A grinding head model construction and display method for visualization of acetabulum grinding

Abstract

The present invention discloses a method for constructing and displaying a grinding head model for visualization of acetabulum grinding, comprising: using a graphics library tool to construct a grid-shaped hemispherical surface, a grid-shaped circular bottom surface and a straight handle in an image world coordinate system; merging the grid-shaped hemispherical surface, the grid-shaped circular bottom surface and the straight handle to form a complete grinding head model; using a rendering pipeline to draw the grinding head model; calling a backface culling function in a graphics library to enable a backface culling attribute corresponding to the grinding head model; using the grinding head model processed with backface culling to grind the acetabulum model, and displaying the result in the same view; the present invention effectively solves the problem of the grinding head blocking the acetabulum model during the acetabulum grinding process, and significantly improves the visualization effect of the operation.

Description

Technical Field

[0001] The invention relates to the field of medical imaging technology, and in particular to a grinding head model construction and display method for visualization of acetabulum grinding. Background Art

[0002] In acetabulum grinding surgery, accurate visualization is crucial for doctors, as it directly affects the accuracy and safety of the surgery. The existing grinding head visualization technology has the following main disadvantages:

[0003] A common way to visualize the grinding head is to use a hemispherical surface model with the same diameter as the real grinding head. Figure 1 However, this display method has obvious problems. During the grinding process, no matter what angle the camera in the image space is at, this display method of the grinding head will block the bone area that the doctor focuses on, thus seriously affecting the doctor's observation and judgment of the surgical area.

[0004] Another common way to visualize the grinding head is to use the mesh display mode of the same hemispherical surface model, such as Figure 2 Although this method allows doctors to observe the bone grinding through the grinding head, there is still an obvious occlusion problem; more importantly, in this display mode, due to the overlapping display of the front and back grids, the posture of the grinding head becomes difficult to judge, which further increases the complexity and risk of the operation.

[0005] In summary, the existing grinding head visualization method has obvious occlusion and posture judgment problems, which seriously affects the accuracy and safety of acetabular grinding surgery. Therefore, a new grinding head model construction and display method is urgently needed to solve the problems in the existing technology and improve the visualization effect and safety of the surgery. Summary of the invention

[0006] The purpose of the present invention is to provide a method for constructing and displaying a grinding head model for visualization of acetabulum grinding in response to the problems existing in the prior art, which effectively solves the problem of the grinding head blocking the acetabulum model during acetabulum grinding and significantly improves the visualization effect of the operation.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for constructing a grinding head model for visualization of acetabulum grinding, comprising:

[0009] Use the graphics library tool to construct the grid-shaped hemispherical splineShell, the grid-shaped circular bottom cap and the straight handle post in the image world coordinate system; merge the grid-shaped hemispherical splineShell, the grid-shaped circular bottom cap and the straight handle post to form a complete grinding head model reamer;

[0010] Use the graphics library tool to construct a grid-shaped hemispherical splineShell in the image world coordinate system, including: using the origin of the image world coordinate system as the sphere center and R as the radius to generate a spherical data body, recorded as sphere; in the image world coordinate system, define an xy plane and generate corresponding plane data, recorded as plane; use plane to cut sphere to obtain the hemispherical shell part located on the positive half axis of the z axis after cutting, recorded as hemisphere; in the image world coordinate system, generate a rectangular data body, recorded as cuboid, with its length, width, The height is set to a, b, and c, where a is much smaller than R, and b and c are both larger than 2R; cuboid is used to crop the sphere to obtain the part of the sphere that falls inside the cuboid, which is recorded as spline; the z-axis of the image world coordinate system is used as the rotation axis, an angle a° is set, and the spline is rotated 180 / a times around the z-axis. If 180 / a is not an integer, it is rounded up, and the graphic data of the spline is copied after each rotation; the spline graphic data obtained by rotation and copying are merged to obtain a grid-like hemispherical surface, which is recorded as splineShell;

