Table of Contents
ISRN Otolaryngology
Volume 2011, Article ID 126520, 6 pages
http://dx.doi.org/10.5402/2011/126520
Research Article

A Fluid Mechanical Interpretation of Hysteresis in Rhinomanometry

Lehrstuhl für Strömungsmechanik, Ruhr-Universität Bochum, 44780 Bochum, Germany

Received 4 July 2011; Accepted 26 July 2011

Academic Editors: D. E. Hornung and S. K. Kim

Copyright © 2011 T. F. Groß and F. Peters. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A hysteresis effect in the pressure/flow rate relationship of nasal breathing has frequently been observed in clinical tests and in lab investigations. Explanations that have been given in the literature are missing a fluid mechanic storage effect coming into play in reciprocating flows. This effect depends primarily on the way the rhinomanometric measurements are set up and not so much on the nose flow itself. This is to be shown by calculations and experiments. The experiments are carried out with orifices because they can represent nose flow and are often implemented in rhinomanometric equipment as flow gauges. To mimic reality also a 1 : 1 nose model is used. It is shown where the hysteresis comes from and what the key parameters for its prediction are. With these results hysteresis in nasal breathing appears in a new light.