a Mechanical & Power Engineering College , Harbin University of Science and Technology , Harbin , China.
Comput Assist Surg (Abingdon). 2017 Dec;22(sup1):212-220. doi: 10.1080/24699322.2017.1389399. Epub 2017 Oct 23.
The objective of this work was to obtain high-quality mesh generation results for the human hip. This study adopted an edge-collapse algorithm based on quadric error metrics to simplify the hip model. The adjacent triangular areas and a cost function that considered the mean value of error were introduced to avoid error accumulation and ensure invariant geometric features. Local mesh refinement was achieved by constructing a comprehensive size field. Finally, high-quality surface and volume meshes were generated using the advancing-front technique (AFT) and Delaunay algorithms. Two human hipbones, 13 muscles, and one articular cartilage sample were modelled. The hip model was simplified and the mesh was generated using the method proposed in this study. The smallest angle of most surface mesh elements was greater than 45°, and the triangular numbers in this optimal angle interval were superior to those generated by the AFT algorithms. Eight quality evaluation parameters of the mesh model were tested using the check-elems tool. The femoral meshing results in this work were more accurate than those obtained with the AFT algorithms. The results of the vastus lateralis mesh generation were superior to the results obtained with the existing algorithm, except for the volume skew parameter. The proportions for the high-quality tetrahedral elements obtained using Wang's algorithm for the femur and the vastuslateralis muscle were 17.81% and 24.50%, respectively. The proportions obtained using the hypermesh software were 16.31% and 22.87% for the femoral and vastuslateralis models, respectively. The proposed method had better adaptability to the complex model. The generated mesh was uniform and contained smooth transitions. The mesh generation result was similar to the original geometric model, which made the assembly model fit more accurately. This was significant for the convergence of the finite-element analysis program.
本工作旨在为人体髋关节生成高质量的网格。为此，采用基于二次误差度量的边折叠算法对髋关节模型进行简化。引入相邻三角形区域和考虑误差均值的代价函数，避免了误差积累并确保了不变的几何特征。通过构建全面的尺寸场实现局部网格细化。最后，使用推进前沿技术（AFT）和 Delaunay 算法生成高质量的表面和体网格。构建了两个人体髋骨、13 块肌肉和一个关节软骨样本模型。采用本文提出的方法对髋骨模型进行简化并生成网格。大多数表面网格元素的最小角大于 45°，且在最优角度区间内的三角形数量优于 AFT 算法生成的数量。使用 check-elems 工具测试了网格模型的 8 个质量评估参数。与 AFT 算法相比，本工作中股骨的网格生成结果更加精确。股外侧肌的网格生成结果除体积翘曲参数外，均优于现有算法。Wang 算法生成的高质量四面体单元在股骨和股外侧肌中的比例分别为 17.81%和 24.50%。hypermesh 软件生成的股骨和股外侧肌模型的比例分别为 16.31%和 22.87%。与现有算法相比，该方法对复杂模型具有更好的适应性。生成的网格均匀且具有平滑过渡。网格生成结果与原始几何模型相似，使得装配模型更加贴合，这对有限元分析程序的收敛性具有重要意义。
