. The sound signal can only make beta not zero in the ultrasonic frequency band, namely a multi-peak Gaussian signal oscillating in a Gaussian envelope.

Fig. 3 is a signal waveform diagram of a typical ultrasound probe. The signal peaks (Peak,0.232V), Peak time points (0.976 μ s), 6dB signal widths (T6 ═ 0.179 μ s) and 20dB signal widths (T20 ═ 0.538 μ s) indicated in the figure are common features for describing signal waveforms. Referring to fig. 3, the main body of the signal waveform of the ultrasound probe is a multi-peak gaussian signal 310 defined by an approximate gaussian envelope 320, plus a wake or ringing component. This is obviously not a strictly gaussian signal. Fortunately, similar to the gaussian beam method, an arbitrary non-gaussian signal waveform can be expressed as a composite of M generalized gaussian signals, as shown in the following equation (6):

in the formula (6), α_m、β_m、Is a Gaussian signal parameter having the same meaning as that of the Gaussian signal parameter in the formula (5), C_mThe combining parameters, collectively called combining parameters, may be real or complex. Equation (6) shows that the signal amplitude F at the field point (x,) is a function of time t and consists of M gaussian signals. M is any integer ≧ 1, typically between 3 and 5. Similar to the naming of the gaussian beam method, equation (6) is referred to as the gaussian signal representation of the fluctuating signal, or gaussian signal method.

The primitive signal beam, i.e. gaussian signal beam, in the preferred embodiment of the present invention is an abbreviation of signal field spatially distributed as a single gaussian beam and having amplitude waveform as a single gaussian signal, and its mathematical expression is the product of the gaussian beam in formula (3) and the gaussian signal in formula (5). In combination with equation (4) and equation (6), the signal field of a two-dimensional ultrasound probe with arbitrary spatial distribution and arbitrary oscillation waveform can be expressed as a linear combination of N × M gaussian beams, as shown in equation (7) below:

in equation (7), the Gaussian beam G_nmThe combined coefficients of (x, z) have been incorporated into the Gaussian signal beam g_nm(t) coefficient of combination C_nmIn (G)_nmReferring to the two-dimensional Gaussian beam function, g, in equation (3)_nmRefer to the generalized gaussian signal in equation (5). In addition to the pin-shaped acoustic field and pin-shaped signal waveform that cannot be realized, a single gaussian beam is said to be the simplest signal field with the smallest achievable image spot, and has analytical and computational advantages, suitable for describing the basis functions of complex signal fields.

The present specification has described a gaussian signal and a gaussian signal method.

The preferred embodiment of the primitive beams involved in steps 220 and 230 of the present invention may include the gaussian beam and gaussian signal described above, i.e., gaussian beam G in equation (7)_nm(x, z) and Gaussian signal g_nm(t) of (d). Therefore, the gaussian beam method and the gaussian signal method described above are also collectively referred to as a gaussian beam method.

In these embodiments, the ultrasonic detection method of the present invention can also obtain the primitive beamline linear combination in advance as follows: the measured sound field distribution and the measured signal waveform of the ultrasonic signal field are taken as the reference, and the parameters and the combination coefficients of each element signal beam in the element signal beam linear combination are calculated by a computer optimization algorithm, so that the field distribution and the signal waveform of the element signal beam linear combination are effectively matched with the measured field distribution and the measured signal waveform. In these embodiments, the parameters and combination coefficients of each primitive beam in the primitive beam linear combination can be calculated according to the method for calculating the optimal gaussian beam combination parameters described above, so as to minimize the field distribution and signal waveform of the primitive beam linear combination and the error between the measured field distribution and the measured signal waveform.

The present invention refers to the previously described gaussian beams containing different beam parameters and signal parameters, collectively referred to as the family of gaussian beams. The primitive bundles include a gaussian bundle family, which is one of the most representative and practical primitive bundles.

In addition to gaussian functions, in other embodiments, bezier functions, laguerre functions, etc. may be used to "modify" the gaussian beams mentioned above, and these modified gaussian beams, gaussian signals, are referred to as a family of modified gaussian beams. The primitive bundles may also be selected from the family of variant gaussian bundles.

In some embodiments, the primitive bundles may also be selected from a family of bundle functions based on a gaussian function, a field function other than a modified gaussian function.

