Lower limb finite element model modeling method and system based on human body characteristics

Abstract

The embodiment of the invention provides a lower limb finite element model modeling method and system based on human body features. The method comprises the steps that historical image data is scanned, lower limb point cloud information in the historical image data is obtained, image processing is conducted on the lower limb point cloud information, and a lower limb geometric model is obtained; performing mesh generation on the geometric model of the lower limb, and selecting a corresponding mesh type, a connection mode and a material type to simulate a finite element model of the lower limb based on the bone type of the lower body; detecting a bone type and a ligament grid of the foot, and selecting a corresponding grid type, a connection mode and a material type to simulate a foot finite element model; detecting a joint structure of a lower limb joint, and selecting a corresponding grid type, a connection mode and a material type to simulate a joint finite element model; epidermis and subcutaneous tissue types of lower limb epidermis and subcutaneous tissue are detected, and corresponding grid types, connection modes and material types are selected to simulate epidermis and subcutaneous tissue finite element models.

Description

Technical Field

[0001] The present invention relates to the technical field of traffic safety, and in particular to a method and system for modeling a lower limb finite element model based on human body characteristics. Background Art

[0002] In today's automobile traffic accidents, in addition to the head, neck, chest and abdomen, which are prone to serious injuries, the lower body is also an important part of the occupants and pedestrians that are prone to serious injuries. The research on the safety protection of the lower body has become one of the urgent problems to be solved in the field of automobile safety. In the field of automobile safety, the research on the lower body includes two methods: physical experiments and numerical model simulation. In actual research, compared with physical experiments, the human finite element model has the advantages of high biological fidelity and reusability. Therefore, the finite element model of the human lower limbs has a large application space in automobile safety research.

[0003] However, the existing data on lower limb models are usually developed based on other countries, which are significantly different from domestic human characteristics and cannot meet physical sign requirements. They have great limitations in the research on domestic automobile safety occupant and pedestrian protection, and will further cause errors in subsequent research. Summary of the invention

[0004] In view of the problems existing in the prior art, an embodiment of the present invention provides a method and system for modeling a lower limb finite element model based on human body characteristics.

[0005] The embodiment of the present invention provides a method for modeling a lower limb finite element model based on human body characteristics, comprising: Scanning historical image data, obtaining lower limb point cloud information in the historical image data, performing image processing on the lower limb point cloud information, and obtaining a lower limb geometric model, wherein the lower limb includes a lower body, a foot, a lower limb joint, and a lower limb epidermis and subcutaneous tissue; Meshing the lower limb geometric model, detecting the bone type of the lower body, and selecting a corresponding mesh type, connection method, and material type based on the bone type of the lower body to simulate a lower body finite element model; Detecting the bone type and ligament mesh of the foot, and selecting corresponding mesh type, connection method and material type based on the bone type and ligament to simulate a finite element model of the foot; Detecting the joint structure of the lower limb joint, and selecting a corresponding mesh type, connection method, and material type based on the joint structure to simulate a joint finite element model; The epidermis and subcutaneous tissue types of the lower limb epidermis and subcutaneous tissue are detected, and corresponding mesh types, connection methods, and material types are selected based on the epidermis and subcutaneous tissue types to simulate the epidermis and subcutaneous tissue finite element model.

[0006] In one embodiment, the method further comprises: Using computer tomography technology, obtaining a CT image of the historical image data; Using magnetic resonance imaging technology to obtain an MRI image of the historical image data; Preprocessing the CT image and the MRI image, and converting the preprocessed image into geometric data through three-dimensional reconstruction; The geometric data of the CT image is symmetrically processed to generate a corresponding skin contour surface model, and the bone geometric data extracted from the MRI is aligned and imported to obtain a lower limb geometric model.

[0007] In one embodiment, the preprocessing comprises: Noise removal, correction of image distortion, and filling cleanup after segmentation of image tissue.

[0008] In one embodiment, the method further comprises: Select eight-node hexahedral elements to simulate the cortical bone and cancellous bone in the lower body skeleton, and connect the cortical bone and cancellous bone through common nodes. Select *MAT_24 as the material type for the cortical bone and *MAT_105 as the material type for the cancellous bone.

