A method for one-time creation of multiple optimized finite element models of bone pin distribution on the pelvis

Abstract

A method for creating multiple finite element models of pelvic bone pin distribution optimization in a single operation includes: creating a three-dimensional model of the damaged pelvic musculoskeletal tissue and bone pins; developing an ABAQUS script file using ABAQUS / Python software to create several finite element models at once; and having the ABAQUS software read this script file to create n finite element models of pelvic musculoskeletal tissue containing bone pins in a single operation. This invention, based on ABAQUS / Python software, utilizes a script file for the simultaneous creation of multiple finite element models of pelvic musculoskeletal tissue containing bone pins, avoiding repetitive work in finite element modeling and effectively improving model creation efficiency.

Description

Technical Field

[0001] This invention relates to a finite element modeling method using secondary software development, specifically a finite element modeling method using ABAQUS / Python software secondary development, for creating multiple finite element models of optimized pelvic bone spicule distribution at once. Background Technology

[0002] ABAQUS is a powerful finite element analysis software with robust nonlinear analysis capabilities. It allows for the development of ABAQUS scripts based on its powerful computational kernel. Furthermore, ABAQUS software has a good scripting interface (ASI), which is developed using the Python language. This allows users to call the kernel from Python, enabling manipulation of the kernel.

[0003] Pelvic fracture reduction surgery often involves sacroiliac joint separation, requiring external force to guide the fracture back to its correct anatomical position. Currently, the primary method involves inserting several bone pins on the affected side of the pelvis and moving these pins to achieve reduction. The pelvic fracture reduction procedure is structurally complex, and traditional surgery relies heavily on the surgeon's experience. Determining the distribution, spatial position, and orientation of the bone pins within the pelvis depends on the surgeon's clinical surgical expertise.

[0004] Robot-assisted pelvic fracture reduction requires the placement of 2-3 bone pins into the affected bone fragment to stabilize and hold the pelvis. As crucial components for transmitting reduction force, the spatial orientation of the bone pins is closely related to the stability of the pelvic clamping, the precision of the reduction surgery, and its safety. Therefore, it is necessary to optimize the spatial orientation of the multiple bone pins placed in the pelvis. The optimal distribution of these pins can be determined using the finite element method.

[0005] Optimization of the spatial pose distribution of pelvic bone pins is an optimization process with the intraoperative uniformity of pelvic stress distribution as the objective function. Due to the nonlinear, viscoelastic, and heterogeneous material properties of pelvic fracture tissues, it is difficult to establish an optimization objective function for analyzing the uniformity of stress distribution in pelvic fracture tissues. Therefore, when using finite element simulation software to optimize the intraoperative pelvic stress distribution and determine the spatial pose of bone pins, it is necessary to create a three-dimensional model of pelvic musculoskeletal tissue containing bone pins with different spatial poses.

[0006] To address the aforementioned technical challenges, this invention addresses the modeling problem of optimizing the spatial pose of bone needles inserted into the pelvis. To improve the ease of model creation, it relates to a method for creating multiple finite element models of bone needle distribution optimization on the pelvis at once, which avoids repetitive work in finite element modeling and effectively improves model creation efficiency. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention relates to a method for creating a finite element model of multiple bone pins distributed in the pelvis in a single operation, used to solve the problem of complex and repetitive finite element modeling. The study investigates the stress distribution of pelvic musculoskeletal tissue damaged by multiple bone pins placed in different spaces of the pelvis under large repositioning forces. A secondary development method using Python on ABAQUS software is employed, and finite element models are created by pre-setting different spatial pose information for the bone pins.

[0008] A method for creating a finite element model of multiple pelvic bone spicule distribution optimizations in a single step comprises three steps:

[0009] Step 1: Creation of a 3D model of the musculoskeletal tissue and bone pins of the damaged pelvis;

[0010] Step 2: Use ABAQUS / Python software to develop an ABAQUS script file that can create multiple finite element models;

[0011] Step 3: The ABAQUS software reads the script file and creates n finite element models of pelvic musculoskeletal tissue containing bone needles at once.

[0012] Step 1: Creation of a 3D model of the damaged pelvic bone and muscle tissue and bone pins.

