Patient-specific finite element model-based vertebroplasty optimization method and related devices

Abstract

The application discloses a vertebroplasty optimization method based on a patient-specific finite element model and related devices, wherein the method comprises the following steps: constructing a patient-specific three-dimensional spine model according to a vertebral bone structure and a vertebral soft tissue structure; discretizing the patient-specific three-dimensional spine model into a tetrahedral finite element grid, assigning bone material properties to each finite element unit according to pixel values of a CT scan image, and assigning soft tissue material properties to intervertebral disc and ligament soft tissue structures; determining an optimal bone cement injection path and an optimal bone cement injection amount of the tetrahedral finite element grid; simulating vertebroplasty in the tetrahedral finite element grid, predicting stress distribution of a vertebra after the vertebroplasty, rigidity of the vertebra, and stress changes of adjacent vertebrae, and presenting simulation results of the simulated vertebroplasty in a three-dimensional visual form. The application realizes individualized optimization and preoperative simulation of vertebroplasty by constructing a patient-specific finite element model, and provides an efficient auxiliary reference surgical plan for a surgeon.

Description

Technical Field

[0001] This invention relates to the fields of artificial intelligence and medical surgical assistance technology, specifically to an optimization method and apparatus for vertebroplasty based on a patient-specific finite element model, and a computing device. Background Technology

[0002] Vertebroplasty is a common spinal surgery used to treat conditions such as spinal compression fractures and osteoporosis. The procedure involves injecting bone cement into the damaged vertebra to enhance its stability and strength.

[0003] However, current vertebroplasty planning and optimization rely primarily on the surgeon's experience and simple image analysis, leading to problems such as bone cement leakage, insufficient vertebral stability, and stress changes in adjacent vertebrae, resulting in poor surgical outcomes and even complications. While finite element analysis is widely used in engineering, no relevant applications in the medical field have been found. Furthermore, existing methods for optimizing bone cement injection paths and volumes are relatively crude, lacking precise stress analysis and optimization algorithms. For example, if the surgeon underestimates the injection path, bone cement may concentrate in the anterior half of the vertebra, resulting in insufficient support in the posterior half and ineffective restoration of the vertebra's load-bearing capacity. Moreover, they cannot present three-dimensional visualization of the simulation results, failing to visually demonstrate the postoperative stress distribution and deformation of the vertebrae.

[0004] To address the aforementioned issues, this invention proposes a method for optimizing vertebroplasty based on a patient-specific finite element model. By constructing a patient-specific finite element model, personalized optimization of vertebroplasty can be achieved, and preoperative simulation can be predicted, providing surgeons with an efficient auxiliary reference surgical plan. Summary of the Invention

[0005] In view of the above problems, the present invention provides a method, apparatus and computing device for optimizing vertebroplasty based on a patient-specific finite element model.

[0006] According to one aspect of the present invention, a method for optimizing vertebroplasty based on a patient-specific finite element model is provided, comprising: Acquire CT scan images and X-ray scan images containing the target vertebra and its adjacent vertebrae; automatically segment the CT scan images and X-ray scan images to extract the vertebral bone structure and vertebral soft tissue structure respectively; construct a patient-specific three-dimensional spinal model based on the vertebral bone structure and vertebral soft tissue structure; The patient-specific three-dimensional spinal model is discretized into a tetrahedral finite element mesh. Bone material properties are assigned to each finite element element based on the pixel values ​​of the CT scan image, and soft tissue material properties are assigned to the intervertebral disc and ligament soft tissue structures. The optimal bone cement injection path of the tetrahedral finite element mesh is determined by the density method, wherein the objective function of the optimal bone cement injection path is to minimize the maximum principal stress of the target vertebral body, and the constraints include the bone cement injection volume and the stability of the target vertebral body. The optimal amount of bone cement to be injected along the optimal bone cement injection path is determined by using the objective functions of minimizing the maximum principal stress of the target vertebra, maximizing the stiffness of the target vertebra, and minimizing the stress variation of adjacent vertebrae. Based on the optimal bone cement injection path and the optimal bone cement injection amount, vertebroplasty is simulated in the tetrahedral finite element mesh to predict the postoperative stress distribution, stiffness, and stress changes of adjacent vertebrae. The simulation results of vertebroplasty are presented in a three-dimensional visualization form, including bone cement distribution, stress cloud map, and deformation map.

[0007] In one alternative approach, the expression for the mapping relationship between the pixel values ​​of the CT scan image and the properties of the bone material is as follows: in, coordinates The elastic modulus of the bone material; This represents the lower limit of the elastic modulus of cancellous bone. This represents the upper limit of the elastic modulus of cortical bone. This is the curvature adjustment coefficient. ; This represents the bone mineral density value corresponding to the bone mineral density inflection point. Indicates coordinates as The bone density value of the pixel.

[0008] In one alternative approach, the sensitivity formula for the objective function that minimizes the maximum principal stress of the target vertebra is: in, Design variables for the unit; Unit volume; This is the effect of the von Mises effect; For strain tensor; It is a fourth-order elastic tensor; A spatial region of a unit; This is the maximum principal stress; It is a double dot product used in tensor operations.

[0009] In an alternative approach, constructing a patient-specific three-dimensional spinal model based on the vertebral bone structure and vertebral soft tissue structure further includes: The surface of the vertebral bone structure and the vertebral soft tissue structure is reconstructed using the Marching Cubes algorithm to generate an initial surface mesh. The surface mesh is obtained by smoothing and simplifying the surface mesh data using the Laplacian Smoothing algorithm. A tetrahedral mesh model conforming to the finite element analysis requirements of the surface mesh was generated using the tetrahedral mesh generation tool TetGen, resulting in a patient-specific three-dimensional spinal finite element model.

[0010] In an alternative approach, determining the optimal bone cement injection path of the tetrahedral finite element mesh using the density method further includes: Assign a density variable to each tetrahedral finite element mesh, perform finite element analysis based on the current density distribution, and calculate the maximum principal stress of the target cone. Calculate the sensitivity of the maximum principal stress to each density variable, update the density variables based on the sensitivity, and check whether the constraints of bone cement volume and vertebral body stability are met. If not, adjust the density variables. The updated density variable distribution is transformed into the actual bone cement injection path to obtain the optimal bone cement injection path of the tetrahedral finite element mesh.

