A visualization method and storage medium for acetabulum grinding

Abstract

The present invention discloses a visualization method for acetabulum grinding. The method determines the grinding area by generating a hemispherical shell model, performs color area division in combination with the vtkbool module, and establishes an acetabulum color separation model. During the operation, the acetabulum color separation model is updated in real time using a grinding head model, and VTK Boolean operations are used to maintain surface smoothness without the need for data format conversion, thereby improving computing efficiency and model accuracy. The present invention effectively solves the problems of granularity and low computing efficiency in the prior art, and provides accurate and efficient visual feedback for navigated acetabulum replacement surgery.

Description

Technical Field

[0001] The present invention relates to the technical field of medical image processing, and in particular to a visualization method and storage medium for acetabulum grinding. Background Art

[0002] Acetabular grinding is a crucial step in navigation-guided acetabular replacement surgery, directly impacting both the success of the surgery and the patient's recovery. Traditional acetabular grinding methods rely heavily on the surgeon's experience and surgical technique, making it difficult to precisely control the amount and location of grinding, which can easily lead to under- or over-grinding. To address these issues, navigation-guided acetabular grinding methods based on computer vision and medical image processing have gained widespread attention and application in recent years.

[0003] However, existing methods for visualizing acetabular grinding using navigation still have some significant technical drawbacks. One common approach is to convert surface mesh data into a three-dimensional image composed of voxels and then perform addition and subtraction operations on the three-dimensional image to visualize the grinding process. While this method can simulate the grinding process to a certain extent, its drawbacks include:

[0004] (1) Decreased model accuracy: When surface mesh data is converted to 3D images, the voxel size of the image is limited, which inevitably leads to a decrease in model accuracy, resulting in a granular (unsmooth) visualization result. This granularity not only affects the visual effect but may also mislead doctors' judgment and operation.

[0005] (2) Low computational efficiency: Each time a cutting operation is performed, the calculated 3D image needs to be converted back into surface mesh data. This data format conversion process is time-consuming, resulting in low visualization computation efficiency. During surgeries with high real-time requirements, this low efficiency may cause screen freezes, affecting the smooth progress of the surgery.

[0006] In order to overcome the above-mentioned defects, some researchers have tried to pre-process the three-dimensional images, such as filtering operations, to improve the smoothness of the visualization results. For example, CN116636902A proposed a method for direct visualization based on three-dimensional image volume drawing. Although it eliminates the step of reconstructing the surface after each cut and improves the computational efficiency, the visualization results still have obvious granularity. CN116824100A has made improvements based on CN116636902A. Through additional filtering operations and specific color mapping tables during the initialization of the three-dimensional image, the volume drawing display has a smoothing effect. However, this method still cannot completely solve the problem of obvious granularity of the newly formed section each time it is cut. Summary of the Invention

[0007] The purpose of the present invention is to provide a visualization method for acetabulum grinding in response to the problems existing in the prior art, thereby solving the problems of granularity, low computational efficiency, etc. in the prior art.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] A visualization method for acetabulum grinding comprises the following steps:

[0010] S1. Generate two hemisphere shell surface mesh models based on the acetabular cup model, denoted as hemisphere_0 and hemisphere_1, respectively. The radius of hemisphere_0 is the same as the outermost hemispherical part of the cup, while the radius of hemisphere_1 is larger than that of hemisphere_0 by a specified buffer distance n.

[0011] S2. Move the cup to the predetermined position of the acetabulum model bone, obtain its transformation matrix T, and apply the transformation matrix T to hemisphere_0 and hemisphere_1, so that they move to the same position as the cup;

[0012] S3. Use the vtkbool module to perform Boolean operations on the bone to generate the green area to be polished, the buffer area Buffer, and the warning area Red. Then create a thin shell White that wraps the Red area to establish the acetabulum color separation model.

[0013] S4. Use the grinding head model reamer to grind the acetabulum color separation model, and update the acetabulum model through real-time difference operation to reflect the grinding process.

[0014] Step S1 specifically includes:

[0015] S1.1. Import an acetabular cup model into the image coordinates. The model is denoted as cup. The outermost layer of the cup is hemispherical. The center of the hemisphere is determined to be the rotation center o of the acetabular cup, and the radius of the hemisphere is determined to be a known value r.

