Arefin Md S, Morsi Yosry S
Biomechanical and Tissue Engineering Laboratory, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia,
Australas Phys Eng Sci Med. 2014 Jun;37(2):413-23. doi: 10.1007/s13246-014-0250-4. Epub 2014 Feb 26.
In this paper, the hemodynamic characteristics inside a physiologically correct three-dimensional LV model using fluid structure interaction scheme are examined under various heart beat conditions during early filling wave (E-wave), diastasis and atrial contraction wave (A-wave). The time dependent and incompressible viscous fluid, nonlinear viscous fluid and the stress tensor equations are coupled with the full Navier-Stoke's equations together with the Arbitrary Lagrangian-Eulerian and elasticity in the solid domain are used in the analysis. The results are discussed in terms of the variation in the intraventricular pressure, wall shear stress (WSS) and the fluid flow patterns inside the LV model. Moreover, changes in the magnitude of displacements on the LV are also observed during diastole period. The results obtained demonstrate that the magnitude of the intraventricle pressure is found higher in the basal region of the LV during the beginning of the E-wave and A-wave, whereas the Ip is found much higher in the apical region when the flow propagation is in peak E-wave, peak A-wave and diastasis. The magnitude of the pressure is found to be 5.4E2 Pa during the peak E-wave. Additionally, WSS elevates with the rise in the E-wave and A-wave but the magnitude decreases during the diastasis phase. During the peak E-wave, maximum WSS is found to be 5.7 Pa. Subsequent developments, merging and shifting of the vortices are observed throughout the filling wave. Formations of clockwise vortices are evident during the peak E-wave and at the onset of the A-wave, but counter clockwise vortices are found at the end of the diastasis and at the beginning of the A-wave. Moreover, the maximum magnitude of the structural displacement is seen in the ventricle apex with the value of 3.7E-5 m.
在本文中,利用流固相互作用方案,对一个生理结构正确的三维左心室模型在早期充盈波(E波)、舒张期和心房收缩波(A波)的各种心跳条件下的血流动力学特性进行了研究。将随时间变化的不可压缩粘性流体、非线性粘性流体和应力张量方程与完整的纳维-斯托克斯方程相耦合,并在分析中使用任意拉格朗日-欧拉方法和固体域中的弹性方程。根据左心室内压力、壁面剪应力(WSS)的变化以及左心室模型内部的流体流动模式对结果进行了讨论。此外,在舒张期还观察到左心室位移大小的变化。所得结果表明,在E波和A波开始时,左心室底部区域的心室内压力较高,而当血流传播处于E波峰值、A波峰值和舒张期时,心尖区域的压力要高得多。在E波峰值时,压力大小为5.4E2 Pa。此外,WSS随着E波和A波的上升而升高,但在舒张期阶段其大小会减小。在E波峰值时,最大WSS为5.7 Pa。在整个充盈波过程中观察到了涡旋的后续发展、合并和移动。在E波峰值和A波开始时,顺时针涡旋的形成很明显,但在舒张期末和A波开始时发现了逆时针涡旋。此外,心室心尖处的结构位移最大幅值为3.7E-5 m。