A femoral model construction system and method

Abstract

The present application relates to a kind of femur model construction system and method.System at least includes three-dimensional model creation module and three-dimensional model extraction module.Three-dimensional model creation module is configured as: the two-dimensional tomogram image data of femoral head site is reconstructed to establish the three-dimensional grid model of femoral head, the three-dimensional grid model of femoral head is by a series of triangular facet mesh set under three-dimensional coordinate system, this three-dimensional grid model at least includes original necrosis model A and original bone model B.Three-dimensional model extraction module traverses each triangular facet mesh of original necrosis model A, the three vertices of each triangular facet mesh are extended to obtain respective corresponding line segment along respective corresponding normal direction, if the three vertices of triangular facet mesh respective corresponding line segment is not intersected with original bone model B, then take out the facet, and it is placed in set S 11 .

Description

[0001] The original basis of the divisional application is patent application No. CN201910878678.2, filed on September 17, 2019, with the title of “Femur integrity analysis system and femur integrity analysis model construction method”. TECHNICAL FIELD

[0002] The present application relates to the field of medical imaging technology, in particular to a femur model construction system and method. BACKGROUND

[0003] It is an indisputable fact that femoral head necrosis seriously endangers the health and quality of life of patients, and its treatment has become a worldwide problem. The difficulties are as follows: the patients with femoral head necrosis are relatively young and are not easy to undergo joint replacement, and if joint replacement is performed, the risk of multiple revisions will be faced; once the femoral head collapses, no matter what treatment is used, the original shape of the femoral head cannot be restored, and osteoarthritis is easy to occur; due to the lack of precise preoperative design, the success rate of current hip preservation treatment is not completely satisfactory; if the young patients succeed in hip preservation, joint replacement can be avoided or significantly delayed, greatly reducing the risk of multiple revisions; if the femoral head collapse can be prevented, the risk of irreversible damage caused by changes in the shape of the femoral head and secondary osteoarthritis can be avoided, therefore, preventing and treating femoral head collapse and keeping the hip joint in its original shape are important principles for maintaining the health of the femoral head.

[0004] The choice of various schemes for treating femoral head necrosis is based on clinical data, however, conventional nuclear magnetic resonance can only estimate the necrotic area from different planar sections, and cannot determine the necrotic volume of the femoral head, the scanning planes before and after treatment are not consistent, and the therapeutic effect cannot be accurately evaluated. More and more researchers have begun to use finite element analysis software to verify the feasibility of surgical schemes. With the popularity of minimally invasive surgery, more people will choose new treatment schemes. For example, core decompression and implantation of a tantalum rod or a titanium alloy support frame, etc., through the femoral head decompression channel, these support devices are implanted into the femoral head for minimally invasive surgery, but the area supported by all these devices is too small, thus there are certain defects. The memory metal nickel-titanium alloy tennis ball designed by Wang Yan is woven from metal wires, although the support area is relatively large, the support force is correspondingly small. In addition, the metal tennis ball needs to open the femoral head, and the trauma is relatively large. It can be seen that although there are many treatment schemes for femoral head necrosis, there is no most reliable scheme, and through finite element analysis verification, many problems are exposed.

[0005] Finite element analysis method is to obtain real data through clinical experiment, and then use computer to build three-dimensional entity model of femoral head, and use finite element analysis software for calculation and analysis. With the help of finite element model, the in-vivo tissue can be non-invasively examined, which can assist the formulation of surgical diagnosis and treatment plan and the simulation of quantitative surgery. Compared with experimental model, the quantitative experiment can more accurately explain the problem by reducing the influence of multiple factors. In order to more realistically simulate the repair effect of the support device on the patient with ischemic necrosis of the femoral head, it is necessary to establish a finite element model for the ischemic necrosis of the femoral head by using finite element analysis.

[0006] A Chinese patent (CN107802378A) discloses a talus local repair body with a porous structure and a design and manufacturing method thereof. The method comprises the following steps: extracting a model of a talus part based on CT data of a patient, reconstructing a three-dimensional model, and exporting an STL format file; importing the STL format file into a three-dimensional modeling software Rhinoceros for reverse modeling design; extracting and fitting a local necrotic surface to obtain a surface that matches the curvature of the surrounding healthy surface; using the fitted surface to design a repair body, determining the position of a fixing nail, and using a grasshopper plug-in to complete the modeling of the porous structure; using laser selective melting technology to prepare a personalized local talus repair body; polishing the upper surface of the repair body, and performing acid etching treatment on the lower porous structure. The patent can achieve the effect of rapid repair, shorten the waiting time of patients, and improve the response speed of repair prosthesis supply.

[0007] A Chinese patent (CN104462636B) discloses a modeling method of a necrotic femoral head repair model based on an umbrella-shaped femoral head support device. The method comprises the following steps: 1. Obtaining a three-dimensional model of the femoral head to be repaired: obtaining a NURBS surface model of the femoral head to be repaired, the femoral head to be repaired being a femoral head with necrotic areas and repaired by a femoral head support device; the femoral head support device is composed of an umbrella-shaped support device and a support sleeve; 2. According to the shape of the umbrella-shaped support device, determine the necrotic area to be separated, and establish a necrotic femoral head model; 3. Establishing a femoral head support device model; 4. Establishing a necrotic femoral head implant model: establishing a three-dimensional model of the necrotic femoral head implant model with an implant channel and the implanted bone; 5. Establishing a necrotic femoral head repair model. The patent method steps are simple, reasonable in design, easy to implement, good in use effect, can simply and quickly establish a repair model of the femoral head support device implanted in the necrotic femoral head, and the quality of the established repair model is high.

[0008] The above patents in the prior art can establish a necrotic femoral head model or obtain a corresponding repair surface of the lesion site through CT / MR scanning image data of the femoral head necrosis, but the modeling method provided by the patents can only establish a repair model of the femoral head support implanted into the necrotic femoral head. However, for subsequent surgical treatment of femoral head necrosis, the modeling method provided by the patents cannot achieve accurate segmentation of the femoral head model, and cannot judge the spatial stereoscopic relationship of the segmented femoral head model during the model construction process, so the model extraction accuracy is low, which will greatly affect the subsequent surgical treatment of femoral head necrosis. Not only can it not meet the femoral head necrosis surgery simulation training of orthopedic doctors, but also cannot fully meet the clinical needs of the surgical treatment of femoral head necrosis. In addition, whether the femoral head necrosis will progress to collapse is closely related to the necrotic surface area, which makes it impossible to further achieve early prediction and prevention of femoral head ischemic necrosis collapse.

