University of Toronto, Institute of Biomaterials and Biomedical Engineering, Toronto, Ontario, Canada.
Int J Numer Method Biomed Eng. 2013 Jan;29(1):104-13. doi: 10.1002/cnm.2500. Epub 2012 Jul 10.
Robust generation of pelvic finite element models is necessary to understand the variation in mechanical behaviour resulting from differences in gender, aging, disease and injury. The objective of this study was to apply and evaluate mesh morphing and mapping techniques to facilitate the creation and structural analysis of specimen-specific finite element (FE) models of the pelvis. A specimen-specific pelvic FE model (source mesh) was generated following a traditional user-intensive meshing scheme. The source mesh was morphed onto a computed tomography scan generated target surface of a second pelvis using a landmarked-based approach, in which exterior source nodes were shifted to target surface vertices, while constrained along a normal. A second copy of the morphed model was further refined through mesh mapping, in which surface nodes of the initial morphed model were selected in patches and remapped onto the surfaces of the target model. Computed tomography intensity based material properties were assigned to each model. The source, target, morphed and mapped models were analyzed under axial compression using linear static FE analysis and their strain distributions evaluated. Morphing and mapping techniques were effectively applied to generate good quality geometrically complex specimen-specific pelvic FE models. Mapping significantly improved strain concurrence with the target pelvis FE model.
为了理解由于性别、年龄、疾病和损伤等差异导致的机械行为变化，需要生成稳健的骨盆有限元模型。本研究的目的是应用和评估网格变形和映射技术，以方便创建和进行骨盆特定于标本的有限元（FE）模型的结构分析。采用传统的用户密集型网格划分方案生成了一个骨盆特定于标本的 FE 模型（源网格）。使用基于标志点的方法，将源网格变形到第二个骨盆的计算机断层扫描生成的目标表面上，其中外部源节点沿法向移动到目标表面顶点，同时受到约束。通过网格映射进一步细化第二个变形模型，其中初始变形模型的表面节点被选择为补丁，并重新映射到目标模型的表面上。为每个模型分配了基于计算机断层扫描强度的材料属性。对源、目标、变形和映射模型进行轴向压缩的线性静态有限元分析，并评估其应变分布。变形和映射技术有效地应用于生成高质量的几何复杂的骨盆特定于标本的 FE 模型。映射显著提高了与目标骨盆 FE 模型的应变一致性。