[0009] In one embodiment, the method further comprises: Select eight-node hexahedral elements to simulate the cortical bone and cancellous bone of the radicular bone and talus in the foot bones, and connect the cortical bone and cancellous bone through common nodes. Select *MAT_24 as the material type of the cortical bone and *MAT_1 as the material type of the cancellous bone. Select eight-node hexahedral elements to simulate the cancellous bones of the cuneiform bones, navicular bones, cuboid bones, metatarsal bones, and phalanges in the foot bones, and select four-node quadrilateral shell elements to simulate the cortical bones. Connect the cortical bones and cancellous bones through common nodes. Select *MAT_24 as the material type for the cortical bones and *MAT_105 as the material type for the cancellous bones. A four-node quadrilateral shell element is selected to simulate the plantar ligament of the metatarsal bones of the foot, wherein the plantar ligament of the metatarsal bones of the foot is connected to the foot bones through a common node; The multi-segment 1D beam element was selected to simulate the deep transverse metatarsal ligament.

[0010] In one embodiment, the method further comprises: Select eight-node hexahedral elements to simulate the meniscus, ligaments and Achilles tendon, and select four-node quadrilateral shell elements to simulate the ankle ligaments. The meniscus, ligaments, Achilles tendon and bones are connected by common nodes, and the ankle ligaments are connected by common nodes to the bones. The material of the meniscus is *MAT_57, the material of the Achilles tendon is *MAT_181, the material of the knee ligament is *MAT_181, and the material of the ankle ligament is *MAT_34.

[0011] In one embodiment, the method further comprises: Select four-node quadrilateral shell elements to simulate the epidermis of the thigh, calf and foot, select three-node triangular shell elements to simulate the epidermis of the knee and ankle joints, select eight-node hexahedral elements to simulate the subcutaneous tissue of the thigh, calf and foot, select four-node tetrahedral elements to simulate the subcutaneous tissue of the knee and ankle joints, and connect the epidermis and subcutaneous tissue through common nodes. Select *MAT_34 as the material for the epidermis and *MAT_181 as the material for the subcutaneous tissue.

[0012] The embodiment of the present invention provides a lower limb finite element modeling system based on human body characteristics, comprising: A geometric model module is used to scan historical image data, obtain lower limb point cloud information in the historical image data, perform image processing on the lower limb point cloud information, and obtain a lower limb geometric model, wherein the lower limb includes the lower body, foot, lower limb joint, lower limb epidermis and subcutaneous tissue; A lower body module, used to mesh the lower limb geometric model, detect the bone type of the lower body, and select a corresponding mesh type, connection method, and material type based on the bone type of the lower body to simulate a lower body finite element model; A foot module, used to detect the bone type and ligament mesh of the foot, and select a corresponding mesh type, connection method and material type based on the bone type and ligament to simulate a foot finite element model; A joint module, used for detecting the joint structure of the lower limb joint, and selecting a corresponding mesh type, connection method and material type based on the joint structure to simulate a joint finite element model; The epidermis and subcutaneous tissue module is used to detect the epidermis and subcutaneous tissue types of the lower limb epidermis and subcutaneous tissue, and select the corresponding grid type, connection method and material type based on the epidermis and subcutaneous tissue types to simulate the epidermis and subcutaneous tissue finite element model.

[0013] An embodiment of the present invention provides an electronic device, including a processor and a memory; The processor is connected to the memory; The memory is used to store executable program code; The processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to execute the method described in one or more embodiments.

[0014] An embodiment of the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the above-mentioned method for modeling a lower limb finite element model based on human body features are implemented.

[0015] In view of the above, in one or more embodiments of the present specification, historical image data are scanned to obtain lower limb point cloud information in the historical image data, and image processing is performed on the lower limb point cloud information to obtain a lower limb geometric model, where the lower limb includes the lower body, foot, lower limb joints, lower limb epidermis and subcutaneous tissue; the lower limb geometric model is meshed, the bone type of the lower body is detected, and the corresponding mesh type, connection method and material type are selected based on the bone type of the lower body to simulate the lower body finite element model; the bone type and ligament mesh of the foot are detected, and the corresponding mesh type, connection method and material type are selected based on the bone type and ligament to simulate the foot finite element model; the joint structure of the lower limb joint is detected, and the corresponding mesh type, connection method and material type are selected based on the joint structure to simulate the joint finite element model; the epidermis and subcutaneous tissue types of the epidermis and subcutaneous tissue of the lower limb are detected, and the corresponding mesh type, connection method and material type are selected based on the epidermis and subcutaneous tissue types to simulate the epidermis and subcutaneous tissue finite element model. In this way, a finite element model of the human lower limbs that conforms to the characteristics of the domestic human body can be established based on the target population, thereby providing accurate research data for automobile safety-related research such as lower limb injury mechanisms and protection strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a flowchart of a method for modeling a lower limb finite element model based on human body characteristics provided by an embodiment of this specification.

