A three-dimensional full-focusing imaging method based on a row-column addressing ultrasonic probe

Abstract

This invention relates to the technical field of ultrasonic three-dimensional imaging, and provides a three-dimensional full-focusing imaging method based on a row-column addressing ultrasonic probe. The method calculates the propagation flight time from each pixel to each array element in three-dimensional space based on the spatial position of the array elements, the imaging area, and the imaging pixel size of the row-column addressing ultrasonic probe. The method acquires a first set of three-dimensional full matrix data by sequentially exciting the row array elements and receiving the echo signals from the column array elements. Similarly, it acquires a second set of three-dimensional full matrix data by sequentially exciting the column array elements and receiving the echo signals from the row array elements. Based on the total propagation flight time from each pixel to each array element, the first and second sets of three-dimensional full matrix data are processed using a three-dimensional full-focusing algorithm to obtain a three-dimensional volumetric image of the measured structure. This method achieves high-resolution, high-quality three-dimensional volumetric imaging while reducing the number of system channels and hardware complexity, and also possesses good engineering feasibility and potential for widespread application.

Description

Technical Field

[0001] This invention relates to the technical field of ultrasonic three-dimensional imaging, and in particular to a three-dimensional full-focusing imaging method based on a row and column addressing ultrasonic probe. Background Technology

[0002] Ultrasonic imaging technology is widely used in non-destructive testing, medical imaging, and other fields, playing a vital role in structural defect assessment and tissue function characterization. With the increasing demands for detection accuracy and information depth in industry and the medical field, three-dimensional ultrasonic imaging is gradually becoming a key development direction in high-end applications.

[0003] However, traditional ultrasonic phased array imaging methods usually rely on large-scale two-dimensional arrays to obtain sufficient imaging aperture and spatial resolution. This requires the configuration of a large number of independent transceiver channels, resulting in high system hardware complexity, expensive equipment, and a heavy burden on data acquisition and processing, which severely limits its promotion and application in practical engineering scenarios.

[0004] Row-column addressing (RCA) ultrasound probes, employing an orthogonal row-column electrode structure, achieve indirect addressing of array elements. This significantly reduces the number of physical channels while retaining the spatial sampling capability of a two-dimensional array, providing an efficient and feasible hardware implementation path for three-dimensional ultrasound imaging. However, due to the unique data acquisition method of RCA probes, existing mature three-dimensional ultrasound imaging methods are difficult to directly adapt. Currently, there is a lack of a universal, easy-to-implement, and high-quality three-dimensional imaging algorithm framework.

[0005] Therefore, there is an urgent need to propose a three-dimensional ultrasound imaging method adapted to row and column addressing ultrasound probes to address the aforementioned shortcomings of existing technologies. Summary of the Invention

[0006] The purpose of this invention is to provide a three-dimensional ultrasound volume imaging method that combines row and column addressing ultrasound probe full matrix data acquisition technology with three-dimensional full-focus imaging algorithm to achieve high-resolution, high-quality three-dimensional ultrasound volume imaging.

[0007] To achieve the above objectives, the present invention provides a three-dimensional total focusing imaging method based on a row-column addressing ultrasound probe, comprising: S1, calculate the propagation flight time from each pixel to each element in three-dimensional space based on the spatial position of the array elements, the imaging area range, and the imaging pixel size of the row and column addressing ultrasonic probe. S2, based on a row-column addressing ultrasonic probe, is excited and emitted row by row through row array elements, and the echo signal is received by column array elements to obtain the first set of three-dimensional full matrix data; S3, based on a row-column addressing ultrasonic probe, is excited column by column through the column array elements, and the echo signal is received by the row array elements to obtain the second set of three-dimensional full matrix data; S4. Based on the total propagation flight time from each pixel to each array element, the first set of three-dimensional full matrix data and the second set of three-dimensional full matrix data are processed by a three-dimensional full focusing algorithm to obtain a three-dimensional volume image of the structure under test.

