Interventional medical needle three-dimensional modeling method and device based on medical perspective

Abstract

The invention provides an interventional medical needle three-dimensional modeling method and device based on a medical perspective. The method is applied to medical imaging field. The method comprises the following steps: acquiring a two-dimensional medical perspective image of a target interventional medical needle; respectively acquiring two-dimensional pixel coordinates of a needle tip and a needle tail on the two-dimensional medical perspective image; coordinate transformation is carried out according to the two-dimensional pixel coordinates of the needle tip and the needle tail, and the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail are obtained; generating a needle passage three-dimensional center line of the target interventional medical needle according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; obtaining radius information of the target interventional medical needle; determining a direction vector according to coordinates of two adjacent points on the three-dimensional center line of the needle passage; generating a spatial circular surface according to coordinate points and radius information on the three-dimensional center line of the needle passage; and constructing a three-dimensional body model of the target interventional medical needle according to the spatial circular surface and the direction vector. According to the invention, the accuracy and efficiency of three-dimensional modeling of the target interventional medical needle are improved.

Description

Technical Field

[0001] The present invention relates to the field of medical imaging, and particularly to a three-dimensional modeling method and device for an interventional medical needle based on a medical perspective view. Background Art

[0002] At present, the rapidly developing computer technology and medical image processing technology provide more reliable support for precision medicine. Among them, medical three-dimensional reconstruction technology can restore the surface information of organs or lesions, and the use of three-dimensional rendering technology makes the model more realistic. Compared with two-dimensional images, it can comprehensively display the spatial position and posture of interventional medical devices (such as interventional needles / puncture needles). Three-dimensional modeling can accurately display the three-dimensional model of in-vivo interventional medical devices, and can display the position, direction and depth of the needle in real time, helping doctors or surgical robots to more accurately locate the target area (such as tumors or diseased tissues) and improve the surgical accuracy.

[0003] In the current technology application, CT and magnetic resonance are generally used for medical three-dimensional reconstruction and surgical planning, but there are still certain limitations. The time for CT images and magnetic resonance scans is relatively long, and during this period, artifacts are easily generated due to patient movement, resulting in problems such as artifacts and blurring in the images. At the same time, when using CT images and magnetic resonance images for accurate three-dimensional modeling, the corresponding tissues of the images need to be segmented. Due to the differences in patient individuals and lesion characteristics, a large number of parameter adjustments and optimizations are required during the segmentation process, resulting in a long time-consuming and low-efficiency process from image acquisition to model completion. Summary of the Invention

[0004] In view of this, on the one hand, the present invention provides a three-dimensional modeling method for an interventional medical needle based on a medical perspective view, including: obtaining a two-dimensional medical perspective image of a target interventional medical needle; respectively obtaining the two-dimensional pixel coordinates of the needle tip and the needle tail on the two-dimensional medical perspective image; performing coordinate conversion according to the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; generating a three-dimensional center line of the needle track of the target interventional medical needle according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; obtaining the radius information of the target interventional medical needle; determining a direction vector according to the coordinates of two adjacent points on the three-dimensional center line of the needle track; generating a spatial circular surface according to the coordinate points on the three-dimensional center line of the needle track and the radius information; and constructing a three-dimensional body model of the target interventional medical needle according to the spatial circular surface and the direction vector.

[0005] Optionally, a three-dimensional centerline of the needle path of the target interventional medical needle is generated based on the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail, including: calculating the slope of the line connecting the needle tip and the needle tail according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; taking the needle tip coordinate point as the starting point, calculating the coordinate points between the needle tip and the needle tail according to the three-dimensional world coordinates of the needle tip, the slope and a preset step size, to obtain a number of coordinate points and three-dimensional world coordinates; connecting all the coordinate points to obtain the three-dimensional centerline of the needle path of the target interventional medical needle.

[0006] Optionally, a three-dimensional solid model of the target interventional medical needle is constructed based on a spatial circular surface and a direction vector, including: respectively taking the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail as the centers of the circles, and taking the radius information as the radius of the circle, to draw two spatial circular surfaces; using the direction vector as the normal vector of the two spatial circular surfaces to obtain a cylinder; generating a three-dimensional solid model of the target interventional medical needle based on the preset voxel value of the cylinder.

[0007] Optionally, the preset voxel value includes the voxel value inside the needle path and the voxel value outside the needle path, and the voxel value inside the needle path is not equal to the voxel value outside the needle path.

