Murashige Tomotaka, Kosaka Ryo, Sakota Daisuke, Nishida Masahiro, Kawaguchi Yasuo, Yamane Takashi, Maruyama Osamu
Annu Int Conf IEEE Eng Med Biol Soc. 2015;2015:270-3. doi: 10.1109/EMBC.2015.7318352.
We have developed a hydrodynamically levitated centrifugal blood pump for extracorporeal circulatory support. In the blood pump, a spiral groove bearing was adopted for a thrust bearing. In the spiral groove bearing, separation of erythrocytes and plasma by plasma skimming has been postulated to occur. However, it is not clarified that plasma skimming occurs in a spiral groove bearing. The purpose of this study is to verify whether plasma skimming occurs in the spiral groove bearing of a hydrodynamically levitated centrifugal blood pump. For evaluation of plasma skimming in the spiral groove bearing, an impeller levitation performance test using a laser focus displacement meter and a microscopic visualization test of erythrocyte flow using a high-speed microscope were conducted. Bovine blood diluted with autologous plasma to adjust hematocrit to 1.0% was used as a working fluid. Hematocrit on the ridge region in the spiral groove bearing was estimated using image analysis. As a result, hematocrits on the ridge region with gaps of 45 μm, 31 μm, and 25 μm were calculated as 1.0%, 0.6%, and 0.3%, respectively. Maximum skimming efficiency in this study was calculated as 70% with a gap of 25 μm. We confirmed that separation of erythrocyte and plasma occurred in the spiral groove bearing with decrease in bearing gap in a hydrodynamically levitated centrifugal blood pump.
我们开发了一种用于体外循环支持的流体动力学悬浮离心式血泵。在该血泵中，采用了螺旋槽轴承作为推力轴承。在螺旋槽轴承中，据推测会发生通过血浆撇取使红细胞与血浆分离的现象。然而，螺旋槽轴承中是否发生血浆撇取尚不清楚。本研究的目的是验证流体动力学悬浮离心式血泵的螺旋槽轴承中是否发生血浆撇取。为了评估螺旋槽轴承中的血浆撇取情况，使用激光聚焦位移计进行了叶轮悬浮性能测试，并使用高速显微镜对红细胞流动进行了微观可视化测试。用自体血浆稀释牛血以将血细胞比容调整至1.0%作为工作流体。使用图像分析估计螺旋槽轴承脊区域的血细胞比容。结果，间隙为45μm、31μm和25μm的脊区域的血细胞比容分别计算为1.0%、0.6%和0.3%。本研究中的最大撇取效率在间隙为25μm时计算为70%。我们证实，在流体动力学悬浮离心式血泵中，随着轴承间隙减小，螺旋槽轴承中发生了红细胞与血浆的分离。
