Preparation method of interbody fusion cage and generation method and device of corresponding model

Abstract

The invention discloses a preparation method of an interbody fusion cage and a generation method and device of a corresponding model, and the generation method comprises the steps: receiving medical image data of a diseased region of a patient, and generating an assembly model of a target bone organ of the patient; generating a finite element simulation assembly model corresponding to the assembly model, and generating a stress nephogram; converting the original model of the interbody fusion cage into an implicit body, and filling random seeds in the space of the implicit body; adding random seed points in the implicit body; and connecting lines are generated among the random seeds in the implicit body, so that a three-dimensional lattice is generated in the implicit body, and the three-dimensional lattice is the interbody fusion cage model. According to the generation method, the porous structure arrangement of the interbody fusion cage can be intelligently driven according to the stress of the interbody fusion cage in the host body, and the stress shielding effect of the interbody fusion cage is accurately reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of intervertebral fusion cages, and in particular to a method for preparing an intervertebral fusion cage, a method for generating a corresponding model, and a device thereof. Background Art

[0002] Intervertebral fusion devices are clinically used to treat spinal infectious and degenerative diseases. The design of the shape is the basis of the intervertebral fusion device. A good shape design supports the vertebral segments after fusion surgery and effectively conducts mechanical conduction to maintain the stability of the entire vertebral body. The design can obtain better mechanical bearing conditions and reduce the volume and weight of the implant.

[0003] After the intervertebral fusion device is implanted into the bone tissue, osteoblasts can only grow along the surface of the structure. Coating the surface with a coating that is conducive to bone growth will be beneficial to the growth of bone cells and promote bone fusion. Due to the small surface area, the traditional intervertebral fusion device can carry less coating overall. The porous intervertebral fusion device has a low relative density and a large surface area, which can effectively carry more coatings, and the interconnectivity of the porous structure can improve the bone conduction ability, which is conducive to the adhesion and proliferation of cells. However, the porous structure of the porous intervertebral fusion devices currently on the market is mostly filled with a single cell array, and its lattice is arranged in equal spacing and size in three-dimensional space, and there is no coating on the surface. This standardized, batch-produced, and serialized intervertebral fusion device is difficult to match the personalized anatomical characteristics of different patients and the special needs of patients with different bone quality, resulting in settlement, fatigue failure, and non-fusion after the fusion device is implanted in the body.

[0004] In order to adapt to the patient's personalized anatomical characteristics, accurately reduce the stress shielding effect of the intervertebral fusion device, improve the stability of the fusion device in the patient's body, and reduce some postoperative complications of the intervertebral fusion device.

[0005] Therefore, how to generate an intervertebral fusion cage becomes a problem that needs to be solved urgently. Summary of the invention

[0006] In view of this, the main purpose of the present invention is to provide a method for preparing an intervertebral fusion cage, a method for generating a corresponding model and a device thereof.

[0007] To achieve the above-mentioned purpose, the technical solution of the present invention is implemented as follows: a method for generating an intervertebral fusion device model, comprising the following steps: receiving medical imaging data of a patient's lesion site, generating an assembly model of the patient's target bone organ, the assembly model comprising at least: an intervertebral disc, articular cartilage, a vertebral body and a skull; generating a finite element simulation assembly model corresponding to the assembly model, and generating a stress cloud map based on the finite element simulation assembly model and a preset intervertebral fusion device original model; converting the intervertebral fusion device original model into an implicit body, and filling random seeds in the space of the implicit body; and rearranging random seed points in the implicit body according to the stress cloud map, and the higher the stress, the denser the random seed distribution; generating lines between random seeds in the implicit body, thereby generating a three-dimensional lattice in the implicit body, and the higher the stress, the denser the lattice, and the three-dimensional lattice is the intervertebral fusion device model.

[0008] As an improvement of an embodiment of the present invention, generating a stress cloud map based on the finite element simulation assembly model and the preset intervertebral fusion device original model specifically includes: using Ntopology software to process the finite element simulation assembly model and the preset intervertebral fusion device original model and obtain a stress field, thereby generating a stress cloud map, and the finite element simulation assembly model includes: a preset intervertebral fusion device original model.