[0008] Optionally, a method for three-dimensional modeling of an interventional medical needle based on a medical perspective view provided by the present invention further includes: performing smoothing processing on the three-dimensional solid model according to a preset smoothing parameter, and the preset smoothing parameter includes an isosurface value and the number of isosurfaces.

[0009] Optionally, the needle tail is any point on the target interventional medical needle in the two-dimensional medical perspective image except the needle tip.

[0010] Optionally, coordinate conversion is performed according to the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the needle tail, including: respectively obtaining the image parameters of the two-dimensional medical perspective image, and the image parameters are the basic attributes of the medical perspective image and the geometric parameters of the imaging system; calculating a target coordinate conversion matrix according to the image parameters, and the target coordinate conversion matrix is used to convert the two-dimensional pixel coordinates of the target point into three-dimensional world coordinates, wherein the target coordinate conversion matrix is composed of the conversion parameters of the two-dimensional pixel coordinate system, the two-dimensional image coordinate system, the three-dimensional camera coordinate system and the three-dimensional world coordinate system; taking the needle tip and the needle tail as the target points, respectively substituting the two-dimensional pixel coordinates of the needle tip and the needle tail of the dual perspectives into the target coordinate conversion matrix, and calculating to obtain the three-dimensional world coordinates of the needle tip and the needle tail.

[0011] Optionally, the image parameters include the image resolution of the medical perspective image, the pixel pitch, the distance from the light source point to the patient in the imaging system, the distance from the light source point to the detection board in the imaging system, the first angle, the second angle, the first angle increment, and the second angle increment.

[0012] Optionally, substitute the two-dimensional pixel coordinates of the tip and the tail of the double-view needle into the target coordinate transformation matrix, and calculate the three-dimensional world coordinates of the tip and the tail of the needle, including: substituting the two-dimensional pixel coordinates of the tip and the tail into the target coordinate transformation matrix respectively to calculate the three-dimensional world coordinates of the initial tip and the initial tail of the double-view needle; processing and calculating respectively according to the initial tip and the initial tail of the double-view needle and the three-dimensional world coordinates to obtain the three-dimensional world coordinates of the tip and the tail of the needle.

[0013] The second aspect of the present invention provides an interventional medical needle three-dimensional modeling device based on a medical perspective view, and the device includes: a processor and a memory connected to the processor; wherein, the memory stores instructions executable by the processor, and when the instructions are executed by the processor, the processor is enabled to execute the above-mentioned interventional medical needle three-dimensional modeling method based on a medical perspective view.

[0014] The present invention first obtains a two-dimensional medical perspective image of a target interventional medical needle. The two-dimensional medical perspective image has a fast acquisition speed, can avoid motion artifacts caused by the patient maintaining a posture for a long time, and ensures the basic quality of the image. Then, the two-dimensional pixel coordinates of the tip and the tail on the image are obtained respectively, and then they are converted into three-dimensional world coordinates, and then the three-dimensional center line of the needle track is generated. The coordinates of the tip and the tail can be directly obtained from the perspective image, saving processing time. Then, the radius information of the needle is obtained, the direction vector is determined based on the coordinates of adjacent points on the center line, and a spatial circular surface is generated using the coordinate points and the radius information on the center line. Finally, a three-dimensional body model of the target interventional medical needle is constructed according to the spatial circular surface and the direction vector. Because the three-dimensional world coordinates of the tip and the tail are accurately obtained, the three-dimensional body model can be accurately constructed. The present invention does not require tissue segmentation of the corresponding image and a large number of parameter adjustments and optimizations, greatly shortening the time from image acquisition to modeling completion and improving the modeling efficiency. Moreover, the accurate three-dimensional body model can intuitively and accurately display the position, direction and depth of the needle track and the tip. Through three-dimensional modeling, doctors can simulate different puncture paths, avoid obstacles such as blood vessels and select the optimal path to ensure that the puncture probe can safely reach the center of the lesion, reduce the surgical risk and improve the success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a flowchart of an interventional medical needle three-dimensional modeling method according to an embodiment of the present invention; Figure 2 This is a flowchart of another three-dimensional modeling method for an interventional medical needle based on a medical perspective view in an embodiment of the present invention. Detailed implementation manners

[0017] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0019] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can also be the communication inside two elements. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0020] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] As Figure 1 shown, an embodiment of the present invention provides a three-dimensional modeling method for an interventional medical needle based on a medical perspective view. This method is executed by an electronic device such as a computer or a server, and specifically includes: S1. Obtain a two-dimensional medical perspective image of the target interventional medical needle.

