C4～C6颈椎有限元模型的建立和多点力学加载方法

背景:人体颈椎运动是多节段之间相互力学及位移关系的变化,建立多节段有限元模型及多点力学加载方法可以为颈椎生物力学研究提供高精度的模型和科学的计算分析方法。目的:建立人体C4~C6颈椎三维有限元模型,并在此基础上提出多点力学加载方法。方法:以正常人C4~C6颈椎CT图像作为数据源,利用Mimics10.0、Ansys11.0有限元分析软件建立三维有限元模型,对其进行多点力学加载测试,模拟生理状态时颈椎的轴向、屈曲、后伸、侧弯、扭转运动,分析各运动状态下C4~C6颈椎关节突和椎间盘的应力和位移改变。结果与结论:建立的C4~C6颈椎有限元模型几何形态逼真,重现了C4~C6颈椎节段解剖结构外形,整体显示直观,表面无过多简化,建成后的三维有限元模型与实体组织具有良好的几何相似性。应力Se、Sz在不同加载工况时,前屈/后伸>侧弯>轴向加载。轴向加载载荷明显小,导致应力位移水平低。提示应用正常人体原始资料构建的C4~C6颈椎有限元模型以及多点力学加载分析的方法科学有效,为颈椎的生物力学研究提供了高精度模型和科学的计算分析方法。

The finite element analysis of the lower cervical spine (C4-C6) under multipoint mechanical loading

BACKGROUND: The motion of human cervical spine is the change of biomechanics and displacement among multiple sections. To establish the finite element model of multiple sections and multipoint mechanical loading can provide a high accuracy model and scientific analysis method for the biomechanics research of the cervical spine. OBJECTIVE: To establish the finite element model of the human lower cervical spine (C4-C6), and put forward multipoint mechanical loading on this basis. METHODS: CT images of normal cervical spine (C4-C6) were got as data sources. Three-dimensional finite element model was established by using Mimics10.0 and Ansys11.0 finite element analysis software, and the model was took under multipoint mechanical loading to imitate the motion of axial, bucking, extension, side-bending and twisting which occur in physiological condition. Change of the stress and the displacement were analyzed under different motion of lower cervical spine (C4-C6). RESULTS AND CONCLUSION: The finite element model which showed geometric shape lifelike, repeated the anatomical structure of cervical spine and had well geometric similarity to physical organization. Under different mechanical loading conditions (Se, Sz), the stress of bucking and extension was bigger than side-bending, and side-bending was bigger than axial. And the level of displacement was very low, this may because of the stress of axial load was very small. The methods of established the finite element model of the human lower cervical spine (C4-C6) and took multipoint mechanical loading are scientific and effective. This provides a high accuracy model and scientific analysis method for the biomechanics research of the cervical spine.