全颈椎有限元模型的建立与验证

Establishment and validation of a three-dimensional finite element model of the cervical spine

背景:有限元分析作为数值计算中的一种离散化方法,具有实验时间短、费用少、对身体无任何破坏、力学性能测试全面及可重复实验等突出优点。以往研究多将其集中应用于腰椎模型,由于颈椎解剖结构及损伤机制复杂,稳定性差等原因,颈椎有限元模型研究不多,并且研究只局限于单椎体和运动节段。目的:建立更为真实、有效的全颈椎三维有限元模型,用于临床生物力学研究。方法:对1名既往无颈椎病史健康男性志愿者的颈椎进行CT扫描成像,应用CAD造型软件Solid-Works2003、HyperMesh软件和ANSYS11.0软件,采用四面体网格划分方法,对颈椎周围组织赋予不同的材料特性,引入接触理论和非线性结构计算方法,建立全颈椎有限元模型。在所建模型上加载模拟脊柱的前屈、后伸、左右侧屈、左右旋转6种工况下的生理活动,并与生物力学实验数据进行对比。结果与结论:所建模型共有97705个节点,372896个单元。所建立模型在前屈/后伸、左右侧弯、左右旋转6种方向的运动范围,理论分析结果与生物力学实测数据高度一致。证实建立的全颈椎三维有限元模型细腻有效,具有良好的生物逼真度,可应用于临床生物力学分析。

BACKGROUND：Finite element analysis,as a numerical calculation of a discrete method,is characterized by short experimental time,less cost,comprehensive mechanical performance test and repeatable experiments.But more focused on the lumbar spine model for the study,due to anatomy and injury mechanisms of cervical complex,poor stability,there are few studies on cervical spine finite element model,and research is limited to a single vertebra and the motion segment. OBJECTIVE：To establish the cervical three-dimensional finite element model and it will be used for clinical study. METHODS：A three dimensional finite element model of the cervical spine was established from the CT scan images of a cadaver cervical spin,Solid-Works2003,HyperMesh and ANSYS11.0.Different material was assigned different mechanical parameter,and we created a cervical three-dimensional finite element model.After setting the boundary,the model is loaded to simulate the flexion/extension,left/right bending and rotating.The relationship of movement and displacement will compare with the results of experiment in vitro. RESULTS AND CONCLUSION：The model has 372 896 solid elements and 97 705 points.Established model in flexion/extension,left/right lateral bending,left/right rotation range of motion in six directions,theoretical analysis results and measured data were highly consistent in biomechanics.Results of analysis of finite element and other experiment results have good coincidence and the method can be used to establish the model of the living cervical spine.