[0011] Use the graphics library tool to construct a grid-shaped circular bottom cap in the image world coordinate system, including: using the z-axis of the image world coordinate system as the rotation axis, rotating the spline graphic data 180 / b times at a preset angle b°, rounding up if 180 / b is not an integer, and copying the spline graphic data after each rotation; merging the spline graphic data obtained by rotation and copying, and recording the result as splineCap; setting the z-axis coordinate value of each point on the splineCap to 0 by setting the transformation matrix, so that the splineCap is attached to the xy plane of the image world coordinate system, and the result is recorded as flat; recalculating the normal vector of each triangle face of flat, and adjusting the normal vectors of all triangle facets to face the negative z half axis of the image world coordinate system; using the origin of the image world coordinate system as the center of the circle and R as the radius, generating a ring graphic data in the xy plane, recorded as circle; merging circle and flat into a graphic data, and recording the result as cap, which is the required grid-shaped circular bottom surface;

[0012] Use the graphics library tool to construct a straight handle post in the image world coordinate system, including: taking the z axis of the image world coordinate system as the axial direction of the cylinder, drawing a cylinder with a bottom radius of r and a height of h, so that the upper bottom surface of the cylinder is located on the xy plane; the cylinder will be used as the straight handle part of the grinding head model, recorded as post;

[0013] The above-mentioned grinding head model Reamer is drawn using the rendering pipeline in the graphics library; the backface culling function in the graphics library is called to turn on the backface culling attribute corresponding to Reamer, so that during the rendering process, only the triangles facing the camera are drawn, while the triangles facing away from the camera are ignored; the acetabulum model bone is ground using Reamer after backface culling, and displayed in the same view;

[0014] During the rendering process, only the triangular facets facing the camera are drawn, while the triangular facets facing away from the camera are ignored, including: defining a plurality of triangular facets constituting surface data, each triangular facet having a normal vector, the normal vector being perpendicular to the triangular facet and being used to determine the direction of the triangular facet; determining a viewpoint vector, the vector being directed from the position of the camera to the triangular facet; calculating the dot product of the normal vector and the viewpoint vector to determine the direction of the triangular facet; judging the direction of the triangular facet according to the result of the dot product, if the dot product is a negative value, it indicates that the front facet of the triangular facet faces the camera; if the dot product is a positive value, it indicates that the back facet of the triangular facet faces the camera; during the rendering process, only the triangular facets facing the camera are drawn, while the triangular facets facing the camera away are ignored;

[0015] The acetabulum model bone is ground with the rearmer that has undergone back-face culling and displayed in the same view, including: rigidly connecting the optical tracking array to the grinding instrument and the patient's acetabulum respectively; transmitting the transformation matrix TcameraToToolRF from the positioning camera coordinate system Fcamera to the instrument tracking array coordinate system FtoolRF, and the transformation matrix TcameraToBoneRF from Fcamera to the bone tracking array coordinate system FboneRF in real time through the positioning camera; performing image registration operations, and using the above two transformation matrices for image navigation and positioning to ensure that the relative position relationship between the patient's acetabulum and the grinding instrument in the real world is consistent with the relative position relationship between the acetabulum model bone and the grinding head model rearmer in the image space; moving the grinding instrument in the real world, and using the established image navigation and positioning relationship to update the positions of the acetabulum model bone and the grinding head model rearmer in the image in real time, so that the relative position relationship between the two in the image space is synchronized with the relative position relationship in the real world.

[0016] A grinding head model display system for visualization of acetabulum grinding comprises: a model generation unit, which uses a graphics library tool to construct a grid-like hemispherical splineShell, a grid-like circular bottom cap and a straight handle post in an image world coordinate system; a model merging unit, which merges the grid-like hemispherical splineShell, the grid-like circular bottom cap and the straight handle post to form a complete grinding head model reamer; a rendering pipeline unit, which uses a rendering pipeline in a graphics library to draw the grinding head model reamer; a backface culling processing unit, which calls a backface culling function in the graphics library and turns on the backface culling attribute corresponding to the reamer, so that in the rendering process, only triangular facets facing the camera are drawn, while triangular facets facing away from the camera are ignored; and a synchronous display unit, which uses the reamer processed with backface culling to grind the acetabulum model bone and display it in the same view.

[0017] A computer-readable storage medium stores a computer program, wherein the computer program implements the above method steps when executed by a processor.