[0011] In an alternative approach, simulating vertebroplasty in the tetrahedral finite element mesh, based on the optimal bone cement injection path and the optimal bone cement injection volume, further includes: The optimal injection path is converted into a spatial coordinate sequence, and the target element set is marked in the finite element mesh; the volume fraction of bone cement in each target element is calculated according to the optimal injection amount, and the injection process is simulated by a progressive filling method; the elastic modulus of the injected bone cement element is linearly transitioned from the bone tissue value to the cement material value. Temperature field distribution is calculated based on nonlinear transient heat conduction equations to simulate the exothermic process of bone cement hydration reaction; the Carreau model is used to describe the non-Newtonian fluid properties of bone cement during the bone cement flow stage and mesh deformation is handled according to the Lagrange-Euler method; stiffness degradation is initiated when the equivalent plastic strain of the element exceeds a preset threshold. The stiffness recovery rate was obtained by comparing the postoperative vertebral body stiffness matrix with the preoperative stiffness, and the pressure increment of adjacent intervertebral discs and the maximum shear strain of the annulus fibrosus were calculated. A particle system was used to simulate the cement diffusion process to simulate vertebroplasty, in which particle color was mapped to injection time, and the transparency channels of the stress cloud map were superimposed to show the distribution of bone cement.

[0012] In an alternative embodiment, during the simulated vertebroplasty, the method further includes: The curing behavior of bone cement is represented by a viscoelastic or viscoplastic constitutive model, which includes the influence factors of the degree of hydration reaction, temperature and strain rate on the mechanical properties of bone cement. The curing behavior of bone cement and its impact on the vertebral microenvironment were incorporated into a coupled biological model to predict the trends of bone tissue remodeling and long-term stability changes within the vertebral body after bone cement injection. The impact on the internal microenvironment included changes in bone marrow pressure, stress-strain changes in osteocytes, and microfractures. When determining the optimal amount of bone cement injected, the vertebral body compressive strength, fatigue life, and stress concentration degree of adjacent vertebral endplates are used as constraints of the optimization objective function.

[0013] In an alternative approach, the method further includes: When transforming the density variable distribution into the bone cement injection path, the density field is smoothed and thresholded to extract the bone cement injection channel. Remove sharp corners and overly thin connections in the geometry of the injection channel to reduce the risk of bone cement leakage; The manufacturability of the optimized bone cement injection path is evaluated based on the accessibility of the puncture needle, the range of injection angles, and the performance of the bone cement injection equipment.

[0014] According to another aspect of the present invention, a vertebroplasty optimization device based on a patient-specific finite element model is provided, comprising: The spinal model construction module is used to acquire CT scan images and X-ray scan images containing the target vertebra and its adjacent vertebrae; automatically segment the CT scan images and X-ray scan images to extract the vertebral bone structure and vertebral soft tissue structure respectively; and construct a patient-specific three-dimensional spinal model based on the vertebral bone structure and vertebral soft tissue structure. The finite element model preprocessing module is used to discretize the patient-specific three-dimensional spinal model into a tetrahedral finite element mesh, assign bone material properties to each finite element unit according to the pixel values ​​of the CT scan image, and assign soft tissue material properties to the intervertebral disc and ligament soft tissue structures. The injection path optimization module is used to determine the optimal bone cement injection path of the tetrahedral finite element mesh using the density method. The objective function of the optimal bone cement injection path is to minimize the maximum principal stress of the target vertebral body, and the constraints include the bone cement injection volume and the stability of the target vertebral body. The injection volume optimization module is used to determine the optimal bone cement injection volume for the optimal bone cement injection path by using the objective functions of minimizing the maximum principal stress of the target vertebra, maximizing the stiffness of the target vertebra, and minimizing the stress change of adjacent vertebrae. The vertebroplasty simulation module is used to simulate vertebroplasty in the tetrahedral finite element mesh according to the optimal bone cement injection path and the optimal bone cement injection amount, predict the stress distribution of the vertebral body, the stiffness of the vertebral body and the stress changes of adjacent vertebral bodies after surgery, and present the simulation results of vertebroplasty in a three-dimensional visualization form. The simulation results include bone cement distribution, stress cloud map and deformation map.

[0015] According to another aspect of the present invention, a computing device is provided, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction that causes the processor to perform the operation corresponding to the above-described optimization method for vertebroplasty based on a patient-specific finite element model.

[0016] According to the solution provided by the present invention, CT scan images and X-ray scan images containing the target vertebra and its adjacent vertebrae are acquired; the CT scan images and X-ray scan images are automatically segmented to extract the vertebral bone structure and vertebral soft tissue structure, respectively; a patient-specific three-dimensional spinal model is constructed based on the vertebral bone structure and vertebral soft tissue structure; the patient-specific three-dimensional spinal model is discretized into a tetrahedral finite element mesh, and bone material properties are assigned to each finite element element according to the pixel values ​​of the CT scan images, and soft tissue material properties are assigned to the intervertebral disc and ligament soft tissue structures; the optimal bone cement injection path of the tetrahedral finite element mesh is determined by the density method, wherein the optimal bone cement... The objective function of the injection path is to minimize the maximum principal stress of the target vertebral body, with constraints including the volume of bone cement injected and the stability of the target vertebral body. The optimal bone cement injection volume for the optimal injection path is determined by using the objective functions of minimizing the maximum principal stress of the target vertebral body, maximizing the stiffness of the target vertebral body, and minimizing the stress variation of adjacent vertebral bodies. Based on the optimal bone cement injection path and the optimal bone cement injection volume, vertebroplasty is simulated in the tetrahedral finite element mesh to predict the postoperative stress distribution, stiffness, and stress variation of adjacent vertebral bodies. The simulation results of the vertebroplasty are presented in a three-dimensional visualization, including bone cement distribution, stress cloud map, and deformation map. This invention achieves personalized optimization of vertebroplasty and predicts preoperative simulations by constructing a patient-specific finite element model, providing surgeons with an efficient auxiliary reference surgical plan. Specifically, a patient-specific three-dimensional spinal model and finite element model are constructed using the patient's own CT scan images and X-ray scan images, more accurately reflecting the patient's spinal structure and mechanical properties, and has high clinical application value. By assigning bone material properties to each finite element unit based on the pixel values ​​of CT scan images and incorporating differences in bone density, the finite element model more realistically reflects the mechanical properties of the bone. Simultaneously, soft tissue material properties are assigned to the intervertebral discs and ligaments to ensure the accuracy of the overall mechanical properties of the spine. The optimal bone cement injection path is determined using the density method, with minimizing the maximum principal stress of the target vertebra as the optimization objective, effectively reducing the risk of postoperative vertebral fracture and improving surgical safety. By minimizing the maximum principal stress of the target vertebra, maximizing its stiffness, and minimizing stress changes in adjacent vertebrae, the optimal amount of bone cement injected is comprehensively sought, thereby improving the stability of the target vertebra while reducing the risk of refracture in adjacent vertebrae. Vertebroplasty is simulated in a tetrahedral finite element mesh to predict postoperative stress distribution, stiffness, and stress changes in adjacent vertebrae. The simulation results are presented in a three-dimensional visualization, allowing for preoperative prediction of surgical outcomes and adjustment of the surgical plan based on the simulation results, reducing surgical risks and improving surgical success rates and outcomes.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart illustrating the optimization method for vertebroplasty based on a patient-specific finite element model according to an embodiment of the present invention is shown. Figure 2 This invention presents a schematic diagram comparing postoperative images of the cemented bone graft group and the uncemented bone graft group using X-ray and CT images according to an embodiment of the present invention. Figure 3 A schematic diagram of the anatomical structure of the human sacrum and hip bone according to an embodiment of the present invention is shown; Figure 4 A schematic diagram of the optimal bone cement injection path for a tetrahedral finite element mesh according to an embodiment of the present invention is shown. Figure 5 A schematic diagram of the frame of the vertebroplasty optimization device based on a patient-specific finite element model according to an embodiment of the present invention is shown. Figure 6 A schematic diagram of the structure of a computing device according to an embodiment of the present invention is shown. Detailed Implementation

