An ultrasonic imaging system for precise acquisition of a cardiac section in any body position

Abstract

The application discloses an ultrasonic imaging system for accurately collecting heart sections in any body position, which comprises a plurality of two-dimensional ultrasonic arrays randomly distributed in space, a multichannel ultrasonic signal collecting module and a three-dimensional ultrasonic imaging module; the plurality of two-dimensional ultrasonic arrays, the multichannel ultrasonic signal collecting module and the three-dimensional ultrasonic imaging module are sequentially connected; wherein the plurality of two-dimensional ultrasonic arrays comprises a plurality of ultrasonic transducer arrays forming sub-area line scanning or sub-area surface scanning or cross surface scanning; the application provides doctors with more detailed images, which is helpful for more accurately positioning and evaluating lesions; can solve the problems of difficulty in collecting correct imaging sections, imaging section changes in motion and the like in wearable ultrasonic heart imaging; is not only suitable for the heart, but also suitable for the brain, the liver, the kidney, the urinary bladder, the abdominal aorta, the inferior vena cava and the like human tissues and parts.

Description

Technical Field

[0001] This invention relates to the field of ultrasound imaging technology, and more specifically to an ultrasound imaging system for accurately acquiring cross-sections of the heart in any body position. Background Technology

[0002] With the advancement of medical technology and the increasing demand for disease monitoring, immediate cardiac monitoring can no longer meet the needs of modern medicine. Precision medicine, telemedicine, intensive care, and intraoperative navigation have placed new demands on cardiac imaging technology. Continuous, non-invasive, and high-precision monitoring of cardiac activity has become an inevitable trend in medical development. Developing wearable cardiac ultrasound technology to achieve non-invasive, high-resolution visualization monitoring of deep tissues is an urgent need for the diagnosis and monitoring of modern heart diseases.

[0003] Transthoracic echocardiography (TCE) requires specific intercostal windows for acoustic emission and reception, which limits the applicable acoustic windows and transducer sizes. Currently, TCE typically uses four common detection windows: the suprasternal notch, the left parasternal notch, the apex, and the subxiphoid process. Common acquisition views include the parasternal left ventricular long-axis view, the parasternal left ventricular short-axis view, the apical four-chamber view, the subxiphoid four-chamber view, and the aortic arch long-axis view. Existing wearable ultrasound technology faces limitations in imaging range and fixed imaging angles, often failing to acquire complete cardiac images or accurately capture clinically valuable cardiac views, thus restricting its practical clinical application. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide an ultrasound imaging system that can accurately acquire cardiac cross-sections in any body position, thereby solving the problem of inaccurate imaging cross-sections encountered in current wearable cardiac ultrasound imaging.

[0005] Technical solution: The present invention provides an ultrasound imaging system for accurately acquiring cardiac cross-sections in any body position, comprising multiple two-dimensional ultrasound arrays randomly distributed in space, a multi-channel ultrasound signal acquisition module, and a three-dimensional ultrasound imaging module; the multiple two-dimensional ultrasound arrays, the multi-channel ultrasound signal acquisition module, and the three-dimensional ultrasound imaging module are connected in sequence; wherein, the multiple two-dimensional ultrasound arrays include multiple ultrasound transducer arrays forming regional line scanning, regional surface scanning, or cross-surface scanning.

[0006] Furthermore, the two-dimensional ultrasound array receives pulsed high-voltage drive signals and converts them into ultrasound signals. After acquiring the ultrasound echo signals, it converts them back into electrical signals and transmits them to the three-dimensional ultrasound imaging module. The two-dimensional ultrasound array is fixed to the target imaging area using medical ultrasound tape, or by using other clamps or robotic arm structures. The two-dimensional ultrasound array couples sound waves with human skin tissue through ultrasound adhesive or other solid or solid-liquid two-phase materials. The other end is connected to the multi-channel ultrasound signal transmission and acquisition module and the host computer through a probe for data transmission.

[0007] Furthermore, the multi-channel ultrasound signal acquisition module is used to acquire signals from the ultrasound array.

[0008] Furthermore, the three-dimensional ultrasound imaging module is used to obtain three-dimensional images through a three-dimensional ultrasound imaging algorithm.

[0009] Furthermore, the two-dimensional ultrasonic array is made of piezoelectric ceramics, piezoelectric single crystals, or fabricated by microelectromechanical methods, and can take the form of a thin wearable rigid ultrasonic patch, a thin wearable flexible ultrasonic patch, or a handheld ultrasonic array.

[0010] Furthermore, the three-dimensional ultrasound imaging algorithm uses an optical three-dimensional camera to capture three-dimensional images of the chest covered by all ultrasound arrays, obtaining the relative spatial positions between the arrays; based on the spatial positions of each array, coordinate transformation is used to combine the acquired local three-dimensional images of the heart into a large-scale three-dimensional image.

