健康人下颈椎的有限元模型构建及分析

Construction and analysis of a finite element model of the inferior cervical spine in healthy people

目的:基于计算机断层扫描(CT)图像数据建立健康人下颈椎C4~C7节段的三维有限元模型,并验证模型有效性和分析其生物力学特性。方法:采集1名健康志愿者的下颈椎CT图像资料,导入Mimics中进行颈椎骨性结构的分割提取,然后在Geomagic studio软件中对颈椎骨性结构模型进行去噪、填补、光顺等操作,进而拟合模型曲面实体,再通过Solidworks软件建立椎间盘髓核、纤维环及关节软骨等结构以及装配模型。最后,在ANSYS软件中添加接触关系、材料属性、边界条件和载荷,测得下颈椎在前屈、后伸、左右侧屈、左右旋转6种工况下的应力变化。结果:本研究构建了包含韧带的下颈椎C4~C7节段的三维有限元模型,包括186746个单元和353873个节点。该模型在各个方向的活动良好,并且各节段的结果均在既往文献的范围内。结论:下颈椎C4~C7节段的有限元模型表现出良好的生物力学性能,可用于下颈椎生物力学分析。

Objective To establish a three-dimensional finite element model of the C4-C7 segment of the inferior cervical spine in healthy individuals based on computed tomography(CT)image data,and to analyze the biomechanical characteristics of the model and verify its validity.Methods The CT image data of the inferior cervical spine of a healthy volunteer were collected and imported into mimics for segmentation and extraction of the cervical spine bone structure.Then the cervical spine bone structure model was de noised,filled and smoothed in Geomagic Studio software,and then the surface entity of the model was fitted.Then the structure and assembly model of intervertebral disc nucleus pulposus,annulus fibrosus and articular cartilage were established by SolidWorks software.Finally,the contact relationship,material properties,boundary conditions and loads were added to the ANSYS software to measure the stress changes of the inferior cervical spine under six working conditions:flexion,extension,lateral flexion and rotation.Results This study successfully established a three-dimensional finite element model of the inferior cervical spine containing ligaments,including 186746 elements and 353873 nodes.The model simulated movements in various directions well,and the mobility of each segment was within the range reported in previous literature.Conclusions The finite element model of the inferior cervical spine C4-C7 passed validity verification and has good biomechanical performance.It can be used for biomechanical analysis of the inferior cervical spine.