Nishida M, Yamane T, Asztalos B
Biomimetics Division, Mechanical Engineering Laboratory, Tsukuba, Ibaraki, Japan.
Artif Organs. 1998 May;22(5):386-92. doi: 10.1046/j.1525-1594.1998.06155.x.
Washout holes in the impeller of a centrifugal blood pump reduce thrombus formation in areas where blood is apt to stagnate, especially in the back gap of the impeller. In this study, flow through the washout holes is quantified by pressure measurement and flow visualization with a 300% scaled-up model to understand the force driving flow through the washout holes and the flow itself. When external circuit resistance is constant, pressure distribution normalized by the square of the tip speed is constant and independent of the impeller rotational speed. The ratio of the flow rate through the washout holes to the flow rate of the external circuit is also constant. When the external circuit resistance increases, the pressure difference at the washout holes between the front and back gap of the impeller increases and generates a greater flow rate through the washout holes.
离心式血泵叶轮中的冲洗孔可减少血液易于停滞区域的血栓形成，尤其是在叶轮的后间隙处。在本研究中，通过压力测量和使用放大300%的模型进行流动可视化来量化通过冲洗孔的流量，以了解驱动流体通过冲洗孔的力以及流体本身。当外部电路阻力恒定时，通过叶尖速度平方归一化的压力分布是恒定的，且与叶轮转速无关。通过冲洗孔的流量与外部电路流量之比也是恒定的。当外部电路阻力增加时，叶轮前后间隙处冲洗孔的压差增大，并产生更大的通过冲洗孔的流量。