[0019] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0020] Figure 1 A flowchart illustrating the optimization method for vertebroplasty based on a patient-specific finite element model according to an embodiment of the present invention is shown. Specifically, as... Figure 1 As shown, it includes the following steps: Step S101: Obtain CT scan images and X-ray scan images containing the target vertebra and its adjacent vertebrae; automatically segment the CT scan images and X-ray scan images to extract the vertebral bone structure and vertebral soft tissue structure respectively; construct a patient-specific three-dimensional spinal model based on the vertebral bone structure and vertebral soft tissue structure.

[0021] In this embodiment, a three-dimensional spinal model is constructed based on the patient's CT and X-ray images. Compared to standardized, average spinal models, this model can accurately reflect individual differences in the patient's bone morphology, density distribution, fracture status, and soft tissue condition. Vertebroplasty not only affects the stability of the vertebral body but also the surrounding intervertebral discs and ligaments. By simultaneously extracting the vertebral bone structure and vertebral soft tissue structure, the overall impact of the surgery on the spine can be more comprehensively assessed.

[0022] Specifically, using a multi-slice spiral CT scanner to obtain images such as... Figure 2 The image shown contains an axial CT image of the target vertebra (e.g., L1) and its adjacent vertebrae (e.g., T12 and L2). Optionally, X-ray scans are used to provide more comprehensive overall information about the spine, where X-rays are used to help confirm the relative positions and overall curvature of the vertebrae. Image segmentation algorithms such as thresholding and region growing are used to automatically identify and extract vertebral bone structures from the CT images. For example, a thresholding algorithm sets a threshold range based on CT values ​​(HU values), marking pixels in the CT image with HU values ​​within this range as bone tissue. Then, morphological operations (dilation, erosion) are used to remove noise and voids from the segmentation results, identifying and extracting soft tissue structures such as intervertebral discs and ligaments. Since soft tissues have low contrast in CT images and are difficult to segment, pre-built shape models of intervertebral discs and ligaments are used to match the models to the CT images, thus achieving soft tissue segmentation. A 3D reconstruction algorithm such as Marching Cubes is used to convert the segmented bone and soft tissue structures into 3D surface models, and these 3D surface models are integrated to form a complete spinal model.

[0023] For example, in planning a vertebroplasty for a 65-year-old patient, a lumbar CT scan was performed to obtain CT images containing the T12, L1, and L2 vertebrae. The bone structure of the T12, L1, and L2 vertebrae in the CT images was segmented, and the structure of the T12-L1 and L1-L2 intervertebral discs was extracted. The Marching Cubes algorithm was used to convert the segmented bone and disc structures into a 3D surface model, and the bone and disc models were integrated into a complete spinal model. The Laplacian Smoothing algorithm was used to smooth the spinal model to remove surface noise and jagged edges, and a mesh simplification algorithm was used to reduce the number of triangles in the spinal model to 500,000 to improve the efficiency of finite element analysis. Finally, a patient-specific 3D spinal model was obtained, which included the skeletal morphology of the T12, L1, and L2 vertebrae, intervertebral disc structure, and bone density information, for subsequent optimization of the vertebroplasty plan.

[0024] In an alternative approach, constructing a patient-specific three-dimensional spinal model based on the vertebral bone structure and vertebral soft tissue structure further includes: The surface of the vertebral bone structure and the vertebral soft tissue structure is reconstructed using the Marching Cubes algorithm to generate an initial surface mesh. The surface mesh is obtained by smoothing and simplifying the surface mesh data using the Laplacian Smoothing algorithm. A tetrahedral mesh model conforming to the finite element analysis requirements of the surface mesh was generated using the tetrahedral mesh generation tool TetGen, resulting in a patient-specific three-dimensional spinal finite element model.

[0025] In this embodiment, the surface meshes of the vertebral bone structure and soft tissue structure are accurately reconstructed using the Marching Cubes algorithm and the Laplacian Smoothing algorithm. A tetrahedral mesh model conforming to the requirements of finite element analysis is generated using the TetGen tool, ensuring the accuracy and reliability of the analysis results. The Laplacian Smoothing algorithm not only simplifies the mesh but also smooths the surface mesh, reducing irregularities and sharp corners, and improving the smoothness and stability of the model.

[0026] Specifically, the Marching Cubes algorithm is used to reconstruct the surface of the vertebral bone and soft tissue structures from voxel data, generating an initial surface mesh. The Marching Cubes algorithm extracts isosurfaces from the voxel data to generate a continuous surface mesh, ensuring surface continuity. The Laplacian Smoothing algorithm minimizes the Laplacian operator of the mesh, reducing irregularities and sharp corners, and smoothing and simplifying the initial surface mesh. The TetGen tool generates a high-quality tetrahedral mesh from the surface mesh, ensuring mesh uniformity and the accuracy of the finite element analysis.

[0027] In one alternative approach, the expression for the mapping relationship between the pixel values ​​of the CT scan image and the properties of the bone material is as follows: in, coordinates The elastic modulus of the bone material; This represents the lower limit of the elastic modulus of cancellous bone. This represents the upper limit of the elastic modulus of cortical bone. This is the curvature adjustment coefficient. ; This represents the bone mineral density value corresponding to the bone mineral density inflection point. Indicates coordinates as The bone density value of the pixel.