[0009] In addition, on the one hand, there is inevitably some difference between the applicant's understanding of the skilled person in the art and the examination department; on the other hand, the inventors have studied a large number of literatures and patents when making the present application, but due to the limited space, all the details and contents are not listed in detail. However, this does not mean that the present application does not have these characteristics of the prior art. On the contrary, the present application already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art in the background art at any time according to the relevant provisions of the examination guidelines. SUMMARY

[0010] In view of the deficiencies of the prior art, the present application provides a femur integrity analysis system, which at least includes a three-dimensional model creation module, a three-dimensional model extraction module and a data analysis module. The three-dimensional model creation module is configured to reconstruct a three-dimensional grid model of the femoral head by two-dimensional tomographic image data of the femoral head part. The three-dimensional grid model of the femoral head is composed of a series of triangular facet mesh sets under a three-dimensional coordinate system. The three-dimensional grid model at least includes an original necrosis model A and an original bone model B. The three-dimensional model extraction module is used to perform at least one distance threshold iteration calculation on the triangular facet mesh sets of the original necrosis model A and the original bone model B by using a distance threshold algorithm about the acetabular lunula or about the original necrosis model A, so as to sequentially complete a spatial coarse registration process and a spatial fine registration process, and extract a processed femoral head weight-bearing accurate area and a necrosis weight-bearing accurate area. The data analysis module is used to cut the femoral head weight-bearing accurate area and the necrosis weight-bearing accurate area according to the cutting surface established thereby, so as to obtain a respective corresponding weight-bearing stress concentration area on the femoral head weight-bearing accurate area and the necrosis weight-bearing accurate area, and perform integrity calculation on at least one of the weight-bearing stress concentration areas.

[0011] The femur integrity analysis system at least includes a three-dimensional model creating module. The three-dimensional model creating module is configured to reconstruct two-dimensional tomographic image data of a femoral head site to establish a three-dimensional mesh model of the femoral head, the three-dimensional mesh model of the femoral head being composed of a series of triangular facet mesh sets under a three-dimensional coordinate system. The three-dimensional mesh model at least includes an original necrosis model A and an original bone model B. The femur integrity analysis system at least includes a three-dimensional model extracting module. The three-dimensional model extracting module is used to perform at least one distance threshold iteration calculation on the triangular facet mesh sets of the original necrosis model A and the original bone model B respectively, thereby sequentially completing a spatial coarse registration process and a spatial fine registration process. The three-dimensional model extracting module is used to extract a femoral head weight-bearing accurate region and a necrosis weight-bearing accurate region after sequentially completing the spatial coarse registration process and the spatial fine registration process. The triangular facet mesh sets of the original necrosis model A and the original bone model B are subjected to at least one distance threshold iteration calculation by using a distance threshold algorithm about an acetabular lunula or about the original necrosis model A. The three-dimensional model extracting module is used to perform at least one distance threshold iteration calculation on the triangular facet mesh sets of the original necrosis model A and the original bone model B by using a distance threshold algorithm, thereby sequentially completing a spatial coarse registration process and a spatial fine registration process, and extracting a processed femoral head weight-bearing accurate region and a necrosis weight-bearing accurate region. The three-dimensional model extracting module is used to perform at least one distance threshold iteration calculation on the triangular facet mesh sets of the original necrosis model A and the original bone model B by using a distance threshold algorithm about an acetabular lunula or about the original necrosis model A, thereby sequentially completing a spatial coarse registration process and a spatial fine registration process, and extracting a processed femoral head weight-bearing accurate region and a necrosis weight-bearing accurate region. The femur integrity analysis system at least includes a data analysis module. The data analysis module is used to cut the femoral head weight-bearing accurate region and the necrosis weight-bearing accurate region according to the cutting surface established thereby, so as to obtain a respective corresponding weight-bearing stress concentration region on the femoral head weight-bearing accurate region and the necrosis weight-bearing accurate region, and perform integrity rate calculation on at least one of the weight-bearing stress concentration regions. The data analysis module is used to cut the femoral head weight-bearing accurate region and the necrosis weight-bearing accurate region according to the cutting surface established thereby, so as to obtain a respective corresponding weight-bearing stress concentration region on the femoral head weight-bearing accurate region and the necrosis weight-bearing accurate region. The data analysis module is used to perform integrity rate calculation on at least one of the weight-bearing stress concentration regions.

[0012] According to a preferred embodiment, the three-dimensional model extraction module performs at least one distance threshold iteration calculation on the triangular facet mesh set of the original necrosis model A and the original bone model B respectively by using the distance threshold algorithm about the acetabular moon surface, so as to complete the spatial coarse registration process and extract the femoral head load area and the necrosis load area; the three-dimensional model extraction module performs at least one distance threshold iteration calculation on the triangular facet mesh set of the femoral head load area and the necrosis load area respectively by using the distance threshold algorithm about the original necrosis model A, so as to complete the spatial fine registration process and extract the further optimized femoral head load accurate area and the necrosis load accurate area.

[0013] The three-dimensional model extraction module completes the spatial coarse registration process by using the distance threshold algorithm about the acetabular moon surface. The three-dimensional model extraction module performs at least one distance threshold iteration calculation on the triangular facet mesh set of the original necrosis model A and the original bone model B respectively by using the distance threshold algorithm about the acetabular moon surface, so as to complete the spatial coarse registration process and extract the femoral head load area and the necrosis load area. The three-dimensional model extraction module completes the spatial fine registration process by using the distance threshold algorithm about the original necrosis model A. The three-dimensional model extraction module performs at least one distance threshold iteration calculation on the triangular facet mesh set of the femoral head load area and the necrosis load area respectively by using the distance threshold algorithm about the original necrosis model A, so as to complete the spatial fine registration process and extract the further optimized femoral head load accurate area and the necrosis load accurate area.

[0014] According to a preferred embodiment, the three-dimensional model extraction module is further configured to perform necrosis segmentation preprocessing on the original necrosis model A in priority before it performs the spatial coarse registration process and the spatial fine registration process, and take the triangular facet mesh set corresponding to the preprocessed necrosis surface model A1 as the data source of the spatial coarse registration process, wherein the necrosis segmentation preprocessing is that the three-dimensional model extraction module traverses each triangular facet mesh of the original necrosis model A by using the distance threshold algorithm, generates a triangular facet mesh set S 11 , extracts the largest connected region in the triangular facet mesh set S 11 , determines the extracted connected region as a necrosis surface region, and establishes a necrosis surface model A1 in the necrosis surface region.

[0015] The three-dimensional model extraction module is further configured to perform necrosis segmentation preprocessing on the original necrosis model A prior to performing the spatial coarse registration process and the spatial fine registration process. The three-dimensional model extraction module takes the triangular facet mesh set corresponding to the preprocessed necrosis surface model Al as the data source of the spatial coarse registration process. The necrosis segmentation preprocessing at least includes the three-dimensional model extraction module traversing each triangular facet mesh of the original necrosis model A using a distance threshold algorithm to generate a triangular facet mesh set S 11 . The necrosis segmentation preprocessing at least includes the three-dimensional model extraction module extracting the largest connected region in the triangular facet mesh set S 11 , determining the extracted connected region as a necrosis surface region, and establishing a necrosis surface model Al in the necrosis surface region.

[0016] According to a preferred embodiment, the spatial coarse registration process of the original necrosis model A is: based on the necrosis surface model Al obtained after the three-dimensional model extraction module performs necrosis segmentation preprocessing on the original necrosis model A, the three-dimensional model extraction module traverses each triangular facet mesh of the necrosis surface model Al using a distance threshold algorithm to generate a triangular facet mesh set S 12 ; the three-dimensional model extraction module extracts the largest connected region in the triangular facet mesh set S 12 , determines the extracted connected region as a necrosis load-bearing region, and establishes a necrosis load-bearing region model A2 in the necrosis load-bearing region.

