We have measured the sedimentation curves of swine erythrocytes in a physiological saline solution in inclined glass tubes. The curves are well fitted to the exponential type equation
for the tilt angle θ in the range of θ < 80° and hematocrits from 10 to 50 %, where ı and t are the medium length along the tube and the elapsed time from the sample injection, respectively. The coefficient a increases with θ and b is proportional to
. The erythrocyte sedimentation rate ESR(θ) = (dı/dt)t → 0 determined from the above empirical equation increases with the increase in
roughly linearly. The experimental results are discussed with reference to the Ponder-Nakamura-Kuroda theory and some recent theories.
