Hemorheological approach to oxygen transport between blood and tissue.

A mathematical model is developed to elucidate micro-hemorheological factors of the oxygen transport between blood and tissue. A two-fluids model is introduced for capillary blood flow, including the non-equilibrium and relative motion between red blood cell (RBC) and plasma. A capillary-tissue unit is devised to describe the oxygen supply to tissue from a couple of capillaries with symmetric antiparallel input and output. Non-equilibrium flows are examined numerically on the basis of the model for various geometrical and dynamical parameters such capillary hematocrit, RBC velocity and flux. It is found that both RBC flux and capillary hematocrit have important influences on the oxygen transfer to tissue. Especially under low capillary hematocrit flow, the lowest oxygen pressure within tissue may appear at the maximal diffusional distance from the capillary between arterial and venous side.