[0017] The spatial coarse registration process of the original necrosis model A at least includes one or more of the following steps: based on the necrosis surface model Al obtained after the three-dimensional model extraction module performs necrosis segmentation preprocessing on the original necrosis model A; the three-dimensional model extraction module traverses each triangular facet mesh of the necrosis surface model Al using a distance threshold algorithm; generates a triangular facet mesh set S 12 ; the three-dimensional model extraction module extracts the largest connected region in the triangular facet mesh set S 12 ; determines the extracted connected region as a necrosis load-bearing region; and establishes a necrosis load-bearing region model A2 in the necrosis load-bearing region.

[0018] According to a preferred embodiment, the spatial coarse registration process of the original bone model B is: the three-dimensional model extraction module traverses each triangular facet mesh of the original bone model B using a distance threshold algorithm to generate a triangular facet mesh set S 21 ; the three-dimensional model extraction module extracts the largest connected region in the triangular facet mesh set S 21The largest connected region in the middle is identified as the femoral head weight-bearing region, and a femoral head weight-bearing area B1 is established within this region.

[0019] According to a preferred embodiment, the execution order of the spatial fine registration process for the original bone model B is prioritized over the execution order of the spatial fine registration process for the original necrotic model A. The 3D model extraction module uses at least a portion of the triangular mesh obtained after performing the spatial fine registration process on the original bone model B as part of the data source for the spatial fine registration process of the original necrotic model A. The execution order of the spatial fine registration process for the original bone model B is prioritized over the execution order of the spatial fine registration process for the original necrotic model A. The 3D model extraction module uses at least a portion of the triangular mesh obtained after performing the spatial fine registration process on the original bone model B as part of the data source for the spatial fine registration process of the original necrotic model A.

[0020] According to a preferred embodiment, the spatial registration process of the original bone model B is as follows: the three-dimensional model extraction module uses a distance threshold algorithm to traverse each triangular mesh of the femoral head weight-bearing area B1, generating a triangular mesh set S. 22 The distance threshold algorithm is used to traverse the triangular mesh set S. 22 For each triangular mesh within the grid, generate a set of triangular meshes S. 23 and triangular mesh set S 24 ; for the triangular mesh set S 23 Denoising is performed to remove isolated noise points within the set, and a new set of triangular meshes S is established. 23 The corresponding load-bearing region model B2, and the triangular mesh set S 24 The corresponding necrotic weight-bearing region model A3, the spatial fine registration process of the original necrotic model A is as follows: perform a Boolean union operation on the necrotic weight-bearing region model A2 and the necrotic weight-bearing region model A3, and obtain the final necrotic weight-bearing region model A4 after the operation. The spatial fine registration process of the original bone model B is as follows: the three-dimensional model extraction module uses a distance threshold algorithm to traverse each triangular facet mesh of the femoral head weight-bearing region B1, generating a triangular facet mesh set S. 22 The distance threshold algorithm is used to traverse the triangular mesh set S. 22 For each triangular mesh within the grid, generate a set of triangular meshes S. 23 and triangular mesh set S 24 ; for the triangular mesh set S 23 Denoising is performed to remove isolated noise points within the set, and a new set of triangular meshes S is established.23 The corresponding weight-bearing area model B2, and a triangular facet mesh set S 24 The corresponding necrosis weight-bearing area model A3. The spatial registration process of the original necrosis model A is: performing a Boolean union operation on the necrosis weight-bearing area A2 model and the necrosis weight-bearing area A3 model, and obtaining the final necrosis weight-bearing area model A4 after the operation.

[0021] According to a preferred embodiment, the data analysis module establishes a cutting surface of the necrosis weight-bearing area model A4 according to the direction of the gravity line corresponding to the femoral head weight-bearing accurate area, based on the fact that the anterolateral two-thirds of the femoral head weight-bearing accurate area is the stress concentration area thereof, and cuts the necrosis weight-bearing area model A4 along the cutting surface to extract the anterolateral two-thirds of the femoral head weight-bearing accurate area model A5. The data analysis module establishes a cutting surface of the weight-bearing area model B2 according to the direction of the gravity line corresponding to the femoral head weight-bearing accurate area, based on the fact that the anterolateral two-thirds of the femoral head weight-bearing accurate area is the stress concentration area thereof, and cuts the weight-bearing area model B2 along the cutting surface to extract the anterolateral two-thirds of the femoral head weight-bearing accurate area model B3. The data analysis module establishes a cutting surface of the necrosis weight-bearing area model A4 according to the direction of the gravity line corresponding to the femoral head weight-bearing accurate area. The anterolateral two-thirds of the femoral head weight-bearing accurate area is the stress concentration area thereof. The data analysis module cuts the necrosis weight-bearing area model A4 along the cutting surface to extract the anterolateral two-thirds of the femoral head weight-bearing accurate area model A5. The data analysis module establishes a cutting surface of the weight-bearing area model B2 according to the direction of the gravity line corresponding to the femoral head weight-bearing accurate area. The anterolateral two-thirds of the femoral head weight-bearing accurate area is the stress concentration area thereof. The data analysis module cuts the weight-bearing area model B2 along the cutting surface to extract the anterolateral two-thirds of the femoral head weight-bearing accurate area model B3.

[0022] A femur integrity analysis model construction method, at least comprising the following steps:

[0023] S1: reconstructing the two-dimensional tomographic image data of the femoral head to establish a three-dimensional mesh model of the femoral head, the three-dimensional mesh model of the femoral head being composed of a series of triangular facet mesh sets in a three-dimensional coordinate system, and the three-dimensional mesh model of the femoral head at least comprising an original necrosis model A and an original bone head model B;

[0024] S2: performing at least one distance threshold iteration calculation on the triangular facet mesh set of the original necrosis model A and the original bone model B respectively by using the distance threshold algorithm about the acetabular lunate surface or about the original necrosis model A, so as to sequentially complete the spatial coarse registration process and the spatial fine registration process, and extract the processed femoral head weight-bearing accurate area and the necrosis weight-bearing accurate area;

[0025] S3: cutting the femoral head weight-bearing accurate area and the necrosis weight-bearing accurate area respectively according to the cutting surface established thereby, so as to obtain the respective corresponding weight-bearing stress concentration areas on the femoral head weight-bearing accurate area and the necrosis weight-bearing accurate area, and perform the integrity calculation on at least one of the weight-bearing stress concentration areas.

[0026] According to a preferred embodiment, the construction method further comprises the following steps: performing at least one distance threshold iteration calculation on the triangular facet mesh set of the original necrosis model A and the original bone model B respectively by using the distance threshold algorithm about the acetabular lunate surface, so as to complete the spatial coarse registration process and extract the femoral head weight-bearing area and the necrosis weight-bearing area; performing at least one distance threshold iteration calculation on the triangular facet mesh set of the femoral head weight-bearing area and the necrosis weight-bearing area respectively by using the distance threshold algorithm about the original necrosis model A, so as to complete the spatial fine registration process and extract the further optimized femoral head weight-bearing accurate area and the necrosis weight-bearing accurate area.

[0027] The application also relates to a femoral model construction system, which comprises at least a three-dimensional model creating module and a three-dimensional model extracting module. The three-dimensional model creating module is configured to reconstruct the two-dimensional tomographic image data of the femoral head part to establish a three-dimensional mesh model of the femoral head, which is composed of a series of triangular facet mesh sets in a three-dimensional coordinate system, and comprises at least an original necrosis model A and an original bone model B. The three-dimensional model extracting module extends the three vertices of each triangular facet mesh of the original necrosis model A along the respective corresponding normal direction to obtain the respective corresponding line segments, and if the respective corresponding line segments of the three vertices of the triangular facet mesh are all not intersected with the original bone model B, the facet is taken out and placed in a set S 11 .