[0008] Furthermore, the row-column addressing ultrasonic probe employs a two-dimensional array transducer with a row-column orthogonal electrode structure. The row-column addressing ultrasonic probe includes a row array element layer and a column array element layer. The row array element layer consists of row array elements distributed in a parallel strip along a first direction, and the column array element layer consists of column array elements distributed in a parallel strip along a second direction. The first direction and the second direction are perpendicular to each other. The row array element layer and the column array element layer are orthogonally stacked in space, and the overlapping area of ​​the two forms the effective array element of the two-dimensional array transducer. Each row array element has a row lead terminal at its end for connecting to an external control circuit, and each column array element has a column lead terminal at its end.

[0009] Furthermore, the propagation flight time from each pixel in the three-dimensional space to each array element is the ultrasonic wave propagation time corresponding to the three-dimensional Euclidean distance between any pixel in the three-dimensional space and the center of the row or column array element. The propagation time from any pixel in the three-dimensional space to the... The first row of array elements, the first The propagation flight times of each array element are as follows:

[0010] The origin of the spatial coordinate system is located at the center of the row-column addressing ultrasound probe. For any pixel in three-dimensional space, It is the first The position of each row of array elements It is the first The position of each array element The speed of sound in the medium.

[0011] Furthermore, the specific steps of step S4 are as follows: For any pixel within the 3D imaging region Calculate the pixel up to the 1st digit. The row array element and the first The sum of the propagation flight times of each array element Based on this, the first set of three-dimensional full matrix data and the second set of three-dimensional full matrix data were time-delayed and aligned, and the echo signals at the corresponding time points were extracted. The two sets of time-delayed and aligned signals are then superimposed, and the superposition results of all element combinations are summed and normalized to obtain the imaging value of that pixel. To achieve coherent enhancement of the echo signal; By traversing all pixels within the three-dimensional imaging region and repeating the above process, a three-dimensional volume image of the measured structure is obtained.

[0012] Furthermore, the imaging value of any pixel in step S4 The formula for calculation is:

[0013] In the formula, and These represent the number of row array elements and column array elements, respectively. For any pixel point to the th The propagation flight time of each array element is, abbreviation; For any pixel point to the th The propagation flight time of each array element is, abbreviation; In order to be in During the propagation flight time, the first The first row element is activated and by the first row element. The echo signal received by each array element In order to be in During the propagation flight time, the first The array element is activated and by the first array element The echo signal received by each row array element.

[0014] The present invention has the following beneficial effects: (1) The present invention uses a row-column addressing ultrasonic probe to obtain the first set of three-dimensional full matrix data and the second set of three-dimensional full matrix data by sequentially exciting and transmitting row by row and receiving column by column. For each imaging point in the imaging area, the total flight time of the sound wave from the excitation array element to the imaging point and then from the imaging point to the receiving array element is calculated point by point. Based on the flight time, all three-dimensional full matrix data are delayed and superimposed point by point to achieve three-dimensional full-field full-focus imaging. Under the premise of reducing the number of system channels and hardware complexity, high-resolution and high-quality three-dimensional volume imaging is achieved. It also has good engineering feasibility and promotion potential, and has important theoretical significance and engineering application value.

[0015] (2) This invention is highly versatile and can be adapted to various row and column addressing ultrasound probes and application scenarios without the need for customized algorithms for specific hardware. At the same time, it has low requirements for hardware equipment. Relying on the low channel characteristics of the row and column addressing probe, it greatly reduces the system hardware complexity and equipment cost, and realizes low-cost, easy-to-promote high-resolution three-dimensional ultrasound imaging.

[0016] (3) The present invention is based on a three-dimensional spatial point-by-point time-delay superposition full-aperture focusing method, which essentially achieves optimal focusing at each voxel position, thereby obtaining higher spatial resolution and better sidelobe suppression capability. At the same time, the method has stronger adaptability to complex propagation paths, can be applied to anisotropic materials, and can effectively handle complex structures such as curved surfaces and welds. In addition, the method has good flexibility and is easy to extend and integrate with various signal processing algorithms. Attached Figure Description

[0017] Figure 1 This is a flowchart of the three-dimensional total focusing imaging method of the present invention.

[0018] Figure 2 This is a general view of a row-column addressable ultrasonic probe array.

