Shear stress related blood damage in laminar couette flow.

摘要: Artificial organs within the blood stream are generally associated with flow-induced damage, particularly hemolysis of red cells. These damaging effects known to be dependent on shear forces and exposure times. The determination a correlation between these flow-dependent properties actual is subject this study. For purpose, Couette device has been developed. A fluid seal based fluorocarbon used separate from secondary external damage effects. rate gap controlled by rotational speed inner cylinder, time amount that axially pumped through per given time. Blood quantified index (IH), which calculated photometric plasma hemoglobin measurements. Experiments conducted at times texp=25 - 1250 ms rates ranging tau=30 up 450 Pa ensuring Taylor-vortex free flow characteristics. remarkably low over broad range However, significant increase in can observed for stresses tau>or= 425 texp>or= 620 ms. Maximum investigated IH=3.5%. results indicate lower than reported earlier studies comparable devices, measurements clearly rather abrupt (i.e., critical levels times) gradual hemolysis, least