基于CT图像和逆向工程方法建立正常人体腰椎三维有限元模型

Establishment of a normal human lumbar three-dimensional finite element model based on CT image and reverse engineering methods

背景：利用有限元法可以分析静止及活动时正常脊柱的生物力学,并预测应力时的风险。目的：建立腰椎L3~L5三维有限元模型。方法：选取一名健康30岁男性志愿者L3~L5薄层CT扫描图像,使用工具软件Geomagic和Ansys,应用逆向工程原理构建三维有限元模型,设定边界条件进行加载,记录角位移及应力集中部位,计算模型的平均刚度。结果与结论：建立L3~L5椎体三维有限元模型,包括椎体、韧带、椎间盘、纤维环和小关节,模型总单元数51905个,通过定量和定性两方面验证模型有效。说明所建立的L3~L5椎体三维有限元模型符合脊柱生物力学特征,可用于进一步脊柱生物力学研究。

BACKGROUND： Finite element method can analyze biomechanics of normal human spinal under stationary and activity, and also can predict risk of stress. OBJECTIVE： To establish a three-dimensional finite element model of normal human L3-L5 motion segment. METHODS： In this study, a detailed L3-L5 level three-dimensional finite element model of a normal aged 30 men was established with the aid of two softwares, Geomagic and Ansys, which can derive a three-dimensional finite element model from CT images. Then border conditions and load were set. Angular displacement and stress concentration sites were recorded. Average model stiffness was calculated. RESULTS AND CONCLUSION： A finite element model of the spinal segments （L3-L5） was developed, including vertebrae, ligament, disc, fibrous ring and the facet joints. The model had 51 905 units. The model was validated by quantitative and qualitative. Three-dimensional finite element model of L3-L5 motion segment is approximate to the natural biomechanical of spine and it can be used for further study.