[0022] Obtain a fluoroscopic image of an interventional medical needle (such as an interventional needle / puncture needle) in the human body. The imaging system is a C-arm X-ray machine, which includes a light source system. The light source system includes a transmitting end and a receiving end. The transmitting end and the receiving end are respectively located on both sides of the medical bed. It mainly emits X-rays through its transmitting end. These rays are attenuated after passing through the human body, and then the receiving end receives these attenuated signals, thereby obtaining a fluoroscopic image. Among them, X-rays are not "light" in the traditional sense. The present invention can be broadly understood as generating the rays required for imaging. Then the transmitting end (i.e., the X-ray source) can be regarded as a part of the light source system, and the light source point mentioned below refers to the transmitting end. At the same time, the C-arm can rotate around the patient to obtain a more comprehensive fluoroscopic image from different angles.

[0023] The fluoroscopic image is a two-dimensional pixel image, a black-and-white image obtained by X-ray fluoroscopy technology. Using the different absorption degrees of different tissues in the human body to X-rays, data with different brightnesses are formed. Common ones include CBCT (Cone Beam CT) images and Digital Subtraction Angiography (DSA) images, etc.

[0024] S2. Respectively obtain the two-dimensional pixel coordinates of the tip and the tail of the needle on the two-dimensional medical fluoroscopic image.

[0025] Image segmentation technology can be used to automatically identify the tip and the tail of the needle, and then calculate their two-dimensional pixel coordinates; or the positions of the tip and the tail of the needle in the image can be manually selected, and then their two-dimensional pixel coordinates can be determined.

[0026] S3. Perform coordinate conversion according to the two-dimensional pixel coordinates of the tip and the tail of the needle to obtain the three-dimensional world coordinates of the tip and the three-dimensional world coordinates of the tail of the needle.

[0027] S4. Generate the three-dimensional center line of the needle path of the target interventional medical needle according to the three-dimensional world coordinates of the tip and the three-dimensional world coordinates of the tail of the needle.

[0028] The three-dimensional world coordinates of the tip and the tail of the needle can be used to calculate the spatial straight line parameters between the two points, and the three-dimensional center line of the needle path of the target interventional medical needle is generated based on these parameters.

[0029] S5. Obtain the radius information of the target interventional medical needle.

[0030] Since the tip of the target interventional medical needle is a cone, its radius information is inconsistent with the radius of the needle path. Therefore, the radius information of the target interventional medical needle is preferably the radius of the needle path except the tip. Obtain the model and parameters of the target interventional medical needle. For example, the needle is a microwave ablation puncture needle, and the diameter except the tip is 2 mm, then the radius of the target interventional medical needle is 1 mm.

[0031] S6. Determine the direction vector based on the coordinates of two adjacent points on the three-dimensional center line of the needle track.

[0032] Using the three-dimensional world coordinates of two adjacent points respectively, by calculating the difference in the coordinate values of the two adjacent points, a vector representing the direction of the line connecting these two points is obtained, so as to reflect the trend of the needle track between these two points.

[0033] S7. Generate a spatial circular surface based on the coordinate points and radius information on the three-dimensional center line of the needle track.

[0034] Taking the coordinate point on the three-dimensional center line of the needle track as the center of the circle, according to the radius, on the plane perpendicular to the tangent direction of the center line of the needle track at this point, a complete circle is drawn. This circular plane formed in the three-dimensional space is the spatial circular surface.

[0035] S8. Construct a three-dimensional model of the target interventional medical needle based on the spatial circular surface and the direction vector.

