Artificial Organ Research Group, Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba, Ibaraki, 305-8564, Japan.
J Artif Organs. 2021 Jun;24(2):157-163. doi: 10.1007/s10047-020-01240-6. Epub 2021 Jan 11.
We have developed a hydrodynamically levitated centrifugal blood pump. In the blood pump having hydrodynamic bearings, the narrow bearing gap has a potential for high hemolysis. The purpose of the this study is to improve hemolysis performance in a hydrodynamically levitated centrifugal blood pump by optimizing a shroud size. The impeller was levitated passively at the position where the thrust forces acting on the impeller were balanced. We focused on a size of a bottom shroud with a hydrodynamic bearing that could change the bottom hydrodynamic force to balance the thrust force at the wide bearing gap for reducing hemolysis. Five test models with various shroud size were compared: 989 mm (HH-10.5), 962 mm (HH-12), 932 mm (HH-13.5), 874 mm (HH-16), and 821 mm (HH-18). A numerical analysis was first performed to estimate the bearing gaps in the test model. The bearing gaps were then measured to validate the numerical analysis. Finally, an in vitro hemolysis test was performed. The numerical analysis revealed that the HH-13.5 model had the widest bearing gap of 129 µm. In the measurement test, the estimation error for the bearing gap was less than 10%. In the hemolysis test, the HH-13.5 model achieved the lowest hemolysis level among the five models. The present study demonstrated that the numerical analysis was found to be effective for determining the optimal should size, and the HH-13.5 model had the optimal shroud size in the developed hydrodynamically levitated centrifugal blood pump to reduce hemolysis.
我们开发了一种液力悬浮离心血泵。在具有液力轴承的血泵中，狭窄的轴承间隙具有产生高溶血的潜力。本研究的目的是通过优化叶轮护罩尺寸来改善液力悬浮离心血泵的溶血性能。叶轮在作用于叶轮的推力平衡的位置上被动悬浮。我们专注于具有液力轴承的底护罩的尺寸，该尺寸可以改变底液动力，以平衡宽轴承间隙处的推力，从而降低溶血。比较了五种具有不同护罩尺寸的测试模型：989mm（HH-10.5）、962mm（HH-12）、932mm（HH-13.5）、874mm（HH-16）和 821mm（HH-18）。首先进行数值分析以估算测试模型中的轴承间隙。然后测量轴承间隙以验证数值分析。最后进行体外溶血测试。数值分析表明 HH-13.5 模型具有最宽的 129µm 轴承间隙。在测量测试中，轴承间隙的估计误差小于 10%。在溶血测试中，五个模型中 HH-13.5 模型的溶血水平最低。本研究表明，数值分析对于确定最佳护罩尺寸是有效的，并且在开发的液力悬浮离心血泵中，HH-13.5 模型具有最佳的护罩尺寸，可以降低溶血。