[0018] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method steps when executing the computer program.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. By constructing a grid-shaped hemispherical surface, a grid-shaped circular bottom surface and a straight handle, and merging them into a complete grinding head model, the grid-shaped structure is composed of a series of lines, so that light and vision can penetrate the grinding head model, effectively reducing the occlusion of the bone model by the grinding head in the image, so that the doctor can more clearly observe the grinding area and the surrounding bone structure during the operation, thereby improving the accuracy and safety of the operation;

[0021] 2. The straight handle design allows doctors to judge the posture of the grinding head by observing the extension direction and position of the straight handle, reducing the impact of viewing angle limitations on surgical operations;

[0022] 3. The application of backface culling technology ensures that the part of the grinding head model that faces away from the camera will not be rendered, thereby greatly reducing the occlusion of the acetabulum model by the grinding head, allowing doctors to observe the details of the acetabulum area more clearly during surgery;

[0023] 4. The combination of back-face culling technology and the grid structure design of the grinding head effectively solves the problem of the grinding head blocking the acetabulum model during the acetabulum grinding process, and significantly improves the visualization effect of the surgery;

[0024] 5. Using back-face culling technology, if a triangle is facing away from the camera, the triangle will not be rendered. This method greatly reduces the rendering of unnecessary triangles, shortens the rendering time, and significantly improves the rendering efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only 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 work.

[0026] Figure 1 It is a schematic diagram of the structure of the grinding head model and the acetabulum model in the prior art of this application;

[0027] Figure 2 It is a schematic diagram of the structure of the grinding head model and the acetabulum model in the prior art of this application;

[0028] Figure 3 This is a schematic diagram of the structure of spherical data in one embodiment of the present application;

[0029] Figure 4 This is a schematic diagram of the structure of a hemispherical shell obtained by cutting spherical data in one embodiment of the present application;

[0030] Figure 5 This is a schematic diagram of the structure of obtaining grid bars by cutting a hemispherical shell in one embodiment of the present application;

[0031] Figure 6 A schematic diagram of the structure of a rotating grid bar obtaining a grid-shaped hemispherical surface in one embodiment of the present application;

[0032] Figure 7 A schematic diagram of the structure of a rotating grid bar obtaining a grid-shaped hemispherical cap in one embodiment of the present application;

[0033] Figure 8 It is a structural schematic diagram of generating a grid-shaped plane from a grid-shaped hemispherical cap in one embodiment of the present application;

[0034] Fig. 9 A schematic diagram of a structure in which a grid-shaped plane generates a grid-shaped circular bottom surface in one embodiment of the present application;

[0035] Fig.10 This is a schematic diagram of the structure of a straight handle in one embodiment of the present application;

[0036] Fig.11 This is a schematic diagram of the structure of a grinding head model assembled in one embodiment of the present application;

[0037] Fig.12This is a schematic diagram of the structure after the back side of the grinding head model is removed in one embodiment of the present application;

[0038] Fig.13 It is a schematic structural diagram showing a grinding head model and an acetabulum model together in one embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In a first aspect of the present application, a method for constructing a grinding head model for visualization of acetabulum grinding is provided, comprising the following steps:

[0041] S1. See Figures 3 to 10 , Use the graphics library tool to construct the grid-shaped hemispherical splineShell, the grid-shaped circular bottom cap and the straight handle post in the image world coordinate system;

[0042] S2, see Fig.11 , the grid-shaped hemispherical splineShell, the grid-shaped circular bottom cap and the straight handle post are combined to form a complete grinding head model reamer.

[0043] Specifically, the tool library used in this embodiment and the following is VTK, which is an open source, cross-platform graphics library for scientific visualization and graphics processing. It provides rich functions and tools for creating, rendering and processing 2D and 3D graphics data, such as volume data, meshes, curves, etc. VTK is usually used in the fields of medical image processing, computational fluid dynamics, earth sciences, computer-aided design, etc. VTK supports common mesh data file formats, such as .stl and .ply. The data type of mesh data in VTK is vtkPolyData. All surface mesh data used in this embodiment and the following are vtkPolyData.

[0044] In this embodiment, a grid-like hemispherical spline Shell, a grid-like circular bottom cap, and a straight handle post are constructed and merged into a complete grinding head model, and the grid-like structure is composed of a series of lines, so that light and sight can penetrate the grinding head model, which effectively reduces the occlusion of the bone model by the grinding head in the image, so that the doctor can observe the grinding area and the surrounding bone structure more clearly during the operation, thereby improving the accuracy and safety of the operation.