[0036] In this embodiment, by first obtaining the two-dimensional medical fluoroscopic image of the target interventional medical needle, the two-dimensional medical fluoroscopic image has a fast acquisition speed, can avoid motion artifacts caused by the patient maintaining a posture for a long time, and ensure the basic quality of the image. Then, the two-dimensional pixel coordinates of the needle tip and the needle tail on the image are obtained respectively, and then they are converted into three-dimensional world coordinates, and then the three-dimensional center line of the needle track is generated. The coordinates of the needle tip and the needle tail can be directly obtained from the fluoroscopic image, saving processing time. Then, the radius information of the needle is obtained, the direction vector is determined based on the coordinates of adjacent points on the center line, the spatial circular surface is generated using the coordinate points and radius information on the center line, and finally, a three-dimensional model of the target interventional medical needle is constructed based on the spatial circular surface and the direction vector. Due to the accurate acquisition of the three-dimensional world coordinates of the needle tip and the needle tail, the three-dimensional model can be accurately constructed. The present invention does not require tissue segmentation of the corresponding image and a large number of parameter adjustments and optimizations, greatly shortening the time from image acquisition to model completion and improving the modeling efficiency. Moreover, the accurate three-dimensional model can intuitively and accurately display the position, direction, and depth of the needle track and the needle tip. Through three-dimensional modeling, doctors can simulate different puncture paths, avoid obstacles such as blood vessels, select the optimal path, ensure that the puncture probe can safely reach the center of the lesion, reduce the surgical risk, and improve the success rate.

[0037] In some alternative embodiments of this embodiment, the needle tail can be any point on the target interventional medical needle in the two-dimensional medical fluoroscopic image except the needle tip. Since the target interventional needle may not enter the human body completely, the needle tail in the two-dimensional fluoroscopic image is not strictly the position of the needle tail. As long as it is any point on the target interventional needle except the needle tip.

[0038] In one embodiment, in step S4, generating the three-dimensional center line of the needle track of the target interventional medical needle based on the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail includes: S41. Calculate the slope of the line connecting the tip and the tail of the needle based on the three-dimensional world coordinates of the tip and the three-dimensional world coordinates of the tail of the needle.

[0039] S42. Taking the tip coordinate point as the starting point, calculate the coordinate points between the tip and the tail according to the three-dimensional world coordinates of the tip, the slope, and a preset step size, to obtain a number of coordinate points and their three-dimensional world coordinates.

[0040] The preset step size is the distance between adjacent points. The preset step size can be flexibly set according to the requirements of precision or speed. When higher precision is required, the preset step size can be set smaller, so that the calculated coordinate points will be denser and can more accurately describe the position of the needle body in space; if more emphasis is placed on the calculation speed, the preset step size can be appropriately increased to reduce the amount of calculation. In this step, the linear interpolation method is used to obtain a number of coordinate points, but it is not limited to this method. The linear interpolation method has simple code and is easy to implement. In addition, the target interventional medical needle is generally a rigid needle and is not prone to deformation problems.

[0041] S43. Connect all the coordinate points to obtain the three-dimensional center line of the needle path of the target interventional medical needle.

[0042] In this embodiment, the three-dimensional center line of the needle path of the target interventional medical needle is determined by obtaining a number of coordinate points between the tip and the tail of the needle. A number of coordinate points can accurately reflect the actual path of the needle in the body, greatly improving the accuracy and precision of the center line. At the same time, the multi-point determination method can effectively reduce the error influence generated during single-point or small-number-of-point measurements, making the center line more conform to the actual situation. This provides a solid foundation for constructing an accurate three-dimensional body model of the medical needle in the follow-up.

[0043] In one embodiment, in step S8, constructing the three-dimensional body model of the target interventional medical needle according to the spatial circular surface and the direction vector includes: S81. Respectively taking the three-dimensional world coordinates of the tip and the three-dimensional world coordinates of the tail of the needle as the centers of the circles, and taking the radius information as the radius of the circle, draw two spatial circular surfaces.

[0044] Respectively taking the three-dimensional world coordinates of the tip and the tail of the needle as the centers of the circles, and taking the radius information as the radius of the circle, draw two circular surfaces in the three-dimensional space. These two circular surfaces are like the "cross-sections" at both ends of the needle.

[0045] S82. Use the direction vector as the normal vectors of the two spatial circular surfaces to obtain a cylinder.

[0046] The direction vector represents the direction of the interventional medical needle from the needle tail to the needle tip. Taking this direction vector as the normal vector of the two previously drawn spatial circular planes, that is, making these two circular planes perpendicular to this direction vector. Since the two spatial circular planes have definite positions (determined by the coordinates of the needle tip and the needle tail) and the same radius, and their normal vectors are the same (i.e., in the same direction), then connecting the edges of these two circular planes forms a cylinder. This cylinder simulates the approximate shape of the interventional medical needle in three-dimensional space.

[0047] S83, Based on the preset voxel values of the cylinder, generate a three-dimensional volume model of the target interventional medical needle.