[0011] Furthermore, the position of the ultrasonic array in space is determined using binocular visual calibration; the transformation relationship between the pixel coordinate system and the world coordinate system is obtained through coordinate system transformation, as shown in the following formula:

[0012]

[0013] Where Zc represents the coordinates of a point in space along the Z direction in the camera coordinate system, and f x and f y c represents the equivalent focal length of the camera in the x and y directions, respectively. x and c y Represents the pixel coordinates of the image center. (u,v) and (X) w ,Y w Z w ) represent the coordinates in the pixel coordinate system and the world coordinate system, respectively.

[0014] Furthermore, the three-dimensional ultrasound imaging module employs ultrasound B-mode imaging or Doppler mode.

[0015] Furthermore, after acquiring a large-scale three-dimensional image of the heart, a specific section is extracted from the large-scale three-dimensional image of the heart to obtain a precise heart section in any body position.

[0016] Beneficial effects: Compared with existing technologies, this invention has the following significant advantages: It can acquire local three-dimensional images of the heart from multiple angles, and can collect more cardiac information than traditional ultrasound imaging technology. Using three-dimensional image registration methods, it can be combined into a large-scale three-dimensional image of the heart, providing doctors with more detailed images and helping to more accurately locate and assess lesions; It can solve problems such as difficulty in acquiring the correct imaging plane and changes in the imaging plane during movement in wearable ultrasound cardiac imaging; It is not only applicable to the heart, but also to human tissues and parts such as the brain, liver, kidneys, bladder, abdominal aorta, and inferior vena cava. Attached Figure Description

[0017] Figure 1 This is a diagram of the overall architecture of the present invention;

[0018] Figure 2 Schematic diagram of ultrasonic array fixation;

[0019] Figure 3 A schematic diagram illustrating the process of locating an ultrasonic array using an optical 3D camera and registering multiple ultrasonic images;

[0020] Figure 4 This is a schematic diagram of the binocular vision calibration method;

[0021] Figure 5 This is a schematic diagram illustrating the transformation between the ultrasonic array coordinate system and the world coordinate system.

[0022] Figure 6 This is a schematic diagram of a multi-ultrasound array acoustic field scanning method;

[0023] Figure 7 This is a schematic diagram of ultrasonic array beamforming.

[0024] Among them, 1. Ultrasonic array; 2. Signal line; 3. 3D optical camera; 4. Ultrasonic array; 5. Ultrasonic adhesive or non-volatile liquid; 6. Thin-film medical tape; 7. Coupling medium such as water bag or hydrogel; 8. Skin; 9. Ultrasonic array. Detailed Implementation

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0026] like Figures 1-7As shown, this embodiment of the invention provides an ultrasound imaging system for accurately acquiring cardiac cross-sections in any body position. Based on the location of the heart, multiple ultrasound arrays 1 are generally fixed at the positions of the 2nd to 5th intercostal spaces. The multiple two-dimensional ultrasound arrays 1 are connected to a multi-channel ultrasound signal acquisition module through a data cable 2 to obtain the ultrasound image of each ultrasound array. The image is then transmitted to a three-dimensional ultrasound imaging module to register the three-dimensional ultrasound images from multiple perspectives to obtain a large-scale three-dimensional image of the heart. Finally, the desired cross-section can be accurately obtained from it.

[0027] Apply an appropriate amount of ultrasonic adhesive or other non-volatile liquid to the sound wave emitting surface of the ultrasonic array and the skin surface. Use a water-filled bladder or hydrogel as the acoustic coupling medium, press the water-filled bladder or hydrogel block between the ultrasonic array and the skin, and then fix the ultrasonic array with airtight medical tape. Figure 2 A schematic diagram of the corresponding ultrasonic array fixation is shown.

[0028] The thoracic region is imaged using binocular three-dimensional optical imaging, ensuring coverage of all ultrasound arrays. This yields high-precision relative spatial positions and three-dimensional orientation angles of the ultrasound arrays. Subsequently, simple and rapid preliminary image registration can be achieved through coordinate transformation. Figure 3 The corresponding process is shown.

[0029] The spatial position of an ultrasound array can be determined using binocular visual calibration. For example... Figure 4 As shown, through coordinate system transformation, the transformation relationship between the pixel coordinate system and the world coordinate system can be obtained as follows:

[0030]

[0031] Zc represents the coordinates of a point in space along the Z direction in the camera coordinate system, f x and f y c represents the equivalent focal length of the camera in the x and y directions, respectively. x and c y Represents the pixel coordinates of the image center. (u,v) and (X) w ,Y w Z w ) represent the coordinates in the pixel coordinate system and the world coordinate system, respectively.