[0013] 1. Reverse reconstruction of a three-dimensional model of damaged pelvic muscular tissue

[0014] Based on the patient's CT scan data of pelvic fracture and combined with human anatomical structure, the medical image processing software Mimics and the reverse engineering software Geomagic Studio were used to reverse reconstruct a three-dimensional digital model of the bone and muscle tissue of the damaged pelvis using contour extraction and layer-by-layer editing segmentation methods.

[0015] 2. Create a 3D model of the bone needle component.

[0016] In the Part module of ABAQUS software, a 3D digital model of the injured pelvic musculoskeletal tissue is imported from SolidWorks software. The file extension is *.x_t. A new 3D model of a bone pin is then created, thus completing the creation of a 3D model of the injured pelvic musculoskeletal tissue and bone pin. The coordinate system of the injured pelvis is O. xyz .

[0017] Step 2: Use ABAQUS / Python software to develop an ABAQUS script file capable of creating multiple finite element models.

[0018] 1. Use Python programming to calculate the spatial pose of the bone fimbriae on the pelvis and save it in a CSV file.

[0019] For the two bone pins that need to be inserted into the injured pelvis, the spatial orientation of the first bone pin is determined based on the fracture type of the injured pelvis and clinical experience; the spatial orientation of the second bone pin is calculated in Python as follows:

[0020] Let the tip and tail points of the second bone needle in the pelvis be P(P) and P(P) respectively. x ,P y ,P z ), Q(Q x Q y Q z ), where P x ,P y ,P z Q x Q y Q z These two points are located in the pelvic coordinate system O. xyz The spatial position and orientation of the bone needle are uniquely determined by these two points, which are the three coordinate components in the equation.

[0021] Let the coordinates of the tip of the bone needle be along the pelvic coordinate system O. xyz The range of variation in the x, y, and z directions is P. x ∈[P x0 ,P xn ], P y ∈[P y0 ,P yn ], P z ∈[P z0 ,P zn ].

[0022] Coordinates of the tip P of the bone needle x ,P y ,P z The coordinates of the needle tip are determined by dividing the interval equally, i.e., the coordinates of the needle tip in the k-th group of bone needle poses are... Where k = (1,2,…,n) is the coordinate of the tip of the bone needle in the kth group, and n is the total number of bone needle tip coordinates.

[0023] Let the coordinates of the tail point of the bone needle be along the pelvic coordinate system O. xyz The ranges of change in the x, y, and z directions are Q, respectively. x ∈[Q x0 Q xn ], Q y ∈[Q y0 Q yn ], Q z ∈[Q z0 Q zn ]

[0024] The coordinates of the tail point Q of the bone needle are calculated in the same way as above, that is, the coordinates of the tail point of the kth group of bone needles are... Where k = (1,2,…,n) is the coordinate of the tail point of the kth bone needle, and n is the total number of tail point coordinates of the bone needle.

[0025] Using the coordinates of the tip P and tail Q of the bone needle in the kth group, and combining them with the length L0 of the bone needle, calculate the second bone needle in the kth group relative to the pelvic coordinate system O. xyz The three azimuth angles α k ,β k ,γ k ,Right now

[0026]

[0027] Where, α k ,β k ,γ k These represent the k-th group of bone needle vectors relative to the pelvic coordinate system O. xyz The direction angles of the three rectangular coordinate axes x, y, z, and k = (1, 2, ..., n) represent the spatial pose of the k-th group of bone needles.

[0028] The spatial pose of all bone needles is calculated using the coordinates of the needle tip and three azimuth angles representing the direction of the bone needle. The calculation results of the spatial pose of the bone needles are saved in a newly created CSV file.

[0029] 2. Read the pose information of n sets of bone needles and create the hole elements of the bone needles on the pelvic musculoskeletal tissue model.