[0018] Figure 2 It is a schematic diagram of the overall mesh division of the lower limb geometric model provided by an embodiment of this specification.

[0019] Figure 3 This is a schematic diagram of the grid division of the thigh part provided in one embodiment of this specification.

[0020] FIG4 is a schematic diagram of partial mesh division of a knee joint provided in an embodiment of the present specification, including FIG4(a) a front view of the knee joint, FIG4(b) a rear view of the knee joint, and FIG4(c) an external view of the knee joint.

[0021] Figure 5 It is a schematic diagram of the mesh division of the calf part provided in one embodiment of this specification.

[0022] Figure 6 This is a schematic diagram of the overall mesh division of the ankle joint and foot provided in one embodiment of this specification.

[0023] Figure 7 This is a schematic diagram of ankle joint mesh division provided by an embodiment of this specification.

[0024] Figure 8 This is a schematic diagram of foot mesh division provided by an embodiment of this specification.

[0025] Fig. 9 It is a structural schematic diagram of a lower limb finite element modeling system based on human body characteristics provided by an embodiment of this specification.

[0026] Fig.10 It is a structural schematic diagram of an electronic device provided by an embodiment of this specification. DETAILED DESCRIPTION

[0027] The subject matter described herein will now be discussed with reference to example embodiments. It should be understood that the discussion of these embodiments is only to enable those skilled in the art to better understand and implement the subject matter described herein, and is not a limitation of the scope of protection, applicability or examples set forth in the claims. The functions and arrangements of the elements discussed can be changed without departing from the scope of protection of the contents of this specification. Various examples can omit, replace or add various processes or components as needed. For example, the described method can be performed in an order different from the described order, and various steps can be added, omitted or combined. In addition, the features described relative to some examples can also be combined in other examples.

[0028] As used herein, the term "including" and its variations represent open terms, meaning "including but not limited to". The term "based on" means "based at least in part on". The terms "one embodiment" and "an embodiment" mean "at least one embodiment". The term "another embodiment" means "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other definitions may be included below, whether explicit or implicit. Unless the context clearly indicates otherwise, the definition of a term is consistent throughout the specification.

[0029] like Figure 1 As shown, an embodiment of the present invention provides a method for modeling a lower limb finite element model based on human body characteristics, comprising: Step S101, scan historical image data, obtain lower limb point cloud information in the historical image data, perform image processing on the lower limb point cloud information, and obtain a lower limb geometric model, wherein the lower limb includes the lower body, foot, lower limb joints, lower limb epidermis and subcutaneous tissue.

[0030] Specifically, the lower limb point cloud information is obtained by scanning the historical image data of the human lower limb, wherein the historical image data may be the image data in the hospital database, and the lower limb point cloud information may use the computer tomography (CT) technology to obtain the high-resolution CT images of the lower limb (including the leg bones, foot bones, and lower limb skin contour surface) in the historical image data, and the scanning covers the entire lower limb from the hip joint to the toe. And the magnetic resonance imaging (MRI) technology is used to obtain the geometric point cloud information of the lower limb of the same human body, especially the soft tissue part, such as muscles, ligaments, etc. MRI images can provide better soft tissue contrast than CT. After obtaining the lower limb point cloud information, image processing is performed to obtain the lower limb geometric model. The method includes a preprocessing step, that is, preprocessing the CT and MRI images, including removing noise, correcting image distortion, etc., to improve the accuracy of subsequent analysis, and then using the automatic threshold segmentation algorithm to preliminarily separate different tissues such as bones and muscles, and then manually filling and cleaning to ensure that the contour boundary of the anatomical structure is clear, and based on the processed medical image file, the point cloud information is converted into the geometric data of the anatomical structure using three-dimensional reconstruction software. The geometric data of the CT image are processed symmetrically. One side (for example, the left side) of the extracted lower limb and skin contour surface geometric data is processed symmetrically to generate a model of the other side (the right side) to ensure symmetry between the two sides. The bone geometric data extracted from the MRI image is imported into the skin contour surface model after symmetrical processing to ensure that the two are accurately aligned to obtain a lower limb geometric model.

[0031] Furthermore, the lower limb geometric model includes the lower body, feet, lower limb joints, lower limb epidermis and subcutaneous tissue, wherein the lower body includes the thigh and calf parts.