[0048] The preset voxel value refers to the value that each small cube (voxel) has when discretely representing an object in three-dimensional space. Based on the cylinder obtained in step S82, fill and assign values to it according to the preset voxel values. For example, the voxel value can represent the material property (such as density, etc.) at that position. By reasonably assigning values to the voxels inside the cylinder, a complete three-dimensional volume model of the target interventional medical needle can be generated. This model exists in the form of three-dimensional data in the computer and can more intuitively display the spatial shape of the target interventional medical needle.

[0049] In this embodiment, by drawing spatial circular planes with the three-dimensional world coordinates of the needle tip and the needle tail as the centers, then constructing a cylinder using the direction vector, and finally generating a three-dimensional volume model of the target interventional medical needle based on the preset voxel values, it is possible to accurately simulate the actual shape of the interventional medical needle in three-dimensional space. This accurate modeling helps doctors more intuitively understand the position and orientation of the needle in the body during the surgical planning stage, so as to more accurately formulate the puncture path, avoid important tissues and organs, and improve the safety and success rate of the surgery. At the same time, the three-dimensional volume model provides basic data for subsequent surgical simulation, navigation and other operations, which is conducive to improving the accuracy and effectiveness of the entire interventional medical process.

[0050] In step S81, the drawing of the spatial circular plane can also be to draw several groups of two spatial circular planes respectively with two adjacent coordinate points as the centers and the radius information as the radius of the circle.

[0051] Select two adjacent coordinate points in sequence from several coordinate points on the three-dimensional center line. Each group of adjacent coordinate points is like the two end points of a small segment on the needle body. Taking the radius information as the radius of the circle, draw two spatial circular planes in three-dimensional space with these two adjacent coordinate points as the centers respectively. By repeating such operations, several sets composed of two spatial circular planes will be obtained.

[0052] Taking the direction vector as the normal vector of the two spatial circular planes in each group, several cylinders are obtained.

[0053] The direction vectors here represent the directions of the needle body on the line segments formed by adjacent coordinate points. For each pair of drawn spatial circular surfaces, the corresponding direction vectors are used as their normal vectors, that is, making these two circular surfaces perpendicular to the direction vector. Since the two circular surfaces have definite positions (determined by adjacent coordinate points) and the same radius, and their normal vectors are the same (i.e., in the same direction), then connecting the edges of these two circular surfaces forms a cylinder. Such operations are performed on all groups of spatial circular surfaces, and finally several cylinders are obtained. These cylinders can be regarded as approximate models of each small segment after the needle body is divided into multiple small segments.

[0054] Set preset voxel values for several cylinders to obtain a three-dimensional volume model of the interventional medical needle.

[0055] By reasonably assigning values to the voxels of each cylinder and combining these cylinders with preset voxel values, a complete three-dimensional volume model of the interventional medical needle can be obtained. This model exists in the computer in the form of three-dimensional data and can comprehensively and meticulously display the spatial shape of the interventional medical needle.

[0056] In this embodiment, by sequentially drawing several groups of spatial circular surfaces with adjacent coordinate points as the centers, constructing several cylinders using direction vectors, and then setting preset voxel values for the cylinders to generate a three-dimensional volume model of the interventional medical needle, it can finely and accurately simulate the actual shape of the interventional medical needle in three-dimensional space, providing a more intuitive and accurate basis for doctors' surgical planning, helping to precisely determine the puncture path, reduce the surgical risk, and at the same time providing reliable basic data for operations such as surgical simulation and navigation, improving the accuracy and effectiveness of interventional medicine.

[0057] Among them, the preset voxel values include the voxel values inside the needle track and the voxel values outside the needle track, and the voxel values inside the needle track are not equal to the voxel values outside the needle track.

[0058] The voxel values inside the needle track refer to the set values of the voxels corresponding to the internal channel of the interventional medical needle, reflecting the internal situation of the needle track; the voxel values outside the needle track are the set values of the voxels corresponding to the external space of the needle, representing the characteristics of the surrounding environment of the needle (such as human tissues). Since the physical properties inside and outside the needle track are different, the two are set to be not equal to distinguish between the inside and outside of the needle track in the three-dimensional model. The specific voxel values can be arbitrary as long as they are different and can distinguish between the inside and outside of the needle track. For example, the voxel value inside the body is set to 1, and the voxel value outside the needle track is set to 0.

