Red Blood Cell Motion and Hematocrit Distribution in a Deforming Capillary

Abstract

Based on the relation between the red blood cell velocity and the blood velocity of the Fahraeus effect, we analyze the motion of a red blood cell in a deforming capillary to investigate how the ventilatory induced deformation affects the transit of the red blood cell through the pulmonary capillary and changes the hematocrit discharged from the capillary. An analytical solution is also obtained for the case of an infinitesimal deformation. The numerical and analytic solutions demonstrate that the variation in discharge hematocrit is proportional to the change of pulmonary capillary blood volume between the time that the red cell enters and the time that it exits the capillary. We also find that this hematocrit variation could be regarded, in terms of transport, to originate from the mid-section of the capillary.