[0030] Based on the built-in Python script interface of ABAQUS, the CSV module of Python language is used to read n sets of bone needle spatial poses stored in CSV files into computer memory;

[0031] In the finite element software ABAQUS, based on the spatial pose information of n sets of bone needle poses, auxiliary points located on the cylindrical surface of the bone needle are determined. The start point, end point, and auxiliary points of the bone needle vector are defined as three reference points P1, P2, and P3 using the function DatumPointByCoordinate. Auxiliary reference axes are created using the function DatumAxisByTwoPoint through reference points P1 and P2. Auxiliary reference planes are created using the function DatumPlaneByThreePoints through reference points P1, P2, and P3. A cross-sectional sketch of the bone needle is constructed on the auxiliary reference plane according to the size parameters of the bone needle. The hole elements on the pelvic model where the bone needles need to be placed are constructed using the function CutRevolve through the created auxiliary reference axes and auxiliary reference planes.

[0032] 3. Assemble the 3D model of the pelvic musculoskeletal tissue and the two bone pins.

[0033] After the bone pin hole elements are created, the two bone pin parts are imported from the Part module through the Assembly module interface. At this time, the imported pose of the two bone pins is the initial pose vector. The coordinate displacement and angle rotation of the initial pose vector and the target pose vector of the two bone pins are calculated and determined by Python programming. The two bone pin parts are then assembled with the 3D model of the pelvic bone and muscle tissue, and script statements that conform to the Python language syntax are created.

[0034] 4. Define the material properties, element properties, contact properties, and load properties of the finite element model.

[0035] In the Material module of ABAQUS software, the material properties of bone tissue, muscle tissue, and bone spurs are defined. In the Interaction module, the contact relationships between parts are defined. The normal behavior of the contact properties between bones and muscles is defined as hard contact, and the tangential behavior is defined as penalized friction. The relationship between bones is constrained by tie binding. Skeletal muscles are considered to have frictionless contact, and their contact behavior is hard contact in the normal direction and frictionless in the tangential direction. In the Load module, the finite element model constraints are defined, and the upper end of the sacrum and the lower ends of the left and right femurs are set to be completely fixed. In the Mesh module, the element size of each part is set to a maximum of 0.1 mm, and the element type is C3D10 tetrahedral element.

[0036] 5. Generate an ABAQUS script file that can create n finite element models at once.

[0037] By combining script statements that read the spatial pose information of bone pins, create fracture hole elements on the pelvic model, and combine the pelvic model and bone pin model, an ABAQUS script file that can create n finite element models at once is generated.

[0038] Step 3: The ABAQUS software reads the script file and creates n finite element models of pelvic musculoskeletal tissue containing bone needles in one go.

[0039] Based on the script file generated in step (2), run the script program in the PDE module of ABAQUS software to obtain the required finite element model of the injured pelvis with bone pins and the required simulation data, specifically including:

[0040] Click "Run Script" under the "File" menu in ABAQUS, switch the directory to the save location of the script file generated in step (2), select the script file, click "OK" to confirm reading the script file, run the script file in the ABAQUS software, and create n finite element models at once, which are three-dimensional finite element models of the pelvic musculoskeletal tissue and two bone pins in different spatial poses after assembly.

[0041] This invention, through secondary development in the software ABAQUS, enables the creation of multiple finite element models of pelvic musculoskeletal tissue containing bone needles in a single step. The bone needles are positioned in different spatial poses, thus avoiding repetitive work in finite element modeling and effectively improving model creation efficiency. These models are then used for subsequent optimization analysis of the spatial pose distribution of the bone needles. Attached Figure Description

[0042] Figure 1 A schematic diagram illustrating a method for creating multiple finite element models of bone spicule distribution in the pelvis at once.

[0043] Figure 2 A three-dimensional model of the damaged pelvic musculoskeletal tissue and bone needles was created.

[0044] Figure 3 This is a finite element model of the injured pelvis containing bone pins generated after running a script file in ABAQUS software.

[0045] Figure 4 The spatial pose of all bone needles is saved in the CSV file. Detailed Implementation

[0046] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described examples are merely some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0047] The embodiments of the present invention will be implemented through the following technical solution: a method for creating multiple finite element models for optimizing the distribution of pelvic spicules at one time, specifically including three steps:

[0048] (1) Creation of a three-dimensional model of the damaged pelvic musculoskeletal tissue and a three-dimensional model of the bone needle;

[0049] (2) Use ABAQUS / Python software to develop an ABAQUS script file that can create multiple finite element models; (3) Use ABAQUS software to read the script file and create n finite element models of pelvic musculoskeletal tissue containing bone needles at once.

