Abstract：
This article describes the numerical efforts made to investigate the influence of a left ventricular assist device (LVAD) on the patient-specific left heart\'s hemodynamics. Two different computational geometries with left heart have been simulated over the entire cardiac cycle (case 1: healthy heart without LVAD and case 2: diseased heart with LVAD). The blood flow was simulated by implementing Bird-Carreau non-Newtonian model. Simulation results show that implantation of LVAD pump imparts major influence on the hemodynamics of the heart; it also provides a cardiac output of 4.87 L/min even at the diastolic phase. Furthermore, post LVAD implantation, approximately eight times more wall shear stress, is noticed at the aorta during the ventricular systole. In particular, major changes in the fluidics are observed inside the aortic region. A possibility of flow stagnation is noticed near the aortic root during the diastolic phase due to the bisection of incoming bloodstreams from the outflow graft. The flow characteristics of the LVAD pump are also observed to be significantly different from the idealized simulations (idealized tubular inlet situation). The observation of this study can help in understanding post-implant critical hemodynamic issues due to pump performance and its subsequent impact on the heart. A simulation approach-based study has been performed to investigate the influence of LVAD on the hemodynamics of a heart. A 3D computational model of a patient-specific heart has been created from CT scan datasets for diastole and systole phases (a). An axial flow blood pump has been implanted computationally into the left heart (b). The implanted blood pump enhances the cardiac output and elevates shear generation (c) and (d).
摘要：
本文介绍了为研究左心室辅助装置（LVAD）对患者特定左心血流动力学的影响而进行的数值研究。已经在整个心动周期上模拟了具有左心脏的两种不同的计算几何结构(情况1:没有LVAD的健康心脏和情况2:具有LVAD的患病心脏)。通过实施Bird-Carreau非牛顿模型来模拟血流。模拟结果表明，LVAD泵的植入会对心脏的血流动力学产生重大影响；即使在舒张期，它也可以提供4.87L/min的心输出量。此外，LVAD植入后,大约八倍以上的壁面剪应力，在心室收缩期间在主动脉处被注意到。特别是,在主动脉区域内观察到射流的主要变化。在舒张期，由于从流出移植物进入的血流被平分，在主动脉根部附近发现了血流停滞的可能性。还观察到LVAD泵的流动特性与理想化模拟(理想化管状入口情况)显著不同。这项研究的观察可以帮助理解植入后由于泵性能及其对心脏的后续影响而引起的关键血液动力学问题。已经进行了基于模拟方法的研究，以研究LVAD对心脏血液动力学的影响。已经从针对舒张期和收缩期的CT扫描数据集创建了患者特异性心脏的3D计算模型(a)。轴流血泵已通过计算植入左心(b)。植入的血泵增强了心输出量并提高了剪切产生(c)和(d)。