[0059] As Figure 2 shown, after constructing the three-dimensional volume model of the target interventional medical needle in step S8, this three-dimensional modeling method of the interventional medical needle based on medical perspective views further includes: S9. Smooth the three-dimensional volume model according to the preset smoothing parameters, and the preset smoothing parameters include the isosurface value and the number of isosurfaces.

[0060] After the construction of the three-dimensional volume model of the target interventional medical needle is completed, to improve its rendering quality, the Marching Cubes algorithm in VTK can be specifically used to smooth the three-dimensional volume model. This algorithm determines whether the 8 vertices of the cube are inside or outside the isosurface, inputs the center line and radius, sets the value of the isosurface and the number of isosurfaces. The value of the isosurface helps to clarify the threshold on the surface of the three-dimensional volume model, while the number of isosurfaces can adjust the fineness of the surface of the three-dimensional volume model. Subsequently, the algorithm calculates the isosurface normal vector, generates the three-dimensional volume data of the needle for rendering, making the surface of the three-dimensional volume model smoother and more continuous, reducing the jagged feeling and irregularity, and significantly improving the rendering quality for providing a better visual presentation.

[0061] In one embodiment, in step S3, coordinate transformation is performed according to the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the needle tail, including: S31, respectively obtain the image parameters of the two-dimensional medical fluoroscopic image, and the image parameters are the basic attributes of the medical fluoroscopic image and the geometric parameters of the imaging system.

[0062] The C-arm X-ray machine is rotated at a predetermined angle to obtain a number of fluoroscopic images, and fluoroscopic images from any multiple perspectives (the number is much less than the total number of fluoroscopic images) are selected from them. Preferably, two perspectives are selected. For example, when the C-arm X-ray machine rotates half a circle by 180°, 180 frames of fluoroscopic images are obtained, and two frames of fluoroscopic images from two perspectives are selected. Selecting fluoroscopic images from multiple perspectives can avoid the lack of single-perspective information and reduce the time for image acquisition and algorithm operation. Too many perspectives of fluoroscopic images will increase the operation cost. Therefore, two perspectives or multiple perspectives can provide complementary information and reduce the processing amount, enabling accurate information to be obtained quickly. Preferably, when selecting fluoroscopic images, the included angle between the first perspective and the second perspective should be controlled between 30° and 150°.

[0063] The image parameters are the default values provided. They can be read from the standard format images of DICOM (Digital Imaging and Communications in Medicine) or measured by technicians or doctors according to the actual environment.

[0064] S32, calculate the target coordinate transformation matrix according to the image parameters. The target coordinate transformation matrix is used to convert the two-dimensional pixel coordinates of the target point into three-dimensional world coordinates. Among them, the target coordinate transformation matrix is composed of the transformation parameters of the two-dimensional pixel coordinate system, the two-dimensional image coordinate system, the three-dimensional camera coordinate system, and the three-dimensional world coordinate system.

[0065] Calculate the transformation matrix between the two-dimensional pixel coordinate system, the two-dimensional image coordinate system, the three-dimensional camera coordinate system, and the three-dimensional world coordinate system according to the image parameters, which is used to convert the two-dimensional pixel coordinates of the target point into three-dimensional world coordinates, and all coordinate systems satisfy the right-hand coordinate system.

[0066] S33. Taking the tip and the tail of the needle as the target points, substitute the two-dimensional pixel coordinates of the tip and the tail of the double-view into the target coordinate transformation matrix respectively, and calculate the three-dimensional world coordinates of the tip and the three-dimensional world coordinates of the tail.

[0067] In this embodiment, by selecting two-dimensional medical fluoroscopic images under any double views, and obtaining the two-dimensional pixel coordinates of the tip and the tail on the fluoroscopic images, a target coordinate transformation matrix is established according to the known fluoroscopic geometric parameters, and the two-dimensional pixel coordinates are converted into three-dimensional world coordinates. Compared with the traditional multi-view shooting and reconstruction algorithms, this method only needs to select the fluoroscopic images under any double views, greatly reducing the shooting time and the computational amount of the reconstruction algorithm. Moreover, this method has low requirements for the acquisition of fluoroscopic data, is applicable to the medical fluoroscopic image processing in various environments, does not require additional external markers or prior calibration, and reduces the operation complexity and preparation work. Specifically, by selecting double views to obtain fluoroscopic images, the single-view information loss is avoided, and at the same time, the processing amount and the computational cost are reduced.