Referring to fig. 1, the shape and size of the image spot varies significantly with the Z-axis. Propagation broadening of the beam, propagation loss, and Y-dimension distribution of the beam are all important factors that contribute to waveform variation with propagation distance z. The change in signal amplitude with time t is also converted to a change with z by the linear relationship of t to z. Combining these factors, the waveform of the reflected signal received by the probe can be expressed as a function of z as shown in equation (8) below:

σ and ∈ in the formula (8) are signal waveform parameters. As shown in FIG. 1, B denotes a reflector, z_BIs the Z coordinate of the reflector, f₁(z_B) And f₂(z_B) Instead of the α and β in equation (5) describing the waveform deformation of the signal with the propagation distance z, C is a real or complex combination coefficient of the gaussian signal. f. of₁() And f₂() May be represented by, but is not limited to, the following formula (9):

auxiliary parameter s introduced in equation (9)₁To s₄The total number of signal parameters of the gaussian signal can be increased to 6.

According to the ultrasonic detection method of the present invention, the mathematical form of the amplitude response of the elementary signal beam obtained in step 220 can be as shown in equation (7) or (8).

In some embodiments, the ultrasonic testing method of the present invention further includes pre-calculating multiple sets of primitive beamline combinations for the same ultrasonic probe using multiple acoustic models of different acoustic media, and in practical applications, switching to use primitive beamline combinations of corresponding acoustic media according to acoustic characteristics of the object to be tested. It will be appreciated that in these embodiments, multiple sets of elementary beamline combinations may be calculated using multiple acoustic models of different acoustic media for the same ultrasound probe according to the methods described previously. In steps 220 and 230, primitive beamline combinations using acoustic media having the same or corresponding acoustic properties are selected based on the acoustic properties of the object under test. Therefore, the accuracy of the ultrasonic detection results for different acoustic media can be improved, and the detection quality fluctuation caused by the acoustic characteristic difference of the detected object is avoided.

In some embodiments, multiple sets of primitive beamline combinations for different fields are calculated for the same detection system ultrasound signal field using the same acoustic model, and in practical applications, primitive beamline combinations for corresponding fields are employed for initial ultrasound amplitude response switching for different fields, including: near field, mid field, far field, paraxial region, and abaxial region. It is understood that according to the embodiments, image quality fluctuation due to the difference of the field regions where the object to be measured is located can be avoided.

Referring to fig. 2, according to the content of the above description, step 210 and step 230 may be specifically implemented, so as to reduce the destructive influence of the image spot existing in the initial ultrasonic amplitude response on the ultrasonic detection result, and improve the accuracy of the ultrasonic detection method. FIGS. 4A-4C are graphs comparing the results of the ultrasonic testing method according to the present invention with the results of a general B-mode ultrasonic test. Wherein, fig. 4A is the same as fig. 1A, and is a simulated measured object composed of independent points in open space; FIG. 4B is a view similar to FIG. 1B, showing a simulated subject image obtained by a normal B-mode ultrasonic examination, which clearly shows the severity of the speckle damage; fig. 4C is a result obtained by imaging a simulated object to be measured according to the ultrasonic detection method of the present invention. Obviously, the ultrasonic detection method obviously reduces the image spot in ultrasonic imaging, and the imaging resolution is obviously improved.

FIG. 5 is an exemplary flow diagram of an ultrasound imaging method of an embodiment of the present invention. Referring to fig. 5, the ultrasonic imaging method of this embodiment includes the following steps:

step 510, an initial ultrasound image of the imaging target is obtained.

Step 520, the initial ultrasound image is decomposed into a linear combination of a plurality of primitive beaming images, wherein each primitive beaming image is an ultrasound image generated on the imaging target by the corresponding primitive beaming in the primitive beaming linear combination.

Step 530, selecting one or more primitive beamlet images from the decomposed primitive beamlet images, and reconstructing one or more final ultrasound images to reduce the image spot error of the final ultrasound image to the image spot error of the selected primitive beamlet image.