[0045] Due to the design of the grid structure, the doctor can observe the position and angle of the grinding head from multiple angles. The grid design can maintain good visibility, allowing the doctor to clearly identify the posture and movement trajectory of the grinding head.

[0046] The straight handle design allows doctors to judge the posture of the grinding head by observing the extension direction and position of the straight handle, reducing the impact of viewing angle limitations on surgical operations.

[0047] In some embodiments, a grid-like hemispherical splineShell is constructed in an image world coordinate system using a graphics library tool, including:

[0048] S1.1. See Figure 3 , let the actual grinding head radius be R. First, use the vtkSphereSource class in the VTK graphics library to generate a complete spherical vtkPolyData data at the origin of the image world coordinate system [0, 0, 0] with r (r is equal to the grinding head radius R) as the radius. The data is recorded as sphere;

[0049] S1.2. See Figure 4 , in the image world coordinate system, define an xy plane and generate the corresponding plane data, denoted as plane;

[0050] S1.3. Use the vtkClipPolyData method to cut the sphere using the plane, and only keep the hemispherical shell part located on the positive half axis of the z axis after cutting. This part of the data is recorded as hemisphere.

[0051] S1.4, see Figure 5 , use the vtkCubeSource class to create a cuboid at the origin of the image world coordinate system [0, 0, 0], whose length, width and height are aligned with the x, y and z axes of the image world coordinate system respectively, and the length is set to a, b and c respectively, where the value of a should be much smaller than R (such as 1 mm), and the values ​​of a and b should be greater than 2R to completely contain the sphere;

[0052] S1.5. See Figure 6 , use the vtkClipPolyData method to cut the sphere with the cuboid, and obtain the part of the sphere that falls inside the cuboid, which is recorded as spline;

[0053] S1.6, see Figure 6, use the vtkTransformPolyDataFilter filter to rotate the spline by a pre-specified small angle a° (such as 3°) with the z-axis of the image world coordinate system as the rotation axis, copy the spline data after each rotation, and repeat this process 180 / a times (if 180 / a is not an integer, round it up);

[0054] S1.7, see Figure 6 , use the vtkAppendPolyData filter to merge the spline graphics data obtained by rotation and copying to obtain a grid-like hemispherical surface, recorded as splineShell.

[0055] Through the operation steps of this embodiment, a spherical data is converted into a hemispherical surface with a grid structure. The grid structure design not only reduces the occlusion of the bone model by the grinding head in the image, but also improves the recognition accuracy of the position and posture of the grinding head by the doctor during the operation. In addition, by adjusting the rotation angle a° and the number of repetitions, the density and shape of the grid-shaped hemispherical surface can be controlled to adapt to different grinding head specifications.

[0056] In some embodiments, using a graphics library tool, constructing a grid-shaped circular bottom cap in an image world coordinate system includes:

[0057] S1.8, see Figure 7 , use the vtkTransformPolyDataFilter filter, rotate the spline data with the z-axis of the image world coordinate system as the rotation axis and a pre-specified larger angle b° (such as 10°) as the rotation step. After each rotation, copy the vtkPolyData data at the current position of the spline, and repeat this process until it rotates 180° (that is, the number of rotations is 180 / b, and if the result is not an integer, round it up);

[0058] S1.9, see Figure 7 , use the vtkAppendPolyData filter to merge the spline graphics data obtained by rotation and copying, and the result is recorded as splineCap;

[0059] S1.10, see Figure 8 , use the vtkTransformPolyDataFilter filter, by setting a specific 4x4 matrix (that is, on the basis of the unit matrix, set the elements of the third row and the third column to 0), set the z-axis coordinate value of each point in the splineCap to 0, so that all points of the splineCap will be projected onto the xy plane of the image world coordinate system, forming a two-dimensional plane data, recorded as flat;

[0060] S1.11. Use the vtkPolyDataNormals filter to process the flat data and recalculate the normal vector of each triangle. Then, use the FlipNormalsOn() method of vtkPolyDataNormals to adjust the normal vector direction of all triangles to the negative z-axis of the image world coordinate system to ensure that the flat display effect is consistent with expectations in the subsequent rendering process.

