胆囊三维有限元力学模型的构建

Construction of three-dimensional mechanical finite element model of gallbladder

目的建立人胆囊三维有限元力学模型,用于胆囊的非侵害性生物力学研究和手术模拟。方法根据胆囊的解剖学数据,在参数化CAD软件PRO/E中建立胆囊的三维交互式CAD模型,以IGES格式导入到通用有限元分析软件ANSYS中,以20节点SOLID95单元划分几何模型并赋材料属性建立有限元模型。模拟胆囊底受钳夹的工况,分析胆囊在位移载荷下的形变和应力分布。结果成功建立了具有几何相似性和物理相似性的三维胆囊有限元模型,包含了胆囊底、体、颈结构,共14 520个单元,82 524个节点。模拟胆囊底受钳夹工况时,形变集中在胆囊底顶部区域,而应力集中在胆囊床边缘和胆囊颈与胆囊管部。结论有限元法可模拟胆囊在手术中的力学响应,可用于胆囊的生物力学研究。

Objective To construct a three-dimensional mechanical finite element model （FEM） of human gallbladder for non-invasive biomechanical research of gallbladder and operation simulation. Methods An interactive CAD model of gallbladder was developed by parametric design software PRO/E using anatomical data, and was transferred into the finite element analysis software ANSYS in IGES format. Subsequently,the geometric model was meshed with 3D 20-node hexahedral structural solid elements and endued with material attributes to build the FEM. The procedure of clampping the gallbladder fundus was simulated with the established FEM, and the deformation and Von Mises Stress was analyzed under displacement loads. Results A 3D FEM of gallbaldder was successfully established, including the fundus, body and neck of gallbladder. The model consisted of 14520 elements and 82524 nodes. It was found that the Von Mises Stress concentration areas were at the periphery of the gallbladder bed and junction of gallbladder neck and cystic duct, and the deformation was centered at the head of gallbladder fundus. Conclusion FEM can simulate the mechanical response in gallbladder operation, and the gallbladder FEM can be used for biomechanical research of the gallbladder.