[0028] According to a preferred embodiment, the three-dimensional model extraction module is configured to perform necrosis segmentation preprocessing on the original necrosis model A in priority before it performs the spatial coarse registration process and the spatial fine registration process, and takes the triangular facet mesh set corresponding to the preprocessed necrosis surface model A1 as the data source of the spatial coarse registration process. Wherein, the three-dimensional model extraction module is used to perform at least one distance threshold iteration calculation on the triangular facet mesh set of the original necrosis model A and the original bone model B respectively by using the distance threshold algorithm about the acetabular lunar surface or about the original necrosis model A, so as to sequentially complete the spatial coarse registration process and the spatial fine registration process, and extract the processed femoral head weight-bearing accurate region and the necrosis weight-bearing accurate region.

[0029] According to a preferred embodiment, the three-dimensional model extraction module traverses each triangular facet mesh of the original necrosis model A, extends the three vertices of each triangular facet mesh along the respective corresponding normal direction by 0.013 m to obtain the respective corresponding line segments, and if the three vertices of the triangular facet mesh all intersect with the acetabular lunar surface along the respective corresponding line segments, the facet is taken out and placed in the set S 12 .

[0030] According to a preferred embodiment, the necrosis weight-bearing region refers to the region corresponding to the surface of the necrosis surface model A1 on which the femur in the acetabular fossa is projected along the gravity line.

[0031] According to a preferred embodiment, the three-dimensional model extraction module traverses each triangular facet mesh of the original bone model B, extends the three vertices of each triangular facet mesh along the respective corresponding normal direction by 0.013 m to obtain the respective corresponding line segments, and if the three vertices of the triangular facet mesh all do not intersect with the acetabular lunar surface along the respective corresponding line segments, the facet is taken out and placed in the set S 21 .

[0032] According to a preferred embodiment, the femoral head weight-bearing region refers to the region corresponding to the original bone model B on which the femur in the acetabular fossa can be projected along the gravity line.

[0033] According to a preferred embodiment, the three-dimensional model extraction module traverses each triangular facet mesh of the femoral head weight-bearing region B1, extends the three vertices of each triangular facet mesh along the respective corresponding normal direction by 0.013 m to obtain the respective corresponding line segments, and if the three vertices of the triangular facet mesh all do not intersect with the original necrosis model A along the respective corresponding line segments, the facet is taken out and placed in the set S 22 .

[0034] According to a preferred embodiment, the three-dimensional model extraction module traverses each triangular facet mesh of the set S 22 , extends each of the three vertices of the triangular facet mesh along the respective corresponding normal in the reverse direction by 0.002 m to obtain a respective corresponding line segment, and if none of the three vertices of the triangular facet mesh has the respective corresponding line segment intersecting the original necrosis model A, the triangular facet mesh is taken out and placed in the set S 23 , otherwise, the triangular facet mesh is placed in the set S 24 .

[0035] The present application also relates to a femur integrity analysis model construction method, which comprises at least the following steps:

[0036] reconstructing two-dimensional tomographic image data of a femoral head part to establish a three-dimensional mesh model of the femoral head, the three-dimensional mesh model of the femoral head being composed of a series of triangular facet mesh sets in a three-dimensional coordinate system, and the three-dimensional mesh model of the femoral head comprising at least an original necrosis model A and an original bone model B; traversing each triangular facet mesh of the original necrosis model A, extending each of the three vertices of the triangular facet mesh along the respective corresponding normal in the reverse direction by 0.013 m to obtain a respective corresponding line segment, and if none of the three vertices of the triangular facet mesh has the respective corresponding line segment intersecting the original bone model B, the triangular facet mesh is taken out and placed in the set S 11 .

[0037] According to a preferred embodiment, the construction method further comprises the following steps:

[0038] performing necrosis segmentation preprocessing on the original necrosis model A in advance before performing the spatial coarse registration process and the spatial fine registration process, and taking the triangular facet mesh set corresponding to the preprocessed necrosis surface model A1 as the data source of the spatial coarse registration process;

[0039] performing at least one distance threshold iteration calculation on the triangular facet mesh sets of the original necrosis model A and the original bone model B by using a distance threshold algorithm about the acetabular lunate surface or about the original necrosis model A, thereby sequentially completing the spatial coarse registration process and the spatial fine registration process, and extracting the processed femoral head weight-bearing accurate region and the necrosis weight-bearing accurate region.

[0040] The femur integrity analysis system and the femur integrity analysis model construction method provided by the present application have at least the following beneficial technical effects:

[0041] The femur integrity analysis model construction method provided by the application greatly reduces the target area and effectively guarantees the convergence of the calculation result by limiting the position distance between the extended line segment on the normal line of the triangular facet vertex and the acetabular crescent surface or the original necrosis model, respectively performing the spatial coarse registration process and the spatial fine registration process, and realizing the accurate segmentation of the three-dimensional grid model of the femoral head part;

[0042] The femur integrity analysis model construction method provided by the application can calculate the necrosis rate of the femoral head load-bearing area in the three-dimensional space to the maximum extent through the interactive analysis and calculation of the load-bearing area model obtained through the spatial coarse registration process and the load-bearing area model obtained after the segmentation through the spatial fine registration process during the model construction process, greatly improves the accuracy of the subsequent calculation of the necrosis rate of the femoral head load-bearing area, and thus can provide more reliable data support for accurately judging the spatial stereoscopic relationship of the femoral head necrosis, adapt to the clinical needs of the surgical treatment of femoral head necrosis and the osteotomy surgery planning of femoral head necrosis, solve the problems that the spatial stereoscopic relationship of femoral head necrosis cannot be accurately judged and the femoral head model extracted has low precision in the prior art, and can further achieve the early prediction and prevention of femoral head ischemic necrosis collapse. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 FIG. 1 is a simplified flowchart of the femur integrity analysis model construction method provided by the application;

[0044] Figure 2 FIG. 2 is a simplified flowchart of the preferred femur integrity analysis model construction method provided by the application;

[0045] Figure 3 FIG. 3 is a simplified module connection relationship diagram of the femur integrity analysis system provided by the application;

[0046] Figure 4 FIG. 4 is a simplified structure diagram of the preferred femur integrity analysis system provided by the application; and

[0047] Figure 5 FIG. 5 is a simplified diagram of the preferred cutting surface provided by the application.

[0048] LIST OF REFERENCE NUMERALS

[0049] 1: three-dimensional model creation module 2: three-dimensional model extraction module 3: data analysis module

[0050] 4: server 5: storage device 6: processor

[0051] 7: bus 8: network adapter 9: I / O interface

[0052] 10: display 11: external device 12: cutting surface

[0053] 13: gravity line direction DETAILED DESCRIPTION

[0054] The application will be described in detail below with reference to the accompanying drawings.

[0055] Example 1

[0056] As Figure 1 shown, the femoral integrity analysis model construction method comprises at least the following steps S1-S3:

[0057] Step S1: reconstructing the two-dimensional tomographic image data of the femoral head part to establish a three-dimensional mesh model of the femoral head, the three-dimensional mesh model of the femoral head being composed of a series of triangular facet mesh sets under a three-dimensional coordinate system, the three-dimensional mesh model at least comprising an original necrosis model A and an original bone model B.