[0068] Specifically, the image parameters include the image resolution, pixel pitch, distance from the light source point to the patient in the imaging system, distance from the light source point to the detection board in the imaging system, first angle, second angle, first angle increment, and second angle increment of the medical fluoroscopic image.

[0069] Among them, the image parameters include the image resolution row, cols, pixel pitch Spacing, distance from the light source point to the patient SOD, distance from the light source point to the detection board SID, first angle , second angle , first angle increment , second angle increment .

[0070] Among them, the distance from the light source point to the detection board in the imaging system is the distance from the transmitting end to the receiving end of the C-arm X-ray machine; the first angle and the second angle are the initial angles of two selected fluoroscopic images, and the first angle increment and the second angle increment are the angles by which the corresponding frames of images are rotated. For example, the angle of the 90th frame is the corresponding initial angle plus the angle increment, that is, the angle of the corresponding viewing angle is obtained. The following descriptions are all based on the dual-view angles of 0° and 90° as examples. In one embodiment, a target coordinate transformation matrix is calculated according to image parameters. The target coordinate transformation matrix is obtained from the transformation matrix between the two-dimensional pixel coordinate system and the two-dimensional image coordinate system, the transformation matrix between the two-dimensional image coordinate system and the three-dimensional camera coordinate system, and the transformation matrix between the three-dimensional camera coordinate system and the three-dimensional world coordinate system. Among them, the transformation matrix between the two-dimensional pixel coordinate system and the two-dimensional image coordinate system is calculated through the image resolution and the pixel pitch, the transformation matrix between the two-dimensional image coordinate system and the three-dimensional camera coordinate system is obtained through the distance from the light source point to the patient, and the transformation matrix between the three-dimensional camera coordinate system and the three-dimensional world coordinate system is calculated through the first angle, the second angle, the first angle increment, and the second angle increment.

[0071] Exemplarily, according to the two-dimensional pixel coordinates (u, v), the canvas center pixel coordinates (row / 2, col / 2), and the two-dimensional image coordinates (x, y), the transformation matrix between the two-dimensional pixel coordinate system and the two-dimensional image coordinate system is as follows: , According to the coordinates (Xc, Yc, Zc) in the three-dimensional camera coordinate system, the transformation matrix between the two-dimensional image coordinate system and the three-dimensional camera coordinate system is as follows: , The current fluoroscopic image rotates around the Z-axis by an angle of , and rotates around the X-axis by an angle of . The coordinates (Xw, Yw, Zw) in the three-dimensional world coordinate system, and the transformation matrix between the three-dimensional camera coordinate system and the three-dimensional world coordinate system is as follows: , , , Finally, the target coordinate transformation matrix is calculated: ， Among them, represents the three-dimensional world coordinates, represents the two-dimensional pixel coordinates, represents the number of pixels in the vertical direction of the fluoroscopic image, represents the number of pixels in the horizontal direction of the fluoroscopic image, represents the pixel pitch, It represents the distance from the light source point to the patient. It represents the distance from the light source point to the detection board. is the rotation matrix, and T represents the offset vector.

[0072] Furthermore, in step S33, the two-dimensional pixel coordinates of the tip and the tail of the double view are respectively substituted into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the tip and the three-dimensional world coordinates of the tail, including: S331, the two-dimensional pixel coordinates of the tip and the tail are respectively substituted into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the initial tip of the double view and the three-dimensional world coordinates of the initial tail.

[0073] S332, respectively process and calculate according to the initial tip and the initial tail of the double view and the three-dimensional world coordinates to obtain the three-dimensional world coordinates of the tip and the three-dimensional world coordinates of the tail.

[0074] Since the image parameters may be inaccurate, the world coordinates obtained by the target coordinate transformation matrix may be inaccurate. Therefore, reprocessing is required to obtain the accurate three-dimensional world coordinates of the tip and the tail. Taking the tip as an example, the three-dimensional world coordinates of the light source points of the double view are calculated using the target coordinate transformation matrix; the light source point of the first view is connected to the corresponding initial tip to obtain the first connection line, and the light source point of the second view is connected to the corresponding initial tip to obtain the second connection line; a point is selected on each of the first connection line and the second connection line such that the midpoint of the line connecting the two selected points is the closest to the first connection line and the second connection line; the midpoint is used as the tip, and the three-dimensional world coordinates of the tip are obtained, and the accurate three-dimensional world coordinates of the tip can be obtained. Then, the three-dimensional world coordinates of the tail can be obtained according to the same steps.