The steps 510 and 530 shown in fig. 5 and the steps 210 and 230 shown in fig. 2 have certain similarities. The difference is that fig. 2 shows an ultrasonic detection method, which may include detection by using ultrasonic signals or detection by using ultrasonic images. Therefore, in the description of fig. 2 and the related contents, a part of the contents related to the ultrasonic image is included. Whereas the steps shown in figure 5 relate only to the method of ultrasound imaging. Therefore, reference is made to the foregoing for a description of fig. 5 and its corresponding ultrasound imaging method. Fig. 5 and the corresponding ultrasonic imaging method are further described below, and the same contents as above will not be described again.

In step 510, the imaging target may correspond to the object under test in step 210. The present invention is not limited to the apparatus for acquiring the initial ultrasound image of the imaging target. Typically, a conventional B-mode probe can be used to acquire an initial ultrasound image of the imaging target. In these embodiments, the initial ultrasound image in step 510 is a B-mode ultrasound medical image.

For a common medical ultrasonic probe, whether a convex array or a linear array is adopted, the ultrasonic probe consists of dozens of even hundreds of small probes called as array elements. Due to differences in materials, processes and the like, each array element cannot be completely the same, so that the acoustic beams formed by the array elements are different, and the form of image spots and the imaging quality are different from probe to probe. The difference can not be quantified and can only be ignored in the existing B-ultrasonic technology. The ultrasonic imaging method of the invention provides an effective way to perform image spot compensation with the measured signal field.

In steps 520 and 530, the primitive beam images, primitive beam linear combinations, final ultrasound images, etc. may correspond to the primitive beam amplitude responses, primitive beam linear combinations, final ultrasound amplitude responses, etc. in step 220, respectively.

In some embodiments, the primitive beamline linear combination equivalently represents the ultrasound signal field that the initial ultrasound image signal was originally generated from.

In combination with the gaussian beam expressions of the above-described formulas (3) and (4) and the gaussian signal expressions of the formulas (7) and (8), the gaussian beam method of the two-dimensional ultrasound image according to the ultrasound imaging method of the present invention can be expressed as the following formula (10):

in the formula (10), the first and second groups,is located at a field point within the signal field range of the ultrasonic probeThe reflection point of (2). And I is the total number of reflection points in the sound beam of the ultrasonic probe.And g_nm() Respectively the square sum signal waveform of the field distribution of the elementary beam, C_nmAre the combining coefficients. As shown in connection with fig. 1, each longitudinal line of the ultrasound image is composed of all echoes in the beam together. G in the formula (10)_nmThe square sign on (x, z) is because the echo sound pressure is the square of the sound pressure at the reflection point. In order to determine the parameters and the combination coefficients in equation (10), the parameters and the combination coefficients may be calculated according to the calculation method of the combination parameters for calculating the optimal gaussian beam combination described above. When the total number of the combined parameters of the ultrasonic probe signal field is large, the parameters can be fixed and optimized in batches and in successive cycles. Usually the total number of combined parameters of the signal field of the ultrasound probe is between a few tens and a few hundreds.

Equation (10) is not limited to imaging applications. Let the coordinate variable x in equation (10) be zero, a one-dimensional gaussian signal beam image, that is, an a-line representation commonly used in ultrasonic nondestructive testing, that is, the variation of the amplitude of the reflected signal with the depth of the measured object, can be obtained, as shown in equation (11):

equations (7), (10), (11) all represent the basic form of the Gaussian beam method used in the present invention, where G_nm()、g_nm() Gaussian beam combinations, each representing a wavefield distribution, and gaussian signal combinations of signal waveforms, collectively referred to as gaussian beam combinations. The combined basis functions can have different dimensions, parameter numbers and mathematical variants (such as Gauss-Bessel variants, Gauss-Laguerre variants and the like), and the purpose of setting the parameters is to decompose a single ultrasonic image containing image spot fouling obtained by the ultrasonic probe into a plurality of clearer and more accurate primitive bundle images.