[0050] Step 1: Creation of 3D models of damaged pelvic musculoskeletal tissue and bone pins

[0051] like Figure 1 Step 1 shows the flowchart of the method for creating a three-dimensional model of damaged pelvic musculoskeletal tissue and bone pins involved in this embodiment, which is as follows:

[0052] 1. Reverse reconstruction of a three-dimensional model of damaged pelvic muscular tissue

[0053] Import the scanned CT tomographic medical images into Mimics software to create a point cloud model of the damaged pelvis.

[0054] Combining human anatomical structure, using medical image processing software Mimics and reverse engineering software Geomagic Studio, and employing contour extraction and layer-by-layer editing manual segmentation methods, the model surface was smoothed and surface-modulated, converting the point cloud model into a solid model, and reconstructing a three-dimensional digital model of the bone and muscle tissue of the damaged pelvis.

[0055] 2. Create a 3D model of the bone needle component.

[0056] In the Part module of ABAQUS software, a 3D digital model of the injured pelvic musculoskeletal tissue is imported from SolidWorks software. The file extension is *.x_t. A new 3D model of a bone pin is then created, thus completing the creation of a 3D model of the injured pelvic musculoskeletal tissue and bone pin. The coordinate system of the injured pelvis is O. xyz The created three-dimensional model of the damaged pelvic musculoskeletal tissue and bone pins, such as Figure 2 As shown.

[0057] Step 2: Use ABAQUS / Python software to develop an ABAQUS script file capable of creating multiple finite element models.

[0058] like Figure 1 Step 2 shows the flowchart of the secondary development method using ABAQUS / Python software involved in this embodiment, which is as follows:

[0059] 1. Use Python programming to calculate the spatial pose of the bone fimbriae on the pelvis and save it in a CSV file.

[0060] In this embodiment, the coordinates of the tip of the bone pin and the center of the tail of the bone pin are recorded as the start and end points of the bone pin pose vector. For the two bone pins that need to be inserted into the injured pelvis, the spatial pose of the first bone pin is determined and fixed according to the fracture type of the injured pelvis and clinical experience. The spatial pose of the second bone pin is calculated according to the following rules:

[0061] Let the tip and tail points of the second bone needle in the pelvis be P(P) and P(P) respectively. x ,P y ,P z ), Q(Q x Q y Q z ), where x, y, z represent the coordinates in the pelvic coordinate system O. xyz The three coordinate components of the bone needle are then uniquely determined by these two points in terms of their spatial position and orientation.

[0062] Let the coordinates of the tip P of the bone needle be along the pelvic coordinate system O. xyz The range of variation in the x, y, and z directions is P. x ∈[P x0 ,P xn ], P y ∈[P y0 ,P yn ], P z ∈[P z0 ,P zn ];

[0063] Coordinates of the tip P of the bone needle x ,P y ,P z The coordinates of the needle tip are determined by dividing the interval equally, i.e., the coordinates of the needle tip in the k-th group of bone needle poses are...

[0064]

[0065] Where k = (1,2,…,n) is the kth group of bone needles, and n is the total number of groups of bone needle tip coordinates;

[0066] Let the coordinates of the tail point Q of the bone needle be along the pelvic coordinate system O. xyz The ranges of change in the x, y, and z directions are Q, respectively. x ∈[Q x0 Q xn ], Q y ∈[Q y0 Q yn ], Q z ∈[Q z0 Q zn ]

[0067] The coordinates of the tail point Q of the bone needle are calculated in the same way as above, that is, the coordinates of the tail point of the kth group of bone needles are... Where k = (1,2,…,n) is the coordinate of the tail point of the kth bone needle, and n is the total number of groups of bone needle tail point coordinates;

[0068] By combining the coordinates of the tip P and tail Q of the k-th bone needle with the length L0 of the bone needle, the vector of the k-th bone needle in the pelvic coordinate system O is calculated. xyz The three azimuth angles α k ,β k ,γ k ,Right now

[0069]

[0070] Where, α k ,β k ,γ k The k-th group of bone needle vectors are located in the pelvic coordinate system O. xyzThe three direction angles;

[0071] The spatial pose of all bone needles can be calculated from the coordinates of the needle tip and the three azimuth angles of the bone needle vector.