[0019] Figure 3 yes Figure 2 A schematic diagram of the distribution of the array elements in the center row.

[0020] Figure 4 yes Figure 2 A schematic diagram of the distribution of array elements in the middle row.

[0021] Figure 5 This is a schematic diagram of the imaging sample in Example 1.

[0022] Figure 6 This is a view of the first set of three-dimensional full matrices obtained in Example 1.

[0023] Figure 7 This is a view of the second set of three-dimensional full matrices obtained in Example 1.

[0024] Figure 8 This is a schematic diagram of the three-dimensional ultrasound imaging results in Example 1. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. However, these embodiments are not intended to limit the present invention. Any similar structures and similar variations of the present invention should be included in the protection scope of the present invention. The commas in the present invention all indicate the relationship between and. The English letters in the present invention are case-sensitive.

[0026] like Figure 1 As shown, this invention provides a three-dimensional total focusing imaging method based on a row-column addressing ultrasound probe, comprising: S1, calculate the propagation flight time from each pixel to each element in three-dimensional space based on the spatial position of the array elements, the imaging area range, and the imaging pixel size of the row and column addressing ultrasonic probe. like Figures 2-4As shown, the row-column addressing ultrasonic probe adopts a two-dimensional array transducer with a row-column orthogonal electrode structure. The row-column addressing ultrasonic probe 10 includes a row array element layer 12 and a column array element layer 14. The row array element layer 12 is composed of row array elements that extend along a first direction and are distributed in a parallel strip shape. The column array element layer 14 is composed of column array elements that extend along a second direction and are distributed in a parallel strip shape. The first direction and the second direction are perpendicular to each other. The row array element layer 12 and the column array element layer 14 are orthogonally stacked in space. The overlapping area of ​​the two forms the effective array element 16 of the two-dimensional array transducer. Each row array element has a row lead terminal 18 for connecting to an external control circuit at its end, and each column array element has a column lead terminal 20 at its end.

[0027] The propagation flight time from each pixel in the three-dimensional space to each array element is the ultrasonic wave propagation time corresponding to the three-dimensional Euclidean distance between any pixel in the three-dimensional space and the center of the row or column array element. The first row of array elements, the first The propagation flight times of each array element are as follows:

[0028] The origin of the spatial coordinate system is located at the center of the row-column addressing ultrasound probe. For any pixel in three-dimensional space, It is the first The position of each row of array elements It is the first The position of each array element The speed of sound in the medium.

[0029] S2, based on a row-column addressing ultrasonic probe, is excited and emitted row by row through row array elements, and the echo signal is received by column array elements to obtain the first set of three-dimensional full matrix data; S3, based on a row-column addressing ultrasonic probe, is excited column by column through the column array elements, and the echo signal is received by the row array elements to obtain the second set of three-dimensional full matrix data; S4, based on the total propagation flight time from each pixel to each array element, performs a three-dimensional full-focusing algorithm on the first set of three-dimensional full matrix data and the second set of three-dimensional full matrix data to obtain a three-dimensional volume image of the measured structure. The specific steps are as follows: For any pixel within the 3D imaging region Calculate the pixel up to the 1st digit. The row array element and the first The sum of the propagation flight times of each array element Based on this, the first set of three-dimensional full matrix data and the second set of three-dimensional full matrix data were time-delayed and aligned, and the echo signals at the corresponding time points were extracted. The two sets of time-delayed and aligned signals are then superimposed, and the superposition results of all element combinations are summed and normalized to obtain the imaging value of that pixel. To achieve coherent enhancement of the echo signal; the imaging value of any pixel. The formula for calculation is:

[0030] In the formula, and These represent the number of row array elements and column array elements, respectively. For any pixel point to the th The propagation flight time of each array element is, abbreviation; For any pixel point to the th The propagation flight time of each array element is, abbreviation; In order to be in During the propagation flight time, the first The first row element is activated and by the first row element. The echo signal received by each array element In order to be in During the propagation flight time, the first The array element is activated and by the first array element The echo signal received by each row array element.

[0031] By traversing all pixels within the three-dimensional imaging region and repeating the above process, a three-dimensional volume image of the measured structure is obtained.

