Marker-containing coupling patch and three-dimensional ultrasound reconstruction apparatus and method based on the coupling patch

Abstract

The application discloses a kind of three-dimensional ultrasound reconstruction device and method based on the coupling patch containing marker coupling patch, coupling patch containing marker includes solid acoustic wave transmission body and the marker line in acoustic wave transmission body;Along the transmission direction of acoustic wave, marker line is arranged at least three layers in acoustic wave transmission body, and the marker line of each layer is located in the same plane perpendicular to acoustic wave transmission direction;The marker line of each layer is at least three, and at least two parallel marker lines of each layer, and at least one is diagonal, i.e diagonal and two parallel marker lines are neither parallel nor perpendicular;In each layer marker line, the shape of at least one layer marker line and the shape of another layer marker line are mirror images, and the parallel line projection of at least one layer marker line and another layer marker line is not completely aligned.The present application uses marker line so that each ultrasound image can appear marker point, so as to deduce the spatial position information of ultrasound image, reconstruct three-dimensional ultrasound image, solve the problems such as complex and high cost of prior art system.

Description

Technical Field

[0001] This invention belongs to the field of ultrasonic three-dimensional reconstruction technology, and specifically relates to a three-dimensional ultrasonic reconstruction device and method with a marked coupling patch and based on the coupling patch. Background Technology

[0002] Ultrasound is the most commonly used medical imaging technology in clinical practice, offering advantages such as real-time imaging, safety, and ease of use. However, clinically used ultrasound imaging is mostly two-dimensional (2D), which presents some challenges in practical application. For example, 2D cross-sectional images are difficult to interpret, and image quality depends heavily on the operator's scanning skills. In contrast, 3D ultrasound provides richer and more intuitive information, offering significant advantages in diagnosis and surgical guidance. Current 3D ultrasound solutions mainly include: 3D ultrasound probes, 3D scanning combined with mechanical structures, and 3D scanning combined with positioning devices (such as electromagnetic tracking and optical tracking equipment). However, existing 3D ultrasound solutions often have high manufacturing costs or high equipment complexity, severely limiting their widespread clinical application. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a three-dimensional ultrasound reconstruction device and method with a marker coupling patch and based on the coupling patch. Combined with firmware and algorithms, it can realize three-dimensional ultrasound reconstruction using traditional two-dimensional ultrasound equipment, thereby solving the problems of high equipment requirements, system complexity and high cost of existing three-dimensional ultrasound technology.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] In a first aspect, the present invention provides a marker coupling sticker comprising a solid acoustic wave transmitter and a marker line located in the acoustic wave transmitter; the acoustic wave transmitter is made of a uniform material, and the marker line is made of a different material from the acoustic wave transmitter.

[0006] Along the direction of sound wave transmission, the marking lines are arranged in at least three layers in the sound wave transmission body, and the marking lines in each layer are located on the same plane perpendicular to the direction of sound wave transmission; each layer has at least three marking lines, each layer has at least two parallel marking lines, and at least one marking line is an oblique line, that is, the oblique line is neither parallel nor perpendicular to the two parallel marking lines.

[0007] In each layer of marking lines, at least one layer of marking lines is a mirror image of another layer of marking lines, and at least one layer of marking lines is not perfectly aligned with the parallel line projections of another layer of marking lines.

[0008] In one embodiment, the interlayer spacing of the marking lines and the distance between the marking lines and the sound wave input and output end faces of the sound wave transmitter are both greater than 3 mm, and the marking lines of each layer penetrate the sound wave transmitter in a direction perpendicular to the sound wave transmission.

[0009] In one embodiment, the material of the acoustic wave transmitter is a hydrogel, and the marking line has an elasticity no less than that of the hydrogel.

[0010] In one embodiment, three layers of marking lines are arranged in the acoustic wave transmitter, each layer consisting of three lines connected end to end in an N-shape. The first layer of marking lines and the second layer of marking lines are mirror images of each other, and the parallel lines of the first layer of marking lines and the parallel lines of the second layer of marking lines are offset in the projection direction.

[0011] In one embodiment, each layer of the acoustic wave transmitter has three marking lines connected end to end in an N-shape. The marking lines of the first layer and the marking lines of the second layer are mirror images of each other, and the two parallel marking lines of the first layer and the two parallel marking lines of the second layer are offset in the projection direction.

