mathLab, Area di Matematica, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy.
mathLab, Area di Matematica, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy; Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, Brescia, Italy.
Med Eng Phys. 2022 Sep;107:103849. doi: 10.1016/j.medengphy.2022.103849. Epub 2022 Jul 11.
Left ventricular assist devices (LVADs) are used to provide haemodynamic support to patients with critical cardiac failure. Severe complications can occur because of the modifications of the blood flow in the aortic region. In this work, the effect of a continuous flow LVAD device on the aortic flow is investigated by means of a non-intrusive reduced order model (ROM) built using the proper orthogonal decomposition with interpolation (PODI) method based on radial basis functions (RBF). The full order model (FOM) is represented by the incompressible Navier-Stokes equations discretized by using a Finite Volume (FV) technique, coupled with three-element Windkessel models to enforce outlet boundary conditions in a multi-scale approach. A patient-specific framework is proposed: a personalized geometry reconstructed from Computed Tomography (CT) images is used and the individualization of the coefficients of the three-element Windkessel models is based on experimental data provided by the Right Heart Catheterization (RHC) and Echocardiography (ECHO) tests. At FOM level, we also consider the pre-surgery configuration in order to further validate the predictive capabilities of the model in several contexts. The ROM has been tested by considering a parametric setting with respect to the LVAD flow, which is a crucial parameter of the problem. We consider a parameter range that covers typical clinical values. The accuracy of the ROM is assessed against results obtained with the FOM both for primal, velocity and pressure, and derived quantities, wall shear stress (WSS). Finally, we briefly discuss the efficiency of our ROM approach.
左心室辅助装置（LVAD）用于为严重心力衰竭患者提供血液动力学支持。由于主动脉区域血流的改变，可能会发生严重的并发症。在这项工作中，使用基于径向基函数（RBF）的本征正交分解插值（PODI）方法构建的非侵入性降阶模型（ROM）来研究连续流 LVAD 装置对主动脉流的影响。全阶模型（FOM）由不可压缩 Navier-Stokes 方程表示，通过有限体积（FV）技术离散化，并结合三元件 Windkessel 模型以多尺度方法强制执行出口边界条件。提出了一种患者特定的框架：使用从计算机断层扫描（CT）图像重建的个性化几何形状，并且三元件 Windkessel 模型的系数的个性化基于右心导管（RHC）和超声心动图（ECHO）测试提供的实验数据。在 FOM 级别，我们还考虑了手术前的配置，以便在多个上下文中进一步验证模型的预测能力。ROM 通过考虑与 LVAD 流量有关的参数设置进行了测试，这是该问题的关键参数。我们考虑了一个涵盖典型临床值的参数范围。ROM 的准确性通过与 FOM 针对原始、速度和压力以及衍生量（壁面剪切应力（WSS））获得的结果进行评估。最后，我们简要讨论了我们的 ROM 方法的效率。
