THE EFFECT OF SEPARATE RED-BLOOD-CELLS ON CAPILLARY TISSUE OXYGENATION CALCULATED WITH A NUMERICAL-MODEL

In simplified models that describe large quantities of capillaries the capillary content is considered to be homogeneous for oxygen transpor t; but, in reality, the capillaries contain discrete red blood cells ( RBCs), and this discreteness will affect oxygen transport from the cap illary to the tissue. This was previously investigated with an analyti cal model, where RBCs were modelled as point-like sources. A numerical approach is used in this investigation, and the results are compared with the analytical model. In both models the effect of the particulat e nature of blood depends on the haematocrit and on the RBC velocity. There is only a minor difference between the two models. For rat heart s, the correction factor used in this study, the extraction pressure, can be up to 3 kPa (23 mmHg).