建立正常人C_(2～7)的三维有限元模型

Construction of C_(2-7) three-dimensional finite element model of normal adults

背景:随着计算机技术的发展,颈椎生物力学研究不再局限于动物或人体尸体实验,计算机模型可以进行更准确的生物力学研究。目的:在已有研究的基础上,建立人体C2～7三维有限元模型,以期为颈椎前路分节段减压融合的生物力学研究提供参考数据。方法:选择1名28岁健康男性志愿者为观察对象,无明显的颈椎病史,扫描前先拍摄颈椎正侧位、斜位、过伸过屈位X射线片以排除颈椎病变。首先根据志愿者CT扫描图片,采用计算机辅助设计数据处理技术,输入相关的材料特性,构建C2～7三维有限元模型。模型重建采用先进的Geomagics系统,可以准确模拟颈椎结构,有限元部分则采用广泛使用的ANSYS系统。其次在1.8N?m作用力下,观察节段运动与力-位移反应,并与国外的实验结果对比,在前屈、后伸、侧弯和旋转等4种工况(载荷状态)下对模型进行验证。结果与结论:整个模型包括C2～7六个椎体、C2/3～6/7五个椎间盘以及后部结构与主要韧带,共有23348个节点和215749个单元。在模拟外力的作用下,模型前屈、后伸、侧弯和旋转工况下的颈椎活动度与以往实验模型结果数据基本吻合。提示所建立的颈椎有限元模型可以模拟颈椎生物力学实验,进行生物力学分析。

BACKGROUND：With the fast development of computer technology,biomechanical study of cervical vertebra is not limited in animal or human corpses,because computer model can provide a more accurate model.OBJECTIVE：To develop a three-dimensional,finite element model of a human C2-7 based on previous studies,and to provide experimental data for the biomechanical study of the cervical spine.METHODS：A normal young 28-year-old male,without obvious cervical spondylosis history,was selected,and C-spine X-rays at posteroanterior,oblique,and over extension and over flexion position were performed to deplete cervical spondylosis.The CT scanning images were dealed with Software Mimics and Geomagic to obtain the finite element,and software ANSYS was used to study the response of the model.Under a 1.8 N？m segmental movement and force displacement response were observed and compared with abroad experimental results.RESULTS AND CONCLUSION：The new finite element model was composed of six vertebrae （C2-7）,five discs （C2/3-6/7） and main ligaments.The model consisted of solid elements with 23 348 nodes and 215 749 units.The results of the biomechanical study were better correlated with the available experimental data.It indicates that the finite element model of cervical spine at C2-7 can be used to imitate the biomechanical experiment of cervical spine.