In some embodiments, the ultrasound imaging method of the present invention further comprises pre-obtaining primitive beam combinations in the following manner: and taking the ultrasonic image of the target array or the acoustic model with known geometric distribution and acoustic characteristics as a calculation reference, and calculating parameters and combination coefficients of all primitive signal beams by using a computer optimization algorithm, so that the ultrasonic image generated by linearly combining the primitive signal beams on the target array or the acoustic model with known geometric distribution and acoustic characteristics is effectively matched with the calculation reference. In these embodiments, using the target point configuration used in the sound field measurement or an acoustic model that mimics biological tissue, an ultrasound image of a target array or acoustic model with known geometric distribution and acoustic characteristics can be obtained, and the ultrasound image is used as a reference for calculation. The parameters and combination coefficients of all primitive beams are calculated according to the method for calculating the optimal Gaussian beam combination parameters, so that the error between the ultrasonic image generated by linear combination of primitive beams on a target array or an acoustic model with known geometric distribution and acoustic characteristics and a calculation reference is minimized.

In some embodiments, the target point information corresponding to the image patch obtained through actual measurement, including the target point position and the reflection coefficient, may be substituted into the gaussian beam combination of formula (10) or (11), and each pixel data on each measured a line is used as the target data, and all combination parameters of the gaussian beam combination are calculated at the same time, so that the sum of the square error between the calculated pixel value and the corresponding target data after the obtained parameters and the target point information are substituted into formula (10) or (11) is the minimum.

After the Gaussian signal beam combination of the probe signal field is established, optimized and approved through the known structure and shape of the object to be measured, namely the geometric configuration, the reflection coefficient and the like of the target lattice, each line A of the B ultrasonic image can be decomposed into a plurality of lines A which are respectively and independently generated by the Gaussian signal beams in actual imaging, the sum of the lines A is added, therefore, a single B ultrasonic image formed by the lines A is decomposed into a plurality of independent Gaussian signal beam images generated by the Gaussian signal beams, the image spot form in each Gaussian signal beam image is simplified, the size is reduced, and the image spot distortion of the ultrasonic image is greatly reduced.

Since each gaussian beam has the best resolution at the waist, in some embodiments, an image with the best overall resolution can be reconstructed from the waist portions of each gaussian beam image. Of course, the decomposed gaussian beam image can also be used directly.

In an embodiment of the present invention, the initial ultrasound image may be a one-dimensional, two-dimensional, or three-dimensional dynamic ultrasound image.

In some embodiments of the invention, the primitive bundles are selected from the group consisting of a family of gaussian bundles, a family of modified gaussian bundles, and a family of bundle functions based on field functions.

In some embodiments of the present invention, the ultrasonic imaging method further includes pre-calculating a plurality of sets of primitive beam combinations for different acoustic media using acoustic models of a plurality of different acoustic media for the same ultrasonic probe, and switching to adopt the primitive beam combinations of the corresponding acoustic media according to acoustic characteristics of an imaging target. For example, in the field of medical imaging, different organs and tissues of a human body have different acoustic characteristics, a plurality of sets of primitive beam combinations can be obtained by pre-calculation according to the corresponding acoustic characteristics, and when a certain organ is subjected to ultrasonic imaging scanning, the primitive beam combination corresponding to the organ is utilized, so that the optimal imaging effect can be obtained. The switching may be performed manually or automatically. For the automatic switching embodiment, functions such as automatic identification of organs can be added, so that corresponding primitive information beam combinations can be automatically called according to the types of the organs, and the intelligence of ultrasonic imaging is further improved.

In some embodiments of the present invention, the same acoustic model is used for the ultrasound signal field of the imaging system to calculate multiple groups of primitive beam combinations for different fields, and in practical applications, the primitive beam combinations of corresponding fields are adopted for the initial ultrasound image switching of different fields, and the different fields include: near field, mid field, far field, paraxial region, and abaxial region.

According to the ultrasonic imaging method, through a Gaussian beam method, not only can the signal fields generated by the ultrasonic probes with uniform array elements be expressed, but also the deformed signal fields generated by the ultrasonic probes with inconsistent array elements can be fully expressed, and full compensation is provided in imaging. The invention uses the actual measurement image of the actual signal field instead of the inferred information of the assumed signal field as the basis for calculating the compensation of the elementary beam combination reference target image spot as the actual measurement instead of the theoretical assumption. The gaussian beam method provides an efficient way to compensate for image speckle with the measured signal field.