[0016] S1.2. Generate a hemisphere shell surface mesh model with the center o as the circle center and the radius r of the hemisphere as the radius. This model is denoted as hemisphere_0. Its bottom surface is flush with the bottom surface of cup to ensure the spatial correspondence between the two.

[0017] S1.3. Similarly, generate another hemispherical shell surface mesh model with the sphere center o as the circle center and r+n as the radius, where n is the thickness of the specified white buffer area.

[0018] Step S2 specifically includes:

[0019] S2.1. Import the acetabulum model into the image coordinate system, denoted as bone. Move the previously imported cup model (cup) to a predetermined position on the acetabulum color separation model (bone) by translation and / or rotation. During the movement, record and obtain the rigid body transformation matrix T of the cup from its initial position to its planned position in the image coordinate system.

[0020] S2.2. Apply the rigid body transformation matrix T to hemisphere_0 and hemisphere_1. By applying this transformation matrix, hemisphere_0 and hemisphere_1 are also moved to the same planned position as cup.

[0021] Step S3 specifically includes:

[0022] S3.1. Use the vtkbool module to perform an intersection operation on bone and hemisphere_0. The resulting surface mesh data is recorded as Green. The vtkActor color corresponding to Green is set to green to indicate the area to be polished.

[0023] S3.2. Use the vtkbool module to perform an intersection operation on bone and hemisphere_1, and record the resulting surface mesh data as Tmp. Use the vtkbool module to perform a difference operation on Tmp and Green, and record the resulting surface mesh data as Buffer. Set the vtkActor color corresponding to Buffer to white to indicate the buffer area.

[0024] S3.3. Use the vtkbool module to perform a difference operation on bone and hemisphere_1. The resulting surface mesh data is recorded as Red. The vtkActor color corresponding to Red is set to red to indicate the warning area.

[0025] In step S3, a thin shell White is created to wrap Red, including:

[0026] S3.4. Copy a piece of Red surface mesh data; use the vtkPolyDataNormals filter to calculate the normal vector for each vertex of the copied Red surface mesh data; use the vtkWarpVector filter to move each vertex of the copied Red surface mesh data along its normal vector direction by a distance m that is much smaller than the accuracy of the navigation system, generating a white thin shell area White that wraps Red; set the vtkActor color corresponding to White to white.

[0027] In step S3, a color separation model of the acetabulum is established, including:

[0028] S3.5. Create a vtkRenderer object as the rendering environment;

[0029] S3.6. For the four areas Green, Buffer, Red, and White, create corresponding vtkActor objects and set their color properties.

[0030] S3.7. Add these four vtkActor objects to the same vtkRenderer so that they can be displayed together in the same scene;

[0031] S3.8. Render the entire scene using VTK's rendering mechanism to create a color-coded acetabulum model, where the area to be polished is green, the buffer area is white, and the area beyond the planned area is red, with the red part obscured by a thin white shell.

[0032] Step S4 specifically includes:

[0033] S4.1. The surface mesh model of the grinding head is called “reamer”. Reamer is a hemispherical shell model with the same size as the actual grinding head.

[0034] S4.2. During the guided grinding process, the acetabulum color model remains stationary in the image, while the real-world grinding head moves in the image. The relative position of the real-world grinding head and the acetabulum model is consistent with the relative position of the real-world grinding head and the patient's acetabulum.

[0035] S4.3. Whenever the position of the reactor changes, the acetabulum color separation model is updated using the Boolean operation function of the VTK tool.

[0036] Step S4.3 specifically includes:

[0037] S4.3.1. Use the vtkbool module to perform a set difference operation on Green and reamer. If reamer and Green intersect, remove the intersecting part from Green, indicating that the part has been ground.

[0038] S4.3.2. Use the vtkbool module to perform a difference operation on the buffer and the reactor. If the buffer and the reactor intersect, remove the intersecting part from the buffer, indicating that it is close to the edge of the planned grinding area.

[0039] S4.3.3. Use the vtkbool module to perform a set difference operation on the red area Red and reactor. If reactor and Red intersect, the intersection is removed from Red, indicating that the system has entered the warning area.