[0072] Using Python's CSV module, create a new CSV file with the extension *.csv to store the spatial poses of the bone pins. Save the pose information of all the bone pins obtained from the above calculations into this CSV file, such as... Figure 4 As shown;

[0073] 2. Read the pose information of n sets of bone needles and create the hole elements of the bone needles on the pelvic musculoskeletal tissue model.

[0074] Based on the built-in Python script interface of ABAQUS, the CSV module of the Python language is used to read the bone needle pose information stored in the CSV file into the computer memory; the pose parameter information is stored in the computer memory in the form of list and dictionary data structures.

[0075] In the finite element software ABAQUS, based on the spatial pose information of n sets of bone needles, auxiliary points located on the cylindrical surface of the bone needles are determined. The start point, end point, and auxiliary points of the bone needle vector are defined as three reference points P1, P2, and P3 using the function DatumPointByCoordinate. Auxiliary reference axes are created using the function DatumAxisByTwoPoint through reference points P1 and P2, and auxiliary reference planes are created using the function DatumPlaneByThreePoints through reference points P1, P2, and P3. A cross-sectional sketch of the bone needles is constructed on the auxiliary reference planes according to the size parameters of the bone needles. Using the created auxiliary reference axes and auxiliary reference planes, the function CutRevolve is used to create the hole elements on the 3D model of the pelvic musculoskeletal tissue in which the bone needles need to be inserted.

[0076] 3. Assemble the three-dimensional model of the pelvic musculoskeletal tissue with the three-dimensional model of the two bone pins;

[0077] After the bone pin hole elements are created, the two bone pin parts are imported from the Part module through the Assembly module interface. At this time, the imported pose of the bone pin is the initial pose vector. The coordinate displacement and angle rotation of the initial pose vector and the target pose vector of the two bone pins are calculated and determined using Python programming. The two bone pin parts are then assembled with the 3D model of the pelvic bone and muscle tissue.

[0078] The initial position of the imported bone needle instance is: the coordinates of the bone needle tip are the origin of the pelvic coordinate system (0,0,0), and the coordinates of the tail center are (0,180,0). The coordinates of the bone needle tip and tail center at the target position are read from a CSV file recording the bone needle pose. Using Python, the bone needle instance is first translated to the target position based on the tip position, and then rotated. The rotation angle is determined by the formula... Sure.

[0079] 4. Define the material properties, element properties, contact properties, and load properties of the finite element model.

[0080] In the Material module of ABAQUS software, the material properties of bone tissue, muscle tissue, and bone spurs are defined respectively. In this embodiment, the damaged bone tissue is constructed using homogeneous solid elements to simulate bone tissue, with an elastic modulus of 7.3 GPa, a Poisson's ratio of 0.3, and a density of 2000 kg·m³. -3 Muscle tissue was simulated using homogeneous solid elements, and its hyperelasticity was fitted using a Mooney-Rivlin 5-parameter constitutive model, with C10 = 0.08556, C20 = -0.05841, C20 = 0.039, C11 = -0.02319, CO2 = 0.00851, and D1 = 3.6527. Bone spicules were simulated using homogeneous solid elements, with an elastic modulus of 110 GPa, a Poisson's ratio of 0.3, and a density of 2770 kg·m³. -3 ;

[0081] In the Interaction module, the contact relationships between tissues are defined. The normal direction of the contact attribute between bones and muscles is defined as hard contact, and the tangential direction is defined as penalized friction. The relationship between bones is bound by tie constraint. The contact between muscles is frictionless, with the normal direction being hard contact and the tangential direction being frictionless.

[0082] In the Load module, define the finite element model constraints and set the upper end of the sacrum and the lower ends of the left and right femurs to be completely fixed.

[0083] In the Mesh module, the maximum unit size of each part is set to 0.1mm, and the unit type is C3D10 tetrahedral unit.

[0084] 5. Generate an ABAQUS script file that can create n finite element models at once.

[0085] The script statements for reading the spatial pose of bone pins, creating fracture hole elements on the pelvic model, and assembling the pelvis and bone pin models are combined to generate an ABAQUS script file that can create n finite element models at once, such as... Figure 3 As shown.