[0058] Preferably, a three-dimensional medical image surface reconstruction algorithm based on segmentation is used to reconstruct the three-dimensional mesh model from the two-dimensional tomographic image data, and the three-dimensional mesh model of the femoral head is obtained through threshold screening, interactive segmentation and three-dimensional reconstruction process. Wherein the two-dimensional tomographic image data can be obtained by imaging device CT and / or imaging device MRI. The three-dimensional mesh model of the femoral head is meshed to discretize the continuous geometric model and obtain the corresponding finite element model. Preferably, the three-dimensional mesh model of the femoral head is meshed. The three-dimensional mesh model at least comprises an original necrosis model A and an original bone model B.

[0059] Step S2: the three-dimensional model extraction module 2 is used to perform at least one distance threshold iteration calculation on the triangular facet mesh sets of the original necrosis model A and the original bone model B respectively by using the distance threshold algorithm about the acetabular lunate surface or about the original necrosis model A, so as to sequentially complete the spatial coarse registration process and the spatial fine registration process, and extract the processed femoral head weight-bearing accurate area and the necrosis weight-bearing accurate area. The femoral integrity analysis model construction method provided by the application greatly reduces the target area and effectively ensures the convergence of the calculation result by using the distance threshold algorithm to limit the position distance between the extension line segment on the normal line of the triangular facet vertex and the acetabular lunate surface or the original necrosis model, respectively performing the spatial coarse registration process and the spatial fine registration process, and realizing the accurate segmentation of the three-dimensional mesh model of the femoral head part.

[0060] Wherein, as Figure 1 shown, step S2 at least comprises the following steps S201-S203:

[0061] Step S201: Prior to performing the spatial coarse registration process and the spatial fine registration process, the original necrosis model A is subjected to a necrosis segmentation preprocessing, and a triangular facet mesh set corresponding to the preprocessed necrosis surface model A1 is taken as the data source of the spatial coarse registration process.

[0062] Preferably, step S201: a distance threshold algorithm is used to traverse each triangular facet mesh of the original necrosis model A to generate a triangular facet mesh set S 11 ; the largest connected region in the triangular facet mesh set S 11 is extracted, the extracted connected region is determined as the necrosis surface region, and a necrosis surface model A1 is established in the necrosis surface region.

[0063] Further preferably, the specific steps of using the distance threshold algorithm to traverse the original necrosis model A are as follows: each triangular facet mesh of the original necrosis model A is traversed, and each triangular facet mesh is extended by 0.013 m along the normal direction of each corresponding vertex to obtain a corresponding line segment, if the three vertices of the triangular facet mesh are not intersected with the original bone model B, the triangular facet mesh is taken out and placed in the set S 11 . Step S201 is used to extract the non-intersecting overlapping region of the original necrosis model A and the femoral head.

[0064] Step S202: At least one distance threshold iteration calculation is performed on the triangular facet mesh set of the original necrosis model A and the original bone model B using the distance threshold algorithm related to the acetabular facet to complete the spatial coarse registration process and extract the femoral head weight-bearing region and the necrosis weight-bearing region.

[0065] More specifically, step S202 at least includes a spatial coarse registration process of the original necrosis model A, which is used to extract the weight-bearing region in which the necrosis surface region is located in the acetabular region, as shown in Figure 2 , which is step S2021-S2022.

[0066] Step S2021: A distance threshold algorithm is used to traverse each triangular facet mesh of the necrosis surface model A1 to generate a triangular facet mesh set S 12 .

[0067] The specific steps of using the distance threshold algorithm to traverse the necrosis surface model A1 are as follows: each triangular facet mesh of the original necrosis model A is traversed, and each triangular facet mesh is extended by 0.013 m along the normal direction of each corresponding vertex to obtain a corresponding line segment, if the three vertices of the triangular facet mesh are intersected with the acetabular facet, the triangular facet mesh is taken out and placed in the set S 12 .

[0068] Step S2022: extracting the triangle mesh set S from the original bone model B 12 The largest connected region in the area is determined as the necrosis load-bearing region, and a necrosis load-bearing region model A2 is established in the necrosis load-bearing region.

[0069] The necrosis load-bearing region refers to a region on the hip bone in the acetabular fossa that can be projected onto the necrosis surface model A1 along the gravity line direction 13 and corresponds to the surface of the necrosis surface model A1.

[0070] More specifically, step S202 includes at least a spatial coarse registration process of the original bone model B, which is used to extract the femoral head load-bearing region in which the femoral head surface region is located in the acetabular fossa region, as shown in Figure 2 The process is steps S2023-S2024.

[0071] Step S2023: using a distance threshold algorithm to traverse each triangle mesh of the original bone model B to generate a triangle mesh set S 21 .

[0072] The specific steps of using the distance threshold algorithm to traverse the necrosis surface model A1 are as follows: traversing each triangle mesh of the original bone model B, extending the three vertices of each triangle mesh along the respective normal direction to obtain respective line segments, and if the three vertices of the triangle mesh each correspond to a line segment that intersects the acetabular crescent surface, then the mesh is taken out and placed in the triangle mesh set S 21 .

[0073] Step S2024: extracting the largest connected region in the area of the triangle mesh set S 21 The extracted connected region is determined as the femoral head load-bearing region, and a femoral head load-bearing region B1 is established in the femoral head load-bearing region.

[0074] The femoral head load-bearing region refers to a region on the hip bone in the acetabular fossa that can be projected onto the femoral head surface along the gravity line direction 13 and corresponds to the femoral head surface. Preferably, the femoral head load-bearing region refers to a region on the hip bone in the acetabular fossa that can be projected onto the original bone model B along the gravity line direction 13 and corresponds to the original bone model B.

[0075] Step S203: using the distance threshold algorithm for the original necrosis model A to perform at least one distance threshold iteration calculation on the triangle mesh sets of the femoral head load-bearing region and the necrosis load-bearing region, to complete the spatial fine registration process and extract the further optimized femoral head load-bearing accurate region and the necrosis load-bearing accurate region.

[0076] More specifically, the step S203 comprises at least a spatial fine registration process of the original bone model B and a spatial fine registration process of the original necrosis model A. The execution order of the spatial fine registration process of the original bone model B is prior to the execution order of the spatial fine registration process of the original necrosis model A, wherein the three-dimensional model extraction module 2 takes the at least partial triangular facet mesh obtained after performing the spatial fine registration process on the original bone model B as the partial data source of the spatial fine registration process of the original necrosis model A.

[0077] Thus, the femoral integrity analysis model construction method provided by the present application can maximize the calculation of the necrosis rate of the femoral head load-bearing area in the three-dimensional space by performing interactive analysis and calculation on the load-bearing area model obtained by the spatial coarse registration process and the load-bearing area model obtained by the spatial fine registration process, greatly improving the accuracy of the subsequent calculation of the necrosis rate of the femoral head load-bearing area, thereby providing more reliable data support for accurately judging the spatial stereoscopic relationship of the femoral head necrosis, adapting to the clinical needs of the surgical treatment of femoral head necrosis and the planning of femoral head necrosis osteotomy, and solving the problems of the existing technology that the spatial stereoscopic relationship of the femoral head necrosis cannot be accurately judged and the femoral head model extracted has low precision, which can further achieve early prediction and prevention of femoral head ischemic necrosis collapse.

