Hemodynamic Principles

Abstract

The steady flow of liquids in rigid tubes is characterized by the Hagen-Poiseuille law:

$$ i = \frac{{\Delta p \cdot {r^4} \cdot \pi }}{{8 \cdot \eta \cdot l}} $$

(1)

where i = the volume flow, which is measured in ml/s, Δ p = the difference between the pressure at the beginning and at the end of the tube, r = the radius, η = the viscosity, and l = the length.