[0009] As an improvement of the embodiment of the present invention, the adding of random seed points in the implicit body according to the stress cloud map specifically includes: obtaining the maximum stress value of the original model of the intervertebral fusion cage based on the finite element analysis algorithm. , and the minimum stress According to the stress cloud map, random seed points are added to the implicit body, and based on the maximum stress , and the minimum stress Controls the distance between random seed points and the distance between two random seeds ,in: is the difference in stress values ​​between the two random seeds, .

[0010] As an improvement of the embodiment of the present invention, the step of generating lines between random seeds in the implicit body, thereby generating a three-dimensional lattice in the implicit body specifically includes: the set of random seeds is , the Thiessen polyhedron is defined as , any two points and The corresponding perpendicular bisector equation is , the Thiessen polyhedron construction equation is , a set of random seeds generated based on the Thiessen polyhedron construction equation The corresponding three-dimensional Thiessen polyhedron is connected by connecting the edges, faces or vertices of the three-dimensional Thiessen polyhedron to form a three-dimensional lattice; wherein the set of random seeds is ,point The coordinates of , n, i and j are all natural numbers, 1≤i≤n, 1≤j≤n, for The set of adjacent points.

[0011] The embodiment of the present invention provides a method for generating an intervertebral fusion device model, comprising the following modules: a data acquisition module, used to receive medical imaging data of a patient's lesion site, and generate an assembly model of the patient's target bone organ, wherein the assembly model at least includes: an intervertebral disc, articular cartilage, a vertebral body, and a skull; a stress cloud map generation module, used to generate a finite element simulation assembly model corresponding to the assembly model, and generate a stress cloud map based on the finite element simulation assembly model and a preset intervertebral fusion device original model; an implicit body generation module, used to transform the intervertebral fusion device original model into an implicit body, fill random seeds in the space of the implicit body; and rearrange random seed points in the implicit body according to the stress cloud map, and the higher the stress, the denser the random seed distribution; an intervertebral fusion device model generation module, used to generate lines between random seeds in the implicit body, thereby generating a three-dimensional lattice in the implicit body, and the higher the stress, the denser the lattice, and the three-dimensional lattice is the intervertebral fusion device model.

[0012] As an improvement of an embodiment of the present invention, the stress cloud map generation module is also used to: use Ntopology software to process the finite element simulation assembly model and the preset intervertebral fusion device original model and obtain the stress field, thereby generating a stress cloud map, and the finite element simulation assembly model includes: a preset intervertebral fusion device original model.

[0013] As an improvement of the embodiment of the present invention, the implicit body generation module is further used to: obtain the maximum stress value of the original model of the intervertebral fusion cage based on the finite element analysis algorithm , and the minimum stress According to the stress cloud map, random seed points are added to the implicit body, and based on the maximum stress , and the minimum stress Controls the distance between random seed points and the distance between two random seeds ,in: is the difference in stress values ​​between the two random seeds, .

[0014] As an improvement of the embodiment of the present invention, the intervertebral fusion cage model generation module is further used for: the set of random seeds is , the Thiessen polyhedron is defined as , any two points and The corresponding perpendicular bisector equation is , the Thiessen polyhedron construction equation is , a set of random seeds generated based on the Thiessen polyhedron construction equation The corresponding three-dimensional Thiessen polyhedron is connected by connecting the edges, faces or vertices of the three-dimensional Thiessen polyhedron to form a three-dimensional lattice; wherein the set of random seeds is ,point The coordinates of , n, i and j are all natural numbers, 1≤i≤n, 1≤j≤n, for The set of adjacent points.

[0015] An embodiment of the present invention further provides a method for preparing an intervertebral fusion device, comprising the following steps: executing the above-mentioned generation method to obtain a three-dimensional lattice; using a 3D printer to print an intervertebral fusion device corresponding to the three-dimensional lattice, wherein the material of the intervertebral fusion device is silk fibroin.

[0016] As an improvement of the embodiment of the present invention, the following steps are further included: immersing the intervertebral fusion cage in deionized water to remove impurities by ultrasonic treatment, and after drying the intervertebral fusion cage, using low-temperature nitrogen plasma treatment to drop BMP2 on the surface of the intervertebral fusion cage to increase the surface hydrophilicity; dissolving BMP2 in a solution with a pH of 7.4 and a concentration of 0.5 The mixture was placed in a PBS buffer at 4° C. for 12-24 hours to generate a BMP2 coating on the surface of the intervertebral fusion cage.

