Design and transient computational fluid dynamics study of a continuous axial flow ventricular assist device
Design and transient computational fluid dynamics study of a continuous axial flow ventricular assist device
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DOI：
10.1097/01.mat.0000124954.69612.83
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发表时间：
2004-05-01
期刊：
影响因子：
4.2
通讯作者：
Olsen, DB
中科院分区：
文献类型：
--
作者：
Song, XW;Untaroiu, A;Olsen, DB
本文从机械的角度设计和研究了一种小型化的轴流泵--室助器。它由引进器、叶轮和扩散器组成。该VAD的主要设计目标是生产一种具有流线型、理想化和畅通性血流路径的轴流泵。对磁力轴承进行了调整，使叶轮完全磁悬浮。由于叶轮的旋转运动和脉动的进口流量，VAD在瞬变条件下运行。给出了设计方法、步骤和迭代次数。用计算流体力学(CFD)方法研究了VAD在暂态条件下的性能。在CFD模拟中实现了旋转和静止两种参考系。在计算过程中，叶轮的进口表面和出口表面分别与导流板和扩散器相连，允许旋转和滑动，以模拟叶轮的真实旋转运动。测定了流量水头曲线，给出了心动周期(包括收缩和舒张期)内压力分布的变化。在磁悬浮轴承设计中，对叶轮的轴向振动也进行了估算。与稳态模拟相比，瞬变CFD模拟需要更多的计算机资源和计算工作量，它为VAD的性能提供了一个范围，而不仅仅是一个点。由于叶轮的脉动流动现象和虚拟旋转运动，与VAD体内植入场景真实相关的暂态模拟是确保VAD设计有效和可靠的关键。ASAIO Journal 2004；50：215-224。
A ventricular assist device (VAD), which is a miniaturized axial flow pump from the point of view of mechanism, has been designed and studied in this report. It consists of an inducer, an impeller, and a diffuser. The main design objective of this VAD is to produce an axial pump with a streamlined, idealized, and nonobstructing blood flow path. The magnetic bearings are adapted so that the impeller is completely magnetically levitated. The VAD operates under transient conditions because of the spinning movement of the impeller and the pulsatile inlet flow rate. The design method, procedure, and iterations are presented. The VAD's performance under transient conditions is investigated by means of computational fluid dynamics (CFD). Two reference frames, rotational and stationary, are implemented in the CFD simulations. The inlet and outlet surfaces of the impeller, which are connected to the inducer and diffuser respectively, are allowed to rotate and slide during the calculation to simulate the realistic spinning motion of the impeller. The flow head curves are determined, and the variation of pressure distribution during a cardiac cycle (including systole and diastole) is given. The axial oscillation of impeller is also estimated for the magnetic bearing design. The transient CFD simulation, which requires more computer resources and calculation efforts than the steady simulation, provides a range rather than only a point for the VAD's performance. Because of pulsatile flow phenomena and virtual spinning movement of the impeller, the transient simulation, which is realistically correlated with the in vivo implant scenarios of a VAD, is essential to ensure an effective and reliable VAD design. ASAIO Journal 2004; 50:215-224.