Assessing nasal obstruction with the nasal acoustic device: a pilot study on distinguishing between subjects with and without chronic rhinosinusitis

This article aims to demonstrate the concept and potential of a novel diagnostic device – the nasal acoustic device (NAD), which captures the nasal breathing sounds over the ala on both sides of the nose. Using the newly defined inspiratory nasal acoustic score (INA score), the unique characteristics of the nasal breathing sounds can be quantified and used for diagnostic purposes. In this pilot study, the NAD was compared with the well-established nasal inspiratory peak flow meter (NIPF) to try to distinguish between subjects with and without chronic rhinosinusitis (CRS). Measurements were made before and after nasal decongestants, which were applied to eliminate the nasal cycle. Patients were divided into two groups based on the presence or absence of CRS, irrespective of other pathological conditions being present. Based on the post-decongestant measurements, the sensitivity/specificity in distinguishing subjects who have CRS (n=11) from subjects who do not (n=29; of whom 13 were controls) were 70%/66% for the NIPF and 82%/79% for the NAD. The non-CRS groups showed statistically significant changes after decongestant for both methods, but the CRS group did not. The results firstly demonstrated that the CRS subjects in this cohort tended to be less responsive to decongestant and therefore the post-decongestant NIPF measurements provided a certain degree of diagnostic value in identifying CRS subjects, but it would appear the NAD better captured the unique sounds associated with CRS, providing a superior diagnostic capability. This study also demonstrates that the NAD can measure the improvement in the nasal airway following treatment effect.