[0017] The preparation method of the intervertebral fusion device, the generation method of the corresponding model and the device thereof provided by the embodiment of the present invention have the following advantages: The embodiment of the present invention discloses a preparation method of the intervertebral fusion device, the generation method of the corresponding model and the device thereof, and the generation method comprises: receiving medical imaging data of the patient's lesion site, generating an assembly model of the patient's target bone organ; generating a finite element simulation assembly model corresponding to the assembly model, generating a stress cloud map; transforming the original model of the intervertebral fusion device into an implicit body, filling random seeds in the space of the implicit body; adding random seed points in the implicit body; generating lines between random seeds in the implicit body, thereby generating a three-dimensional lattice in the implicit body, and the three-dimensional lattice is the intervertebral fusion device model. The generation method can intelligently drive the arrangement of the porous structure of the intervertebral fusion device according to the stress on the intervertebral fusion device in the host body, and accurately reduce the stress shielding effect of the intervertebral fusion device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A schematic diagram of a flow chart of a method for generating an intervertebral fusion cage model provided in an embodiment of the present invention; Figure 2 A schematic diagram of original bone segmentation and reconstruction provided by an embodiment of the present invention; Figure 3A , Figure 3B and Figure 3C A schematic diagram of reverse reconstruction of a skeleton provided by an embodiment of the present invention; Figure 4A A fusion device assembly model corresponding to the intervertebral fusion device provided in an embodiment of the present invention; Figure 4B An intervertebral disc provided by an embodiment of the present invention; Figure 4C An exploded view of an intervertebral disc provided by an embodiment of the present invention; Figure 5A The finite element analysis stress results provided by the embodiment of the present invention; Figure 5B A schematic diagram of stress of an intervertebral fusion device provided by an embodiment of the present invention; Figure 5C Schematic diagram for describing the ratio of displacement to stress; Figure 6 A stress cloud diagram provided by an embodiment of the present invention; Fig. 7A Schematic diagram of filling the implicit volume space of the intervertebral fusion cage with a random point Q; Figure 7B Schematic diagram of random points P after rearrangement according to stress data; Fig. 8A It is the original intervertebral fusion cage; Figure 8B Intervertebral fusion cage designed for stress field drive. DETAILED DESCRIPTION

[0019] The present invention will be described in detail below in conjunction with the embodiments shown in the accompanying drawings. However, the embodiments do not limit the present invention, and any structural, methodological, or functional changes made by a person skilled in the art based on the embodiments are all within the protection scope of the present invention.

[0020] The following description and accompanying drawings fully illustrate the specific embodiments of this article so that those skilled in the art can practice them. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of this article includes the entire scope of the claims, as well as all available equivalents of the claims. Herein, the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0021] The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in this document indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this document and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of this document, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can also be the internal communication of two elements, it can be a direct connection, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0022] Embodiment 1 of the present invention provides a method for generating an intervertebral fusion cage model, such as Figure 1 As shown, the following steps are included: Step 101: receiving medical image data of a patient's lesion site, and generating an assembly model of the patient's target bone organ, wherein the assembly model at least includes: an intervertebral disc, articular cartilage, a vertebral body, and a skull.

[0023] Here, if Figure 2 , Figure 3A , Figure 3B and Figure 3CAs shown in the figure, in practice, a CT (Computed Tomography) machine can be used to collect medical imaging data from patients, and a three-dimensional model of the patient's skull, cervical spine, thoracic spine and other bone structures can be reconstructed through computer three-dimensional segmentation technology. Specifically, CT scanning can obtain high-resolution tomographic images of the patient's body parts. These images are processed by a computer, and the contour and structural information of the bones are extracted using a three-dimensional segmentation algorithm to generate an accurate three-dimensional digital model.

[0024] Optionally, the model can be optimized and adjusted through reverse engineering software to ensure the accuracy of its geometry and size. 3D printing or other rapid prototyping technologies can also be used to convert the digital model into a physical model.