[0032] In addition, after obtaining the geometric model of the lower limbs, model optimization and inspection can be performed, such as smoothing the bone model, eliminating burrs and irregular structures, and ensuring a smooth bone surface; separating the geometric boundaries of ligaments and soft tissues, relaxing and smoothing their appearance to make them more natural; checking and eliminating interference between the bone structures of the lower limbs to ensure that there is no overlap or penetration between the parts; and finally exporting the surface IGES files of the lower limbs and epidermis to provide high-quality geometric models for subsequent finite element analysis and simulation.

[0033] Step S102, meshing the lower limb geometric model, detecting the bone type of the lower body, and selecting a corresponding mesh type, connection method, and material type based on the bone type of the lower body to simulate a lower body finite element model.

[0034] Specifically, meshing is performed on the geometric model of the lower limbs. For example, finite element analysis software (such as Abaqus, LS-DYNA, etc.) is used to mesh each mesh unit, and then the bone type of the lower body in the mesh unit is determined. The bone type includes cortical bone and cancellous bone, and the properties of each type of material are defined in the software. The overall geometric model of the lower limb after meshing is as follows: Figure 2 As shown in the figure, it includes 1. thigh; 2. knee joint; 3. calf; 4. ankle joint; 5. foot. The overall model of each part can be further subdivided, such as Figure 3 The schematic diagram of the mesh division of the thigh shown in FIG4 includes: 11, thigh epidermis; 12, thigh subcutaneous tissue; 13, femur; 14, patella. The schematic diagram of the mesh division of the knee joint shown in FIG4 (including three parts, (a) front view of the knee joint, (b) rear view of the knee joint, (c) external view of the knee joint) includes: 21, patellar ligament; 22, medial meniscus; 23, lateral meniscus; 24, anterior cruciate ligament; 25, tibial collateral ligament; 26, posterior cruciate ligament; 27, fibular collateral ligament; 28, knee joint epidermis; 29, knee joint subcutaneous tissue. Figure 5 The schematic diagram of the mesh division of the calf shown in FIG. 1 includes: 31, calf epidermis; 32, calf subcutaneous tissue; 33, fibula; 34, tibia. Figure 6 The overall schematic diagram of the ankle joint and foot mesh division is shown. Figure 7 The figure is a schematic diagram of the mesh division of the ankle joint, including: 41, ankle joint ligament; 42, Achilles tendon; 43, ankle joint epidermis; 44, ankle joint subcutaneous tissue. Figure 8 The schematic diagram of the foot mesh division shown includes: 51, calcaneus; 52, talus; 53, cuneiform bone, 54, navicular bone, 55, cuboid bone, 56, metatarsal bones, 57, phalanges, 58, foot ligaments, 59, foot epidermis; 510, foot subcutaneous tissue.

[0035] For the cortical and cancellous bones of the lower body, i.e. the thigh and calf, different element types are used. Cortical bones are usually harder and cancellous bones are softer, so they need to be modeled separately. Eight-node hexahedral elements (Hexahedral Elements) are selected to simulate the main bones of the lower body (femur, patella, fibula, tibia) (including cortical and cancellous bones). This element type has high accuracy in simulating complex geometries and stress distribution. Shared Nodes are used between the cortical and cancellous bones to ensure a smooth transition and continuity between the two materials. Shared node connections can avoid unreasonable stress concentration at the interface. For the material type, *MAT_105 material is selected for the cancellous bones of the femur, fibula, tibia, and patella of the lower body. *MAT_105 is a commonly used nonlinear elastic material model, suitable for simulating the mechanical behavior of cancellous bone. When setting parameters, it includes density, elastic modulus, Poisson's ratio, nonlinear parameters, etc. Select *MAT_24 material for the cortical bone of the femur, fibula, tibia, and patella of the lower body. *MAT_24 is a linear elastic material model, suitable for simulating the mechanical behavior of cortical bone. When setting parameters, it includes density, elastic modulus, Poisson's ratio, etc. In addition, for the shell elements (Shell Elements) attached to the surface of the body element in contact, select *MAT_9 material. *MAT_9 is a general linear elastic material model, suitable for simulating the mechanical behavior of thin shell structures.

[0036] Step S103, detecting the bone type and ligament mesh of the foot, and selecting corresponding mesh type, connection method and material type based on the bone type and ligament to simulate a finite element model of the foot.