[0075] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0076] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices produce means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0077] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including instruction means that implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0078] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0079] Obviously, the above embodiments are merely examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A three-dimensional modeling method for an interventional medical needle based on a medical perspective view, characterized in that, Including: Obtaining a two-dimensional medical fluoroscopy image of a target interventional medical needle; Respectively obtaining the two-dimensional pixel coordinates of the needle tip and the needle tail on the two-dimensional medical fluoroscopy image; Performing coordinate transformation according to the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; Generating a three-dimensional center line of the needle path of the target interventional medical needle according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; Obtaining the radius information of the target interventional medical needle; Determining a direction vector according to the coordinates of two adjacent points on the three-dimensional center line of the needle path; Generating a spatial circular surface according to the coordinate points on the three-dimensional center line of the needle path and the radius information; Constructing a three-dimensional volume model of the target interventional medical needle according to the spatial circular surface and the direction vector.

2. The method according to claim 1, wherein The generating the three-dimensional center line of the needle path of the target interventional medical needle according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail includes: Calculating the slope of the line connecting the needle tip and the needle tail according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; Taking the needle tip coordinate point as the starting point, calculating the coordinate points between the needle tip and the needle tail according to the three-dimensional world coordinates of the needle tip, the slope and a preset step length to obtain a number of coordinate points and three-dimensional world coordinates; Connecting all the coordinate points to obtain the three-dimensional center line of the needle path of the target interventional medical needle.

3. The method according to claim 1, wherein The constructing the three-dimensional volume model of the target interventional medical needle according to the spatial circular surface and the direction vector includes: Respectively taking the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail as the centers of circles, and taking the radius information as the radius of the circle to draw two spatial circular surfaces; Taking the direction vector as the normal vector of the two spatial circular surfaces to obtain a cylinder; Generating a three-dimensional volume model of the target interventional medical needle based on the preset voxel value of the cylinder.

4. The method according to claim 3, characterized in that, The preset voxel value includes the voxel value inside the needle path and the voxel value outside the needle path, and the voxel value inside the needle path is not equal to the voxel value outside the needle path.

5. The method according to claim 4, characterized in that, It also includes: Performing smoothing processing on the three-dimensional volume model according to a preset smoothing parameter, where the preset smoothing parameter includes an isosurface value and an isosurface number.

6. The method according to claim 1, wherein The needle tail is any point on the target interventional medical needle except the needle tip in the two-dimensional medical fluoroscopy image.

7. The method according to claim 1, wherein The performing coordinate transformation according to the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail includes: Respectively obtaining the image parameters of the two-dimensional medical fluoroscopy image, where the image parameters are the basic attributes of the medical fluoroscopy image and the geometric parameters of the imaging system; Calculating a target coordinate transformation matrix according to the image parameters, where the target coordinate transformation matrix is used to convert the two-dimensional pixel coordinates of a target point into three-dimensional world coordinates, and the target coordinate transformation matrix is composed of the transformation parameters of a two-dimensional pixel coordinate system, a two-dimensional image coordinate system, a three-dimensional camera coordinate system and a three-dimensional world coordinate system; Taking the needle tip and the needle tail as target points, respectively substituting the two-dimensional pixel coordinates of the needle tip and the needle tail with double perspectives into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

8. The method according to claim 7, wherein The image parameters include the image resolution of the medical fluoroscopic image, the pixel pitch, the distance from the light source point in the imaging system to the patient, the distance from the light source point in the imaging system to the detection board, the first angle, the second angle, the first angle increment, and the second angle increment.

9. The method according to claim 7, wherein The step of respectively substituting the two-dimensional pixel coordinates of the tip and the tail of the double view into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the tip and the three-dimensional world coordinates of the tail includes: Respectively substitute the two-dimensional pixel coordinates of the tip and the tail into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the initial tip and the three-dimensional world coordinates of the initial tail of the double view; Respectively perform processing and calculation according to the initial tip and the initial tail of the double view and the three-dimensional world coordinates to obtain the three-dimensional world coordinates of the tip and the three-dimensional world coordinates of the tail.

10. An interventional medical needle three-dimensional modeling device based on a medical perspective view, characterized in that It includes: A processor and a memory connected to the processor; wherein, the memory stores instructions executable by the processor, and the instructions are executed by the processor to enable the processor to execute the three-dimensional modeling method of the interventional medical needle based on the medical fluoroscopic image according to any one of claims 1-9.

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