[0025] Based on the above-mentioned reconstructed three-dimensional model, a fusion assembly model of the intervertebral disc, articular cartilage, vertebral body and skull at the patient's lesion site is further constructed. First, the approximate contour curve of the intervertebral disc is outlined on the vertebral surface according to the anatomical structure. Through the stretching operation, the curve is converted into a three-dimensional entity to form the preliminary geometric shape of the intervertebral disc. Next, the surface of the adjacent segmental vertebra is used to perform Boolean operation cutting on the entity to ensure that the shape of the intervertebral disc completely matches the vertebral surface. Then, the vertebral endplate structure of the intervertebral disc is generated by offsetting the cut vertebral surface inward (for example, 1mm, etc.). After the endplate is created, the vertebral endplate can be temporarily hidden for subsequent operations.

[0026] Next, the remaining structure is cut by offsetting the outer surface of the intervertebral disc inward to separate the nucleus pulposus and the annulus fibrosus. Specifically, the boundary of the nucleus pulposus is formed by offsetting the outer surface of the intervertebral disc inward by a certain distance, and then the three-dimensional model of the nucleus pulposus is cut out using Boolean operations. The remaining intervertebral disc structure naturally forms the annulus fibrosus part. This process not only accurately restores the anatomical structure of the intervertebral disc, but also provides a high-quality digital model foundation for subsequent biomechanical analysis, surgical planning or personalized implant design.

[0027] Step 102: generating a finite element simulation assembly model corresponding to the assembly model, and generating a stress cloud map based on the finite element simulation assembly model and a preset intervertebral fusion cage original model.

[0028] Here, if Figure 4A , Figure 4B and Figure 4CAs shown, a fusion assembly model of the intervertebral disc, articular cartilage, vertebral body and skull of the patient's diseased part can be constructed. The adjacent segment vertebrae are displayed in the 3D software, and the approximate curve of the intervertebral disc is outlined on the surface of the cone. After the stretching command, the body is formed, and then the adjacent segment vertebrae are used to cut it. The upper and lower end plates are obtained by offsetting the cut vertebral surface by 1mm. The upper and lower end plates are hidden. The outer surface of the intervertebral disc is offset inward to cut the remaining structure to form the nucleus pulposus and the annulus fibrosus. Among them, Figure 5A is the stress result of finite element analysis, Figure 5B is the intervertebral fusion cage stress, Figure 5C Schematic diagram of the ratio of displacement to stress. Figure 6 A stress contour is shown.

[0029] Here, the limit simulation result data corresponding to the assembly model is generated, and a stress cloud map is generated based on the limit simulation result data and the preset intervertebral fusion device original model. Specifically, the assembly model is first simulated and calculated using finite element analysis software to simulate its mechanical behavior under specific loads and boundary conditions, and extract data such as stress, strain, and displacement of key parts. Then, these simulation result data are compared and analyzed with the preset intervertebral fusion device original model, and a stress cloud map is generated using visualization technology. The stress cloud map can intuitively display the stress distribution of the intervertebral fusion device in different areas, help identify areas of high stress concentration, and evaluate its structural strength and fatigue life.

[0030] Here, the finite element analysis algorithm can be used to simulate the assembly model. Before simulation, the model needs to be assigned materials, contact relationships, mesh division, and boundary conditions to obtain the stress, strain, and displacement results of the intervertebral fusion device. Among them, the contact relationship is that all contacts are set to binding contact, and the mesh division uses tetrahedral units to divide the model. The boundary conditions are: fix all degrees of freedom on the lower surface of the vertebral body (T1) and apply 50N pressure on the head to simulate the pressure generated by the head's own weight.

[0031] Material parameters are shown in the following table:

[0032] The finite element analysis algorithm uses mathematical approximation methods to simulate real physical systems (geometry and load conditions). By using simple and interacting elements (i.e. units), a finite number of unknown quantities can be used to approximate a real system with infinite unknown quantities. Finite element analysis replaces complex problems with simpler problems and then solves them. It regards the solution domain as consisting of many small interconnected subdomains called finite elements, assumes a suitable (simpler) approximate solution for each unit, and then derives the total satisfaction conditions of the domain (such as the equilibrium conditions of the structure) to obtain the solution to the problem. Because the actual problem is replaced by a simpler problem, this solution is not an exact solution, but an approximate solution. Since most actual problems are difficult to obtain exact solutions, and finite elements not only have high calculation accuracy, but can also adapt to various complex shapes, they have become an effective engineering analysis tool.

[0033] The process of generating stress cloud diagram can be divided into the following steps: Step 1: Load the finite element simulation results (RST file), which contains the stress, strain, displacement and other data of each node of the intervertebral fusion cage during the simulation process; ensure that the simulation results match the original model of the intervertebral fusion cage, including the geometry, mesh division and material properties.