[0028] In this embodiment, the bone material properties (elastic modulus) of each finite element unit are determined by the pixel values ​​(HU values, Hounsfield Units) of the CT scan image, enabling patient-specific material assignment and thus improving the accuracy of finite element analysis. Because the influence of bone mineral density (HU values) is considered, different degrees of osteoporosis can be distinguished, and different elastic moduli can be assigned to bones of different densities. The Sigmoid function ensures a continuous change between the elastic modulus and bone mineral density, avoiding abrupt changes in material properties between different bone density regions, thereby improving the stability of the finite element analysis.

[0029] Step S102: Discretize the patient-specific three-dimensional spinal model into a tetrahedral finite element mesh, assign bone material properties to each finite element unit according to the pixel values ​​of the CT scan image, and assign soft tissue material properties to the intervertebral disc and ligament soft tissue structures.

[0030] In this embodiment, the pixel values ​​of CT scan images are directly converted into bone material properties (elastic modulus, etc.) of finite element elements, more accurately reflecting the density distribution and mechanical properties of the patient's individual bones, thereby improving the accuracy of vertebroplasty simulation. Traditional finite element models typically use uniform or partitioned material properties, failing to capture subtle density differences within the bone. Assigning material properties to the intervertebral discs and ligaments allows for a more comprehensive assessment of the impact of vertebroplasty on the overall stability and biomechanics of the spine. The finite element model forms the basis for subsequent optimization of bone cement injection paths and volumes; only by basing these on the distribution of material properties can the optimal treatment plan truly suited to the patient be found.

[0031] Step S103: Determine the optimal bone cement injection path of the tetrahedral finite element mesh using the density method. The objective function of the optimal bone cement injection path is to minimize the maximum principal stress of the target vertebral body, and the constraints include the bone cement injection volume and the stability of the target vertebral body.

[0032] In this embodiment, the density method can automatically search for the optimal bone cement injection path, reducing manual intervention, minimizing the maximum principal stress of the target vertebral body, and lowering the risk of vertebral fracture. By optimizing the bone cement injection path, the stress distribution within the vertebral body is made more uniform, avoiding stress concentration. By constraining the bone cement injection volume and vertebral stability, stress is reduced without overusing bone cement or compromising the overall stability of the vertebral body. Furthermore, it can find the injection path most suitable for the patient's individual anatomy and bone density, thus achieving personalized treatment.

[0033] Specifically, a density variable is assigned to each tetrahedral finite element mesh. Finite element analysis is performed based on the current density distribution to calculate the maximum principal stress of the target vertebral body. The sensitivity of the maximum principal stress to each density variable is calculated. The density variables are updated based on the sensitivity. It is checked whether the constraints of bone cement volume and vertebral body stability are met. If not, the density variables are adjusted. The updated density variable distribution is converted into the actual bone cement injection path to obtain the optimal bone cement injection path of the tetrahedral finite element mesh.

[0034] For example, initialize the density variables of all elements in the tetrahedral finite element mesh to 0.1. Apply a compressive load to the vertebral body and perform finite element analysis to calculate the maximum principal stress of the target vertebral body as 10 MPa. Calculate the sensitivity of the maximum principal stress to the density variable of each element (e.g., the sensitivity of element A is -0.05 MPa / unit density, and the sensitivity of element B is -0.02 MPa / unit density). Update the density variables using the gradient descent method. If the step size is 0.1, the new density of element A is 0.1 + 0.1 × 0.05 = 0.105, and the new density of element B is 0.1 + 0.1 × 0.02 = 0.102. Calculate the bone cement volume under the current density distribution. Assuming the maximum allowable bone cement volume is 5 mL, and the current volume is 4 mL, the volume constraint is satisfied. Calculate the buckling load factor of the vertebral body. Assuming the set minimum buckling load factor is 2.0, and the current value is 2.2, the stability constraint is satisfied. Repeat the above steps until the maximum principal stress converges to a lower value. like Figure 4 As shown, the final density distribution is thresholded, and units with density values ​​higher than 0.8 (17, 18) are considered as bone cement injection areas. These areas are then smoothed to obtain the final bone cement injection path. The bone cement injection path optimized by the density method effectively reduces the maximum principal stress of the vertebral body, thereby reducing the risk of fracture and improving the efficacy of vertebroplasty, while meeting the constraints of bone cement volume and vertebral body stability.

[0035] Step S104: Using the objective functions of minimizing the maximum principal stress of the target vertebra, maximizing the stiffness of the target vertebra, and minimizing the stress variation of adjacent vertebrae, determine the optimal amount of bone cement to be injected through the optimal bone cement injection path.

[0036] In this embodiment, minimizing stress changes in adjacent vertebrae reduces the risk of adjacent vertebral fractures due to vertebroplasty. The injection of bone cement alters the stress distribution; excessive stress changes in adjacent vertebrae can easily lead to stress fractures. Simultaneously minimizing principal stress and maximizing stiffness makes the target vertebra more stable under load, with a more uniform stress distribution, thus improving its fracture resistance. The amount of bone cement injected, obtained through multi-objective optimization, avoids excessive or insufficient injection, thereby improving surgical success rates and patient quality of life.

[0037] For example, assuming the target vertebra is L3, the injection path has been determined using the density method. The constraints of the objective function are: maximum bone cement volume: 6 ml; vertebral body compressive strength: >5 MPa; stress concentration at adjacent vertebral endplates: <15 MPa. The optimal solution is found by iteratively improving the bone cement injection volume through simulation of biological evolution (such as genetic evolutionary algorithms). In each iteration, the objective function value corresponding to different injection volumes is evaluated, and selection, crossover, and mutation operations are performed based on fitness (the reciprocal of the objective function value). After multiple iterations, the optimal bone cement injection volume is found to be 4.5 ml. This injection volume minimizes the maximum principal stress and stiffness of the L3 vertebra, minimizes stress changes in the L2 and L4 vertebrae, and satisfies all constraints. The vertebral body model after injecting 4.5 ml of bone cement is visualized, showing the bone cement distribution, stress contour map, and deformation diagram. The physician estimates the treatment effect and makes necessary adjustments based on the visualization results.

[0038] In one alternative approach, the sensitivity formula for the objective function that minimizes the maximum principal stress of the target vertebra is: in, Design variables for the unit; Unit volume; This is the effect of the von Mises effect; For strain tensor; It is a fourth-order elastic tensor; A spatial region of a unit; This is the maximum principal stress; It is a double dot product used in tensor operations.