Fig. 6A-6C are contrast images of an image obtained by the ultrasonic imaging method according to the present invention and a general B-mode ultrasonic image. Fig. 6A is an image of a simulated object. The simulated measured object is a model generated by computer simulation, and the positions and acoustic reflection coefficients of all object points in the model are randomly generated by a computer. The circular area 601-609 at the specific 9 in fig. 6A is 9 low-reflectivity areas with diameters of 1, 2, and 3 mm, respectively, simulating different sizes of lesion tissues. Fig. 6B is a B-mode ultrasound image of a simulated object obtained by normal B-mode ultrasound imaging, and it can be seen that, due to the destructive image of the image patch, the smaller low-value region is not resolved, and the image of the larger low-value region is also blurred and cannot be resolved. Fig. 6C is an image of a simulated measured object obtained by the ultrasonic imaging method according to the present invention, which not only greatly reduces the image spot and has a resolution to a low-value region significantly higher than that of a B-mode ultrasonic image, but also displays a plurality of small discrete object points in the simulated measured object with corresponding image points.

In another embodiment of the present invention, after obtaining a set of gaussian beam combinations according to a certain target configuration, another set of different new target configurations may be used to obtain another set of measured image spot images, the new target information and the previously obtained gaussian beam combinations are substituted into the formula (10) or (11), the image spot images of the new target configurations are calculated, and the accuracy or effectiveness of the previously obtained gaussian beam combinations is evaluated through the difference analysis between the measured image spots and the calculated image spots. And if necessary, continuing to optimize the Gaussian beam combination by using the new actually measured image spot image data. In this way, the gaussian beam combination of the ultrasound signal field can be optimized even further.

In another embodiment of the invention, the target point density configuration most suitable for calculating the Gaussian beam combination can be found out according to the rule between the target point configuration density and the Gaussian beam combination by setting the densities of different target point configurations and calculating the corresponding Gaussian beam combination. And configuring the target point density for ultrasonic detection or imaging of the object to be detected.

In another embodiment of the invention, the target can be partially increasedRadius, adjusting the reflection coefficient of the corresponding ball target in equation (10) or (11)Thereby calculating the influence of the increase of the reflection area of the target point on the reflection coefficient. According to the embodiment, the relation between the area of the target point and the reflection coefficient can be found, so that the calculation of the beam combination can be adjusted according to the size of the target point when the signal field of the probe is calculated.

In another embodiment of the present invention, the area configuration of the target point most suitable for calculating the gaussian beam combination can be found out by changing the radii of all the targets and calculating the corresponding gaussian beam combination according to the rule between the size of the target and the gaussian beam combination.

The invention also includes an ultrasonic testing device comprising a memory and a processor. Wherein the memory is for storing a combination of elementary beams of the ultrasound signal field that have been obtained in advance and computer instructions; the processor is used for executing the computer instructions to realize the ultrasonic detection method of the invention. Therefore, the description and drawings of the ultrasonic detection method of the present invention can be used to explain the ultrasonic detection apparatus of the present invention.

The invention also includes an ultrasound imaging device comprising a memory and a processor. Wherein the memory is for storing a combination of elementary beams of the ultrasound signal field that have been obtained in advance and computer instructions; the processor is configured to execute the computer instructions to implement the ultrasound imaging method of the present invention. Therefore, the description of the present specification with respect to the ultrasonic imaging method of the present invention and the accompanying drawings can be used to explain the ultrasonic imaging apparatus of the present invention.

The invention also includes an ultrasonic testing system comprising an ultrasonic probe, a memory and a processor. Wherein the ultrasonic probe is adapted to generate an ultrasonic signal field and to acquire one or more initial ultrasonic amplitude responses of the object to be measured; the memory is used for storing element beam combination of the ultrasonic signal field obtained in advance and computer instructions; the processor is used for executing the computer instructions to realize the ultrasonic detection method of the invention. Therefore, the description and drawings of the present specification with respect to the ultrasonic detection method of the present invention can be used to explain the ultrasonic detection system of the present invention. The present invention is not limited to the ultrasonic probe, and the ultrasonic probe may be various ultrasonic probes applied to the fields of industry, agriculture, medicine, and the like. In the ultrasonic inspection system, a plurality of ultrasonic probes may be included, and for each ultrasonic probe, its element beam combination may be established by the ultrasonic inspection method of the present invention and stored in the memory for recall.

