Low stress shear-induced hemolysis in capillary flow.

: An experimental investigation was undertaken to evaluate shear-induced blood damage behavior in capillaries within the clinically relevant low-stress regime (stress less than 300 dynes/cm2). As a result of these studies, it was determined that: blood damage increases most rapidly during the initial seconds of capillary residence time and then increases more slowly thereafter; there is a minimum capillary length through which red blood cells must travel, before any significant leakage of hemoglobin occurs; capillary blood damage correlates with wall shear rate as H alpha gamma . n, where the exponent depends on the blood sample tested; experimental results for the largest capillary tested indicated a blood cell damage mechanism based on 2 competing factors: a) time of shearing and b) shearing intensity level; the theoretical model developed to describe capillary blood damage is in good agreement with the experimental results. The blood damage model is discussed in another report and is based on the simultaneous contribution of surface and bulk hydrodynamic and mass transfer effects.