[0061] S1.12. Use the vtkRegularPolygonSource class to generate a circular graphic data in the xy plane with the origin of the image world coordinate system as the center and R as the radius, denoted as circle;

[0062] S1.13, see Fig. 9 , circle and flat are combined into one graphic data, and the result is recorded as cap, which is the required grid-shaped circular bottom surface.

[0063] This embodiment generates a circular bottom surface with a grid-like structure by controlling the rotation step of the spline data. This grid-like design not only maintains the basic shape of the circular bottom surface, but also reduces the occlusion of surrounding structures in the image, thereby improving the clarity of the surgical field of view. Secondly, the correct position and orientation of the grid-like circular bottom surface cap in the image world coordinate system are ensured through coordinate transformation and normal vector adjustment.

[0064] In some embodiments, using a graphics library tool, constructing a straight handle post in an image world coordinate system includes:

[0065] S1.14, see Fig.10 , with the z-axis of the image world coordinate system as the axis of the cylinder, draw a cylinder with a base radius of r and a height of h, so that the upper base of the cylinder is located on the xy plane.

[0066] Specifically, according to the design requirements of the grinding head, determine the bottom radius r and height h of the straight rod part. It should be noted that the values ​​of r and h should be set reasonably and should not be too large, so as not to adversely affect the overall visual effect and operation of the grinding head. Using the vtkCylinderSource class in the VTK graphics library, draw a cylinder with a bottom radius r and a height h, taking the z-axis of the image world coordinate system as the axis of the cylinder. By adjusting the parameters of vtkCylinderSource, the upper bottom surface of the cylinder falls exactly on the xy plane of the image world coordinate system to ensure the vertical alignment of the straight rod part and the circular bottom surface of the grinding head;

[0067] S1.15. The cylinder will be used as the straight handle part of the grinding head model and is recorded as post.

[0068] This embodiment draws a cylinder that meets the design requirements as the straight handle part of the grinding head by accurately controlling the bottom radius r and height h. Secondly, the vtkCylinderSource class in the VTK graphics library is used to draw the cylinder, which greatly simplifies the construction process and improves the construction efficiency and accuracy. In addition, by ensuring the vertical alignment of the straight rod part with the circular bottom surface of the grinding head, the grinding head model meets the design requirements.

[0069] A second aspect of the present application provides a grinding head model display method for acetabulum grinding visualization, comprising:

[0070] S3, the above-mentioned grinding head model reamer is loaded into the VTK environment as data of vtkPolyData type, and the reamer model is drawn using the conventional rendering pipeline of VTK;

[0071] S4. See Fig.12 , get the vtkActor object of the grinding head model reamer, call the BackfaceCullingOn() method of the vtkActor object, turn on its backface culling attribute, and cull the backface corresponding to reamer, so that during the rendering process, only the triangles facing the camera are drawn, and the triangles facing away from the camera are ignored;

[0072] S5. See Fig.13 , the acetabulum model bone is ground using Reamer after backface culling and displayed in the same view.

[0073] During the visualization process of acetabulum grinding, the grinding head model is often located above the acetabulum model. If backface culling is not performed, some parts of the grinding head, especially the back part facing the camera, may block the key areas of the acetabulum model and affect the doctor's observation. The application of backface culling technology ensures that the part of the grinding head model facing away from the camera will not be rendered, thereby greatly reducing the occlusion of the acetabulum model by the grinding head, allowing the doctor to observe the details of the acetabulum area more clearly during the operation; the hemispherical surface and bottom surface of the grinding head model adopt a grid structure design. The grid structure not only maintains the basic shape of the grinding head, but also allows the doctor to see the acetabulum area behind it through the grinding head through its unique gap design. The combined application of backface culling technology and the grinding head grid structure design effectively solves the problem of the grinding head blocking the acetabulum model during acetabulum grinding, and significantly improves the visualization effect of the operation.

[0074] In addition, by using back-face culling technology, if a triangle is facing away from the camera, the triangle will not be rendered. This method greatly reduces the rendering of unnecessary triangles, shortens the rendering time, and significantly improves rendering efficiency.