[0012] A second aspect of the present invention provides a three-dimensional ultrasound reconstruction device, comprising a two-dimensional ultrasound scanning device and the marker-containing coupling patch described in the first aspect;

[0013] One end of the acoustic wave transmitter with the marked coupling patch is attached to the area to be scanned along the direction of acoustic wave transmission, and the other end is connected to the probe of the two-dimensional ultrasonic scanning device.

[0014] In one embodiment, the three-dimensional ultrasound reconstruction device further includes a support frame;

[0015] The support frame is a hollow shell, and its inner surface is attached to the outer surface of the marked coupling sticker except for the two ends of the sound wave transmission direction; the shell has small holes at the ends corresponding to each marked line, and the marked lines are fixed to the small holes.

[0016] A third aspect of the present invention provides a three-dimensional ultrasound reconstruction method, implemented based on the three-dimensional ultrasound reconstruction device described in the second aspect. One end of the marked coupling patch is attached to the area to be scanned. The probe is positioned perpendicular to the surface of the marked coupling patch and scanned along the directions of the two parallel marked lines to obtain a sequence of ultrasound images. The sequence of ultrasound images is then calculated according to the following procedure:

[0017] Step 1: Extract a rectangular region of interest (ROI) smaller than the thickness of the marker coupling patch from the ultrasound image; within the ROI, segment a sub-region with at least 3×m marker points using an adaptive threshold, where m is the number of marker line layers, arranged sequentially from layer 1 to layer m along the sound wave transmission direction. In each layer, the two parallel marker lines and the oblique line each form a marker point in the ultrasound image; calculate the coordinates (u) of each marker point in the i-th layer of marker lines in the two-dimensional image coordinate system. xi ,u yi The two-dimensional image coordinate system has one corner of the image as its origin;

[0018] Step 2: Based on the position of the marker points and the size parameters of the two parallel marker lines and the oblique line in each layer, calculate the position of the ultrasound image relative to the three-dimensional marker line coordinate system. The ultrasound image is perpendicular to the plane where the marker lines are located. The three-dimensional marker line coordinate system is defined as follows: with one intersection point of the marker lines in the first layer as the origin, the x-axis is the direction of the parallel marker lines, the y-axis is perpendicular to the parallel marker lines and faces the other parallel marker line, and the z-axis is perpendicular to the plane where the marker lines are located, forming a right-handed coordinate system with the x-axis and y-axis.

[0019] Step 3: Calculate the rotation angle of the ultrasound image, where the rotation angle is the angle formed by the imaging plane rotating clockwise from the x-axis direction around the z-axis direction in the three-dimensional marker line coordinate system;

[0020] Step 4: Calculate the pose of each ultrasound image and perform three-dimensional ultrasound reconstruction using all the ultrasound images with calculated positions.

[0021] In one embodiment, in step 2, the distance between the two parallel marking lines in each layer of marking lines is W, the angle between the oblique line and the two parallel marking lines is θ, and the displacement of the i-th layer of marking lines relative to the first layer of marking lines is (0, b). i ,c i In the i-th layer of marker lines, the marker points formed by the two parallel marker lines in the ultrasound image are P, respectively. li and P ri The marked point formed by the diagonal line is P. ci P li With P ci Distance is W li P ci With P ri Distance is W ri The position of the ultrasound image, that is, the position of the origin in the two-dimensional image coordinate system in the marker line coordinate system, is (T x ,T y ,T z );(T x ,T y ,T z ) and P ci coordinates (t) xi ,t yi ,t zi They have the following relationship:

[0022]

[0023]

[0024] In one embodiment, the rotation angle is calculated using the following formula:

[0025]

[0026] In the formula, β is the rotation angle of the ultrasound image, and β≤90.

[0027] In one embodiment, step 4, for a given image sequence, is based on each ultrasound image I... k Position (T) x ,T y ,T z And the rotation angle β, to obtain I for each ultrasound image k In the three-dimensional marker line coordinate system, the plane normal vector n k Record ultrasound image I k The three-dimensional coordinates of any point on the top are P k Select the 3D mesh space to be interpolated. For each voxel v to be interpolated in the space (a voxel is a cubic mesh), its voxel value is determined based on its 3D coordinates P. v Confirmed, voxel v distance from ultrasound image I k distance d k The following vectors are used to calculate:

[0028] d k =(P v -P k )·n k

[0029] Calculate the distance from voxel v to all ultrasound images, and take d. k The ultrasound image corresponding to the smallest value of q, P v Projected onto d k The smallest values ​​of the first q are D1 to D2. q The corresponding ultrasound image yields the pixel values ​​(pixel1 to Pixel1) for each of the q projection points. q Finally, the voxel value of voxel v is obtained through interpolation. v :

[0030]

[0031] D t D j Indicates that P v Projected onto d k The t-th and j-th smallest values, pixel t This represents the pixel value corresponding to the t-th projection point.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] Compared to three-dimensional ultrasound probes and three-dimensional ultrasound using positioning devices, this invention has lower system complexity and cost.