[0078] The spatial fine registration process of the original bone model B is used to remove noise data from the femoral head load-bearing area extracted in the previous step, and the specific steps are as follows: Figure 2 As shown in the figure, the process is steps S2031-S2033.

[0079] Step S2031: using a distance threshold algorithm to traverse each triangular facet mesh of the femoral head load-bearing area B1 to generate a triangular facet mesh set S 22 .

[0080] The specific steps of using the distance threshold algorithm to traverse the femoral head load-bearing area B1 are as follows: traversing each triangular facet mesh of the femoral head load-bearing area B1, extending the three vertices of each triangular facet mesh along the respective normal direction by 0.013m to obtain the respective line segments, if the three vertices of the triangular facet mesh are not intersected by the respective line segments, then the facet is taken out and placed in the triangular facet mesh set S 22 .

[0081] Step S2032: using a distance threshold algorithm to traverse each triangular facet mesh in the triangular facet mesh set S 22 to generate a triangular facet mesh set S 23 and a triangular facet mesh set S 24 .

[0082] wherein the distance threshold algorithm is used to traverse the triangular mesh set S 22 The specific steps are as follows: traversing the triangular mesh set S 22 Each triangular mesh is extended by 0.002m along the respective normal direction to obtain a respective line segment. If the three vertices of the triangular mesh are not intersected by the original necrosis model A, the triangular mesh is taken out and placed in the triangular mesh set S 23 Otherwise, it is placed in the triangular mesh set S 24 .

[0083] Step S2033: The triangular mesh set S 23 is denoised to remove isolated noise points in the set, and a negative weight area model B2 corresponding to the triangular mesh set S 23 is established, and a necrosis negative weight area model A3 corresponding to the triangular mesh set S 24 .

[0084] More specifically, step S203 includes at least a spatial fine registration process of the original necrosis model A. This process is used to combine the necrosis negative weight area model A3 extracted in the previous step with the necrosis negative weight area model A2 to achieve accurate extraction of the necrosis negative weight area. This process includes at least step S2034.

[0085] Step S2034: Boolean union operation is performed on the necrosis negative weight area A2 model and the necrosis negative weight area A3 model, and the final necrosis negative weight area model A4 is obtained after the operation.

[0086] Preferably, the Boolean union operation is performed on the necrosis negative weight area A2 model and the necrosis negative weight area A3 model to obtain the final necrosis negative weight area model A4. The final necrosis negative weight area model A4 is obtained by adding and combining the necrosis negative weight area A2 model and the necrosis negative weight area A3 model into one object. Specifically, the Boolean union operation can be performed on the necrosis negative weight area A2 model and the necrosis negative weight area A3 model using the Boolean operation tool in the image processing software, such as Mimics, to obtain the final necrosis negative weight area model A4. The Boolean operation is defined as a logical deduction method of numerical symbols, including union, intersection and subtraction. This logical operation method is used in image processing operations to combine simple basic figures to produce new shapes, and the two-dimensional Boolean operation is developed to three-dimensional Boolean operation. The Boolean union operation is defined as an operation to combine two models, and the intersecting part is deleted. After the operation, the two objects become one object.

[0087] Step S3: cutting the femoral head precise load area and the necrotic precise load area according to the established cutting surface 12, so as to obtain the corresponding load stress concentration area on the femoral head precise load area and the necrotic precise load area, and calculate the integrity rate of at least one of the load stress concentration areas.

[0088] Step S3 at least includes the following steps S301-S303:

[0089] Step S301: cutting the necrotic precise load area according to the established cutting surface 12, so as to obtain the corresponding load stress concentration area on the necrotic precise load area.

[0090] Preferably, the load stress concentration area on the necrotic load area model A4 is the outer two-thirds of the front of the necrotic load area. Step S301 is used to extract the necrotic load area of the outer two-thirds of the front of the acetabular fossa. Step S301 can be: establishing the cutting surface 12 of the necrotic load area model A4 according to the gravity line direction 13 corresponding to the femoral head precise load area, based on the outer two-thirds of the front of the necrotic load area on the necrotic precise load area as the load stress concentration area, cutting the necrotic load area model A4 along the cutting surface 12, to extract the outer two-thirds of the front of the necrotic load area model A4 as the model A5.

[0091] As shown in Figure 5 , the cutting surface 12 is an inner-outer side distinguishing reference surface, which is defined as the plane to which the innominate bone inside the acetabular fossa belongs along the gravity line direction 13, and can be used to distinguish the inner-outer side of the femoral head load area. The user can determine the inner-outer side of the load area by adjusting the position of the reference surface.

[0092] Step S302: cutting the femoral head precise load area according to the established cutting surface 12, so as to obtain the corresponding load stress concentration area on the femoral head precise load area.

[0093] Preferably, the load stress concentration area on the femoral head precise load area is the outer two-thirds of the front of the femur. Step S302 is used to extract the femoral load area of the outer two-thirds of the front of the acetabular fossa. Step S302 can be: establishing the cutting surface 12 of the load area model B2 according to the gravity line direction 13 corresponding to the femoral head precise load area, based on the outer two-thirds of the front of the femur on the femoral head precise load area as the load stress concentration area, cutting the load area model B2 along the cutting surface 12, to extract the outer two-thirds of the front of the femur on the load area model B2 as the model B3.

[0094] Step S303: calculating the integrity rate of at least one of the load stress concentration areas.

[0095] Preferably, step S303 is used to calculate the integrity rate of the weight-bearing area in the anterolateral two-thirds of the femur. Specifically, step S303 involves obtaining the surface area S based on model A5 of the necrotic anterolateral two-thirds area. A The surface area S of the femur was obtained based on model B3 located at the anterolateral two-thirds of the femur. B , from surface area S A and surface area S B The total surface area S of the anterolateral two-thirds weight-bearing zone and the integrity rate Rate of the lateral femoral weight-bearing zone, where S = S A +S B , Among them, the surface area S of model B3 at the anterolateral two-thirds of the femur was obtained. B This refers to the surface area of ​​the intact portion of the femur in the anterior two-thirds of the lateral region, calculated using model A5 at the anterior two-thirds of the necrotic region. A This refers to the surface area of ​​the necrotic region within the anterior two-thirds of the lateral aspect of the femur.

[0096] Preferably, step S303: Obtain the surface area S of the stress concentration area corresponding to the necrotic load-bearing precise area. A The surface area S of the femoral head is obtained based on the stress concentration area corresponding to the precise weight-bearing region. B , from surface area S A and surface area S B The total surface area S of the anterolateral two-thirds weight-bearing zone and the integrity rate Rate of the lateral femoral weight-bearing zone, where S = S A +S B Rate = S B / S. The Femoral Lateral Weight-Bearing Zone Integrity Rate is calculated as the area of ​​the intact femoral surface portion within the anterolateral two-thirds of the weight-bearing zone, relative to the total area of ​​the weight-bearing zone within that region. More preferably, step S303 further includes displaying the surface projection area of ​​the currently intact femoral portion and the necrotic projection area via a display 10 or an external device 11, such as a VR display device; that is, projecting the necrotic anterolateral two-thirds model A5 and the anterolateral two-thirds femoral model B3 onto the original necrotic model A and the original bone model B, respectively.