[0039] In this embodiment, the von Mises equivalent stress ( ) and maximum principal stress ( This allows for a more precise assessment of the impact of bone cement injection on vertebral stress distribution, contributing to improved success rates in vertebroplasty and better postoperative recovery. By calculating the design variables for each unit (…),… The sensitivity to the maximum principal stress allows for rapid adjustment of the bone cement injection path and volume to achieve optimal stress distribution.

[0040] Step S105: Based on the optimal bone cement injection path and the optimal bone cement injection amount, simulate vertebroplasty in the tetrahedral finite element mesh, predict the postoperative stress distribution, vertebral stiffness, and stress changes of adjacent vertebrae, and present the simulation results of vertebroplasty in a three-dimensional visualization form. The simulation results include bone cement distribution, stress cloud map, and deformation map.

[0041] In this embodiment, the simulation process considers various physical phenomena, including the non-Newtonian fluid properties of bone cement, the exothermic process of hydration reaction, curing behavior, and the impact of bone cement injection on the vertebral microenvironment. The simulation results are closer to reality. Therefore, by predicting the stress distribution, stiffness recovery, and stress changes in adjacent vertebrae after bone cement injection, doctors can assess the treatment effect and further optimize the bone cement injection path and volume based on the simulation results to achieve the best treatment outcome. The simulation results, including bone cement distribution, stress cloud maps, and deformation diagrams, are presented through three-dimensional visualization, allowing doctors to more intuitively understand the postoperative condition of the vertebrae.

[0042] Specifically, the optimized bone cement injection path is transformed into a coordinate sequence in three-dimensional space to determine the specific injection location. The volume fraction of bone cement within each target element is calculated based on the optimal injection amount to simulate the filling ratio during the injection process. A progressive filling method is used to simulate the injection process, gradually increasing the volume fraction of bone cement within the target element until the calculated value is reached. The material properties (such as elastic modulus) of the injected bone cement elements are linearly transitioned from bone tissue values ​​to cement material values ​​to reflect the reinforcing effect of the bone cement. During the bone cement flow stage, the Carreau model is used to describe the non-Newtonian fluid properties of the bone cement, simulating its flow and diffusion within the vertebral body. The Lagrange-Euler method is used to handle mesh deformation, and the temperature field distribution is calculated based on the nonlinear transient heat conduction equation to simulate the exothermic process of the bone cement hydration reaction. Viscoelastic or viscoplastic constitutive models are used to represent the curing behavior of the bone cement, including the influence factors of the degree of bone cement hydration reaction, temperature, and strain rate on the mechanical properties of the bone cement. Stiffness degradation is initiated when the equivalent plastic strain of an element exceeds a preset threshold to simulate vertebral damage. By coupling biological models to study the curing behavior of bone cement and its impact on the vertebral microenvironment (such as changes in bone marrow pressure, stress-strain changes in osteocytes, and microfractures), the trend of bone tissue remodeling and long-term stability changes within the vertebral body after bone cement injection was predicted. The stiffness recovery rate was calculated by comparing the postoperative vertebral stiffness matrix with the preoperative stiffness to assess the strengthening effect of bone cement. The pressure increment of adjacent intervertebral discs and the maximum shear strain of the annulus fibrosus were calculated to evaluate the mechanical effects of bone cement injection on adjacent vertebral bodies. When determining the optimal amount of bone cement injected, vertebral compressive strength, fatigue life, and stress concentration in the endplates of adjacent vertebral bodies were used as constraints in the optimization objective function. A particle system was used to simulate the cement diffusion process to simulate vertebroplasty. Particle colors were used to map injection time and display the filling sequence and extent of bone cement. Stress cloud maps were used to display the stress distribution of the vertebral body and adjacent vertebral bodies, and overlays of transparency channels showed the bone cement distribution, facilitating observation of the impact of bone cement on vertebral stress.

[0043] For example, a 70-year-old female patient with an L1 vertebral compression fracture due to osteoporosis requires vertebroplasty. Based on the aforementioned optimization method, the optimal bone cement injection path was determined to be two channels entering the vertebral body from the left and right posterolateral sides, with an optimal injection volume of 4 ml. The injection path was converted into a spatial coordinate sequence to determine the injection location. A progressive filling method was used to simulate the gradual injection process of bone cement and update material properties. The exothermic hydration reaction and curing process of bone cement were simulated. Simulation results showed that the maximum principal stress of the L1 vertebral body was significantly reduced postoperatively, the stiffness recovery rate reached 80%, the pressure increase of adjacent intervertebral discs was within an acceptable range, and the maximum shear strain of the annulus fibrosus did not exceed the threshold. Figure 3 As shown, the visualization results show the distribution of bone cement inside the vertebral body, and the stress cloud map shows that the bone cement effectively disperses the stress in the vertebral body. The iliac crest 1 is used for surface localization; the anterior superior iliac spine 2 is the protruding point of the anterior part of the iliac bone; the posterior superior iliac spine 3 is the protruding point of the posterior part of the iliac bone, located above the sacroiliac joint; the ischial tuberosity 4 is the protruding part of the ischium; the pubic symphysis 5 is the part where the two pubic bones are connected by fibrocartilage; the sacrum 6 is located at the base of the spine, formed by the fusion of five sacral vertebrae, and is a commonly used puncture point for epidural anesthesia; the sacral angles (8, 9) are associated with the coccyx; the iliac crest 10 is a bony landmark used for surface localization; the anterior superior iliac spines (11, 12, 13) are used for surface localization; the posterior superior iliac spines (14-1, 14-2) are located above the sacroiliac joint; the ischial tuberosity 15 is the main point of weight-bearing when sitting; and the pubic symphysis (7, 16) is the part connected by fibrocartilage. Through simulation results, doctors confirmed that this injection protocol effectively enhances vertebral stability with minimal impact on adjacent vertebrae.

[0044] In an alternative approach, the method further includes: When transforming the density variable distribution into the bone cement injection path, the density field is smoothed and thresholded to extract the bone cement injection channel. Remove sharp corners and overly thin connections in the geometry of the injection channel to reduce the risk of bone cement leakage; The manufacturability of the optimized bone cement injection path is evaluated based on the accessibility of the puncture needle, the range of injection angles, and the performance of the bone cement injection equipment.

[0045] In this embodiment, sharp corners and overly thin connections are potential risk points for bone cement leakage. Sharp corners and overly thin connections are removed by smoothing the density field, making the extracted injection channel clearer and preventing leakage into the spinal canal or surrounding soft tissue. The optimized injection path is evaluated based on the accessibility of the puncture needle, the range of injection angles, and the performance limitations of the bone cement injection equipment, avoiding the dilemma that the theoretically optimal solution cannot be achieved in practice.