[0032] Example 1 This embodiment uses the proposed method to image the aluminum alloy sample under test and its internal defects.

[0033] like Figure 5 As shown, a standardized ultrasonic guided wave evaluation block conforming to ASTM E2491-23 was selected. It is made of aluminum alloy and has dimensions of [missing information]. The measured longitudinal wave velocity is In the central region of the sample, at a distance from the surface At depth, multiple diameters are machined at 5° intervals. Artificial defects such as holes are defined as follows: The coordinate system is defined with the upper left front vertex of the specimen as the origin, and along the width direction of the specimen (front-to-back direction, from the origin to the other side of the specimen). The axis, along the length of the specimen (horizontally to the right), is defined as... The axis, along the height direction of the specimen (vertically downwards), is defined as... axis.

[0034] The specific steps of using this scheme for three-dimensional full-focus imaging of the aluminum alloy sample to be tested include: S1, calculate the propagation flight time from each pixel to each element in three-dimensional space based on the spatial position of the array elements, the imaging area range, and the imaging pixel size of the row and column addressing ultrasonic probe. Among them, the row-column addressing ultrasonic probe is Channel structure, center frequency is The spacing between array elements is The aperture length of the array element is The excitation signal has a duration of A negative square wave pulse, with an excitation voltage of The data sampling rate is The number of sampling points per channel is Point. The imaging area is set to The image pixel size is .

[0035] The propagation flight time from each pixel in the three-dimensional space to each array element is the ultrasonic wave propagation time corresponding to the three-dimensional Euclidean distance between any pixel in the three-dimensional space and the center of the row or column array element. The first row of array elements, the first The formula for calculating the propagation flight time of each array element is:

[0036] The origin of the spatial coordinate system is located at the center of the row-column addressing ultrasound probe. For any pixel in three-dimensional space, It is the first The position of each row of array elements It is the first The position of each array element The speed of sound in the medium.

[0037] S2, based on a row-column addressable ultrasonic probe, sequentially excites and transmits data row by row through row array elements, and receives the echo signals through column array elements to acquire the first set of three-dimensional full matrix data, such as... Figure 6 As shown; S3, based on a row-column addressable ultrasonic probe, is generated by sequentially exciting column array elements and receiving echo signals from row array elements to obtain the second set of three-dimensional full matrix data, such as... Figure 7 As shown; where, Figure 6 and Figure 7The blank space in the middle is due to the use of a 64-element phased array probe for full matrix acquisition. To facilitate image display and layout, the data blocks of the middle channels have been omitted, and only the A-scan signals of some channels are selected for display. This does not mean that there was no effective echo data during the actual acquisition process.

[0038] S4, based on the total propagation flight time from each pixel to each array element, performs a three-dimensional full-focusing algorithm on the first set of three-dimensional full matrix data and the second set of three-dimensional full matrix data to obtain a three-dimensional volume image of the measured structure. The specific steps are as follows: For any pixel within the 3D imaging region Calculate the pixel up to the 1st digit. The row array element and the first The sum of the propagation flight times of each array element Based on this, the first set of three-dimensional full matrix data and the second set of three-dimensional full matrix data were time-delayed and aligned, and the echo signals at the corresponding time points were extracted. The two sets of time-delayed and aligned signals are then superimposed, and the superposition results of all element combinations are summed and normalized to obtain the imaging value of that pixel. To achieve coherent enhancement of the echo signal; the imaging value of any pixel. The formula for calculation is:

[0039] By traversing all pixels within the 3D imaging region and repeating the above process, a 3D volumetric image of the measured structure is obtained, such as... Figure 8 As shown, the pixel values ​​in the figure are normalized to their maximum values ​​and displayed in a range of -20 dB to 0 dB. In the color scale on the right, brighter colors indicate higher pixel amplitudes and a greater likelihood of defects in the corresponding area. The figure clearly shows the interface echo on the upper surface of the sample, verifying the consistency between the imaging area and the sample size. The position and arrangement of the internal defect holes correspond perfectly to the preset distribution, with the defect signals appearing as high-brightness areas, clearly distinguishable from background noise. Artificial defect holes with a diameter of only 2 mm are clearly identifiable in the 3D image, and there is no significant overlap of defects at different angles, indicating that this method has good spatial resolution and defect recognition capabilities. The overall imaging shows no obvious artifacts and low noise levels, verifying the coherence enhancement effect and noise suppression capability of the 3D full-focusing imaging algorithm based on row and column addressing probes.

