基于CT图像全颈椎三维有限元模型的建立及验证

目的:建立全颈椎三维有限元模型并进行验证.方法:通过CT扫描机对中国人体50百分位健康成年男性志愿者颈椎进行扫描,获取颈椎骨骼坐标数据,利用Mimics软件将图像坐标数据转换成ASCII格式的点云数据,并利用CATIA软件对点云数据进行前处理,通过Geomagic曲面建模功能完成颈椎几何模型重构,并将几何模型导入到有限元前处理软件Hypermesh.采用映射网格划分法分别对颈椎皮质骨、松质骨、椎间盘以及各主要韧带等结构进行了网格划分和模拟.同时,利用现有的颈椎材料参数进行比例和功能缩放来定义稀缺的材料参数,最终建立一个解剖结构描述准确、全面的全颈椎有限元模型.结果:整个模型共有22 512个实体单元,14 180个壳/膜单元.利用颈椎离体坠落实验对模型的有效性进行了验证.结论:模型具有良好的生物逼真度,可应用于研究颈椎在汽车碰撞事故中的动态响应和损伤机制.

Development and verification of a 3-dimensional finite element model of the human neck based on CT images

OBJECTIVE: To establish a 3-dimensional finite element model. METHODS: The coordinate data of the vertebras were obtained from the CT scan images of Chinese 50th percentile healthy male adult volunteers' cervical spine, converted into point cloud data, and stored as ASCII file using Mimics software. CATIA software was used to preprocess and Geomagic software was used to establish the geometry model of the C0 approximately C7 cervical spine. The geometry model was meshed by Hypermesh software. Mapped mesh method was used to mesh cortical bone, trabecular bone, intervertebral disk, ligaments, etc. Some material parameters were defined from other available material parameters using proportion and function scale method. RESULTS: The model had 22 512 solid elements and 14 180 shell/membrane elements. The model was validated by the cervical spine drop test. CONCLUSION: The model has good biofidelity and can be used to study the dynamic response and injury mechanism of the cervical spine in the car accidents.