[0034] Step 2: Extract key data Extract stress data (such as Von Mises stress, principal stress, etc.) from the RST file, which reflects the stress conditions in different areas of the intervertebral fusion cage. If necessary, other related data such as strain and displacement can also be extracted to comprehensively evaluate the mechanical properties of the intervertebral fusion cage.

[0035] Step 3: Mapping with the original model The extracted stress data is mapped to the original model of the intervertebral fusion cage to ensure that the stress value of each node or unit corresponds to the geometric position of the model. This step requires checking the accuracy of the mapping to avoid data loss or errors.

[0036] Step 4: Generate stress cloud map Here, the stress cloud map intuitively displays the stress distribution on the surface of the intervertebral fusion cage through color gradient. Usually, high stress areas are represented by red, low stress areas are represented by blue, and the middle areas are represented by gradient colors.

[0037] Step 103: transforming the original model of the intervertebral fusion cage into an implicit body, filling random seeds in the space of the implicit body; and rearranging random seed points in the implicit body according to the stress cloud map, and the higher the stress, the denser the random seed distribution.

[0038] Step 104: Generate lines between random seeds in the implicit body, so as to generate a three-dimensional lattice in the implicit body, and the higher the stress, the denser the lattice. The three-dimensional lattice is the intervertebral fusion cage model.

[0039] The generation method provided in the embodiment of the present invention can intelligently drive the arrangement of the porous structure of the intervertebral fusion device according to the stress exerted on the intervertebral fusion device in the host body, and accurately reduce the stress shielding effect of the intervertebral fusion device.

[0040] In this embodiment, generating a stress cloud map based on the finite element simulation assembly model and the preset intervertebral fusion device original model specifically includes: using Ntopology software to process the finite element simulation assembly model and the preset intervertebral fusion device original model and obtain a stress field, thereby generating a stress cloud map, and the finite element simulation assembly model includes: a preset intervertebral fusion device original model.

[0041] Here, Ntopology software is an efficient design platform for additive manufacturing. The platform has pre-installed a large number of commonly used design toolkits for additive manufacturing. Engineers can establish a workflow by calling several preset toolkits or independently developing customized toolkits to achieve parametric design of complex geometric structures.

[0042] In this embodiment, Fig. 7A and Figure 7B As shown, the adding of random seed points in the implicit body according to the stress cloud map specifically includes: obtaining the maximum stress value of the original model of the intervertebral fusion cage based on the finite element analysis algorithm , and the minimum stress According to the stress cloud map, random seed points are added to the implicit body, and based on the maximum stress , and the minimum stress Controls the distance between random seed points and the distance between two random seeds ,in: is the difference in stress values ​​between the two random seeds, .

[0043] Here, in practice, the STP format model of the intervertebral fusion cage can be converted into an implicit surface representation through implicit modeling technology (such as the RBF method based on the signed distance function or the Marching Cubes algorithm). This mathematical expression can more flexibly describe the topological structure of complex geometric bodies. Figure 6 As shown in Figure 1, after the implicit body transformation is completed, the Poisson disk sampling algorithm is used to generate a random seed point distribution that meets the spatial constraints in the implicit body space. This process controls the point set density by adjusting the neighborhood radius parameter in the acceptance-rejection sampling.

[0044] The spatial distribution of seed points is driven by the stress cloud map obtained by finite element analysis: First, the extreme values ​​of the stress field of the intervertebral fusion cage are extracted ( and ), and then construct a nonlinear mapping relationship based on the Ramp function to convert the continuous stress value range Map to a preset point spacing range The specific implementation adopts the piecewise linear interpolation method, which automatically reduces the sampling interval to 100% in the area with large stress gradient (usually occurring at the edge contact surface of the fusion device). , forming a dense point set to improve the accuracy of subsequent mesh reconstruction; in low stress areas (such as the central hollow structure), the spacing is increased to , realizing the optimal allocation of computing resources. This adaptive point cloud generation method not only ensures the characterization accuracy of the key mechanical areas, but also avoids the computational redundancy caused by uniform sampling, providing an optimized discretization basis for subsequent topology optimization or additive manufacturing path planning. .