[0037] Specifically, the mesh units of the foot are detected, including cortical bone and cancellous bone, as well as ligament meshes (including the plantar ligament of the metatarsal bones and the deep transverse ligament of the metatarsal bones). Then eight-node hexahedral units are selected to simulate the cortical bone and cancellous bone of the calcaneus and talus of the foot, as well as the cancellous bone of the cuneiform bone, navicular bone, cuboid bone, metatarsal bone, and phalanges of the foot, while the cortical bone of the cuneiform bone, navicular bone, cuboid bone, metatarsal bone, and phalanges of the foot is simulated using four-node quadrilateral shell units. The cortical bone and cancellous bone are connected by common nodes. For the cancellous bone of the calcaneus and talus of the foot, *MAT_1 material is selected, for the cancellous bone of the cuneiform bone, navicular bone, cuboid bone, metatarsal bone, and phalanges of the foot, *MAT_105 material is selected, and for the cortical bone of the calcaneus, talus, cuneiform bone, navicular bone, cuboid bone, metatarsal bone, and phalanges of the foot, *MAT_24 material is selected. In addition, for the ligament part of the foot, a four-node quadrilateral shell element can be selected to simulate the plantar ligament of the metatarsal bones of the foot. The plantar ligament of the metatarsal bones of the foot is connected to the foot bones through a common node, and the *MAT_34 material can be selected. A multi-segment 1D beam element is selected to simulate the deep transverse metatarsal ligament, where the node position of the beam element can be determined by the characteristics of the solid ligament, including but not limited to the length, width, thickness, anatomical characteristics, etc. of the solid ligament, and the material can be selected as *MAT_1 material.

[0038] Step S104, detecting the joint structure of the lower limb joint, and selecting a corresponding mesh type, connection method and material type based on the joint structure to simulate a joint finite element model.

[0039] Specifically, the mesh units of the joint structure are detected. The joints of the lower limbs include the knee joint and the ankle joint. The knee joint includes the meniscus and ligaments, and the ankle joint includes the ligaments and the Achilles tendon. Among them, for the meniscus and ligaments of the knee joint and the Achilles tendon of the ankle joint, eight-node hexahedral units are selected for simulation, while the ankle joint ligaments are simulated by four-node quadrilateral shell units. The meniscus and ligaments of the knee joint are connected by common nodes, and the ligaments and Achilles tendon of the ankle joint are connected by common nodes. In addition, the material of the meniscus is *MAT_57, the material of the Achilles tendon is *MAT_181, the material of the knee ligament is *MAT_181, and the material of the ankle ligament is *MAT_34.

[0040] Step S105, detecting the epidermis and subcutaneous tissue types of the lower limb epidermis and subcutaneous tissue, and selecting corresponding mesh types, connection methods and material types based on the epidermis and subcutaneous tissue types to simulate the epidermis and subcutaneous tissue finite element model.

[0041] Specifically, the types of epidermis and subcutaneous tissue of the lower limbs include epidermis and subcutaneous tissue of the thigh, epidermis and subcutaneous tissue of the calf, epidermis and subcutaneous tissue of the foot, epidermis and subcutaneous tissue of the knee joint, and epidermis and subcutaneous tissue of the ankle joint. Among them, the epidermis of the thigh, calf, and foot can be simulated by four-node quadrilateral shell elements, while the epidermis of the joints (knee joints and ankle joints) can be simulated by three-node triangular shell elements. The subcutaneous tissue of the thigh, calf, and foot can be simulated by eight-node hexahedral elements, while the subcutaneous tissue of the joint can be simulated by four-node tetrahedral elements. In addition, for each type of epidermis and subcutaneous tissue, part of the mesh surface at the corresponding position can be extracted as the inner surface of the subcutaneous tissue at the corresponding position. For example, for the thigh epidermis and subcutaneous tissue, part of the mesh surface of the femoral shaft can be extracted as the inner surface of the thigh subcutaneous tissue. For the foot epidermis and subcutaneous tissue, based on the geometry of the foot epidermis, the inner envelope surface of the foot wrapped around the foot bone is generated by scaling and deformation as the inner surface of the foot subcutaneous tissue. For each type of epidermis and subcutaneous tissue, the epidermis and subcutaneous tissue can be connected through a common node. For each of the above epidermis and subcutaneous tissue types, the material of the epidermis is *MAT_34, and the material of the subcutaneous tissue is *MAT_181.

[0042] In addition, the above-mentioned lower body finite element model, foot finite element model, joint finite element model, epidermis and subcutaneous tissue finite element model can construct a lower limb finite element model. Moreover, after each finite element model is formed, a preliminary static or dynamic analysis can be performed, and the stress distribution, deformation, etc. can be checked to ensure that the model conforms to the expected mechanical behavior, thereby verifying the rationality and accuracy of the model.