[0040] S4.3.4. Use the vtkImplicitPolyDataDistance filter to determine whether each vertex in the White area is inside the realer mesh model; if the vertex is inside the realer, use the vtkClipPolyData filter to remove the vertex and its adjacent parts from the White and update the White area.

[0041] A computer-readable storage medium stores a computer program, wherein the computer program implements the above method steps when executed by a processor.

[0042] 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-mentioned method steps when executing the computer program.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] By directly performing Boolean operations on the surface mesh data, the process of converting the surface mesh data into voxel-based image data and then performing operations is avoided, and the fineness and smoothness of the original surface mesh data are retained, making the visualization of the polishing results smoother and free of granularity.

[0045] Traditional voxel-based cutting and reconstruction methods require image-to-surface reconstruction after each cut. This conversion process is time-consuming and can easily cause screen freezes. However, the surface Boolean operations in this application are performed directly on the surface mesh data without the need for data format conversion, thereby greatly improving computational efficiency and reducing system latency.

[0046] Since the conversion between surface mesh data and voxel image data is avoided, the present application can more accurately preserve the geometric details and morphological features of the model, improve the accuracy of the polished model, and make the visualization results closer to the real situation;

[0047] During the grinding process, this application intuitively reflects the relative position relationship between the grinding head and the acetabulum model and the grinding progress through real-time updates of different color areas. When the grinding exceeds the planned area, the display of the red warning area can immediately remind the operator to pay attention and avoid possible surgical risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 This is a schematic structural diagram of an acetabular cup model in one embodiment of the present application;

[0050] Figure 2 This is a structural diagram of the hemisphere shell surface grid model hemisphere_0 in one embodiment of the present application;

[0051] Figure 3 This is a structural diagram of a hemisphere shell surface grid model hemisphere_1 in one embodiment of the present application;

[0052] Figure 4 This is a schematic diagram of moving a cup from an initial position to a planned position in one embodiment of the present application;

[0053] Figure 5 This is a schematic diagram of moving hemisphere_0 and hemisphere_1 to planned positions in an embodiment of the present application;

[0054] Figure 6 This is a schematic diagram of the intersection operation of bone and hemisphere_0 in one embodiment of the present application;

[0055] Figure 7 This is a schematic diagram of performing an intersection operation on bone and hemisphere_1, and a difference operation on Tmp and Green in one embodiment of the present application;

[0056] Figure 8 This is a schematic diagram of performing a difference operation on bone and hemisphere_1 in one embodiment of the present application;

[0057] Figure 9 This is a schematic diagram of generating a thin shell region White in one embodiment of the present application;

[0058] Figure 10 A schematic diagram of an acetabulum color separation model in one embodiment of the present application;

[0059] Figure 11 Schematic diagram of updating the acetabulum color model in one embodiment of the present application. DETAILED DESCRIPTION

[0060] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0061] In a first aspect of the present application, a method for visualizing acetabulum grinding is provided, comprising the following steps:

[0062] S1. Generate two hemisphere shell surface mesh models based on the acetabular cup model, denoted as hemisphere_0 and hemisphere_1, respectively. The radius of hemisphere_0 is the same as the outermost hemispherical part of the cup, while the radius of hemisphere_1 is larger than that of hemisphere_0 by a specified buffer distance n.

[0063] Specifically, by generating two hemispheres with different radii, hemisphere_0 and hemisphere_1, we can precisely define the acetabular area (Green) that requires grinding, as well as the buffer area (Buffer) and warning area (Red) that may exceed the planned grinding area. The buffer distance n can be specified based on the specific situation, such as setting n to 1mm, to meet different surgical requirements.

[0064] S2. Move the cup to the predetermined position of the acetabulum model bone, obtain its transformation matrix T, and apply the transformation matrix T to hemisphere_0 and hemisphere_1, so that they move to the same position as the cup, providing an accurate benchmark for subsequent intersection and difference operations.

[0065] S3. Use the vtkbool module to perform Boolean operations on the bone to generate the green area to be polished, the buffer area Buffer, and the warning area Red. Create a thin shell White that wraps the Red area to establish the acetabulum color separation model.