[0045] In this embodiment, generating lines between random seeds in the implicit body, thereby generating a three-dimensional lattice in the implicit body specifically includes: The set of random seeds is , the Thiessen polyhedron is defined as , any two points and The corresponding perpendicular bisector equation is , the Thiessen polyhedron construction equation is , a set of random seeds generated based on the Thiessen polyhedron construction equation The corresponding three-dimensional Thiessen polyhedron is connected by connecting the edges, faces or vertices of the three-dimensional Thiessen polyhedron to form a three-dimensional lattice; wherein the set of random seeds is ,point The coordinates of , n, i and j are all natural numbers, 1≤i≤n, 1≤j≤n, for The set of adjacent points.

[0046] A Thiessen polyhedron, also known as a Voronoi diagram, is a set of continuous polygons consisting of perpendicular bisectors connecting two adjacent line segments. The distance from any point in a Thiessen polygon to the control points that make up the polygon is less than the distance to the control points of other polygons.

[0047] Here, after obtaining the random seed point distribution, a three-dimensional Thiessen structure is constructed in the implicit volume space according to the geometric partitioning principle of the Voronoi diagram. The specific process includes the following steps: Step 1: Voronoi triangulation calculation, using the incremental Delaunay triangulation algorithm (such as the CGAL library or the Paravoronoi method), taking the seed points as the generating points (Sites), and calculating the spatial Voronoi cells under the implicit volume constraint. Each Voronoi cell is composed of a set of convex polyhedra, whose boundaries are the perpendicular bisectors of adjacent seed points, thus forming a continuous spatial mosaic structure.

[0048] Step 2: Stress-lattice density coupling. Since the seed point distribution is regulated by the stress field (dense in high stress areas and sparse in low stress areas), the generated Tyson naturally presents gradient topological characteristics. In high stress areas (such as the fusion device-endplate contact interface), smaller lattice unit sizes (~100–300μm) can improve local stiffness and fatigue resistance; while in low stress areas (such as internal cavities), larger lattice units (~500–1000μm) help reduce mass and promote bone ingrowth.

[0049] Step 3: Implicit body boundary clipping, using the implicit surface signed distance field (SDF) to perform Boolean operations on Voronoi units, remove redundant structures beyond the boundaries of the fusion device, ensure that the lattice is strictly confined within the target geometry, and retain the naturally transitional pore morphology. The resulting porous intervertebral fusion device model has both mechanical adaptability and biocompatibility. Among them, the gradient Voronoi structure provides a higher density of support units in the stress concentration area to effectively disperse the load; the large pore area (low stress area) provides space for bone cell migration and vascularization, which meets the requirements of bionic design.

[0050] Embodiment 2 of the present invention provides a method for generating an intervertebral fusion cage model, comprising the following modules: The data acquisition module is used to receive medical image data of the patient's lesion site and generate an assembly model of the patient's target bone organ, wherein the assembly model at least includes: an intervertebral disc, articular cartilage, a vertebral body and a skull.

[0051] The stress cloud map generating module is used to generate a finite element simulation assembly model corresponding to the assembly model, and to generate a stress cloud map based on the finite element simulation assembly model and a preset intervertebral fusion cage original model.

[0052] The implicit body generation module is used to transform the original model of the intervertebral fusion device into an implicit body, fill random seeds in the space of the implicit body; and rearrange the random seed points in the implicit body according to the stress cloud map, and the higher the stress, the denser the random seed distribution.

[0053] The intervertebral fusion cage model generation module is used to generate lines between random seeds in the implicit body, so as to generate a three-dimensional lattice in the implicit body, and the higher the stress, the denser the lattice, and the three-dimensional lattice is the intervertebral fusion cage model.

[0054] In this embodiment, the stress cloud map generating module is further used to: use Ntopology software to process the finite element simulation assembly model and the preset intervertebral fusion device original model and obtain the stress field, thereby generating a stress cloud map, and the finite element simulation assembly model includes: a preset intervertebral fusion device original model.

[0055] In this embodiment, the implicit volume generation module is also used to: obtain the maximum stress value of the original model of the intervertebral fusion cage based on the finite element analysis algorithm , and the minimum stress According to the stress cloud map, random seed points are added to the implicit body, and based on the maximum stress , and the minimum stress Controls the distance between random seed points and the distance between two random seeds ,in: is the difference in stress values ​​between the two random seeds, .

