Measurement of Flow in Straight Tubes by Means of the Dilution Technique

Abstract

The effect of a laminar velocity distribution on the dilution technic as applied to the measurement of flow in straight tubes has been analyzed mathematically and experimentally for both blood and water. Formulae derived from Poiseuille''s law agree with the observed data for homogeneous fluids such as water but show discrepancies when applied to blood. Data are presented to show that blood does not flow in accordance with the laws for laminar flow. The appln. of these principles to the measurement of cardiac output is discussed.