A reevaluation and discussion on the threshold limit for hemolysis in a turbulent shear flow.
One major factor of red blood cell damage induced by artificial heart valves is the magnitude of turbulent shear stresses in the flow field. An often-cited threshold for hemolysis is 400 N/m(2) (Sallam and Hwang, Biorheology 21 (1984) 783). This value, however, was measured with a one-component laser Doppler anemometer and was not calculated from the major principal Reynolds shear stress, therefore underestimating the threshold. This study performed flow field measurements under similar conditions, using a two-component laser Doppler anemometer and determining major principal Reynolds shear stress, to reevaluate the hemolytic threshold as 800 N/m(2) with an exposure time of 1 ms. The Kolmogorov length scales, approximately 9 microm, are capable of inflicting direct damage to the red blood cells. These results will serve as a more accurate reference in future heart valve design and testing.
Lu
P C
PC
Department of Water Resources, and Environmental Engineering, Tamkang University, Taipei 251, Taiwan, R.O.C. lupc@mail.tku.edu.tw
Lai
H C
HC
Liu
J S
JS
D001783:Blood Flow Velocity / Q000502:physiology; D006350:Heart Valve Prosthesis / Q000592:standards*; D006461:Hemolysis / Q000502:physiology*; D018056:Hemorheology / Q000295:instrumentation / Q000592:standards; D006801:Humans; D008422:Materials Testing / Q000295:instrumentation; D008954:Models, Biological; D013314:Stress, Mechanical