BioCardioLab, Fondazione Toscana Gabriele Monasterio, Massa, Italy; Department of Information Engineering, University of Pisa, Pisa, Italy.
Department of Enterprise Engineering, University of Rome Tor Vergata, Rome, Italy.
Med Eng Phys. 2021 May;91:68-78. doi: 10.1016/j.medengphy.2020.09.005. Epub 2020 Sep 18.
Numerical simulations to evaluate thoracic aortic hemodynamics include a computational fluid dynamic (CFD) approach or fluid-structure interaction (FSI) approach. While CFD neglects the arterial deformation along the cardiac cycle by applying a rigid wall simplification, on the other side the FSI simulation requires a lot of assumptions for the material properties definition and high computational costs. The aim of this study is to investigate the feasibility of a new strategy, based on Radial Basis Functions (RBF) mesh morphing technique and transient simulations, able to introduce the patient-specific changes in aortic geometry during the cardiac cycle. Starting from medical images, aorta models at different phases of cardiac cycle were reconstructed and a transient shape deformation was obtained by proper activating incremental RBF solutions during the simulation process. The results, in terms of main hemodynamic parameters, were compared with two performed CFD simulations for the aortic model at minimum and maximum volume. Our implemented strategy copes the actual arterial variation during cardiac cycle with high accuracy, capturing the impact of geometrical variations on fluid dynamics, overcoming the complexity of a standard FSI approach.
数值模拟评估胸主动脉血流动力学包括计算流体动力学（CFD）方法或流固耦合（FSI）方法。虽然 CFD 通过应用刚性壁简化来忽略沿心动周期的动脉变形，但另一方面，FSI 模拟需要对材料特性定义和高计算成本进行大量假设。本研究的目的是研究一种新策略的可行性，该策略基于径向基函数 (RBF) 网格变形技术和瞬态模拟，能够在心动周期中引入主动脉几何形状的患者特异性变化。从医学图像出发，在心动周期的不同阶段重建了主动脉模型，并通过在模拟过程中适当激活增量 RBF 解来获得瞬态形状变形。主要血流动力学参数的结果与在最小和最大容积下对主动脉模型进行的两次 CFD 模拟进行了比较。我们实现的策略可以高精度地模拟心动周期中的实际动脉变化，捕捉几何变化对流体动力学的影响，克服标准 FSI 方法的复杂性。