[0043] The embodiment of the present invention provides a method for modeling a finite element model of a lower limb based on human body characteristics, which scans historical image data, obtains lower limb point cloud information in the historical image data, performs image processing on the lower limb point cloud information, and obtains a lower limb geometric model, wherein the lower limb includes a lower body, a foot, a lower limb joint, and a lower limb epidermis and subcutaneous tissue; meshes the lower limb geometric model, detects the bone type of the lower body, and selects a corresponding mesh type, connection method, and material type based on the bone type of the lower body to simulate a lower body finite element model; detects the bone type and ligament mesh of the foot, and selects a corresponding mesh type, connection method, and material type based on the bone type and ligament to simulate a foot finite element model; detects the joint structure of the lower limb joint, and selects a corresponding mesh type, connection method, and material type based on the joint structure to simulate a joint finite element model; detects the epidermis and subcutaneous tissue types of the epidermis and subcutaneous tissue of the lower limb, and selects a corresponding mesh type, connection method, and material type based on the epidermis and subcutaneous tissue types to simulate a finite element model of the epidermis and subcutaneous tissue. In this way, a finite element model of the human lower limbs that conforms to the characteristics of the domestic human body can be established based on the target population, thereby providing accurate research data for automobile safety-related research such as lower limb injury mechanisms and protection strategies.

[0044] See also Fig. 9 , Fig. 9 Schematic diagram of the structure of a lower limb finite element modeling system based on human body characteristics provided in an embodiment of the present application. Fig. 9 As shown, the system comprises: The geometric model module S901 is used to scan the historical image data, obtain the lower limb point cloud information in the historical image data, perform image processing on the lower limb point cloud information, and obtain the lower limb geometric model, wherein the lower limb includes the lower body, foot, lower limb joint, lower limb epidermis and subcutaneous tissue; The lower body module S902 is used to mesh the lower limb geometric model, detect the bone type of the lower body, and select the corresponding mesh type, connection method and material type based on the bone type of the lower body to simulate the lower body finite element model; The foot module S903 is used to detect the bone type and ligament mesh of the foot, and select the corresponding mesh type, connection method and material type based on the bone type and ligament to simulate the foot finite element model; The joint module S904 is used to detect the joint structure of the lower limb joint, and select the corresponding mesh type, connection method and material type based on the joint structure to simulate the joint finite element model; The epidermis and subcutaneous tissue module S905 is used to detect the epidermis and subcutaneous tissue types of the epidermis and subcutaneous tissue of the lower limbs, and select the corresponding grid type, connection method and material type based on the epidermis and subcutaneous tissue types to simulate the finite element model of the epidermis and subcutaneous tissue. Those skilled in the art can clearly understand that the technical solutions of the embodiments of the present application can be implemented with the help of software and / or hardware. The "unit" and "module" in this specification refer to software and / or hardware that can independently complete or cooperate with other components to complete specific functions, where the hardware can be, for example, a field programmable gate array (Field-Programmable Gate Array, FPGA), an integrated circuit (Integrated Circuit, IC), etc.

[0045] Each processing unit and / or module of the embodiments of the present application may be implemented by an analog circuit that implements the functions described in the embodiments of the present application, or may be implemented by software that executes the functions described in the embodiments of the present application.

[0046] See also Fig.10 , which shows a schematic diagram of the structure of an electronic device involved in an embodiment of the present application, the electronic device can be used to implement Figure 1 The method in the embodiment shown. Fig.10 As shown, the electronic device 1000 may include: at least one processor 1001 , at least one network interface 1004 , a user interface 1003 , a memory 1005 , and at least one communication bus 1002 .

[0047] The communication bus 1002 is used to realize the connection and communication between these components.

[0048] The user interface 1003 may include a display screen (Display) and a camera (Camera). Optionally, the user interface 1003 may also include a standard wired interface and a wireless interface.

[0049] The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a WI-FI interface).

[0050] Among them, the processor 1001 may include one or more processing cores. The processor 1001 uses various interfaces and lines to connect various parts of the entire electronic device 1000, and executes various functions and processes data of the terminal 1000 by running or executing instructions, programs, code sets or instruction sets stored in the memory 1005, and calling data stored in the memory 1005. Optionally, the processor 1001 can be implemented in at least one hardware form of digital signal processing (Digital Signal Processing, DSP), field programmable gate array (Field-Programmable Gate Array, FPGA), and programmable logic array (Programmable Logic Array, PLA). The processor 1001 can integrate one or a combination of a processor (Central Processing Unit, CPU), a graphics processor (Graphics Processing Unit, GPU) and a modem. Among them, the CPU mainly processes the operating system, user interface and application programs; the GPU is responsible for rendering and drawing the content to be displayed on the display screen; the modem is used to process wireless communications. It can be understood that the above-mentioned modem may not be integrated into the processor 1001, and it can be implemented separately through a chip.