[0097] Preferably, the method for constructing the femoral integrity analysis model further includes an extraction process of the lunate plane of the acetabulum, which includes at least the following steps:

[0098] Two-dimensional tomographic image data of the hip joint are reconstructed to establish a three-dimensional mesh model of the hip joint. The three-dimensional mesh model of the hip joint is composed of a series of triangular mesh sets in a three-dimensional coordinate system.

[0099] Each vertex of the three-dimensional mesh model of the hip joint part is traversed, each vertex is extended along the respective corresponding normal direction to obtain a respective corresponding line segment, if each respective corresponding line segment on the vertex intersects the femur and the original necrosis model A, the intersection vertex number is extracted and placed in the vertex number set S 31

[0100] Each triangular facet mesh of the three-dimensional mesh model of the hip joint part is traversed, if the three vertices of the triangular facet mesh belong to the subset of the vertex number set S 31 , the triangular facet mesh is extracted and constitutes the triangular facet mesh set S 32 ;

[0101] As shown in Figure 5 , the triangular facet mesh set S 32 is denoised to remove isolated noise points in the set, and the connected region S33 with the most vertex number in the triangular facet mesh set S 32 is extracted, and the extracted connected region S 33 is determined as the corresponding side acetabular crescent surface.

[0102] Preferably, the two-dimensional tomographic image data is reconstructed into a three-dimensional mesh model by using a segmentation-based three-dimensional medical image surface reconstruction algorithm, and the three-dimensional mesh model of the femoral head is obtained through threshold screening, interactive segmentation and three-dimensional reconstruction process. The two-dimensional tomographic image data can be obtained by the imaging device CT and / or the imaging device MRI. The three-dimensional mesh model of the hip joint part is meshed, so that the continuous geometric model is discretized to obtain a corresponding finite element model. Preferably, the three-dimensional mesh model of the hip joint part is surface meshed.

[0103] Preferably, the normal corresponding to the vertex mentioned in each embodiment of the application is the vertex normal, which is defined as the vector nx1, y1, z1 after normalizing the coordinates of the three-dimensional vertex P when the coordinates of P are x, y, z. Preferably, the triangular facet mesh mentioned in each embodiment of the application is defined as at least including one fixed edge and two edges that can be elastically deformed, and the fixed edge and the two edges that can be elastically deformed together constitute a rigid elastic system. The two edges that can be elastically deformed can be used for finite element calculation, for example, by differentiating the triangular facet to infinitely approximate the unit element, so as to integrate the corresponding model of the actual hip bone and femur.

[0104] Embodiment 2

[0105] This embodiment provides a structural schematic block diagram of a server 4 suitable for the embodiments of the application, as shown in Figure 4 ​The illustration shown is merely an example and does not limit the functionality or scope of the embodiments of the present invention. Server 4 is represented in the form of a general-purpose server 4, which includes at least one processor 6, a storage device 5, and a bus 7 for connecting the processor 6 and the storage device 5. The bus 7 represents one or more of several types of bus 7 architectures, including a storage device 5 bus 7 or a storage device 5 controller, a peripheral bus 7, a graphics acceleration port, a processor 6, or a local bus 7 using any of the various bus 7 architectures. For example, these architectures include, but are not limited to, one or more of industry-standard architecture buses 7, microchannel architecture buses 7, enhanced ISA buses 7, and peripheral component interconnect buses 7. Server 4 typically includes various computer system readable media. These media can be any available media accessible to server 4, including volatile and non-volatile media, removable and non-removable media.

[0106] Storage device 5 may include computer system readable media in the form of volatile memory, such as random access memory and / or cache memory. Server 4 may further include other removable / non-removable, volatile / non-volatile computer system storage media. For example, storage device 5 may be used to read and write non-removable, non-volatile magnetic media (hard disk drives). Disk drives for reading and writing to removable non-volatile disks and optical disc drives for reading and writing to removable non-volatile optical discs, such as read-only optical discs, digital video discs, or other optical media, may be provided. In these cases, each drive may be connected to bus 7 via one or more data media interfaces. Storage device 5 may include at least one program product having a set or at least one program module configured to perform the functions of the embodiments of the present invention.

[0107] A program / utility having a set or at least one program module can be stored in, for example, storage device 5. Such program modules include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. The program modules typically perform the functions and / or methods described in the embodiments of the present invention. Server 4 can also communicate with one or more external devices 11, such as a keyboard, pointing terminal, display 10, etc., and can also communicate with one or more terminals that enable a user to interact with server 4, and / or with any terminal that enables server 4 to communicate with one or more other computing terminals, such as a network card, modem, etc. This communication can be performed via an input / output (I / O) interface. Furthermore, server 4 can also communicate with one or more networks, such as a local area network (LAN), a wide area network (WAN), and / or a public network such as the Internet, via network adapter 8. Figure 4As shown, network adapter 8 communicates with other modules of server 4 via bus 7. Although not shown in the figure, other hardware and / or software modules can be used in conjunction with server 4, including at least one or more of the following: microcode, terminal driver, redundant processor 6, external disk drive array, disk array system, tape drive, and data backup storage system, etc.

[0108] The processor 6 executes various functional applications and data processing by running programs stored in the storage device 5, such as implementing the femoral integrity analysis model construction method provided in this embodiment of the invention, which includes at least the following steps:

[0109] S1: Reconstruct the CT sequence images of the femoral head to obtain a three-dimensional mesh model of the femoral head. The three-dimensional mesh model of the femoral head consists of a series of triangular mesh sets in a three-dimensional coordinate system. The three-dimensional mesh model includes at least the original necrosis model A and the original bone model B.

[0110] S2: Using a distance thresholding algorithm based on the acetabular lunate plane or the original necrosis model A, perform at least one distance thresholding iteration on the triangular mesh sets of the original necrosis model A and the original bone model B, thereby completing the spatial coarse registration process and the spatial fine registration process in sequence, and extracting the processed femoral head weight-bearing region and necrosis weight-bearing region.

[0111] S3: Cut the weight-bearing area of ​​the femoral head and the necrotic weight-bearing area according to the cutting surface 12 established on the weight-bearing area of ​​the femoral head, so as to obtain the areas on the weight-bearing area of ​​the femoral head and the necrotic weight-bearing area respectively corresponding to the anterior two-thirds of the lateral acetabulum, and calculate the integrity rate of the weight-bearing area at the lateral two-thirds of the femoral head based on at least one area obtained by cutting.

[0112] Example 3

[0113] like Figure 3 As shown, the three-dimensional model creation module 1, the three-dimensional model extraction module 2, and the data analysis module 3 provided by the present invention can each be a computer-readable storage medium storing a computer program. When the program is executed by the processor 6, it implements the femoral integrity analysis model construction method provided in the embodiments of the present invention, which includes at least the following steps:

[0114] S1: Reconstruct the CT sequence images of the femoral head to obtain a three-dimensional mesh model of the femoral head. The three-dimensional mesh model of the femoral head consists of a series of triangular mesh sets in a three-dimensional coordinate system. The three-dimensional mesh model includes at least the original necrosis model A and the original bone model B.

