Tsukiya Tomonori, Taenaka Yoshiyuki, Tatsumi Eisuke, Takano Hisateru
Department of Artificial Organs, National Cardiovascular Center of Japan.
ASAIO J. 2002 Jan-Feb;48(1):76-82. doi: 10.1097/00002480-200201000-00015.
To reduce the possible thrombogenicity of the pump studied, pump characteristics and washout conditions were compared between a pump with a semi-open and a pump with a full-open impeller. A difference in hydrodynamic performance was observed between the semi-open impeller and the full-open impeller; the pressure in the former was less by approximately 10%, and the maximum attainable efficiency decreased from 0.41 to 0.34. The flow pattern, as visualized by the oil film method, showed that the washout condition was enhanced by addition of the shroud, especially at the bottom region of the pump where the blood flow tended to be stagnant. The stagnant area was observed in the suction side of the impeller in both models, where the vortices shed from the impeller tip contributed to the washout. It was also shown that the flow entering the bottom region was circumferentially uniform in the full-open impeller, whereas in the semi-open impeller the flow was not uniform and entered primarily from the vicinity of the outlet port. The semi-open impeller, thus, was demonstrated to have better washout conditions than the full-open impeller regardless of a slight decrease in hydrodynamic efficiency.
为降低所研究泵的潜在血栓形成性，对具有半开式叶轮的泵和具有全开式叶轮的泵的泵特性及冲洗条件进行了比较。观察到半开式叶轮和全开式叶轮在流体动力性能方面存在差异；前者的压力约低10%，最大可达效率从0.41降至0.34。通过油膜法可视化的流动模式表明，添加护罩可增强冲洗条件，尤其是在泵的底部区域，此处血流往往趋于停滞。在两种模型的叶轮吸入侧均观察到停滞区域，叶轮尖端脱落的涡流有助于冲洗。还表明，进入底部区域的流动在全开式叶轮中沿周向均匀，而在半开式叶轮中流动不均匀，主要从出口端口附近进入。因此，尽管流体动力效率略有下降，但半开式叶轮的冲洗条件优于全开式叶轮。
