摘要
目的:采取三维有限元的方法,建立脊柱颈胸结合部有限元模型,给予纯力矩载荷测试模型各FSU的正常运动范围,验证模型的有效性并对其应力分布模式进行探讨。方法:利用螺旋CT连续扫描获得正常成年人颈胸部原始DICOM数据图像,采用Mimics软件进行数据处理后导入ANSYS软件,得到颈胸结合部模型骨性结构的三维实体。添加椎间盘和主要韧带结构,椎间盘采用壳-核单元,分别代表纤维环与髓核;韧带采用2节点缆索单元构造,韧带的起止点及横截面积根据参考文献确定。C6-7以及C7-T1关节突关节均定义为有摩擦系数的非线性接触关节。模型中T1下表面在所有方向上完全固定,在模型C6施加2.0Nm纯力矩,对模型进行屈曲、背伸、侧屈及轴向旋转试验,试验结果与体外生物力学试验进行对比验证。结果:所建的颈胸模型包括169317个节点和106242个单元,并且与体外生物力学试验结果基本吻合,能够通过验证,有限元受力云图可以看出,模型在外力作用下运行状况良好。结论:该试验为临床医生对脊柱颈胸交界区的三维有限元模型的建立提供了一种便捷而精确的方法,为计算机分析及研究该模型局部结构在各种受力情况下的生物力学表现创造了条件。
Objective：To establish the cervicothoracic spine finite element model with three-dimensional finite element method,verify the effectiveness of this model and explore the stress distribution. Methods： DICOM image data of one normal healthy young male volunteer were obtained by spiral CT scan and processed with Mimics software. Datas were imported to ANSYS software to become a 3D entity. Disc structure and the main ligament were added. Disc structure was added using the shell-nuclear unit,representing the annulus fibrosus and nucleus pulposus. Ligament structure was established with 2-node cable element, the beginning and ending points of the ligament and the cross-sectional area were determined in accordance with references. C6,7 and CTTI facet joints were definded as the nonliner contact joints with friction coefficient. The lower surface of TI in all the directions was completely fixed in this model. In the model 2.0 Nm pure torque were imposed on C6,and the extension, flexion, axial rotation and lateral bending experiment were conducted. The experimental results were compared with the in vitro biomeehanical tests. Results：The cervieothoracie spine finite element model included 169 317 nodes and 106 242 units,and consistent with the in vitro biomechanical tests. The three-dimensional finite element model was in good running under external force. Conclusion：h is a convenient and precise method for physicians to establish the finite element model of the eervieothoracic junction. This method facilitates the computer study on the biomeehanical behavior of the local structures of the model under various pressure conditions.
出处
《中国骨伤》
CAS
2010年第1期5-8,共4页
China Journal of Orthopaedics and Traumatology
关键词
颈椎
胸椎
有限元分析
生物力学
Cervical vertebrae
Thoracic vertebrae
Finite element analysis
Biomechanics