[0032] In the above formula,

[0033]

[0034] The intrinsic parameter matrix M1 depends on the camera specifications and is generally composed of known or calibrable parameters. The extrinsic parameter matrix M2 is determined based on the rotation matrix R and translation matrix T between the world coordinate system and the camera coordinate system. Specifically, if the camera coordinate system rotates around the world coordinate system X... w axis, Y wAxis and Z w The included angles of the axes are α, β, and γ, and the offset is T. x ,T y ,T z Then R and T can be expressed as

[0035]

[0036] In the case of binocular positioning, there are two sets of pixel coordinate systems, PCS1 and PCS2. The accurate coordinates (X, X, Y) of any spatial location in the world coordinate system can be obtained using the least squares method. w ,Y w Z w )for

[0037]

[0038] H and U represent the augmentations of the two sets of parameter matrices and pixel coordinates, respectively.

[0039] Given two sets of pixel coordinates, the specific location of the ultrasonic array can be obtained. The ultrasonic array coordinate system can be determined as follows: First, determine the center position of the ultrasonic array according to the above formula, and construct the ultrasonic array coordinate system with the major axis of the array as the x-axis, the minor axis as the y-axis, and the axis perpendicular to the plane where the array is located as the z-axis. In the world coordinate system, the vectors corresponding to the x and y axes can be determined by arbitrarily choosing two points, and the vector corresponding to the z-axis can be determined by the cross product of the above two vectors.

[0040] like Figure 5 As shown, given the relative spatial position of the ultrasound array and its orientation angle in three-dimensional space, two sets of coordinate transformation relationships can be obtained.

[0041]

[0042] Rotation matrix and translation matrix R Xx and T Xx The solution method is similar to that for the extrinsic parameter matrix M2, T Xx This indicates the coordinates of the array center in the world coordinate system.

[0043] like Figure 6As shown, two-dimensional ultrasound arrays include regional line scanning, regional surface scanning, and cross-surface scanning. The first method involves dividing the entire scanning area into several lines, each scanned sequentially, suitable for spatial arrangements where multiple arrays are parallel or perpendicular. The second method involves dividing the entire scanning area into several sub-regions, each scanned block by block, suitable for parallel arrangements of multiple arrays; high frame rates can be achieved using plane wave composite imaging, but certain requirements apply to array arrangement. The third method involves dividing the scanning area into several intersecting surfaces, with some overlap between each surface. Complete three-dimensional data is obtained through multiple scans, suitable for situations where multiple arrays must be arranged in an intersecting manner; however, due to unavoidable acoustic field overlap, it may face strong acoustic field interference.

[0044] A multi-channel ultrasound signal acquisition module acquires ultrasound signals from various arrays and reconstructs a three-dimensional cardiac image using beamforming. For example... Figure 7 As shown, a surface scanning imaging of the three-dimensional region below the two-dimensional ultrasound array is performed using a spatial composite plane wave acoustic field method. The plane wave makes an angle θ with the y-axis, and the ultrasound signal acquired by the nth element of the array is p. n (t), its spatial location is (x n ,y n If the spatial position (x, y, z) within the imaging region is a given acoustic emission transmission time between the nth element and the target element, then the acoustic emission transmission time between the target element and the target element within the imaging region is...

[0045] t em = (z·cosθ+y·sinθ) / c,

[0046] The sound reflection transmission time is

[0047]

[0048] Therefore, the total transmission and reception time delay is...

[0049]

[0050] Let c be the speed of sound in the tissue. By superimposing the sound signals emitted and received by N piezoelectric units and plane waves at M angles, the pixel value at position (x, y, z) can be determined as follows:

[0051]

[0052] Based on the above algorithm, local three-dimensional ultrasound images of the heart corresponding to each ultrasound array are obtained, and then the coordinate transformation formula is used.

[0053]

[0054] The pixel value at position (Xw, Yw, Zw) can then be obtained.

[0055] p(X w Y w Z w )=p(R Xx -1 x+T Xx )

[0056] θ1, θ2, and θ3 represent the x-axis and x-axis, respectively. w axis, y-axis and Y w The axis and z-axis and Z w The included angle of the axis, T X T Y T Z This indicates the location of the array center in the world coordinate system.

[0057] A real-time three-dimensional ultrasound image of the human body can be viewed as a superposition of images obtained from multiple adjusted ultrasound arrays. With K ultrasound arrays, a real-time three-dimensional image can be represented as...

[0058]

[0059] Specific heart sections are extracted from large-scale 3D images of the heart to precisely obtain the desired heart cross-section. The location of the desired heart cross-section is determined, and the cross-section can be represented by a plane equation.