[0086] Step 3: The ABAQUS software reads the script file and creates n finite element models of pelvic musculoskeletal tissue containing bone needles in one go.

[0087] like Figure 1 As shown in step 3, based on the script file generated in step 2, the script program is run in the PDE module of the ABAQUS software to obtain the required finite element model of the injured pelvis containing bone pins and the required simulation data, specifically including:

[0088] In ABAQUS, click "Run Script" under the "File" menu, switch the directory to the save location of the script file generated in step 2, select the script file, and click "OK" to confirm reading the script file. This creates n finite element models at once, which are finite element models of pelvic musculoskeletal tissue and two bone pins in different spatial poses assembled together.

[0089] This invention relates to a method for creating an optimized finite element model of pelvic spicule distribution using ABAQUS / Python software secondary development. The method involves importing medical tomographic images of the injured pelvis requiring optimization analysis, and then using medical image processing software Mimics and reverse engineering software Geomagic Studio to reconstruct a three-dimensional digital model of the injured musculoskeletal tissue. The finite element analysis software is used to set the material properties, cross-sectional properties, contact properties, and analysis methods of the finite element model. Based on n sets of spicule pose parameters read from the computer memory, an ABAQUS script file is generated using Python. The script file is then read in the ABAQUS finite element software to create several finite element models at once. The specific spicule pose information is stored in a CSV document; creating different finite element models only requires manipulating the CSV document, which is very convenient.

[0090] To facilitate use and ensure that the aforementioned method is easy to understand and reproduce, this embodiment provides some source code as follows:

[0091]

[0092]

[0093]

[0094]

[0095] The above embodiments of the present invention provide a method for creating multiple finite element models of pelvic bone spur distribution optimization at one time, comprising three steps: creating a three-dimensional model of the damaged pelvic musculoskeletal tissue and bone spurs; using ABAQUS / Python software for secondary development to create an ABAQUS script file capable of creating several finite element models at one time; and reading this script file in the ABAQUS software to create n finite element models of pelvic musculoskeletal tissue containing bone spurs at one time.

[0096] The above embodiments of the present invention utilize secondary development of the software ABAQUS / Python to create n finite element models of multiple bone pins implanted in the pelvic musculoskeletal tissue at once. These models can be used for spatial pose optimization analysis of multiple bone pins implanted in the pelvis, avoiding repetitive work in finite element modeling and effectively improving model creation efficiency.

