Acoustic Rhinometry (AR): An Alternative Method to Image Nasal Airway Geometry

Abstract

In acoustic rhinometry (AR) a sound pulse enters the nasal cavity, where it is reflected due to changes in the local impedances. From the incident and reflected sound signal we use the Ware-Aki algorithm to calculate an a readistance relationship. The method has been validated in nasal cavity models with known dimensions, and in humans and animals, where the dimensions were measured by other methods as well, (CT-scanning, MR scanning and fluid displacement). In small animals AR seems to underestimate the cross-sectional areas, probably due to violation of several assumptions for the method. Future studies should aim at development of better-scaled equipment, better sound generation, better microphones, better algorithms, and better validation