[0034] This invention is very simple and convenient in practical use. It only requires scanning based on a coupling patch in a prescribed manner; the resulting sequence of ultrasound images can then be used for three-dimensional ultrasound reconstruction.

[0035] This invention can be combined with various types of two-dimensional ultrasound, and has a certain degree of universality. Attached Figure Description

[0036] Figure 1 This is a three-dimensional schematic diagram of the marker coupling patch in an embodiment of the present invention.

[0037] Figure 2 This is a three-dimensional schematic diagram of the connecting frame in an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the combination of the marking coupling sticker and the support frame in an embodiment of the present invention.

[0039] Figure 4 This is a schematic diagram of the overall structure and usage of the three-dimensional ultrasound device in an embodiment of the present invention.

[0040] Figure 5 This is a flowchart of the three-dimensional reconstruction in an embodiment of the present invention.

[0041] Figure 6 This is a schematic diagram of coordinate transformation in an embodiment of the present invention.

[0042] Figure 7 This is the three-dimensional ultrasound reconstruction result obtained using ultrasound sequences in an embodiment of the present invention. Detailed Implementation

[0043] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and examples.

[0044] The purpose of this invention is to provide a low-cost and convenient three-dimensional ultrasound solution. Traditional three-dimensional ultrasound solutions either rely on expensive three-dimensional probes or utilize complex positioning devices, making it difficult to simultaneously control cost and equipment complexity. The purpose of this invention is to achieve low-cost and convenient three-dimensional ultrasound reconstruction without the need for external tracking and positioning equipment. Specifically, this invention designs a solid coupling patch with marked lines. In actual use, the operator only needs to cover the area to be scanned with the coupling patch and perform ultrasound scanning together with the patch. Marked feature points will appear in the image. Simultaneously, this invention proposes a three-dimensional ultrasound reconstruction method. Using the marked feature points, the position of the ultrasound image relative to the marked lines can be calculated, and the scanned sequence of ultrasound images can be reconstructed into a three-dimensional image, achieving three-dimensional ultrasound reconstruction. This device has the advantages of low cost, easy integration with existing two-dimensional ultrasound equipment, and convenient use.

[0045] like Figure 1As shown, the marker-coupled patch of the present invention includes a solid acoustic wave transmitter 1, in which marker lines 2 are arranged. The acoustic wave transmitter 1 is made of a uniform material and serves as the medium for transmitting sound waves. The marker lines 2 are made of a different material than the acoustic wave transmitter 1, so that the features of the marker points can be clearly displayed in the ultrasound images.

[0046] In this invention, at least three layers of marking lines 2 are arranged along the direction of sound wave propagation in the sound wave transmitter 1. For ease of subsequent calculation, each layer of marking lines 2 is located on the same plane, and this plane is perpendicular to the direction of sound wave propagation. Furthermore, each layer of marking lines 2 consists of at least three lines, of which at least two lines are parallel and are denoted as parallel marking lines, and at least one line is neither parallel nor perpendicular to the parallel marking lines and is denoted as an oblique line. It is worth noting that although theoretically, subsequent calculations can be performed with two layers of marking lines, the stability is generally difficult to meet clinical requirements; therefore, this invention is designed with at least three layers.

[0047] In each layer of the marker line 2, the shape of the marker line 2 in at least one layer is a mirror image of the shape of the marker line 2 in another layer, and the projection of the parallel marker line in at least one layer is not completely aligned with the projection of the parallel marker line in another layer. That is, at least two layers of parallel marker lines are not completely aligned in the projection direction, and there is a preset displacement.