[0066] S4. Use the grinding head model reamer to grind the acetabulum color separation model, and update the acetabulum model through real-time difference operation to reflect the grinding process.

[0067] In summary, by directly performing Boolean operations on surface mesh data, the process of converting surface mesh data into three-dimensional images is avoided, thereby reducing the accuracy loss caused by voxel size and improving the smoothness and accuracy of the visualization results.

[0068] By generating and dynamically coloring color area templates, the operator can intuitively understand the current grinding progress and position, making it easier to adjust the operation in a timely manner and improving the safety and success rate of the operation.

[0069] It should be noted that vtkbool is an open source tool library developed based on VTK, focusing on Boolean operations on surface mesh data; vtkbool can perform union operations (Union), intersection operations (Intersection) and difference operations (Difference) on two surface mesh data, thereby meeting the needs of complex three-dimensional graphics processing; the input and output of vtkbool are both spatial closed geometric bodies, which enables it to maintain data integrity and accuracy when processing three-dimensional models.

[0070] It should be noted that the data types of all surface mesh data used in this embodiment are vtkPolyData; vtkPolyData is a data structure used to represent polygon data in VTK. It can store geometric information such as vertices, edges, and faces, as well as related attribute information such as color and texture. vtkPolyData is an efficient and flexible data type for processing three-dimensional graphics data.

[0071] In some embodiments, step S1 specifically includes:

[0072] S1.1、 Figure 1 As shown, the acetabular cup model is imported into the image coordinates and is denoted as cup. The outermost layer of the cup is hemispherical. The center of the hemisphere is determined to be the rotation center o of the acetabular cup, and the radius of the hemisphere is a known value r.

[0073] S1.2, such as Figure 2 As shown in the figure, with the center o as the center of the circle and the radius r of the hemisphere as the radius, a hemispherical shell surface mesh model is generated. The model is recorded as hemisphere_0, and its bottom surface is flush with the bottom surface of the cup to ensure the correspondence between the two in spatial position, so that the generated Green area can accurately reflect the part of the acetabulum that needs to be ground.

[0074] S1.3, such as Figure 3 As shown in the figure, another hemispherical shell surface mesh model is generated with the sphere center o as the circle center and r+n as the radius, where n is the thickness of the specified white buffer area. By setting the buffer layer, the operator can adjust the grinding path in time to avoid over-grinding.

[0075] This embodiment accurately imports the acetabular cup model, generates two hemispherical shell surface mesh models with different radii, and sets a reasonable buffer area, thereby providing a basis for subsequent grinding area planning and dynamic coloring.

[0076] In some embodiments, step S2 specifically includes:

[0077] S2.1, such as Figure 4 As shown, the acetabulum model is imported into the image coordinates and the model is recorded as bone. The previously imported acetabulum cup model cup is moved to the predetermined position on the acetabulum color separation model bone by translation and / or rotation. During the movement, the rigid body transformation matrix T that the cup undergoes from the initial position to the planned position in the image coordinate system is recorded and obtained.

[0078] S2.2, such as Figure 5 As shown, the rigid body transformation matrix T is applied to hemisphere_0 and hemisphere_1. By applying this transformation matrix, hemisphere_0 and hemisphere_1 are also moved to the same planned position as cup.

[0079] This embodiment achieves accuracy and consistency in grinding area planning by precisely moving the acetabular cup model to a predetermined position, recording a transformation matrix, and applying the transformation matrix to the hemispherical shell model.

[0080] In some embodiments, in step S3, a vtkbool module is used to perform a Boolean operation on bone to generate a to-be-polished area Green, a buffer area Buffer, and a warning area Red, respectively, including:

[0081] S3.1, such as Figure 6 As shown, the vtkbool module is used to perform an intersection operation on bone and hemisphere_0. The resulting surface mesh data is recorded as Green, and the vtkActor color corresponding to Green is set to green to indicate the area to be polished.

[0082] S3.2, such as Figure 7 As shown, the vtkbool module is used to perform an intersection operation on bone and hemisphere_1, and the resulting surface mesh data is recorded as Tmp; the vtkbool module is used to perform a difference operation on Tmp and Green, and the resulting surface mesh data is recorded as Buffer. The vtkActor color corresponding to Buffer is set to white to indicate the buffer area.

