51黑料吃瓜在线观看,51黑料官网|51黑料捷克街头搭讪_51黑料入口最新视频

Objective This work focused on the hemodynamic (velocity, pressure, wall shear stress, vortex) effect of artificial heart blood pump on the left ventricle by the means of numerical simulation. Methods The left atrial pressure, aortic pressure and the left ventricular volume of the 3 situations (healthy, heart failure, assisted) were derived from the lumped parameter cardiovascular model, which was used as the boundary conditions. Then we used the volume data to build 3D geometry models of the 3 situations at end-systole phase. In the work, the hyper-elastic material Ogden was chosen to stand for myocardium. We carried out the numerical simulation by the means of computational fluid dynamics (CFD), compared the left ventricular pressure (LVP) in simulation and physiology, and the hemodynamic index between the heart failure (HF) and artificial heart blood pump assisted situations. The LVP and the velocity were used to evaluate the perfusion and ventricular unloading, while the wall shear stress (WSS) and vortex were used to evaluate the flow pattern. Results The LVP of the simulation and the physiology in healthy situation were the same. The pressure dropped 1788Pa and 1455Pa respectively in heart failure and assisted situations during the systole and the pressure drop speed was much higher in assisted situation. The peak WSS were 4.3Pa and 3.8Pa during diastole, 4.1Pa and 1.3Pa during systole in HF and assisted situations. The peak velocities were 1.61m/s and 0.68m/s in HF and assisted situations during systole, yet the duration of ejecting were 0.25s and 0.65s. As a result, the left ventricular ejection fraction (LVEF) increased from 43.6% to 52.7%. The existence duration of lower vortex increased from 0.35s to 0.51s in HF and assisted situations, and the blood separated from the upper vortex in assisted situation. Conclusions The LVP in simulation and physiology were the same, demonstrating the simulation method available. The artificial heart blood pump assisted can help to decrease the LVP and the ventricular load, extend the ejecting duration and improve perfusion. What’s more, it can reduce the WSS, enhance the vortex and extend the duration of vortex existence.