Fåhraeus-Vejlens effect: margination of platelets and leukocytes in blood flow through branches.

The distribution of platelets and leukocytes was studied in tube flow at T-junctions. The diameters were 200 microns for the main channel and 100 microns for the side branch, or 100 microns and 80 microns, respectively. The concentrations of platelets and leukocytes in the blood collected from the side branch and in the blood from the reservoir were measured using blood samples with different levels of fibrinogen. The concentration of platelets in the blood from the side branch was found to be about 1.2-1.5 times higher than in the reservoir. This ratio was found dependent on the feed hematocrit and fibrinogen concentration. The concentration of leukocytes in the blood from the side branch was about 0.9-1.4 times the value of the blood in the reservoir depending slightly on the fibrinogen concentration.