Validity of a New Respiratory Resistance Measurement Device to Detect Glottal Area Change

Objective To determine the correlation between respiratory resistance (Rr) values measured with the Airflow Perturbation Device (APD) to laryngoscopic images of glottal area (GA) in feigned paradoxical vocal fold motion (PVFM), also known as vocal cord dysfunction. Hypothesis There is a strong inverse relationship between Rr and GA such that laryngeal constriction can be detected and quantified by APD-measured Rr. Study Design Prospective, single subject study. Methods A healthy adult feigned breathing that was characteristic of PVFM. Rr and GA were simultaneously recorded, synchronized, and analyzed for three complete breathing cycles with significant glottal constriction occurring during inspiration. Results Cross-correlation analysis revealed a strong negative correlation (−0.824) between GA and Rr during feigned PVFM breathing such that Rr increased when GA decreased. Conclusion APD-measured Rr appears to be a viable noninvasive method for diagnostic screening and monitoring of treatment outcomes for individuals presenting with dyspnea related to PVFM.