[0046] For example, suppose the bone cement injection path optimized using the density method forms a "Y"-shaped structure inside the vertebral body. However, from a posterolateral approach, the angle at which the puncture needle reaches the ends of the two branches of this "Y"-shaped structure is too large, making the surgical procedure difficult. Accessibility analysis of the puncture needle reveals that it is not safe to reach the ends of the two branches from the current approach. By adjusting the optimization algorithm and increasing the constraints on puncture needle accessibility, the generated injection path can better match actual surgical procedures (e.g., adjusting the puncture approach point to a transpedicular approach to obtain a better angle).

[0047] According to the solution provided by the present invention, CT scan images and X-ray scan images containing the target vertebra and its adjacent vertebrae are acquired; the CT scan images and X-ray scan images are automatically segmented to extract the vertebral bone structure and vertebral soft tissue structure, respectively; a patient-specific three-dimensional spinal model is constructed based on the vertebral bone structure and vertebral soft tissue structure; the patient-specific three-dimensional spinal model is discretized into a tetrahedral finite element mesh, and bone material properties are assigned to each finite element element according to the pixel values ​​of the CT scan images, and soft tissue material properties are assigned to the intervertebral disc and ligament soft tissue structures; the optimal bone cement injection path of the tetrahedral finite element mesh is determined by the density method, wherein the optimal bone cement... The objective function of the injection path is to minimize the maximum principal stress of the target vertebral body, with constraints including the volume of bone cement injected and the stability of the target vertebral body. The optimal bone cement injection volume for the optimal injection path is determined by using the objective functions of minimizing the maximum principal stress of the target vertebral body, maximizing the stiffness of the target vertebral body, and minimizing the stress variation of adjacent vertebral bodies. Based on the optimal bone cement injection path and the optimal bone cement injection volume, vertebroplasty is simulated in the tetrahedral finite element mesh to predict the postoperative stress distribution, stiffness, and stress variation of adjacent vertebral bodies. The simulation results of the vertebroplasty are presented in a three-dimensional visualization, including bone cement distribution, stress cloud map, and deformation map. This invention achieves personalized optimization of vertebroplasty and predicts preoperative simulations by constructing a patient-specific finite element model, providing surgeons with an efficient auxiliary reference surgical plan. Specifically, a patient-specific three-dimensional spinal model and finite element model are constructed using the patient's own CT scan images and X-ray scan images, more accurately reflecting the patient's spinal structure and mechanical properties, and has high clinical application value. By assigning bone material properties to each finite element unit based on the pixel values ​​of CT scan images and incorporating differences in bone density, the finite element model more realistically reflects the mechanical properties of the bone. Simultaneously, soft tissue material properties are assigned to the intervertebral discs and ligaments to ensure the accuracy of the overall mechanical properties of the spine. The optimal bone cement injection path is determined using the density method, with minimizing the maximum principal stress of the target vertebra as the optimization objective, effectively reducing the risk of postoperative vertebral fracture and improving surgical safety. By minimizing the maximum principal stress of the target vertebra, maximizing its stiffness, and minimizing stress changes in adjacent vertebrae, the optimal amount of bone cement injected is comprehensively sought, thereby improving the stability of the target vertebra while reducing the risk of refracture in adjacent vertebrae. Vertebroplasty is simulated in a tetrahedral finite element mesh to predict postoperative stress distribution, stiffness, and stress changes in adjacent vertebrae. The simulation results are presented in a three-dimensional visualization, allowing for preoperative prediction of surgical outcomes and adjustment of the surgical plan based on the simulation results, reducing surgical risks and improving surgical success rates and outcomes.

[0048] Figure 5A schematic diagram of the framework of a vertebroplasty optimization device based on a patient-specific finite element model according to an embodiment of the present invention is shown. The vertebroplasty optimization device based on a patient-specific finite element model includes: The spinal model construction module 510 is used to acquire CT scan images and X-ray scan images containing the target vertebra and its adjacent vertebrae; automatically segment the CT scan images and X-ray scan images to extract the vertebral bone structure and vertebral soft tissue structure respectively; and construct a patient-specific three-dimensional spinal model based on the vertebral bone structure and vertebral soft tissue structure. The finite element model preprocessing module 520 is used to discretize the patient-specific three-dimensional spinal model into a tetrahedral finite element mesh, assign bone material properties to each finite element unit according to the pixel values ​​of the CT scan image, and assign soft tissue material properties to the intervertebral disc and ligament soft tissue structures. The injection path optimization module 530 is used to determine the optimal bone cement injection path of the tetrahedral finite element mesh by the density method, wherein the objective function of the optimal bone cement injection path is to minimize the maximum principal stress of the target vertebra, and the constraints include the bone cement injection volume and the stability of the target vertebra. The injection volume optimization module 540 is used to determine the optimal bone cement injection volume for the optimal bone cement injection path with the objective functions of minimizing the maximum principal stress of the target vertebra, maximizing the stiffness of the target vertebra, and minimizing the stress change of adjacent vertebrae. Vertebroplasty simulation module 550 is used to simulate vertebroplasty in the tetrahedral finite element mesh according to the optimal bone cement injection path and the optimal bone cement injection amount, predict the stress distribution of the vertebral body, the stiffness of the vertebral body and the stress changes of adjacent vertebral bodies after surgery, and present the simulation results of vertebroplasty in a three-dimensional visualization form. The simulation results include bone cement distribution, stress cloud map and deformation map.

[0049] Figure 6 The diagram shows a structural schematic of an embodiment of the computing device of the present invention. The specific embodiments of the present invention do not limit the specific implementation of the computing device.

[0050] like Figure 6 As shown, the computing device may include: a processor 602, a communications interface 604, a memory 606, and a communications bus 608.

[0051] The processor 602, communication interface 604, and memory 606 communicate with each other via communication bus 608. Communication interface 604 is used to communicate with other network elements such as clients or other servers. The processor 602 executes program 610, specifically performing the relevant steps in the above-described embodiment of the vertebroplasty optimization method based on a patient-specific finite element model.

[0052] Specifically, program 610 may include program code that includes computer operation instructions.

