Polygonal surface processing and mesh generation tools for the numerical simulation of the cardiac function

Abstract

In order to simulate the cardiac function for a patient‐specific geometry, the generation of the computational mesh is crucially important. In practice, the input is typically a set of unprocessed polygonal surfaces coming either from a template geometry or from medical images. These surfaces need ad‐hoc processing to be suitable for a volumetric mesh generation. In this work we propose a set of new algorithms and tools aiming to facilitate the mesh generation process. In particular, we focus on different aspects of a cardiac mesh generation pipeline: (1) specific polygonal surface processing for cardiac geometries, like connection of different heart chambers or segmentation outputs; (2) generation of accurate boundary tags; (3) definition of mesh‐size functions dependent on relevant geometric quantities; (4) processing and connecting together several volumetric meshes. The new algorithms—implemented in the open‐source software vmtk—can be combined with each other allowing the creation of personalized pipelines, that can be optimized for each cardiac geometry or for each aspect of the cardiac function to be modeled. Thanks to these features, the proposed tools can significantly speed‐up the mesh generation process for a large range of cardiac applications, from single‐chamber single‐physics simulations to multi‐chambers multi‐physics simulations. We detail all the proposed algorithms motivating them in the cardiac context and we highlight their flexibility by showing different examples of cardiac mesh generation pipelines.

Presence of Left Atrial Fibrosis May Contribute to Aberrant Hemodynamics and Increased Risk of Stroke in Atrial Fibrillation Patients

“…Due to the LA geometry preprocessing, extension of PVs, and LA volume meshing, the LA hemodynamic models did not align with the initially segmented LA geometries. Therefore, to accurately and efficiently register the initial LA segmentation to the final LA hemodynamic models, we employed a projection technique ( Regazzoni et al, 2020 ; Fedele and Quarteroni, 2021 ). In the framework of the VMTK library (28) ( Schroeder et al, 2004 ), we performed either a finite-element expansion or closest-point interpolation to project imaging data from the initial LA segmentation to the final LA hemodynamic volumetric mesh.…”

Electro-Mechanical Whole-Heart Digital Twins: A Fully Coupled Multi-Physics Approach

“…In the case of whole heart models, a semi-automatic workflow has been proposed by Strocchi et al [39]. However, a manual adjustment of the discretized model is still necessary and multiple tools are available to make this process more efficient (e.g., meshtool [83], vmtk [84]). Since anatomy is highly individualized, it is necessary to ensure the comparability between datasets.…”

Mathematical and numerical models for the cardiac electromechanical function

“…We generate the computational mesh using vmtk (https://www.vmtk. org) [4] and the recently proposed tools for cardiac mesh generation [25]. This computational mesh T h , diaplayed in Fig.…”