[0075] In some embodiments, during the rendering process, only the triangles facing the camera are drawn, while the triangles facing away from the camera are ignored, including:

[0076] S4.1. define a plurality of triangular facets constituting surface data, each triangular facet having a normal vector, the normal vector being perpendicular to the triangular facet and being used to determine the orientation of the triangular facet;

[0077] S4.2, determining a viewpoint vector, which points from the camera position to the triangle patch;

[0078] S4.3, calculating the dot product of the normal vector and the viewpoint vector to determine the orientation of the triangle;

[0079] S4.4. Determine the orientation of the triangle according to the result of the dot product. If the dot product is a negative value, it means that the front of the triangle faces the camera; if the dot product is a positive value, it means that the back of the triangle faces the camera.

[0080] S4.5. During the rendering process, only the triangles whose front faces face the camera are drawn, and the triangles whose back faces face the camera are ignored.

[0081] The acetabulum model bone is ground by Reamer after backface culling and displayed in the same view, including:

[0082] S5.1. rigidly attaching an optical tracking array to a grinding instrument and a acetabulum of a patient;

[0083] S5.2, transmitting back in real time through the positioning camera the transformation matrix TcameraToToolRF from the positioning camera coordinate system Fcamera to the tool tracking array coordinate system FtoolRF, and the transformation matrix TcameraToBoneRF from Fcamera to the bone tracking array coordinate system FboneRF;

[0084] S5.3, perform image registration operation, and use the above two transformation matrices for image navigation positioning to ensure that the relative position relationship between the patient's acetabulum and the grinding instrument in the real world is consistent with the relative position relationship between the acetabulum model bone and the grinding head model reamer in the image space;

[0085] S5.4. Move the grinding instrument in the real world, and use the established image navigation positioning relationship to update the positions of the acetabulum model bone and the grinding head model reamer in the image in real time, so that the relative position relationship between the two in the image space is synchronized with the relative position relationship in the real world.

[0086] The third aspect of the present application provides a grinding head model display system for acetabulum grinding visualization, comprising:

[0087] The model generation unit uses the graphics library tool to construct the grid-shaped hemispherical splineShell, the grid-shaped circular bottom cap and the straight handle post in the image world coordinate system;

[0088] The model merging unit merges the grid-shaped hemispherical splineShell, the grid-shaped circular bottom cap and the straight handle post to form a complete grinding head model reamer;

[0089] The rendering pipeline unit uses the rendering pipeline in the graphics library to draw the grinding head model reamer;

[0090] The back-face culling processing unit calls the back-face culling function in the graphics library and turns on the back-face culling attribute corresponding to the reamer, so that during the rendering process, only the triangles facing the camera are drawn, while the triangles facing away from the camera are ignored;

[0091] Synchronous display unit, using Reamer with backface culling to grind the acetabulum model bone and display it in the same view.

[0092] According to a fourth aspect of the present application, a computer-readable storage medium is provided, wherein a computer program is stored in the computer-readable storage medium, wherein the computer program implements the above-mentioned method steps when executed by a processor.

[0093] According to a fifth aspect of the present application, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method steps when executing the computer program.

[0094] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0095] In the description of the present specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish descriptions and cannot be understood as indicating or suggesting relative importance. It should also be understood that although the terms "first", "second", etc. are used to describe various elements in some embodiments of the present application in the text, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first table can be named as the second table, and similarly, the second table can be named as the first table without departing from the scope of the various described embodiments. The first table and the second table are both tables, but they are not the same table.

[0096] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0097] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A grinding head model display method for acetabulum grinding visualization, characterized in that: include: Use the graphics library tool to construct the grid-shaped hemispherical splineShell, grid-shaped circular bottom cap and straight handle post in the image world coordinate system; Combine the grid-shaped hemispherical splineShell, grid-shaped circular bottom cap and straight handle post to form a complete grinding head model reamer; The grinding head model reamer is drawn using the rendering pipeline in the graphics library; Call the backface culling function in the graphics library and turn on the backface culling attribute corresponding to the realmer, so that during the rendering process, only the triangles facing the camera are drawn, and the triangles facing away from the camera are ignored; The acetabulum model bone is ground using Reamer with backface culling and displayed in the same view.