[0053] Processor 602 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The computing device includes one or more processors, which may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0054] Memory 606 is used to store program 610. Memory 606 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0055] According to the solution provided by the present invention, CT scan images and X-ray scan images containing the target vertebra and its adjacent vertebrae are acquired; the CT scan images and X-ray scan images are automatically segmented to extract the vertebral bone structure and vertebral soft tissue structure, respectively; a patient-specific three-dimensional spinal model is constructed based on the vertebral bone structure and vertebral soft tissue structure; the patient-specific three-dimensional spinal model is discretized into a tetrahedral finite element mesh, and bone material properties are assigned to each finite element element according to the pixel values ​​of the CT scan images, and soft tissue material properties are assigned to the intervertebral disc and ligament soft tissue structures; the optimal bone cement injection path of the tetrahedral finite element mesh is determined by the density method, wherein the optimal bone cement... The objective function of the injection path is to minimize the maximum principal stress of the target vertebral body, with constraints including the volume of bone cement injected and the stability of the target vertebral body. The optimal bone cement injection volume for the optimal injection path is determined by using the objective functions of minimizing the maximum principal stress of the target vertebral body, maximizing the stiffness of the target vertebral body, and minimizing the stress variation of adjacent vertebral bodies. Based on the optimal bone cement injection path and the optimal bone cement injection volume, vertebroplasty is simulated in the tetrahedral finite element mesh to predict the postoperative stress distribution, stiffness, and stress variation of adjacent vertebral bodies. The simulation results of the vertebroplasty are presented in a three-dimensional visualization, including bone cement distribution, stress cloud map, and deformation map. This invention achieves personalized optimization of vertebroplasty and predicts preoperative simulations by constructing a patient-specific finite element model, providing surgeons with an efficient auxiliary reference surgical plan. Specifically, a patient-specific three-dimensional spinal model and finite element model are constructed using the patient's own CT scan images and X-ray scan images, more accurately reflecting the patient's spinal structure and mechanical properties, and has high clinical application value. By assigning bone material properties to each finite element unit based on the pixel values ​​of CT scan images and incorporating differences in bone density, the finite element model more realistically reflects the mechanical properties of the bone. Simultaneously, soft tissue material properties are assigned to the intervertebral discs and ligaments to ensure the accuracy of the overall mechanical properties of the spine. The optimal bone cement injection path is determined using the density method, with minimizing the maximum principal stress of the target vertebra as the optimization objective, effectively reducing the risk of postoperative vertebral fracture and improving surgical safety. By minimizing the maximum principal stress of the target vertebra, maximizing its stiffness, and minimizing stress changes in adjacent vertebrae, the optimal amount of bone cement injected is comprehensively sought, thereby improving the stability of the target vertebra while reducing the risk of refracture in adjacent vertebrae. Vertebroplasty is simulated in a tetrahedral finite element mesh to predict postoperative stress distribution, stiffness, and stress changes in adjacent vertebrae. The simulation results are presented in a three-dimensional visualization, allowing for preoperative prediction of surgical outcomes and adjustment of the surgical plan based on the simulation results, reducing surgical risks and improving surgical success rates and outcomes.

[0056] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination of all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed can be employed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose. Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims listing several devices, several of these devices may be embodied by the same hardware item. Unless otherwise specified, the steps in the above embodiments should not be construed as limiting the order of execution.

Claims

1. A method for optimizing vertebroplasty based on a patient-specific finite element model, characterized in that, include: Acquire CT scan images and X-ray scan images containing the target vertebra and its adjacent vertebrae; automatically segment the CT scan images and X-ray scan images to extract the vertebral bone structure and vertebral soft tissue structure respectively; construct a patient-specific three-dimensional spinal model based on the vertebral bone structure and vertebral soft tissue structure; The patient-specific three-dimensional spinal model is discretized into a tetrahedral finite element mesh. Bone material properties are assigned to each finite element element based on the pixel values ​​of the CT scan image, and soft tissue material properties are assigned to the intervertebral disc and ligament soft tissue structures. The optimal bone cement injection path for the tetrahedral finite element mesh is determined using the density method. The objective function of this optimal path is to minimize the maximum principal stress of the target vertebral body, with constraints including bone cement injection volume and vertebral body stability. Specifically, determining the optimal path involves: assigning a density variable to each tetrahedral finite element mesh; performing finite element analysis based on the current density distribution to calculate the maximum principal stress of the target vertebral body; calculating the sensitivity of the maximum principal stress to each density variable; updating the density variables based on the sensitivity; checking if the constraints of bone cement volume and vertebral body stability are met; adjusting the density variables if not; and finally, converting the updated density variable distribution into the actual bone cement injection path to obtain the optimal path for the tetrahedral finite element mesh. The optimal amount of bone cement to be injected through the optimal bone cement injection path is determined by using the objective functions of minimizing the maximum principal stress of the target vertebral body, maximizing the stiffness of the target vertebral body, and minimizing the stress variation of adjacent vertebral bodies. The vertebral body compressive strength, fatigue life, and stress concentration degree of adjacent vertebral endplates are used as constraints on the optimization objective function. Based on the optimal bone cement injection path and the optimal bone cement injection volume, vertebroplasty is simulated in the tetrahedral finite element mesh to predict the postoperative stress distribution, stiffness, and stress changes in adjacent vertebrae. The simulation results of the vertebroplasty are presented in a three-dimensional visualization, including bone cement distribution, stress cloud map, and deformation map. The simulation of vertebroplasty in the tetrahedral finite element mesh based on the optimal bone cement injection path and the optimal bone cement injection volume further includes: The optimal injection path is converted into a spatial coordinate sequence, and the target element set is marked in the finite element mesh; the volume fraction of bone cement in each target element is calculated according to the optimal injection amount, and the injection process is simulated by a progressive filling method; the elastic modulus of the injected bone cement element is linearly transitioned from the bone tissue value to the cement material value. Temperature field distribution is calculated based on nonlinear transient heat conduction equations to simulate the exothermic process of bone cement hydration reaction; the Carreau model is used to describe the non-Newtonian fluid properties of bone cement during the bone cement flow stage and mesh deformation is handled according to the Lagrange-Euler method; stiffness degradation is initiated when the equivalent plastic strain of the element exceeds a preset threshold. The stiffness recovery rate was obtained by comparing the postoperative vertebral body stiffness matrix with the preoperative stiffness, and the pressure increment of adjacent intervertebral discs and the maximum shear strain of the annulus fibrosus were calculated. A particle system was used to simulate the cement diffusion process to simulate vertebroplasty, in which particle color was mapped to injection time, and the transparency channels of the stress cloud map were superimposed to show the distribution of bone cement.