[0048] exist Figure 1 The illustrated embodiment presents a structural form with a marker coupling patch that is more suitable for practical needs. The acoustic wave transmitter 1 consists of two cuboids of different sizes; the larger cuboid is located at the top (closer to the ultrasound probe), and its top surface supports the ultrasound probe; the smaller cuboid is located at the bottom (closer to the area to be scanned), and its bottom surface contacts the area to be scanned. The acoustic wave transmitter 1 contains m layers of marker lines 2 (m=3 in this embodiment); the interval between each layer, and the distance from the marker lines 2 to the top and bottom surfaces of the coupling patch (i.e., the acoustic wave input and output end faces of the acoustic wave transmitter 1) are all greater than 3mm. Furthermore, the marker lines 2 of each layer penetrate the acoustic wave transmitter 1 in a direction perpendicular to the acoustic wave transmission direction to facilitate subsequent observation and calculation. In this embodiment, each layer of marker lines 2 consists of three straight lines located on the same plane, joined end-to-end to form an N-shaped configuration. Among them, the first layer of marking lines and the second layer of marking lines are mirror images of each other, that is, N-shaped and I-shaped respectively, and the parallel lines of the first layer of marking lines and the parallel lines of the second layer of marking lines are offset in the projection direction.

[0049] The material of the sound wave transmitter 1 of this invention is a solid hydrogel, which is relatively soft and can adhere well to the skin. The marking line 2 is a solid of a different material from the sound wave transmitter 1. The marking line 2 has a certain elasticity. Obviously, its elasticity should not be lower than that of the material of the sound wave transmitter 1, i.e., the hydrogel.

[0050] Based on this marked coupling patch, the present invention also provides a three-dimensional ultrasound reconstruction device, which utilizes a conventional, low-cost two-dimensional ultrasound scanning device and the marked coupling patch to achieve three-dimensional ultrasound reconstruction. Specifically, one end of the acoustic wave transmitter 1 with the marked coupling patch along the acoustic wave transmission direction can be attached to the area to be scanned, and the other end can be connected to the ultrasound probe of the two-dimensional ultrasound scanning device.

[0051] The reconstruction principle of this invention is as follows: Marker lines 2 are used to ensure that each ultrasound image has a marker point, and the features of the marker points can be used to infer the spatial location information of the ultrasound image. After determining the location of each ultrasound image, in the grid space to be reconstructed, each voxel to be reconstructed can be obtained by weighted averaging of the neighboring image pixels, with the closer the distance, the greater the weight.

[0052] Furthermore, for ease of use in practice, the three-dimensional ultrasonic reconstruction device of the present invention may also include a support frame 3, such as... Figure 2 and Figure 3 As shown. One form of the support frame 3 is a hollow shell, the inner surface of which can be bonded to the outer surface of the coupling patch containing the markings, except for the two ends in the direction of sound wave transmission. Small holes 4 are opened on the shell corresponding to the ends of each marking line 2. The small holes 4 are used to fix the marking lines 2 during the preparation stage of the coupling patch. The marking lines 2 and the small holes 4 are fixed by any feasible method such as adhesive.

[0053] The two-dimensional ultrasound scanning device used in this invention is a general clinical two-dimensional ultrasound, characterized by its ability to export ultrasound images or its configuration with an image acquisition card.

[0054] refer to Figure 4 Based on the aforementioned three-dimensional ultrasound reconstruction device, one end containing the marked coupling patch is attached to the area to be scanned 5. The ultrasound probe 6 of a two-dimensional ultrasound device is perpendicular to the surface of the marked coupling patch (within reach), and slowly scans along the direction of two parallel marked lines; thus, a sequence of ultrasound images is obtained. The images are transmitted to a computer 7 for algorithm processing. The sequence of ultrasound images is then processed according to... Figure 5 The process shown involves calculations such as marker detection, translation calculation, rotation calculation, and interpolation reconstruction; ultimately, three-dimensional ultrasound reconstruction can be achieved. The specific method is as follows:

[0055] Marker detection: A rectangular region of interest slightly smaller than the thickness of the marker coupling patch is extracted from the ultrasound image; within the region of interest, an adaptive threshold is calculated to segment sub-regions containing 3×m markers, and then the coordinates (u, m) of each marker point in the i-th layer of the marker line in the two-dimensional image coordinate system are determined. xi ,u yi The two-dimensional image coordinate system uses a corner of the image (such as the upper left corner) as its origin, such as... Figure 6As shown, m is the number of layers of marker lines. The marker lines are arranged sequentially from layer 1 to layer m along the direction of sound wave transmission. In each layer, two parallel marker lines and an oblique line form a point in the ultrasound image, which is denoted as the marker point.