[0097] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made according to the purpose of the invention. Any changes, modifications, substitutions, combinations or simplifications made based on the spirit and principle of the technical solution of the present invention shall be equivalent substitutions. As long as they meet the purpose of the invention and do not deviate from the technical principle and inventive concept of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A method for creating multiple finite element models for optimizing the distribution of bone spicules in the pelvis at one time, characterized in that, It includes the following three steps: (1) Creation of a three-dimensional model of the bone and muscle tissue and bone needles of the injured pelvis; (2) Develop a script file based on ABAQUS / Python software that can create multiple finite element models, including: a) Use Python programming to calculate the spatial pose of n sets of bone pins on the pelvis and save them in a CSV file; b) Read the spatial poses of n sets of bone needles and create the hole elements of the bone needles on the pelvic musculoskeletal tissue model; c) Assemble the pelvic bone and muscle tissue with the two bone pins; d) Generate an ABAQUS script file that can create n finite element models at once; (3) The ABAQUS software reads the script file and creates n finite element models of pelvic musculoskeletal tissue containing bone needles at one time; Step (2) includes the following four key points: Key Point 1: Use Python programming to calculate the spatial pose vector of the bone pins on the pelvis and save it in a CSV file; For the two bone pins that need to be inserted into the injured pelvis, the spatial orientation of the first bone pin and the second bone pin are determined based on the fracture type of the injured pelvis and clinical experience, and the specific calculations are as follows: Let the tip and tail points of the second bone needle be respectively... , ,in These two points are located in the pelvic coordinate system. The spatial position and orientation of the bone needle are uniquely determined by these two points, which are the three coordinate components in the equation. Let the coordinates of the bone needle tip be... In the pelvic coordinate system Middle x, y, z The range of change in the three directions is , , Coordinates of the tip of the bone needle The interval is divided equally to determine the i-th... k The coordinates of the needle tip in the bone needle position are: ,in k =(1,2, … , n ) is the first k Coordinates of the tip of the bone needle. n This represents the total number of bone needle tips; Let the coordinates of the tail point of the bone needle be... Along the pelvic coordinate system Middle x, y, z The range of change in the three directions is , , The coordinates of the tail point of the bone needle are calculated in the same way as above, that is, the first... k The coordinates of the tail point of the bone needle are ,in k =(1, 2, …, n ) is the first k Coordinates of the tail point of the bone needle. n This represents the total number of needle tail points on the bone needle. By the k Group of bone needle tips With the k Group needle tail point The coordinates, combined with the length of the bone needle L 0, can calculate the first k Bone needles in the model coordinate system The three azimuth angles ,Right now ， ， ； The spatial pose of all bone needles can be calculated from the coordinates of the bone needle tip and the three azimuth angles of the bone needle vector; the calculation results of the above bone needle spatial pose are saved in a CSV file. Key Point 2: Read the pose information of n sets of bone needles and create the hole elements of the bone needles on the pelvic musculoskeletal tissue model: The CSV module in Python reads n sets of spatial poses of bone pins from a CSV file; in the ABAQUS software, based on the spatial poses of the n sets of bone pins, the hole elements for inserting bone pins are created on the 3D model of the pelvic musculoskeletal tissue. Key Point 3: Assemble the pelvic bone and muscle tissue with the two bone needle models; After the bone pin hole elements in the pelvic model are created, the two bone pin parts are imported from the Part module through the Assembly module interface. At this time, the imported pose of the bone pin is the initial pose vector. The coordinate displacement and angle rotation of the initial pose vector and the target pose vector of the two bone pins are calculated and determined using Python programming, and the pelvic musculoskeletal tissue and the two bone pin models are assembled. Key Point 4: Generate an ABAQUS script file that can create n finite element models at once; The script statements for reading the spatial pose of bone pins, creating fracture hole elements on the pelvic model, and assembling the pelvic and bone pin models are combined to generate an ABAQUS script file that can create n finite element models at once. The method for creating the bone pinhole element in point 2 is as follows: Based on the read bone needle pose, auxiliary points located on the cylindrical surface of the bone needle are determined. The start point, end point, and auxiliary points of the bone needle vector are defined as three reference points P1, P2, and P3 using the function DatumPointByCoordinate. Auxiliary reference axes are created using the function DatumAxisByTwoPoint through reference points P1 and P2. Auxiliary reference planes are created using the function DatumPlaneByThreePoints through reference points P1, P2, and P3. A cross-sectional sketch of the bone needle is constructed on the auxiliary reference plane according to the size parameters of the bone needle. The hole elements on the pelvic model where the bone needle needs to be placed are constructed using the function CutRevolve through the created auxiliary reference axes and auxiliary reference planes.

2. The method for creating a finite element model of multiple pelvic bone spicule distribution optimization at one time according to claim 1, characterized in that, Step (1) specifically includes: A three-dimensional digital model of the injured pelvic musculoskeletal tissue was reconstructed using the medical image processing software Mimics and the reverse engineering software Geomagic Studio. The three-dimensional digital model of the injured pelvic musculoskeletal tissue was imported from SolidWorks software into the Part module of ABAQUS, with the file extension *.x_t. A new three-dimensional model of a bone pin was created, completing the creation of the three-dimensional model of the injured pelvic musculoskeletal tissue and bone pin. The coordinate system of the injured pelvis is as follows: .

3. The method for creating multiple finite element models for optimizing the distribution of pelvic spicules in a single operation, as described in claim 1, is characterized in that... Step (3) specifically includes: Run the script program in the PDE module of the ABAQUS software. Click "RunScript" under the "File" menu in ABAQUS, switch the directory to the save location of the script file generated in step 2, select the script file, click "OK" to confirm, read the script file, and create n finite element models at once. These are three-dimensional finite element models that integrate pelvic musculoskeletal tissue with bone pins in different spatial poses.

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