The invention also includes an ultrasound imaging system comprising an ultrasound probe, a memory and a processor. Wherein the ultrasonic probe is adapted to generate an ultrasonic signal field and acquire an initial ultrasonic image of an imaging target; the memory is used for storing element beam combination of the ultrasonic signal field obtained in advance and computer instructions; the processor is configured to execute the computer instructions to implement the ultrasound imaging method of the present invention. Therefore, the description and drawings of the present specification with respect to the ultrasonic imaging method of the present invention can be used to explain the ultrasonic imaging system of the present invention. The present invention is not limited to the ultrasonic probe, and the ultrasonic probe may be various ultrasonic probes for imaging applied to the fields of industry, agriculture, medicine, and the like. In the ultrasonic imaging system, a plurality of ultrasonic probes may be included, and for each ultrasonic probe, its element beam combination may be established by the ultrasonic imaging method of the present invention and stored in the memory for recall.

Fig. 7A-7C are schematic block diagrams of three embodiments of an ultrasound inspection device and system, an ultrasound imaging device and system, and an ultrasound imaging system of the present invention.

Referring to fig. 7A-7C, the object under test 701 is used to indicate the object under test in step 210 or the imaging target in step 510, and is not included in the apparatus and system of the present invention. Where the ultrasound probe 710 is an ultrasound probe in various systems of the present invention and the processor 721 and memory 722 are processors and memories in various devices and systems of the present invention.

In the embodiment shown in fig. 7A, each apparatus and system of the present invention, including the ultrasound probe 710, the processor 721 and the memory 722, is a stand-alone apparatus and system, and there is no connection with other ultrasound devices, so that the ultrasonic detection method and/or the imaging method of the present invention can be implemented, the influence of the image spot on the ultrasonic detection and imaging can be removed, and the detection and imaging accuracy can be improved.

In the embodiment shown in fig. 7B, the processor 721 and the memory 722 of each apparatus and system of the present invention together form a built-in ultrasound detecting and/or imaging apparatus 720, and are built in other ultrasound equipment 730, and as an integral part of the ultrasound equipment 730, the functions that can be realized by the ultrasound detecting method and/or imaging method of the present invention can be realized. In such an embodiment, the built-in ultrasound detection and/or imaging apparatus 720 of the present invention may be a built-in device card.

In the embodiment shown in fig. 7C, the processor 721 and the memory 722 of each apparatus and system of the present invention together form an external ultrasound detecting and/or imaging apparatus 720, which can receive signals from the ultrasound probe 710 together with other ultrasound devices 730, and can implement the functions of the ultrasound detecting method and/or imaging method of the present invention. In such an embodiment, the external ultrasound detection and/or imaging device 720 of the present invention may be an external equipment box.

Aspects of the present invention may be embodied entirely in hardware, entirely in software (including firmware, resident software, micro-code, etc.) or in a combination of hardware and software. The above hardware or software may be referred to as "data block," module, "" engine, "" unit, "" component, "or" system. The processor may be one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), digital signal processing devices (DAPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or a combination thereof. Furthermore, aspects of the present invention may be represented as a computer product, including computer readable program code, embodied in one or more computer readable media. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips … …), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD) … …), smart cards, and flash memory devices (e.g., card, stick, key drive … …).

The invention also includes a computer readable medium having stored computer program code which, when executed by a processor, may implement the ultrasound detection method and the ultrasound imaging method of the invention.

The computer readable medium may comprise a propagated data signal with the computer program code embodied therein, for example, on a baseband or as part of a carrier wave. The propagated signal may take any of a variety of forms, including electromagnetic, optical, and the like, or any suitable combination. The computer readable medium can be any computer readable medium that can communicate, propagate, or transport the program for use by or in connection with an instruction execution system, apparatus, or device. Program code on a computer readable medium may be propagated over any suitable medium, including radio, electrical cable, fiber optic cable, radio frequency signals, or the like, or any combination of the preceding.

Similarly, it should be noted that in the preceding description of embodiments of the invention, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to suggest that the claimed subject matter requires more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

While the present invention has been described with reference to the present specific embodiments, it will be appreciated by those skilled in the art that the above embodiments are merely illustrative of the present invention and various equivalent modifications or substitutions may be made without departing from the spirit of the invention, and therefore, changes and modifications to the above embodiments within the spirit of the invention are intended to fall within the scope of the appended claims.