[0056] Translation calculation: Based on the position of the marker points and the size parameters of the two parallel marker lines and the oblique line in each layer of marker line 2, the position of the ultrasound image relative to the three-dimensional marker line coordinate system can be calculated, where the ultrasound image is perpendicular to the plane containing marker line 2. For example... Figure 6 As shown, the three-dimensional marker line coordinate system of this invention is defined as follows: in the top view, with one intersection point of the first layer of marker lines as the origin, the x-axis is the direction parallel to the marker line, the y-axis is perpendicular to the parallel marker line and faces the other parallel marker line, and the z-axis is perpendicular to the plane where the marker line is located, forming a right-handed coordinate system with the x-axis and y-axis.

[0057] For example, in each layer of marker line 2, let the distance between two parallel marker lines be W, the angle between the oblique line and the two parallel marker lines be θ, and the displacement of the i-th layer marker line relative to the first layer marker line be (0, b). i ,c i Marker line 2 will form marker points in the ultrasound image. Specifically, in marker line 2 of the i-th layer, the marker points formed by the two parallel marker lines in the ultrasound image are P1, P2, P3, and P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14, P15, P16, P17, P18, P19, P10, P11, P12, P13, li and P ri The marked point formed by the diagonal line is P. ci P li With P ci Distance denoted as W li P ci With P ri Distance denoted as W ri In the three-dimensional marker line coordinate system, let P be... ci The coordinates are (t) xi ,t yi ,t zi ); This can be obtained using the principle of similar triangles:

[0058]

[0059] Taking the origin in the two-dimensional image coordinate system as the position of the ultrasound image, its position in the three-dimensional marker line coordinate system is (T x ,T y ,T z ); then (T) x ,T y ,T z ) and P ci coordinates (t) xi ,t yi ,t zi They have the following relationship:

[0060]

[0061] Rotation angle calculation: Considering that the scanning process specifies that the probe is perpendicular to the surface containing the marker coupling patch and scans slowly, the actual rotation angle mainly considers the rotation angle around the z-axis; let the rotation angle β of the ultrasound image be the angle formed by the imaging plane clockwise around the z-axis from the x-axis direction in the three-dimensional marker line coordinate system. β can be calculated according to the properties of right triangles. To ensure the uniqueness of β, the scanning process can specify β≤90.

[0062]

[0063] Interpolation reconstruction: For each ultrasound image, its pose is calculated using the following algorithm; finally, three-dimensional ultrasound reconstruction is performed using all ultrasound images with calculated positions.

[0064] Specifically, for a given image sequence, calculate I for each ultrasound image. k Its position (T) can be obtained by translation. x ,T y ,T z Then, by combining this with its rotation angle β, the I of each ultrasound image can be obtained. k In the three-dimensional marker line coordinate system, the plane normal vector n k Record ultrasound image I k The three-dimensional coordinates of any point on the top are P k Select the 3D mesh space to be interpolated. For each voxel v to be interpolated in the space, its voxel value is determined based on its 3D coordinates P. v Confirmed, voxel v distance from ultrasound image I k distance d k The following vectors are used to calculate:

[0065] d k =(P v -P k )·n k

[0066] Calculate the distance from voxel v to all ultrasound images, and take d. k The ultrasound image corresponding to the smallest value of q (for example, q = 4), P v Projected onto d k The smallest values ​​of the first q are D1 to D2. q The corresponding ultrasound image yields the pixel values ​​(pixel1 to Pixel1) for each of the q projection points. q Finally, the voxel value of voxel v is obtained through interpolation. v :

[0067]

[0068] Dt D j Indicates that P v Projected onto d k The t-th and j-th smallest values, pixel t This represents the pixel value corresponding to the t-th projection point.

