We describe an approach to construct hexahedral solid NURBS (Non-Uniform Rational B-Splines) meshes for patient-specific vascular geometric models from imaging data for use in isogeometric analysis. First, image processing techniques, such as contrast enhancement, filtering, classification, and segmentation, are used to improve the quality of the input imaging data. Then, lumenal surfaces are extracted by isocontouring the preprocessed data, followed by the extraction of vascular skeleton via Voronoi and Delaunay diagrams. Next, the skeleton-based sweeping method is used to construct hexahedral control meshes. Templates are designed for various branching configurations to decompose the geometry into mapped meshable patches. Each patch is then meshed using one-to-one sweeping techniques, and boundary vertices are projected to the lumenal surface. Finally, hexahedral solid NURBS are constructed and used in isogeometric analysis of blood flow. Piecewise linear hexahedral meshes can also be obtained using this approach. Examples of patient-specific arterial models are presented.

中文翻译：

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用于血流等几何分析的患者特定血管 NURBS 建模


我们描述了一种根据成像数据为患者特定的血管几何模型构建六面体实体 NURBS（非均匀有理 B 样条）网格的方法，用于等几何分析。首先，使用对比度增强、滤波、分类和分割等图像处理技术来提高输入成像数据的质量。然后，通过对预处理数据进行等值轮廓提取管腔表面，然后通过 Voronoi 和 Delaunay 图提取血管骨架。接下来，使用基于骨架的扫描方法构建六面体控制网格。模板专为各种分支配置而设计，可将几何体分解为映射的可网格化面片。然后使用一对一扫描技术对每个面片进行网格划分，并将边界顶点投影到管腔表面。最后，构建六面体实体 NURBS 并将其用于血流的等几何分析。使用这种方法也可以获得分段线性六面体网格。提供了患者特异性动脉模型的示例。