A Biomechanical Approach for the Study of Deformation of Red Cells in Narrow Capillaries

This model focuses on the behavior of capillary-tissue fluid exchange system when the diameter of the capillary is less than that of red cell. In vivo and in vitro observations indicate that the width of the gapbetween the red cell and the vessel wall is generally small compared to the radius of the capillary for a single file flow of red cell in narrow vessel, particularly if the vessel diameter is less than about 6 mm through squeezing flow of plasma in the gap between a cell moving through a capillary of smaller diameter than that of the cell. The study reveals the results for the resistance to flow for differentvalues of deformed red cell shapes, cell velocities and permeability. The analysis concludes that the resistance to flow decreases as permeability decreases. Because of these changes, tissues behaves like an impermeable surface. It has been shown that the resistance to flow in gap decreases as cell velocityincreases. The significance of the present model over the existing models has been pointed out by comparing the results with other theories both analytically and numerically. This information could be useful in the development of new diagnosis tools for many diseases.

Keywords:

Permeability , Capillary-tissue Exchange , Single File Flow , Plasma , Red Cells