[0056] In this embodiment, the intervertebral fusion cage model generation module is further used for: the set of random seeds is , the Thiessen polyhedron is defined as , any two points and The corresponding perpendicular bisector equation is , the Thiessen polyhedron construction equation is , a set of random seeds generated based on the Thiessen polyhedron construction equation The corresponding three-dimensional Thiessen polyhedron is connected by connecting the edges, faces or vertices of the three-dimensional Thiessen polyhedron to form a three-dimensional lattice; wherein the set of random seeds is ,point The coordinates of , n, i and j are all natural numbers, 1≤i≤n, 1≤j≤n, for The set of adjacent points.

[0057] Embodiment 3 of the present invention provides a method for preparing an intervertebral fusion cage, comprising the following steps: Step 1: Execute the generation method in Example 1 to obtain a three-dimensional lattice.

[0058] Step 2: Using a 3D printer, print an intervertebral fusion device corresponding to the three-dimensional lattice.

[0059] In this embodiment, the material of the intercone fusion device is silk fibroin.

[0060] In practice, the intervertebral fusion cage can be immersed in deionized water to remove impurities by ultrasound, and after drying, the intervertebral fusion cage is treated with low-temperature nitrogen plasma to drop BMP2 on the surface of the intervertebral fusion cage to increase the surface hydrophilicity; BMP2 is dissolved in a solution with a pH of 7.4 and a concentration of 0.5 The mixture was placed in a PBS buffer at 4° C. for 12-24 hours to generate a BMP2 coating on the surface of the intervertebral fusion cage.

[0061] here, Fig. 8A This is the original model of the intervertebral fusion cage. Figure 8B The intervertebral fusion cage is obtained by the preparation method.

[0062] Here, the intervertebral fusion device was first placed in ultrapure deionized water (resistivity ≥ 18.2MΩ·cm) and treated with an ultrasonic cleaner with a frequency of 40kHz for 30 minutes to thoroughly remove the processing debris and organic contaminants remaining on the surface. After cleaning, the fusion device was placed in a vacuum drying oven and dried at 60°C for 4 hours to ensure complete removal of moisture. Subsequently, the dried fusion device was placed in a low-temperature plasma treatment system (power 100W, working gas pressure 50Pa), and high-purity nitrogen (purity 99.999%) was introduced for surface activation treatment for 5 minutes. This process bombards the material surface with high-energy particles in the plasma, which can increase the surface roughness at the nanoscale and introduce oxygen-containing polar groups (such as -OH, -COOH), so that the contact angle is reduced from 75° to below 25°, significantly improving the surface hydrophilicity.

[0063] BMP-2 (rhBMP-2) was dissolved in PBS buffer (10 mM phosphate, 150 mM NaCl, pH 7.4) sterilized by filtration through a 0.22 μm filter membrane to prepare a concentration of 0.5 The working solution was added evenly to the surface of the treated fusion device using a micropipette (50 μL per square centimeter), and placed in a 4°C biochemical incubator for 16 hours. During this process, BMP-2 molecules were gradually adsorbed to the surface of the activated material through electrostatic interactions and hydrogen bonding to form a monolayer coating. Finally, the unbound proteins were gently rinsed three times with PBS buffer. ELISA test confirmed that the surface BMP-2 loading reached (85±5) ng / cm². In vitro cell experiments showed that the coating could significantly promote the osteogenic differentiation of MC3T3-E1 cells (ALP activity increased by 3.2 times, p<0.01).

[0064] It should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0065] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for generating an intervertebral fusion cage model, characterized in that: The following steps are involved: Receiving medical image data of a patient's lesion site, and generating an assembly model of the patient's target bone organ, wherein the assembly model at least includes: an intervertebral disc, articular cartilage, a vertebral body, and a skull; Generating a finite element simulation assembly model corresponding to the assembly model, and generating a stress cloud map based on the finite element simulation assembly model and a preset intervertebral fusion cage original model; The original model of the intervertebral fusion cage is transformed into an implicit body, and random seeds are filled in the space of the implicit body; and according to the stress cloud map, random seed points are rearranged in the implicit body, and the higher the stress, the denser the random seed distribution; In the implicit body, lines are generated between random seeds, so as to generate a three-dimensional lattice in the implicit body. The higher the stress, the denser the lattice. The three-dimensional lattice is the intervertebral fusion cage model.

