Continuous Flow Left Ventricular Assist Devices (CF-LVADs) generally operate at a constant speed whilst supporting a failing heart. However, constant speed CF-LVAD support may cause complications and increase the morbidity rates in the patients. Therefore, different varying speed operating modes for CF-LVADs have been proposed to generate more physiological blood flow, which may reduce complication rates under constant speed CF-LVAD support. The proposed varying speed CF-LVAD algorithms simulate time-dependant dynamics and three dimensional blood flow patterns in aorta under varying speed CF-LVAD support remain unclear. The aim of this study is to evaluate three dimensional blood flow patterns in a patient-specific aorta model under co-pulsating and counter-pulsating CF-LVAD support modes driven by speed and flow rate control algorithms using numerical simulations. Aortic blood flow was evaluated for 10,000 rpm constant speed CF-LVAD support generating 4.71 L/min mean flow rate over a cardiac cycle. Co-pulsating and counter-pulsating CF-LVAD speed control operated the pump at the same average speed over a cardiac cycle and co-pulsating and counter-pulsating CF-LVAD flow rate control generated the same average flow rate over cardiac cycle as in the constant speed pump support. Simulation results show that the utilised counter-pulsating pump flow rate control may decrease the haemolysis to a third compared to the most commonly employed constant speed pump operating mode. Moreover, CF-LVAD support utilising counter-pulsating pump flow rate control generated the most favourable hemodynamic characteristics, i.e. low Dean number, least wall shear stress and least haemolysis values among the investigated cases.

连续流左心室辅助设备（CF-LVAD）通常以恒定速度运行，同时支持心脏衰竭。但是，恒速CF-LVAD支持可能会导致并发症并增加患者的发病率。因此，已经提出了用于CF-LVAD的不同变速操作模式以产生更多的生理血流，这可以降低在恒速CF-LVAD支持下的并发症发生率。所提出的变速CF-LVAD算法模拟时变动力学，并且在变速CF-LVAD支持下主动脉中的三维血流模式仍然不清楚。这项研究的目的是在数值和速度控制算法驱动的共脉动和反脉动CF-LVAD支持模式下，评估患者特定主动脉模型中的三维血流模式。在10,000 rpm恒速CF-LVAD支架上评估主动脉血流量，在整个心动周期内产生4.71 L / min的平均流速。脉动和反脉动CF-LVAD速度控制在心动周期内以相同的平均速度运行泵，而脉动和反脉动CF-LVAD流量控制在心动周期内产生的平均流量与泵相同。恒速泵支持。仿真结果表明，与最常用的恒速泵运行模式相比，采用的反脉冲泵流量控制可将溶血降至三分之一。此外，在研究案例中，利用反脉冲泵流量控制的CF-LVAD支持产生了最有利的血液动力学特征，即低Dean数，最小壁切应力和最小溶血值。