[0051] Among them, the memory 1005 may include a random access memory (Random Access Memory, RAM) and may also include a read-only memory (Read-Only Memory). Optionally, the memory 1005 includes a non-transitory computer-readable storage medium. The memory 1005 can be used to store instructions, programs, codes, code sets or instruction sets. The memory 1005 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store data involved in the above-mentioned various method embodiments, etc. The memory 1005 may also be optionally at least one storage device located away from the aforementioned processor 1001. As Fig.10 As shown, the memory 1005 as a computer storage medium may include an operating system, a network communication module, a user interface module, and program instructions.

[0052] exist Fig.10In the electronic device 1000 shown, the user interface 1003 is mainly used to provide an input interface for the user and obtain the data input by the user; and the processor 1001 can be used to call the interactive application based on image generation stored in the memory 1005, and specifically perform the following operations: scan the historical image data, obtain the lower limb point cloud information in the historical image data, perform image processing on the lower limb point cloud information, and obtain the lower limb geometric model, the lower limb includes the lower body, foot, lower limb joints, lower limb epidermis and subcutaneous tissue; mesh the lower limb geometric model, detect the bone type of the lower body, and based on the bone type of the lower body Select the corresponding mesh type, connection method and material type to simulate the lower body finite element model; detect the bone type and ligament mesh of the foot, and select the corresponding mesh type, connection method and material type based on the bone type and ligament to simulate the foot finite element model; detect the joint structure of the lower limb joints, and select the corresponding mesh type, connection method and material type based on the joint structure to simulate the joint finite element model; detect the epidermis and subcutaneous tissue types of the lower limb epidermis and subcutaneous tissue, and select the corresponding mesh type, connection method and material type based on the epidermis and subcutaneous tissue types to simulate the epidermis and subcutaneous tissue finite element model.

[0053] The present application also provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the steps of the above method are implemented. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a micro drive, and a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0054] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0055] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0056] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0057] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0058] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0059] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, disk or optical disk and other media that can store program codes.

[0060] A person skilled in the art may understand that all or part of the steps in the various methods of the above embodiments may be completed by entering a program to instruct related hardware, and the program may be stored in a computer-readable memory, which may include a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0061] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for modeling a lower limb finite element model based on human body characteristics, characterized in that: include: Scanning historical image data, obtaining lower limb point cloud information in the historical image data, performing image processing on the lower limb point cloud information, and obtaining a lower limb geometric model, wherein the lower limb includes a lower body, a foot, a lower limb joint, and a lower limb epidermis and subcutaneous tissue; Meshing the lower limb geometric model, detecting the bone type of the lower body, and selecting a corresponding mesh type, connection method, and material type based on the bone type of the lower body to simulate a lower body finite element model; Detecting the bone type and ligament mesh of the foot, and selecting corresponding mesh type, connection method and material type based on the bone type and ligament to simulate a finite element model of the foot; Detecting the joint structure of the lower limb joint, and selecting a corresponding mesh type, connection method, and material type based on the joint structure to simulate a joint finite element model; The epidermis and subcutaneous tissue types of the lower limb epidermis and subcutaneous tissue are detected, and corresponding mesh types, connection methods, and material types are selected based on the epidermis and subcutaneous tissue types to simulate the epidermis and subcutaneous tissue finite element model.

2. The method for modeling a lower limb finite element model based on human body characteristics according to claim 1, characterized in that: The scanning of historical image data, obtaining lower limb point cloud information in the historical image data, and performing image processing on the lower limb point cloud information to obtain a lower limb geometric model include: Using computer tomography technology, obtaining a CT image of the historical image data; Using magnetic resonance imaging technology to obtain an MRI image of the historical image data; Preprocessing the CT image and the MRI image, and converting the preprocessed image into geometric data through three-dimensional reconstruction; The geometric data of the CT image is symmetrically processed to generate a corresponding skin contour surface model, and the bone geometric data extracted from the MRI is aligned and imported to obtain a lower limb geometric model.

3. The method for modeling a lower limb finite element model based on human body characteristics according to claim 2, characterized in that: The preprocessing comprises: Noise removal, correction of image distortion, and filling cleanup after segmentation of image tissue.

