A theoretical model for the Fahræus effect in medium-large microvessels

This paper presents a mathematical model capable to reproduce a celebrated phenomenon in blood microcir-culation known as Fahr AE us effect, since its discovery by Robin Fahr AE us (1929). This consists in a decaying of the relative hematocrit in small vessels as the vessel diameter decreases. The key point of the model is a formula, direct consequence of the basic principles of fluid dynamics, that links the relative hematocrit to the reservoir hematocrit and the vessel diameter, which confirms the observed behavior. To test the model we selected, among the few experiments carried on since then, those performed by Barbee and Cokelet (1971). The agreement is remarkable. An extended comparison is also carried out with a celebrated empirical formula proposed by Pries et al. (1992) to describe the same phenomenon.

Automated summary

This paper presents a mathematical model that can reproduce the Fahr Aeus effect, a phenomenon in blood microcirculation. The model is validated by experiments and shows remarkable agreement with observed behavior, as well as a comprehensive comparison with an existing empirical formula.