[0069] In one specific embodiment of the present invention, the larger cuboid comprising the acoustic wave transmitter 1 has dimensions of 84mm × 70mm × 11mm, and the smaller cuboid has dimensions of 84mm × 60mm × 5mm. The top surface of the larger cuboid is used to contact and form the ultrasonic probe, and the bottom surface of the smaller cuboid is used to contact the surface of the area to be scanned. The distances of the three layers of marking lines 2 from the top surface are 3mm, 8mm, and 11mm, respectively. The first and third layers of marking lines are shaped like an "N", and the second layer of marking lines is a mirror image of the "N", with a 5mm displacement to the left of the first layer of marking lines in the horizontal plane. The outer shell of the support frame 3 is 3mm thick. After being combined with the marked coupling patch, the bottom surface of the coupling patch is exposed, facilitating contact with the skin during scanning. In use, the ultrasonic probe 6 is placed perpendicular to the top surface of the coupling patch, along the "N" line from top to bottom (see...). Figure 4 (Left top view), the scan is performed slowly, and the ultrasound images can be directly exported from the computer 7 in the ultrasound equipment or collected using an image acquisition card.

[0070] In marker detection, each ultrasound image contains 9 high-brightness markers. Marker detection is mainly achieved by calculating an adaptive threshold. Let t be the adaptive threshold for the k-th ultrasound image. k ,t k The calculation process is as follows: First, the image is sharpened. Then, a threshold is set starting from 255 and decreasing. The image is binarized using each threshold. The number of connected components in the binarized image is then counted. When the number of connected components first reaches 9, the threshold is denoted as t. max_k When the number of connected components in the binary image changes again from 9 as the threshold decreases, let the threshold be t. min_k Then the adaptive threshold t k =(t max_k +t min_k ) / 2. Using t k The region where the marker point is located can be segmented, and the position of the marker point can be obtained by calculating the geometric center of each connected region.

[0071] In translation calculations, such as Figure 6As shown, let W be the distance between the two parallel lines of line N, and let γ be the angle between the oblique line of line N and the two parallel lines. Line N passes through the ultrasound image. Let the intersection point of the two lines at the upper left corner of the top line of line N be the origin of the coordinate system. In the top view of line N, let the x-axis be upward (along the direction of the parallel lines of line N), the y-axis be to the right (perpendicular to the direction of the parallel lines of line N), and the z-axis be perpendicular to the plane where line N is located. Together with the x-axis and y-axis, they form a right-handed coordinate system.

[0072] Figure 7 The diagram illustrates the results of three-dimensional ultrasound reconstruction using ultrasound sequences, demonstrating that the marker lines and corresponding three-dimensional images can be accurately reconstructed. The reconstruction process only requires generating a sequence of ultrasound images with marker point features using a marker-coupled patch, eliminating the need for additional complex positioning equipment.

Claims

1. A three-dimensional ultrasound reconstruction method, implemented based on a three-dimensional ultrasound reconstruction device, the three-dimensional ultrasound reconstruction device comprising a two-dimensional ultrasound scanning device and a marker-coupled patch; one end of the acoustic wave transmitter of the marker-coupled patch along the acoustic wave transmission direction is attached to the area to be scanned, and the other end is connected to the probe of the two-dimensional ultrasound scanning device; the marker-coupled patch comprises a solid acoustic wave transmitter and marker lines located in the acoustic wave transmitter; the acoustic wave transmitter is made of a uniform material, and the marker lines are made of a different material from the acoustic wave transmitter; along the acoustic wave transmission direction, the marker lines are arranged in at least three layers in the acoustic wave transmitter, and the marker lines in each layer are located on the same plane perpendicular to the acoustic wave transmission direction; each layer has at least three marker lines, each layer has at least two parallel marker lines, and at least one marker line is an oblique line, that is, the oblique line is neither parallel nor perpendicular to the two parallel marker lines; in each layer of marker lines, the shape of at least one layer of marker lines is a mirror image of the shape of another layer of marker lines, and the projection of the parallel lines of at least one layer of marker lines is not completely aligned with the projection of the parallel lines of another layer of marker lines; characterized in that... One end of the marked coupling patch is attached to the area to be scanned. The probe is positioned perpendicular to the surface of the marked coupling patch, and scanning is performed along the two parallel marked lines to obtain a sequence of ultrasound images. The sequence of ultrasound images is then calculated according to the following procedure: Step 1: Extract a rectangular region of interest (ROI) smaller than the thickness of the marker coupling patch from the ultrasound image; within the ROI, segment a sub-region with at least 3×m marker points using an adaptive threshold, where m is the number of marker line layers, arranged sequentially from layer 1 to layer m along the sound wave transmission direction. In each layer, the two parallel marker lines and the oblique line each form a marker point in the ultrasound image; calculate the coordinates (u) of each marker point in the i-th layer of marker lines in the two-dimensional image coordinate system. xi ,u yi The two-dimensional image coordinate system has one corner of the image as its origin; Step 2: Based on the position of the marker points and the size parameters of the two parallel marker lines and the oblique line in each layer, calculate the position of the ultrasound image relative to the three-dimensional marker line coordinate system. The ultrasound image is perpendicular to the plane where the marker lines are located. The three-dimensional marker line coordinate system is defined as follows: with one intersection point of the marker lines in the first layer as the origin, the x-axis is the direction of the parallel marker lines, the y-axis is perpendicular to the parallel marker lines and faces the other parallel marker line, and the z-axis is perpendicular to the plane where the marker lines are located, forming a right-handed coordinate system with the x-axis and y-axis. Step 3: Calculate the rotation angle of the ultrasound image, whereby the rotation angle is the angle formed by the imaging plane rotating clockwise from the x-axis direction around the z-axis direction in the three-dimensional marker line coordinate system; Step 4: Calculate the position of each ultrasound image, and use all the ultrasound images with calculated positions to perform three-dimensional ultrasound reconstruction. In step 2, in each layer of marking lines, the distance between the two parallel marking lines is W, the angle between the oblique line and the two parallel marking lines is θ, and the displacement of the i-th layer of marking lines relative to the first layer of marking lines is (0, b). i ,c i In the i-th layer of marker lines, the marker points formed by the two parallel marker lines in the ultrasound image are P, respectively. li and P ri The marked point formed by the diagonal line is P. ci P li With P ci Distance is W li P ci With P ri Distance is W ri The position of the ultrasound image, that is, the position of the origin in the two-dimensional image coordinate system in the marker line coordinate system, is (T x ,T y ,T z );(T x ,T y ,T z ) and P ci coordinates (t) xi ,t yi ,t zi They have the following relationship:

