The Fahraeus effect in sheet flows with a gap thickness of 4 to 36 microns.
We measured the Fahraeus effect of blood flowing in a sheet flow model formed with two glass slides. The number of red blood cells in the sheet flow was counted to determine a sheet hematocrit Hs and the discharge hematocrit Hd was measured from blood collection. For a Hd in the range of 3 to 30 percent, we find that Hs/Hd is about .83 for a gap of 4.1 microns. When the discharge hematocrit is 30 percent, the ratio decreases to .66 as the gap approaches 7 microns and then increases as the gap becomes thicker. The results indicate that the hematocrit ratio for a gap thicker than 4.1 microns is an increasing function of the discharge hematocrit. The value of Hs/Hd found for the sheet flow models and its dependence on Hd are comparable to those of circular tubes when their diameter equals the gap thickness.
Deng
L H
LH
Biomechanics Institute, Chongqing University, Sichuan, China.
Wu
Y P
YP
Wang
G R
GR
Yang
R F
RF
Lee
J S
JS
D001783:Blood Flow Velocity; D002196:Capillaries / Q000502:physiology*; D004548:Elasticity; D004912:Erythrocytes; D006400:Hematocrit / Q000379:methods*; D006801:Humans; D008955:Models, Cardiovascular; D011652:Pulmonary Circulation