腰椎活动节段精确有限元模型的建立(英文)  

An Accurately Represented Finite Element Model of Lumbar Motion Segment

作　　者：刘耀升[1] 陈其昕[1] 李方财[1] 唐小君[1] 方杰[1] 廖胜辉[2] 余世策[3] 

机构地区：[1]浙江大学医学院附属第二医院骨科研究所,浙江杭州310009 [2]State Key Laboratory of CAD and CG,Department of Computer Science and Engineering,Zhejiang University [3]Structural Engineering Institute,College of Architecture Engineering,Zhejiang University

出　　处：《航天医学与医学工程》2007年第2期79-86,共8页Space Medicine & Medical Engineering

基　　金：Supported by Research Founds of Ministryof Health,China.WKJ2005-Z-046

摘　　要：目的采用一种新型CAD方法用CT资料精确建立腰椎L4-L5节段三维非线性有限元模型。方法用一种改良的“非种子区域分割方法”提取腰椎目标区域得到二值图像;再用反应腰椎曲度的“最佳切割平面”从初始表面模型获得非平行的切割轮廓线并建立“分段线性子空间”;后者经仿射变换到“规则子空间”后快速重构腰椎曲面,最后经逆变换恢复原三维空间的形状特征。将L4-L5节段表面模型所有结点的坐标数据和三角面片信息导入ANSYS进行网格划分。结果所构建的有限元模型包含L4-L5节段所有重要解剖结构,压缩、屈曲、伸直载荷下有限元模型的预测结果与实验生物力学结果相符合。结论包含先进算法的CAD技术实现了腰椎复杂几何模型的快速、精确建模。Objective To construct a detailed, 3-dimensional, anatomically accurate finite element （FE） model of lumbar L4-L5 segment from CT data with a new kind of computer aided design （CAD） method. Methods A modified ＂no-seed region segmentation＂ was done to extract the interest region in the CT scan images and produce a binary image. ＂Best cross-section planes＂ accounting for the preferential direction dictated by lumbar spine were placed on the initial iso-surface model, forming a ＂non-regular piecewise subspace＂. This subspace and the embedded iso-surface mode were transformed by local affine transforms to a ＂regular subspace＂, in which a surface mesh of high quality was generated quickly. Finally a reverse transform procedure was employed to recover the shape feature of the lumbar surface mesh of lumbar L4-L5 in the original 3-dimensional space, which was then imported into ANSYS for the 3-dimensional FE mesh construction. Results All complicated anatomical features of the L4-L5 segment were explicitly represented in the unprecedented finite element model. The predicted results for compression, flexion and extension correlated well with experimental data under similar loading configurations. Conclusion The presented CAD method containing advanced algorithm implements fast and accurate simulation of such complicated geometry with fine mesh representation for lumbar FE analysis.

关 键 词：生物力学 腰椎 有限元模型 建模 算法 

分 类 号：R319[医药卫生—基础医学]