基于CT扫描及CAD技术建立下腰椎三维有限元模型

背景：近年来,计算机技术和有限元理论的飞速发展为构建腰椎模型提供了技术支持,有限元模型的精确性和可靠性显著提高,为研究椎间盘、椎板切除、腰椎融合、脊柱内固定材料等临床相关的生物力学问题提供了更好的平台。目的：应用三维有限元法建立L3～5腰椎活动节段力学模型。方法：通过CT扫描、Unigraphics V18.0软件进行影像边界记录、定标等方法,按照点、线、面、体的顺序重建三维结构,采用CAD数据处理技术,输入相关的材料特性,验证重建模型的有效性。结果与结论：建立下腰椎的三维有限元模型（L3～5）,分析结果证明其在仿真分析中是可行的,可以模拟生物力学实验。建立的模型共有6482个节点,31326个单元,生成网格时利用网格生成器的扫掠和优化功能,尽量依据模型的几何外形,使网格生成的最少,兼顾了对建模准确性和计算可行性,同时又能充分满足对腰椎的生物力学研究。

Construction of a three-dimensional finite element model of lower lumbar spine based on computed tomography images and computer aided design

BACKGROUND：Currently,the rapid developments of computer technology and finite element theory provide technical supports for construction of lumbar spine models.The finite element model with high accuracy and reliability provides better platform for clinical biomechanics,such as intervertebral discs,lamina excision,lumbar fusion,and spinal internal fixation materials.OBJECTIVE：To construct a lumber spine （L3-5） biomechanical model using three-dimensional finite element method.METHODS：Reconstructing the skeleton through CT scan,recording the edges of image,calibrating in sequence of point,line,face and solid.Mapped-mesh technique was used to obtain the finite element,adopt finite element commercial software package Unigraphics V18.0 was used to study the response of the disc model.RESULTS AND CONCLUSION：The finite element model of lower lumbar spine （L3-5） was reconstructed,which can simulate biomechanical experiment.There were 6 482 nodes and 31 326 units in the model.Based on geometrical shape of model,the mesh generation was reducedminimum utilizing mesh generator,which can not only ensure model accuracy and calculation feasibility,but also meet needs of biomechanical studies.