[0040] The above results demonstrate that the imaging method of this application can achieve high-contrast, high-resolution three-dimensional volumetric imaging of small-sized, multi-angle distributed defects while significantly reducing the number of hardware channels, thus verifying the effectiveness and engineering application potential of the method.

[0041] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

Claims

1. A method for three-dimensional full focusing imaging based on a row-column addressing ultrasonic probe, characterized in that, include: S1, calculate the propagation flight time from each pixel to each element in three-dimensional space based on the spatial position of the array elements, the imaging area range, and the imaging pixel size of the row and column addressing ultrasonic probe. S2, based on a row-column addressing ultrasonic probe, is excited and emitted row by row through row array elements, and the echo signal is received by column array elements to obtain the first set of three-dimensional full matrix data; S3, based on a row-column addressing ultrasonic probe, is excited column by column through the column array elements, and the echo signal is received by the row array elements to obtain the second set of three-dimensional full matrix data; S4, based on the total propagation flight time from each pixel to each array element, performs a three-dimensional full-focusing algorithm on the first set of three-dimensional full matrix data and the second set of three-dimensional full matrix data to obtain a three-dimensional volume image of the measured structure. The specific steps are as follows: For any pixel within the 3D imaging region Calculate the pixel up to the 1st digit. The row array element and the first The sum of the propagation flight times of each array element Based on this, the first set of three-dimensional full matrix data and the second set of three-dimensional full matrix data were time-delayed and aligned, and the echo signals at the corresponding time points were extracted. The two sets of time-delayed and aligned signals are then superimposed, and the superposition results of all element combinations are summed and normalized to obtain the imaging value of that pixel. To achieve coherent enhancement of the echo signal; By traversing all pixels within the three-dimensional imaging region and repeating the above process, a three-dimensional volume image of the measured structure is obtained.

2. The three-dimensional full-focusing imaging method based on a row-column addressing ultrasonic probe according to claim 1, characterized in that, The row-column addressing ultrasonic probe employs a two-dimensional array transducer with a row-column orthogonal electrode structure. The row-column addressing ultrasonic probe includes a row array element layer and a column array element layer. The row array element layer consists of row array elements distributed in a parallel strip along a first direction, and the column array element layer consists of column array elements distributed in a parallel strip along a second direction. The first direction and the second direction are perpendicular to each other. The row array element layer and the column array element layer are orthogonally stacked in space, and the overlapping area of ​​the two forms the effective array element of the two-dimensional array transducer. Each row array element has a row lead terminal at its end for connecting to an external control circuit, and each column array element has a column lead terminal at its end.

3. The three-dimensional full-focusing imaging method based on a row-column addressing ultrasonic probe according to claim 2, characterized in that, The propagation flight time from each pixel in the three-dimensional space to each array element is the ultrasonic wave propagation time corresponding to the three-dimensional Euclidean distance between any pixel in the three-dimensional space and the center of the row or column array element. The first row of array elements, the first The propagation flight times of each array element are as follows: The origin of the spatial coordinate system is located at the center of the row-column addressing ultrasound probe. For any pixel in three-dimensional space, It is the first The position of each row of array elements It is the first The position of each array element The speed of sound in the medium.

4. The three-dimensional full-focusing imaging method based on a row-column addressing ultrasonic probe according to claim 1, characterized in that, The imaging value of any pixel point in step S4 The calculation formula is: wherein and are the number of row and column elements, respectively. For any pixel point to the th The propagation flight time of each array element is, abbreviation; For any pixel point to the th The propagation flight time of each array element is, abbreviation; In order to be in During the propagation flight time, the first The first row element is activated and by the first row element. The echo signal received by each array element In order to be in During the propagation flight time, the first The array element is activated and by the first array element The echo signal received by each row array element.

Images