[0083] S3.3, such as Figure 8 As shown, the vtkbool module is used to perform a difference operation on bone and hemisphere_1. The obtained surface mesh data is recorded as Red, and the vtkActor color corresponding to Red is set to red to indicate the warning area.

[0084] In summary, in this embodiment, the to-be-polished area Green, the buffer area Buffer, and the warning area Red are generated through Boolean operations and color identification, which provides support for grinding and visualization during the surgical process.

[0085] In some embodiments, in step S3, creating a thin shell White that wraps Red includes:

[0086] S3.4, such as Figure 9 As shown, copy a piece of Red surface mesh data; use the vtkPolyDataNormals filter to calculate the normal vector for each vertex of the copied Red surface mesh data; use the vtkWarpVector filter to move each vertex of the copied Red surface mesh data along its normal vector direction by a distance m much smaller than the accuracy of the navigation system (such as 0.01mm), generating a white thin shell area White that wraps Red; set the vtkActor color corresponding to White to white.

[0087] The main purpose of this step is to generate a tightly wrapped but slightly different volume white shell area White outside the warning area Red, so as to avoid the striped display problem caused by the identical volume shapes of the Red and White areas during rendering. By adding a tiny white border to the Red area, namely the White area, the visual distinction can be significantly improved, allowing operators to more clearly identify the boundary between the warning area and the normal grinding area.

[0088] In some embodiments, in step S3, establishing an acetabulum color separation model includes:

[0089] S3.5. Create a vtkRenderer object as the rendering environment.

[0090] S3.6. Create corresponding vtkActor objects for the Green, Buffer, Red, and White regions, and set their color properties. A vtkActor is the basic unit used to represent 3D graphics objects in VTK. It associates graphics data with rendering properties.

[0091] S3.7. Add these four vtkActor objects to the same vtkRenderer so that they are displayed together in the same scene to form a complete acetabulum color separation model.

[0092] S3.8. Render the entire scene using VTK's rendering mechanism, where the area to be polished is green, the buffer area is white, and the area beyond the planned area is red, with the red part obscured by a thin white shell. Figure 10 shown.

[0093] In summary, through the above steps, the VTK-based acetabulum color separation model achieves accurate geometric reconstruction and provides intuitive operation feedback and safety warnings through visualization technology.

[0094] In some embodiments, step S4 specifically includes:

[0095] S4.1. The surface mesh model of the grinding head is referred to as “reamer”. Reamer is a hemispherical shell model with the same size as the real grinding head, thereby accurately simulating the shape and movement of the real grinding head in the virtual environment.

[0096] S4.2. During the guided polishing process, the acetabulum color model remains stationary in the image, and the reactor moves in the image as the real-world grinding head moves. The relative position relationship between the reactor and the acetabulum model conforms to the relative position relationship between the real-world grinding head and the patient's acetabulum.

[0097] S4.3. Whenever the position of the reactor changes, the acetabulum color separation model is updated using the Boolean operation function of the VTK tool to simulate the removal effect of the grinding head on the acetabulum.

[0098] In summary, in this embodiment, the acetabulum model will be updated in real time as the grinding head moves, showing the current grinding status. The distribution and changes of different color areas can intuitively reflect the progress of grinding and whether it exceeds the planned range. If the grinding exceeds the planned area, the red area Red will be exposed, sending a warning signal to the operator to remind him to pay attention and adjust the grinding operation.

[0099] In some embodiments, step S4.2 specifically includes:

[0100] S4.2.1. Rigidly attach an optical tracking array to the grinding instrument and the patient's acetabulum.

[0101] S4.2.2. The positioning camera transmits in real time 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;

[0102] S4.2.3. Perform image registration, using the two transformation matrices for image navigation and positioning to ensure that the relative positional relationship between the patient's acetabulum and the grinding instrument in the real world is consistent with the relative positional relationship between the acetabulum model and the grinding instrument model in image space.

[0103] S4.2.4. When the grinding instrument moves in the real world, use the established image navigation positioning relationship to update the positions of the acetabulum model and the grinding instrument model 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.

