基于CT图像构建的腰椎三维有限元模型

背景：与实验生物力学研究相比，有限元分析方法具有独特的优越性。如何准确地构建腰椎节段有限元模型是有限元分析的关键。目的：建立人体腰椎三维有限元模型用于生物力学分析。方法：利用GE 64排螺旋CT对成年男性腰部进行扫描，得到351层DICOM格式断层图像，应用Mimics软件进行三维重建，将所得模型以.stl格式导入Solidworks，生成实体模型，最后导入Ansys赋予材料属性并划分网格，得到便于分析的有限元模型。与体外生物力学实验数据对比，完成模型验证。结果与结论：成功地建立了表面光滑、外观逼真的腰椎有限元模型。该模型共有144 411个节点，88 742个单元，具有较高的准确性，且可以方便地施加约束和载荷，进行有限元分析。为临床腰椎三维有限元模型建立提供了一种精确而实用的方法，所建模型可以用来模拟腰椎生物力学实验。

Establishing a three-dimensional finite element model of human lumbar spine based on CT images

BACKGROUND:Compared with the method of experiment biomechanics, the finite element analysis methods have unique advantages. How to establish the lumbar spine finite element model accurately is the key point of the finite element analysis.OBJECTIVE:To develop a three-dimensional finite element model of human lumbar spine for biomechanical studies.METHODS:A normal adult male lumbar spine was scanned by GE 64-slice spiral CT, which obtained 351-layer pictures in DICOM format, the three-dimensional reconstruction model was established by Mimics software, and then, the model was introduced into Solidworks in the format of .stl to create physical model. Finally, the model was introduced into Ansys software, a convenient finite element model was obtained after assigning parameters and meshing. The validity of the model was verified by comparing the result with that of the in vitro biomechanical experiments.RESULTS AND CONCLUSION:The three-dimensional finite element model of lumbar spine was established smoothly and distinctly. There were 144 411 nodes and 88 742 units in the model. The model had a high accuracy, and it conveniently applied the load and constraints for the finite element analysis. The way in this study was an exact and practical one to establish the finite element model of lumbar spine for clinical doctors. The model could simulate the lumbar spine biomechanical experiment.