采用体绘制方法建立人股骨三维有限元模型及其应力分析

背景：目前股骨三维有限元研究建模方法有多种,而采用体绘制分体建模方法还未曾报道过。 目的：采用体绘制方法建立股骨三维有限元实体模型,对所建实体模型模拟力学载荷得出股骨应力分布,并与既往股骨力学实验比较,评估体绘制方法的可行性。 方法：将CT扫描图像去噪等预处理后,采用体绘制技术,利用Mimics和Ansys软件建立人股骨有限元模型,并在Mimics软件中赋予股骨材质,并模拟人体正常站立位时股骨载荷情况。 结果与结论：采用体绘制方法建立的人股骨三维有限元模型,包括皮质骨、松质骨及髓腔解剖结构,网格化后共生成63 900个节点,43 552个实体单元;模拟载荷显示股骨压应力区域主要集中在股骨内侧、尤其是股骨距部位,张应力主要集中于股骨颈外侧、股骨干外侧。表明体绘制方法可以建立高仿真、接近股骨解剖结构股骨三维有限元模型实体模型,可以探索股骨的内部结构,展现其内部细节,模拟股骨生物力学分布。关键词：体绘制;股骨;实体模型;有限元;力学分布 doi:10.3969/j.issn.1673-8225.2012.17.003

Stress analysis and establishment of three-dimensional finite element model of human femur by volume rendering

BACKGROUND: At present, there are several research methods of femoral three-dimensional (3-D) finite element modeling, but studies on the 3-D finite element solid model of femur by volume rendering method are few. OBJECTIVE: To establish the 3-D finite element solid model of human femur by volume rendering method, to obtain the stress distribution of the model through simulation of mechanical loading, and to assess the feasibility of this method by comparing with the previous femoral biomechanical experiments. METHODS: CT images was preprocessed by images denoising and other methods, then the 3-D finite element solid model of human femur was constructed by using Mimics and Ansys softwares through adopting rendering technique. And, the loading conditions of femur at the position of standing were simulated by importing the femur material parameter to the Mimics software. RESULTS AND CONCLUSION: The 3-D finite element solid model of human femur includes cortical bone, cancellous bone and anatomical structure of cavity, and there were 63 900 nodes and 43 552 elements generated in total after meshing. Results of simulation of the loading conditions showed that the femur compressive stress primarily concentrated in the inner side of femur, especially in the calcar femorale, and the tensile stress mainly concentrated in the outside of collum femoris and shaft of femur. The 3-D finite element solid model of human femur with high quality simulation and reflection of the anatomical structure of femur can be created by volume rendering method. So, this model can be applied to study the internal structure and details of femur, and simulate the biomechanical property of femur.