[0104] In some embodiments, as Figure 11 As shown, step S4.3 specifically includes:

[0105] S4.3.1. Use the vtkbool module to perform a difference operation on Green and reamer. If reamer and Green intersect, remove the intersecting part from Green, indicating that the part has been ground. Then use the updated Green area surface mesh data to redraw the corresponding part in the acetabulum color separation model, so that the ground part is reflected in real time.

[0106] S4.3.2. Use the vtkbool module to perform a difference operation on the buffer and the realmer. If the buffer and the realmer intersect, remove the intersecting part from the buffer, indicating that it is close to the edge of the planned grinding area. Then use the updated buffer area surface mesh data to redraw the corresponding part of the acetabulum color separation model to ensure that when the grinding approaches the planned edge, the buffer area can accurately reflect the remaining safety range.

[0107] S4.3.3. Use the vtkbool module to perform a difference operation on the red area Red and the reactor. If reactor and Red intersect, the intersection is removed from Red, indicating that the warning area has been entered. Use the updated surface mesh data of the Red area to redraw the corresponding part of the acetabulum model to ensure that when the grinding exceeds the planned area, the red area can reflect the dangerous area in real time and issue a warning to the operator.

[0108] S4.3.4. Use the vtkImplicitPolyDataDistance filter to determine whether each vertex on the White area is inside the reamer mesh model; if the vertex is inside the reamer, use the vtkClipPolyData filter to remove the vertex and its adjacent parts from the White, and update the White area; the result of the clipping operation is a new White area surface mesh data, which reflects the remaining part after the grinding head penetrates the white thin shell; use the clipped White area surface mesh data to update the corresponding part in the acetabulum color separation model, so that when the grinding head penetrates the white thin shell, the red warning area will be exposed, providing a clear warning signal to the operator.

[0109] In this embodiment, through the above four sub-steps, the acetabulum color separation model can be updated in real time, accurately reflecting the movement trajectory and removal effect of the grinding head, and providing doctors or operators with intuitive and accurate surgical navigation and warning information.

[0110] According to a second aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, wherein the computer program implements the above-mentioned method steps when executed by a processor.

[0111] According to a third 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.

[0112] 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 this application.

[0113] In the description of this application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish descriptions and should not be understood as indicating or implying relative importance. It should also be understood that although the terms "first", "second", etc. are used in the text to describe various elements in some embodiments of the present application, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first table can be named a second table, and similarly, a second table can be named a first table without departing from the scope of the various described embodiments. Both the first table and the second table are tables, but they are not the same table.

[0114] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0115] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A visualization method for acetabulum grinding, characterized in that: The following steps are involved: S1. Generate two hemisphere shell surface mesh models based on the acetabular cup model, denoted as hemisphere_0 and hemisphere_1, respectively. The radius of hemisphere_0 is the same as the outermost layer of the cup, while the radius of hemisphere_1 is larger than that of hemisphere_0 by a specified buffer distance n. S2, move the cup to the predetermined position of the acetabulum model bone, obtain its transformation matrix T, and apply the transformation matrix T to hemisphere_0 and hemisphere_1; S3. Use the vtkbool module to perform Boolean operations on the bone to generate the green area to be polished, the buffer area Buffer, and the warning area Red. Create a thin shell White that wraps the Red area to establish the acetabulum color separation model. S4, using the grinding head modelreamer to grind the acetabulum color separation model, and updating the model through real-time difference operation to reflect the grinding process; In step S3, establishing the acetabulum color separation model includes: S3.

5. Create a vtkRenderer object as the rendering environment; S3.

6. For the four areas Green, Buffer, Red, and White, create corresponding vtkActor objects and set their color properties. S3.

7. Add these four vtkActor objects to the same vtkRenderer so that they can be displayed together in the same scene; S3.

8. Render the entire scene using VTK's rendering mechanism to create a color-coded acetabulum model, where the area to be polished is green, the buffer area is white, and the area beyond the planned area is red, with the red portion obscured by a thin shell. Step S4 specifically includes: S4.

1. The surface mesh model of the grinding head is called “reamer”. Reamer is a hemispherical shell model with the same size as the actual grinding head. S4.

2. During the guided grinding process, the acetabulum color model remains stationary in the image, while the real-world grinding head moves in the image. The relative position of the real-world grinding head and the acetabulum model is consistent with the relative position of the real-world grinding head and the patient's acetabulum. S4.