2. A grinding head model display method for acetabulum grinding visualization according to claim 1, characterized in that: Use the graphics library tools to construct a grid-like hemispherical splineShell in the image world coordinate system, including: With the origin of the image world coordinate system as the center of the sphere and R as the radius, a spherical data volume is generated, which is recorded as sphere; In the image world coordinate system, define an xy plane and generate the corresponding plane data, denoted as plane; Use plane to cut sphere, and obtain the hemispherical shell part located on the positive half axis of z axis after cutting, which is recorded as hemisphere; In the image world coordinate system, a cuboid data volume is generated with the origin as the center, denoted as cuboid, and its length, width, and height are set to a, b, and c respectively, where a is much smaller than R, and b and c are both greater than 2R; Use cuboid to clip the sphere and obtain the part of the sphere that falls inside the cuboid, which is recorded as spline; Take the z-axis of the image world coordinate system as the rotation axis, set an angle a°, rotate the spline around the z-axis 180 / a times, and copy the spline's graphic data after each rotation; The spline graphic data obtained by rotation and copying are merged to obtain a grid-like hemispherical surface, which is recorded as splineShell.

3. A grinding head model display method for acetabulum grinding visualization according to claim 2, characterized in that: Use the graphics library tools to construct a grid-shaped circular bottom cap in the image world coordinate system, including: Taking the z-axis of the image world coordinate system as the rotation axis, rotate the spline graphic data 180 / b times at a preset angle b°, and copy the spline graphic data after each rotation; The spline graphics data obtained by rotation and copying are merged, and the result is recorded as splineCap; By setting the transformation matrix, the z-axis coordinate value of each point on the splineCap is set to 0, so that the splineCap is attached to the xy plane of the image world coordinate system, and the result is recorded as flat; Recalculate the normal vector of each triangle of the flat surface, and adjust the normal vectors of all triangles to face the negative z-axis of the image world coordinate system; With the origin of the image world coordinate system as the center and R as the radius, a ring graphic data is generated in the xy plane, which is recorded as circle; Merge circle and flat into one graphic data, and record the result as cap, which is the required grid-shaped circular bottom surface.

4. The method for displaying a grinding head model for visualization of acetabulum grinding according to claim 1, characterized in that: Use the graphics library tools to construct a straight handle post in the image world coordinate system, including: With the z-axis of the image world coordinate system as the axis of the cylinder, draw a cylinder with a base radius of r and a height of h, so that the upper base of the cylinder is located on the xy plane; The cylinder will be used as the straight handle part of the grinding head model and is recorded as post.

5. The method for displaying a grinding head model for visualization of acetabulum grinding according to claim 1, characterized in that: During rendering, only the triangles facing the camera are drawn, while those facing away from the camera are ignored, including: Define multiple triangular facets constituting the surface data, each triangular facet has a normal vector, the normal vector is perpendicular to the triangular facet and is used to determine the orientation of the triangular facet; Determine a viewpoint vector that points from the camera's position to the triangle patch; Calculate the dot product of the normal vector and the view vector to determine the orientation of the triangle; The orientation of the triangle is determined based on the result of the dot product. If the dot product is a negative value, it means that the front of the triangle faces the camera; if the dot product is a positive value, it means that the back of the triangle faces the camera. During rendering, only the triangles facing the camera are drawn, while the triangles facing the camera from the back are ignored.

6. A grinding head model display system for visualization of acetabulum grinding, characterized in that: include: The model generation unit uses the graphics library tool to construct the grid-shaped hemispherical splineShell, the grid-shaped circular bottom cap and the straight handle post in the image world coordinate system; The model merging unit merges the grid-shaped hemispherical splineShell, the grid-shaped circular bottom cap and the straight handle post to form a complete grinding head model reamer; The rendering pipeline unit uses the rendering pipeline in the graphics library to draw the grinding head model reamer; The back-face culling processing unit calls the back-face culling function in the graphics library and turns on the back-face culling attribute corresponding to the reamer, so that during the rendering process, only the triangles facing the camera are drawn, while the triangles facing away from the camera are ignored; Synchronous display unit, using Reamer with backface culling to grind the acetabulum model bone and display it in the same view.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, wherein the computer program implements the method steps of any one of claims 1 to 5 when executed by a processor.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method steps of any one of claims 1 to 5 are implemented.

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