2. The three-dimensional ultrasound reconstruction method according to claim 1, characterized in that, In step 3, the rotation angle is calculated using the following formula: In the formula, β is the rotation angle of the ultrasound image, and β≤90.

3. The three-dimensional ultrasound reconstruction method according to claim 1, characterized in that, In step 4, for a given image sequence, based on each ultrasound image I... k Position (T) x ,T y ,T z And the rotation angle β, to obtain I for each ultrasound image k In the three-dimensional marker line coordinate system, the plane normal vector n k Record ultrasound image I k The three-dimensional coordinates of any point on the top are P k Select the three-dimensional mesh space to be interpolated. For each voxel v to be interpolated in the space, its voxel value is determined based on its three-dimensional coordinates P. v Confirmed, voxel v distance from ultrasound image I k distance d k The following vectors are used to calculate: d k =(P v -P k )·n k Calculate the distance from voxel v to all ultrasound images, and take d. k The ultrasound image corresponding to the smallest value of q, P v Projected onto d k The smallest values ​​of the first q are D1 to D2. q The corresponding ultrasound image yields the pixel values ​​(pixel1 to Pixel1) for each of the q projection points. q Finally, the voxel value of voxel v is obtained through interpolation. v : D t D j Indicates that P v Projected onto d k The t-th and j-th smallest values, pixel t This represents the pixel value corresponding to the t-th projection point.

4. The three-dimensional ultrasound reconstruction method according to claim 1, characterized in that, The interlayer spacing of the marking lines and the distance between the marking lines and the sound wave input / output end faces of the sound wave transmitter are both greater than 3mm. The marking lines of each layer penetrate the sound wave transmitter in a direction perpendicular to the sound wave transmission.

5. The three-dimensional ultrasound reconstruction method according to claim 1, characterized in that, The material of the acoustic wave transmitter is hydrogel, and the marking line has an elasticity no less than that of the hydrogel.

6. The three-dimensional ultrasound reconstruction method according to claim 1, characterized in that, In the sound wave transmitter, each layer of marking lines consists of three lines, which are connected end to end in an N-shape. The marking lines of the first layer and the marking lines of the second layer are mirror images of each other, and the two parallel marking lines of the first layer and the two parallel marking lines of the second layer are offset in the projection direction.

7. The three-dimensional ultrasound reconstruction method according to claim 1, characterized in that, The three-dimensional ultrasound reconstruction device also includes a support frame; The support frame is a hollow shell, and its inner surface is attached to the outer surface of the marked coupling sticker except for the two ends of the sound wave transmission direction; the shell has small holes at the ends corresponding to each marked line, and the marked lines are fixed to the small holes.

Images