2. The method for optimizing vertebroplasty based on a patient-specific finite element model according to claim 1, characterized in that, The expression for the mapping relationship between the pixel values ​​of the CT scan image and the properties of the bone material is as follows: in, coordinates The elastic modulus of the bone material; This represents the lower limit of the elastic modulus of cancellous bone. This represents the upper limit of the elastic modulus of cortical bone. This is the curvature adjustment coefficient. ; This represents the bone mineral density value corresponding to the bone mineral density inflection point. Indicates coordinates as The bone density value of the pixel.

3. The method for optimizing vertebroplasty based on a patient-specific finite element model according to claim 1, characterized in that, The sensitivity formula for the objective function that minimizes the maximum principal stress of the target vertebra is: in, Design variables for the unit; Unit volume; This is the effect of the von Mises effect; For strain tensor; It is a fourth-order elastic tensor; A spatial region of a unit; This is the maximum principal stress; It is a double dot product used in tensor operations.

4. The method for optimizing vertebroplasty based on a patient-specific finite element model according to claim 1, characterized in that, The construction of a patient-specific three-dimensional spinal model based on the vertebral bone structure and vertebral soft tissue structure further includes: The surface of the vertebral bone structure and the vertebral soft tissue structure is reconstructed using the Marching Cubes algorithm to generate an initial surface mesh. The surface mesh is obtained by smoothing and simplifying the surface mesh data using the Laplacian Smoothing algorithm. A tetrahedral mesh model conforming to the finite element analysis requirements of the surface mesh was generated using the tetrahedral mesh generation tool TetGen, resulting in a patient-specific three-dimensional spinal finite element model.

5. The method for optimizing vertebroplasty based on a patient-specific finite element model according to claim 1, characterized in that, During the simulated vertebroplasty procedure, the method further includes: The curing behavior of bone cement is represented by a viscoelastic or viscoplastic constitutive model, which includes the influence factors of the degree of hydration reaction, temperature and strain rate on the mechanical properties of bone cement. The curing behavior of bone cement and its impact on the vertebral microenvironment were incorporated into a coupled biological model to predict the trends of bone tissue remodeling and long-term stability changes within the vertebral body after bone cement injection. The impact on the internal microenvironment included changes in bone marrow pressure, stress-strain changes in osteocytes, and microfractures.

6. The method for optimizing vertebroplasty based on a patient-specific finite element model according to claim 1, characterized in that, The method further includes: When transforming the density variable distribution into the bone cement injection path, the density field is smoothed and thresholded to extract the bone cement injection channel. Remove sharp corners and overly thin connections in the geometry of the injection channel to reduce the risk of bone cement leakage; The manufacturability of the optimized bone cement injection path is evaluated based on the accessibility of the puncture needle, the range of injection angles, and the performance of the bone cement injection equipment.

7. A vertebroplasty optimization device based on a patient-specific finite element model, characterized in that, Implementing the vertebroplasty optimization method based on a patient-specific finite element model as described in any one of claims 1-6, comprising: The spinal model construction module is used to acquire CT scan images and X-ray scan images containing the target vertebra and its adjacent vertebrae; automatically segment the CT scan images and X-ray scan images to extract the vertebral bone structure and vertebral soft tissue structure respectively; and construct a patient-specific three-dimensional spinal model based on the vertebral bone structure and vertebral soft tissue structure. The finite element model preprocessing module is used to discretize the patient-specific three-dimensional spinal model into a tetrahedral finite element mesh, assign bone material properties to each finite element unit according to the pixel values ​​of the CT scan image, and assign soft tissue material properties to the intervertebral disc and ligament soft tissue structures. The injection path optimization module is used to determine the optimal bone cement injection path of the tetrahedral finite element mesh using the density method. The objective function of the optimal bone cement injection path is to minimize the maximum principal stress of the target vertebral body, with constraints including bone cement injection volume and the stability of the target vertebral body. Specifically, determining the optimal bone cement injection path of the tetrahedral finite element mesh using the density method includes: assigning a density variable to each tetrahedral finite element mesh; performing finite element analysis based on the current density distribution to calculate the maximum principal stress of the target vertebral body; calculating the sensitivity of the maximum principal stress to each density variable; updating the density variables based on the sensitivity; checking whether the constraints of bone cement volume and vertebral body stability are met; if not, adjusting the density variables; and converting the updated density variable distribution into the actual bone cement injection path to obtain the optimal bone cement injection path of the tetrahedral finite element mesh. The injection volume optimization module is used to determine the optimal bone cement injection volume for the optimal bone cement injection path with the objective functions of minimizing the maximum principal stress of the target vertebra, maximizing the stiffness of the target vertebra, and minimizing the stress variation of adjacent vertebrae; wherein, the vertebral compressive strength, fatigue life, and stress concentration degree of adjacent vertebral endplates are used as constraints of the optimization objective function. The vertebroplasty simulation module is used to simulate vertebroplasty in a tetrahedral finite element mesh according to the optimal bone cement injection path and the optimal bone cement injection volume, predict the postoperative stress distribution of the vertebral body, the vertebral body stiffness, and the stress changes of adjacent vertebral bodies, and present the simulation results of the vertebroplasty in a three-dimensional visualization form. The simulation results include bone cement distribution, stress cloud map, and deformation map; wherein, simulating vertebroplasty in the tetrahedral finite element mesh according to the optimal bone cement injection path and the optimal bone cement injection volume further includes: The optimal injection path is converted into a spatial coordinate sequence, and the target element set is marked in the finite element mesh; the volume fraction of bone cement in each target element is calculated according to the optimal injection amount, and the injection process is simulated by a progressive filling method; the elastic modulus of the injected bone cement element is linearly transitioned from the bone tissue value to the cement material value. Temperature field distribution is calculated based on nonlinear transient heat conduction equations to simulate the exothermic process of bone cement hydration reaction; the Carreau model is used to describe the non-Newtonian fluid properties of bone cement during the bone cement flow stage and mesh deformation is handled according to the Lagrange-Euler method; stiffness degradation is initiated when the equivalent plastic strain of the element exceeds a preset threshold. The stiffness recovery rate was obtained by comparing the postoperative vertebral body stiffness matrix with the preoperative stiffness, and the pressure increment of adjacent intervertebral discs and the maximum shear strain of the annulus fibrosus were calculated. A particle system was used to simulate the cement diffusion process to simulate vertebroplasty, in which particle color was mapped to injection time, and the transparency channels of the stress cloud map were superimposed to show the distribution of bone cement.

8. A computing device, comprising: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction that causes the processor to perform the operation corresponding to the vertebroplasty optimization method based on the patient-specific finite element model as described in any one of claims 1-6.

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