4. The method for modeling a lower limb finite element model based on human body characteristics according to claim 1, characterized in that: The step of selecting a corresponding mesh type, connection method, and material type based on the bone type of the lower body to simulate a finite element model of the lower body includes: Select eight-node hexahedral elements to simulate the cortical bone and cancellous bone in the lower body skeleton, and connect the cortical bone and cancellous bone through common nodes. Select *MAT_24 as the material type for the cortical bone and *MAT_105 as the material type for the cancellous bone.

5. The method for modeling a lower limb finite element model based on human body characteristics according to claim 1, characterized in that: The simulating of the foot finite element model by selecting a corresponding mesh type, connection method and material type based on the bone type and ligament includes: Select eight-node hexahedral elements to simulate the cortical bone and cancellous bone of the radicular bone and talus in the foot bones, and connect the cortical bone and cancellous bone through common nodes. Select *MAT_24 as the material type of the cortical bone and *MAT_1 as the material type of the cancellous bone. Select eight-node hexahedral elements to simulate the cancellous bones of the cuneiform bones, navicular bones, cuboid bones, metatarsal bones, and phalanges in the foot bones, and select four-node quadrilateral shell elements to simulate the cortical bones. Connect the cortical bones and cancellous bones through common nodes. Select *MAT_24 as the material type for the cortical bones and *MAT_105 as the material type for the cancellous bones. A four-node quadrilateral shell element is selected to simulate the plantar ligament of the metatarsal bones of the foot, wherein the plantar ligament of the metatarsal bones of the foot is connected to the foot bones through a common node; The multi-segment 1D beam element was selected to simulate the deep transverse metatarsal ligament.

6. The method for modeling a lower limb finite element model based on human body characteristics according to claim 1, characterized in that: The method of simulating a joint finite element model by selecting a corresponding mesh type, connection method and material type based on the joint structure includes: Select eight-node hexahedral elements to simulate the meniscus, ligaments and Achilles tendon, and select four-node quadrilateral shell elements to simulate the ankle ligaments. The meniscus, ligaments, Achilles tendon and bones are connected by common nodes, and the ankle ligaments are connected by common nodes to the bones. The material of the meniscus is *MAT_57, the material of the Achilles tendon is *MAT_181, the material of the knee ligament is *MAT_181, and the material of the ankle ligament is *MAT_34.

7. The method for modeling a lower limb finite element model based on human body characteristics according to claim 1, characterized in that: The simulating the finite element model of the epidermis and subcutaneous tissue by selecting the corresponding mesh type, connection method and material type based on the epidermis and subcutaneous tissue types includes: Select four-node quadrilateral shell elements to simulate the epidermis of the thigh, calf and foot, select three-node triangular shell elements to simulate the epidermis of the knee and ankle joints, select eight-node hexahedral elements to simulate the subcutaneous tissue of the thigh, calf and foot, select four-node tetrahedral elements to simulate the subcutaneous tissue of the knee and ankle joints, and connect the epidermis and subcutaneous tissue through common nodes. Select *MAT_34 as the material for the epidermis and *MAT_181 as the material for the subcutaneous tissue.

8. A lower limb finite element modeling system based on human body characteristics, characterized in that: The system comprises: A geometric model module is used to scan historical image data, obtain lower limb point cloud information in the historical image data, perform image processing on the lower limb point cloud information, and obtain a lower limb geometric model, wherein the lower limb includes the lower body, foot, lower limb joint, lower limb epidermis and subcutaneous tissue; A lower body module, used to mesh the lower limb geometric model, detect the bone type of the lower body, and select a corresponding mesh type, connection method, and material type based on the bone type of the lower body to simulate a lower body finite element model; A foot module, used to detect the bone type and ligament mesh of the foot, and select a corresponding mesh type, connection method and material type based on the bone type and ligament to simulate a foot finite element model; A joint module, used for detecting the joint structure of the lower limb joint, and selecting a corresponding mesh type, connection method and material type based on the joint structure to simulate a joint finite element model; The epidermis and subcutaneous tissue module is used to detect the epidermis and subcutaneous tissue types of the lower limb epidermis and subcutaneous tissue, and select the corresponding grid type, connection method and material type based on the epidermis and subcutaneous tissue types to simulate the epidermis and subcutaneous tissue finite element model.

9. An electronic device comprising a processor and a memory; The processor is connected to the memory; The memory is used to store executable program code; The processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method according to any one of claims 1 to 7.

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