A spline-based hexahedral mesh generator for patient-specific coronary arteries

TL;DR

This paper introduces a novel spline-based hexahedral mesh generator tailored for complex coronary artery geometries, enabling accurate, high-quality meshes without post-processing, validated through simulations and quality assessments.

Contribution

The paper presents a new spline-based meshing technique for coronary arteries that handles complex geometries and bifurcations without surface reconstruction or smoothing.

Findings

Generated meshes meet quality standards for haemodynamics simulations.

The method outperforms existing mesh generators in complex vessel geometries.

Finite element simulations validate the accuracy of the generated meshes.

Abstract

This paper presents a spline-based hexahedral mesh generator for tubular geometries commonly encountered in haemodynamics studies, in particular coronary arteries. We focus on techniques for accurately meshing vessels with stenoses and aneurysms, as well as non-planar bifurcations. Our approach incorporates several innovations, including a spline-based description of the vessel geometry in both the radial and the longitudinal directions, the use of Hermite curves for modeling non-planar bifurcations, and a generalization to non-planar n intersecting branches. This method eliminates the need for a concrete vessel surface, grid smoothing, and other post-processing. A technique to generate grids with boundary layers is also presented. We validate the generated meshes using commonly employed quality indices, compare them against state-of-the-art mesh generators and apply our method to complex coronary trees. Finally, we present finite element fluid flow simulations with physiological boundary conditions. To validate the proposed framework, a wall-shear-stress-based convergence test and computations of haemodynamic indices are also presented.