[0060] AX w +BY w +CZ w +D=0

[0061] A, B, and C are the components of the plane's normal vector, and D is the distance between the plane and the origin.

[0062] Given the normal vector n = [A, B, C] of the plane and a known point P0 = [x0, y0, z0] on the tangent plane, substitute them into the above formula to calculate D.

[0063]

[0064] Iterate through all pixels of the 3D image and determine whether each pixel lies on the plane using the plane equation:

[0065] |AX wi +BY wi +CZ wi +D|<ε

[0066] The pixel values ​​of points that meet the above conditions are extracted to generate a two-dimensional cross-sectional image.

[0067] This invention uses multiple ultrasound arrays fixed in the 2nd to 5th intercostal spaces, with stable contact between the arrays and the skin ensured by acoustic coupling media and medical tape. A binocular 3D optical imaging method is used to acquire the relative spatial position and 3D spatial orientation angle of the ultrasound arrays. Preliminary image registration is achieved through coordinate transformation, obtaining the transformation relationship between the pixel coordinate system and the world coordinate system. High-voltage pulses are applied to the ultrasound arrays using circuit control. By precisely controlling the excitation delay of the piezoelectric units, regional line scanning, regional surface scanning, and cross-surface scanning are performed to achieve precise control of the beam shape and direction of the multiple ultrasound arrays. A 3D cardiac image is reconstructed using beamforming. Finally, a spatial geometric algorithm is used to extract specific sections from a large-scale 3D cardiac image, generating a 2D cross-sectional image, achieving precise acquisition of specific cardiac sections.

Claims

1. An ultrasound imaging system for accurately acquiring cardiac cross-sections in any body position, characterized in that, The system comprises multiple two-dimensional ultrasound arrays randomly distributed in spatial locations, a multi-channel ultrasound signal acquisition module, and a three-dimensional ultrasound imaging module; these arrays are sequentially connected. The multiple two-dimensional ultrasound arrays include multiple ultrasound transducer arrays forming regional line scanning, regional surface scanning, or cross-surface scanning. Each two-dimensional ultrasound array receives pulsed high-voltage drive signals, converts them into ultrasound signals, acquires ultrasound echo signals, converts them back into electrical signals, and transmits them to the three-dimensional ultrasound imaging module. The two-dimensional ultrasound arrays are fixed to the target imaging area using medical ultrasound tape, or by employing other clamps or robotic arm structures. The two-dimensional ultrasound array couples sound waves between one end and human skin tissue via ultrasound adhesive or other solid or solid-liquid two-phase materials, while the other end connects to a multi-channel ultrasound signal transmission and acquisition module and a host computer for data transmission. The three-dimensional ultrasound imaging algorithm captures three-dimensional images of the chest covered by all ultrasound arrays using an optical three-dimensional camera, obtaining the relative spatial positions between the arrays. Based on the spatial positions of each array, coordinate transformation is used to combine the acquired three-dimensional images of various parts of the heart into a large-scale three-dimensional image. The position of the ultrasound array in space is determined using a binocular visual calibration method. The transformation relationship between the pixel coordinate system and the world coordinate system is obtained through coordinate system transformation, as shown in the following formula: ； Where Zc represents the coordinates of a point in space along the Z direction in the camera coordinate system, and f x and f y c represents the equivalent focal length of the camera in the x and y directions, respectively. x and c y Represents the pixel coordinates of the image center; (u, v) and (X) w ,Y w Z w () represents the coordinates in the pixel coordinate system and the world coordinate system, respectively; After acquiring a large-scale three-dimensional image of the heart, a specific section is extracted from the large-scale three-dimensional image of the heart to obtain a precise heart section in any body position.

2. The ultrasound imaging system for accurately acquiring cardiac cross-sections in any body position according to claim 1, characterized in that, The multi-channel ultrasound signal acquisition module is used to acquire signals from the ultrasound array.

3. The ultrasound imaging system for accurately acquiring cardiac cross-sections in any body position according to claim 1, characterized in that, The three-dimensional ultrasound imaging module is used to obtain three-dimensional images through three-dimensional ultrasound imaging algorithms.

4. The ultrasound imaging system for accurately acquiring cardiac cross-sections in any body position according to claim 1, characterized in that, Two-dimensional ultrasonic arrays are made of piezoelectric ceramics, piezoelectric single crystals, or fabricated by microelectromechanical methods. They take the form of thin wearable rigid ultrasonic patches, thin wearable flexible ultrasonic patches, or handheld ultrasonic arrays.

5. The ultrasound imaging system for accurately acquiring cardiac cross-sections in any body position according to claim 1, characterized in that, The three-dimensional ultrasound imaging module uses ultrasound B-mode imaging or Doppler mode.

Images