Numerical model of total artificial heart hemodynamics and the effect of its size on stress accumulation.
Numerical model of total artificial heart hemodynamics and the effect of its size on stress accumulation.
复制标题
全人工心脏血流动力学的数值模型及其大小对应力积累的影响。
DOI：
10.1109/embc.2014.6944909
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Bluestein,Danny
中科院分区：
文献类型：
--
作者：
Marom,Gil;Chiu,Wei-Che;Slepian,MarvinJ;Bluestein,Danny
全人工心脏（TAH）是一种双心室机械循环支持装置，可替代终末期充血性心力衰竭患者的心脏。该器械通过气动激活横膈膜改变心室腔容积，起到血泵的作用。流入和流出心室由机械心脏瓣膜控制。本研究的目的是评价TAH的血流状态，并估计收缩期血栓形成的可能性。为了实现这一目标，三个不同尺寸的TAH的数值模型，包括变形的隔膜和血液从左室到主动脉的流动，被引入。一个多相模型与注射的血小板颗粒被用来计算他们的轨迹。沿着血小板轨迹计算三种模型中的剪切应力累积，并比较代表器械“血栓形成足迹”的概率密度函数。所计算的流态成功地捕获了二尖瓣返流以及在收缩期间打开和关闭主动脉瓣的流。在所有三种型号中均发现了生理速度幅度，预计较小器械的速度更高，应力累积增加。
The total artificial heart (TAH) is a bi-ventricular mechanical circulatory support device that replaces the heart in patients with end-stage congestive heart failure. The device acts as blood pump via pneumatic activation of diaphragms altering the volume of the ventricular chambers. Flow in and out of the ventricles is controlled by mechanical heart valves. The aim of this study is to evaluate the flow regime in the TAH and to estimate the thrombogenic potential during systole. Toward that goal, three numerical models of TAHs of differing sizes, that include the deforming diaphragm and the blood flow from the left chamber to the aorta, are introduced. A multiphase model with injection of platelet particles is employed to calculate their trajectories. The shear stress accumulation in the three models are calculated along the platelets trajectories and their probability density functions, which represent the `thrombogenic footprint' of the device are compared. The calculated flow regime successfully captures the mitral regurgitation and the flows that open and close the aortic valve during systole. Physiological velocity magnitudes are found in all three models, with higher velocities and increased stress accumulation predicted for smaller devices.