[0115] S2: performing at least one distance threshold iteration calculation on the triangular facet mesh set of the original necrosis model A and the original bone model B respectively by using the distance threshold algorithm about the acetabular lunate surface or about the original necrosis model A, so as to complete the spatial coarse registration process and the spatial fine registration process in sequence, and to extract the processed femoral head load area and the necrosis load area;

[0116] S3: cutting the femoral head load area and the necrosis load area respectively according to the cutting surface 12 established on the femoral head load area, so as to cut the area corresponding to the lateral two-thirds area of the acetabular fossa on the femoral head load area and the necrosis load area respectively, and to calculate the integrity of the lateral two-thirds load area of the femoral head according to the at least one area obtained by cutting.

[0117] The computer storage medium can take any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or apparatus, or any suitable combination of the above. More specific examples of the computer-readable storage medium can include one or more of the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical fiber, a portable compact disk read-only memory, an optical storage device, a magnetic storage device, or any suitable combination of the above. Preferably, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0118] The computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, in which the computer-readable program code is carried. Such a propagated data signal can take any of a variety of forms, including but not limited to electro-magnetic, optical, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium that is not a storage medium and that can be used to carry or store the program code for use by or in connection with an instruction execution system, apparatus, or device.

[0119] The program code contained on the computer-readable medium can be transmitted using any suitable medium, such as wireless, wireline, optical fiber, RF, etc., or any suitable combination of the above.

[0120] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0121] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design many alternative realizations without departing from the scope of the present application. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. It is appreciated that features of the application that are, individually, known, individually bring only a fraction of the benefit to those in the art, but when combined, bring the combined benefits that are claimed by this application. The application should not be construed as limited to the embodiments set forth herein for descriptive purposes, as these embodiments merely exemplify the principles of the application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A femoral model construction system, comprising at least a three-dimensional model creation module (1) and a three-dimensional model extraction module (2). The three-dimensional model creation module (1) is configured to: reconstruct a three-dimensional mesh model of the femoral head from two-dimensional tomographic scan image data of the femoral head, wherein the three-dimensional mesh model of the femoral head is composed of a series of triangular mesh sets in a three-dimensional coordinate system, and the three-dimensional mesh model includes at least the original necrosis model A and the original bone model B, characterized in that, Before the spatial coarse registration process and the spatial fine registration process are executed in the three-dimensional model extraction module (2), the original necrotic model A is given priority to be preprocessed by necrotic segmentation, and the triangular mesh set corresponding to the necrotic surface model A1 obtained after preprocessing is used as the data source for the spatial coarse registration process. Using a distance thresholding algorithm based on the lunate plane of the acetabulum, at least one distance thresholding iteration is performed on the triangular mesh sets of the original necrosis model A and the original bone model B, respectively, to complete the spatial coarse registration process and extract the femoral head weight-bearing region and the necrosis weight-bearing region. Using the distance threshold algorithm for the original necrosis model A, at least one distance threshold iteration calculation is performed on the triangular mesh set of the femoral head weight-bearing region and the necrosis weight-bearing region, respectively, to complete the spatial fine registration process and extract the further optimized precise weight-bearing region of the femoral head and the precise weight-bearing region of the necrosis. The three-dimensional model extraction module (2) traverses each triangular facet mesh of the original necrotic model A, and extends the three vertices of each triangular facet mesh along their respective normal directions to obtain their respective line segments. If none of the line segments corresponding to the three vertices of the triangular facet mesh intersect with the original bone model B, then the facet is extracted and placed in set S. 11 middle.

2. The femoral model construction system according to claim 1, characterized in that, The three-dimensional model extraction module (2) traverses each triangular facet mesh of the original necrotic model A, and extends the three vertices of each triangular facet mesh along their respective normal directions to obtain their respective line segments. If the line segments corresponding to the three vertices of the triangular facet mesh intersect the lunate plane of the acetabulum, then the facet is extracted and placed in set S. 12 middle.

3. The femoral model construction system according to claim 1, characterized in that, The necrotic load-bearing area extracted by the three-dimensional model extraction module (2) after completing the spatial coarse registration process refers to the area of ​​the hip bone located in the acetabulum that is projected onto the necrotic surface model A1 along the gravity line direction (13) and corresponds to the surface of the necrotic surface model A1.

4. The femoral model construction system according to claim 1, characterized in that, The three-dimensional model extraction module (2) traverses each triangular facet mesh of the original bone model B, and extends the three vertices of each triangular facet mesh along their respective normal directions to obtain their respective line segments. If the line segments corresponding to the three vertices of the triangular facet mesh intersect the lunate plane of the acetabulum, then the facet is extracted and placed in the triangular facet mesh set S. 21 middle.

5. The femoral model construction system according to claim 1, characterized in that, The femoral head load-bearing area extracted by the three-dimensional model extraction module (2) after completing the spatial coarse registration process refers to the area of ​​the hip bone located in the acetabulum that can be projected onto the original bone model B along the gravity line direction (13) and corresponds to the original bone model B.

6. The femoral model construction system according to claim 1, characterized in that, The three-dimensional model extraction module (2) traverses each triangular facet mesh of the femoral head weight-bearing area B1, and extends the three vertices of each triangular facet mesh along their respective normal directions to obtain their respective line segments. If the line segments corresponding to the three vertices of the triangular facet mesh do not intersect with the original necrosis model A, then the facet is extracted and placed in the triangular facet mesh set S. 22 middle.

7. The femoral model construction system according to claim 6, characterized in that, The three-dimensional model extraction module (2) traverses the triangular mesh set S. 22 For each triangular mesh, extend the three vertices of each triangular mesh along their respective normals in the opposite direction to obtain their respective line segments. If none of the line segments corresponding to the three vertices of the triangular mesh intersect the original necrotic model A, then remove the mesh and place it in the triangular mesh set S. 23 Otherwise, place it in the triangular mesh set S. 24 middle.

8. A method for constructing a femoral integrity analysis model, characterized in that, At least the following steps are included: Two-dimensional tomographic scan images of the femoral head are reconstructed to establish a three-dimensional mesh model of the femoral head. The three-dimensional mesh model of the femoral head consists of a series of triangular mesh sets in a three-dimensional coordinate system. The three-dimensional mesh model includes at least the original necrosis model A and the original bone model B. Before performing the spatial coarse registration process and the spatial fine registration process, the original necrotic model A is first subjected to necrotic segmentation preprocessing, and the triangular mesh set corresponding to the necrotic surface model A1 obtained after preprocessing is used as the data source for the spatial coarse registration process. Using a distance thresholding algorithm based on the lunate plane of the acetabulum, at least one distance thresholding iteration is performed on the triangular mesh sets of the original necrosis model A and the original bone model B, respectively, to complete the spatial coarse registration process and extract the femoral head weight-bearing region and the necrosis weight-bearing region. Using the distance threshold algorithm for the original necrosis model A, at least one distance threshold iteration calculation is performed on the triangular mesh set of the femoral head weight-bearing region and the necrosis weight-bearing region, respectively, to complete the spatial fine registration process and extract the further optimized precise weight-bearing region of the femoral head and the precise weight-bearing region of the necrosis. Traverse each triangular mesh of the original necrotic model A, and extend the three vertices of each triangular mesh along their respective normal directions to obtain their respective line segments. If none of the line segments corresponding to the three vertices of the triangular mesh intersect with the original bone model B, then remove the mesh and place it in set S. 11 middle.

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