2. The generation method according to claim 1, characterized in that: The generating of the stress cloud map based on the finite element simulation assembly model and the preset intervertebral fusion cage original model specifically includes: The finite element simulation assembly model and the preset intervertebral fusion device original model are processed by using Ntopology software to obtain a stress field, thereby generating a stress cloud map. The finite element simulation assembly model includes: a preset intervertebral fusion device original model.

3. The generation method according to claim 1, characterized in that: The adding of random seed points in the implicit body according to the stress cloud map specifically includes: Based on the finite element analysis algorithm, the maximum stress value of the original model of the intervertebral fusion cage was obtained. , and the minimum stress According to the stress cloud map, random seed points are added to the implicit body, and based on the maximum stress , and the minimum stress Controls the distance between random seed points and the distance between two random seeds ,in: is the difference in stress values ​​between the two random seeds, .

4. The generation method according to claim 1, characterized in that: Generating lines between random seeds in the implicit body, thereby generating a three-dimensional lattice in the implicit body specifically includes: The set of random seeds is , the Thiessen polyhedron is defined as , any two points and The corresponding perpendicular bisector equation is , the Thiessen polyhedron construction equation is , a set of random seeds generated based on the Thiessen polyhedron construction equation The corresponding three-dimensional Thiessen polyhedron is connected by connecting the edges, faces or vertices of the three-dimensional Thiessen polyhedron to form a three-dimensional lattice; wherein the set of random seeds is ,point The coordinates of , n, i and j are all natural numbers, 1≤i≤n, 1≤j≤n, for The set of adjacent points.

5. A device for generating an intervertebral fusion cage model, characterized in that: Includes the following modules: A data acquisition module, for receiving medical imaging data of a patient's lesion site, and generating an assembly model of the patient's target bone organ, wherein the assembly model at least includes: an intervertebral disc, articular cartilage, a vertebral body, and a skull; A stress cloud map generating module, used to generate a finite element simulation assembly model corresponding to the assembly model, and to generate a stress cloud map based on the finite element simulation assembly model and a preset intervertebral fusion cage original model; An implicit body generation module, used for converting the original model of the intervertebral fusion device into an implicit body, filling random seeds in the space of the implicit body; and rearranging random seed points in the implicit body according to the stress cloud map, and the higher the stress, the denser the random seed distribution; The intervertebral fusion cage model generation module is used to generate lines between random seeds in the implicit body, so as to generate a three-dimensional lattice in the implicit body, and the higher the stress, the denser the lattice, and the three-dimensional lattice is the intervertebral fusion cage model.

6. The generating device according to claim 5, characterized in that The stress cloud map generation module is also used for: The finite element simulation assembly model and the preset intervertebral fusion device original model are processed by using Ntopology software to obtain a stress field, thereby generating a stress cloud map. The finite element simulation assembly model includes: a preset intervertebral fusion device original model.

7. The generating device according to claim 5, characterized in that The implicit body generation module is also used for: Based on the finite element analysis algorithm, the maximum stress value of the original model of the intervertebral fusion cage was obtained. , and the minimum stress ; According to the stress cloud map, random seed points are added to the implicit body, and based on the maximum stress value , and the minimum stress Controls the distance between random seed points and the distance between two random seeds ,in: is the difference in stress values ​​between the two random seeds, .

8. The generating device according to claim 5, characterized in that The intervertebral fusion cage model generation module is also used for: The set of random seeds is , the Thiessen polyhedron is defined as , any two points and The corresponding perpendicular bisector equation is , the Thiessen polyhedron construction equation is , a set of random seeds generated based on the Thiessen polyhedron construction equation The corresponding three-dimensional Thiessen polyhedron is connected by connecting the edges, faces or vertices of the three-dimensional Thiessen polyhedron to form a three-dimensional lattice; wherein the set of random seeds is ,point The coordinates of , n, i and j are all natural numbers, 1≤i≤n, 1≤j≤n, for The set of adjacent points.

9. A method for preparing an intervertebral fusion cage, characterized in that: The following steps are involved: Execute the generation method according to any one of claims 1 to 4 to obtain a three-dimensional lattice; The intervertebral fusion device corresponding to the three-dimensional lattice is printed using a 3D printer.

10. The preparation method according to claim 9, characterized in that: The material of the intercone fusion device is silk fibroin.

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