Institute of Structural Analysis, Graz University of Technology, Graz, Austria.
Institute of Computer Graphics and Vision, Graz University of Technology, Graz, Austria.
Int J Numer Method Biomed Eng. 2024 Nov;40(11):e3860. doi: 10.1002/cnm.3860. Epub 2024 Aug 29.
The article presents a semi-automatic approach to generating structured hexahedral meshes of patient-specific aortas ailed by aortic dissection. The condition manifests itself as a formation of two blood flow channels in the aorta, as a result of a tear in the inner layers of the aortic wall. Subsequently, the morphology of the aorta is greatly impacted, making the task of domain discretization highly challenging. The meshing algorithm presented herein is automatic for the individual lumina, whereas the tears require user interaction. Starting from an input (triangle) surface mesh, we construct an implicit surface representation as well as a topological skeleton, which provides a basis for the generation of a block-structure. Thereafter, the mesh generation is performed via transfinite maps. The meshes are structured and fully hexahedral, exhibit good quality and reliably match the original surface. As they are generated with computational fluid dynamics in mind, a fluid flow simulation is performed to verify their usefulness. Moreover, since the approach is based on valid block-structures, the meshes can be made very coarse (around 1000 elements for an entire aortic dissection domain), and thus promote using solvers based on the geometric multigrid method, which is typically reliant on the presence of a hierarchy of coarser meshes.
本文提出了一种半自动方法，用于生成由主动脉夹层引起的特定于患者的主动脉的结构化六面体网格。这种情况表现为主动脉内部层之间的撕裂导致两个血流通道的形成。随后，主动脉的形态受到很大影响，使得域离散化的任务极具挑战性。本文提出的网格算法对于各个管腔是自动的，而撕裂需要用户交互。从输入的（三角形）表面网格开始，我们构建一个隐式表面表示以及拓扑骨架，为块结构的生成提供基础。然后，通过超限映射进行网格生成。生成的网格是结构化的和全六面体的，具有良好的质量，并可靠地匹配原始表面。由于它们是为计算流体动力学而生成的，因此进行了流体流动模拟以验证其有用性。此外，由于该方法基于有效的块结构，因此可以将网格做得非常粗糙（整个主动脉夹层域约有 1000 个元素），从而促进使用基于几何多重网格方法的求解器，这通常依赖于更粗糙的网格层次结构的存在。