3. Whenever the position of the reactor changes, the acetabulum color separation model is updated using the Boolean operation function of the VTK tool.

2. The visualization method for acetabulum grinding according to claim 1, characterized in that: Step S1 specifically includes: S1.

1. Import an acetabular cup model into the image coordinates. The model is denoted as cup. The outermost layer of the cup is hemispherical. The center of the hemisphere is determined to be the rotation center o of the acetabular cup, and the radius of the hemisphere is determined to be a known value r. S1.

2. Generate a hemisphere shell surface mesh model with the center o as the circle center and the radius r of the hemisphere as the radius. This model is denoted as hemisphere_0. Its bottom surface is flush with the bottom surface of cup to ensure the spatial correspondence between the two. S1.

3. Similarly, generate another hemispherical shell surface mesh model with the sphere center o as the circle center and r+n as the radius, where n is the thickness of the specified buffer area.

3. The visualization method for acetabulum grinding according to claim 1, characterized in that: Step S2 specifically includes: S2.

1. Import the acetabulum model into the image coordinate system, denoted as bone. Move the previously imported cup model (cup) to a predetermined position on the acetabulum color separation model (bone) by translation and / or rotation. During the movement, record and obtain the rigid body transformation matrix T of the cup from its initial position to its planned position in the image coordinate system. S2.

2. Apply the rigid body transformation matrix T to hemisphere_0 and hemisphere_1. By applying this transformation matrix, hemisphere_0 and hemisphere_1 are also moved to the same planned position as cup.

4. The visualization method for acetabulum grinding according to claim 1, characterized in that: In step S3, the vtkbool module is used to perform Boolean operations on bone to generate the to-be-polished area Green, the buffer area Buffer, and the warning area Red, respectively, including: S3.

1. Use the vtkbool module to perform an intersection operation on bone and hemisphere_0. The resulting surface mesh data is recorded as Green. The vtkActor color corresponding to Green is set to green to indicate the area to be polished. S3.

2. Use the vtkbool module to perform an intersection operation on bone and hemisphere_1, and record the resulting surface mesh data as Tmp. Use the vtkbool module to perform a difference operation on Tmp and Green, and record the resulting surface mesh data as Buffer. Set the vtkActor color corresponding to Buffer to white to indicate the buffer area. S3.

3. Use the vtkbool module to perform a difference operation on bone and hemisphere_1. The resulting surface mesh data is recorded as Red. The vtkActor color corresponding to Red is set to red to indicate the warning area.

5. The visualization method for acetabulum grinding according to claim 4, characterized in that: In step S3, the creation of the thin shell White that wraps Red includes: S3.

4. Copy a piece of Red surface mesh data; use the vtkPolyDataNormals filter to calculate the normal vector for each vertex of the copied Red surface mesh data; use the vtkWarpVector filter to move each vertex of the copied Red surface mesh data along its normal vector direction by a distance m that is much smaller than the accuracy of the navigation system, generating a white thin shell area White that wraps Red; set the vtkActor color corresponding to White to white.

6. The visualization method for acetabulum grinding according to claim 1, characterized in that: Step S4.3 specifically includes: S4.3.

1. Use the vtkbool module to perform a set difference operation on Green and reamer. If reamer and Green intersect, remove the intersecting part from Green, indicating that the part has been ground. S4.3.

2. Use the vtkbool module to perform a difference operation on the buffer and the reactor. If the buffer and the reactor intersect, remove the intersecting part from the buffer, indicating that it is close to the edge of the planned grinding area. S4.3.

3. Use the vtkbool module to perform a set difference operation on the red area Red and reactor. If reactor and Red intersect, the intersection is removed from Red, indicating that the area has entered the warning zone. S4.3.

4. Use the vtkImplicitPolyDataDistance filter to determine whether each vertex in the White area is inside the realer mesh model; if the vertex is inside the realer, use the vtkClipPolyData filter to remove the vertex and its adjacent parts from the White and update the White area.

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 according to any one of claims 1 to 6 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, wherein: When the processor executes the computer program, the method steps according to any one of claims 1 to 6 are implemented.

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