title: Realistic glottal motion and airflow rate during human breathing.
abstract: The glottal geometry is a key factor in the aerosol delivery efficiency for treatment of lung diseases. However, while glottal vibrations were extensively studied during human phonation, the realistic glottal motion during breathing is poorly understood. Therefore, most current studies assume an idealized steady glottis in the context of respiratory dynamics, and thus neglect the flow unsteadiness related to this motion. This is particularly important to assess the aerosol transport mechanisms in upper airways. This article presents a clinical study conducted on 20 volunteers, to examine the realistic glottal motion during several breathing tasks. Nasofibroscopy was used to investigate the glottal geometrical variations simultaneously with accurate airflow rate measurements. In total, 144 breathing sequences of 30s were recorded. Regarding the whole database, two cases of glottal time-variations were found: "static" or "dynamic" ones. Typically, the peak value of glottal area during slow breathing narrowed from 217 ± 54 mm(2) (mean ± STD) during inspiration, to 178 ± 35 mm(2) during expiration. Considering flow unsteadiness, it is shown that the harmonic approximation of the airflow rate underevaluates the inertial effects as compared to realistic patterns, especially at the onset of the breathing cycle. These measurements provide input data to conduct realistic numerical simulations of laryngeal airflow and particle deposition.
authors.affiliation: CNRS, Aix Marseille Université, Centrale Marseille, IRPHE UMR 7342, 13384, Marseille, France. Electronic address: Scheinherr@irphe.univ-mrs.fr.
authors.forename: Adam
authors.initials: A
authors.lastname: Scheinherr
authors.affiliation: CNRS, Aix Marseille Université, Centrale Marseille, IRPHE UMR 7342, 13384, Marseille, France; CNRS, 3SR, F-38000 Grenoble, France; Univ. Grenoble Alpes, 3SR, F-38000, Grenoble, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Bailly
authors.affiliation: CNRS, Aix Marseille Université, Centrale Marseille, IRPHE UMR 7342, 13384, Marseille, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Boiron
authors.affiliation: CNRS, Aix Marseille Université, LPL UMR 7309, 13100, Aix-en-Provence, France; APHM, ENT Department, La Timone Hospital, 13385, Marseille, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Lagier
authors.affiliation: CNRS, Aix Marseille Université, LPL UMR 7309, 13100, Aix-en-Provence, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Legou
authors.affiliation: Air Liquide Healthcare, CRCD, 78354, Jouy en Josas, France.
authors.forename: Marine
authors.initials: M
authors.lastname: Pichelin
authors.affiliation: Air Liquide Healthcare, CRCD, 78354, Jouy en Josas, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Caillibotte
authors.affiliation: CNRS, Aix Marseille Université, LPL UMR 7309, 13100, Aix-en-Provence, France; APHM, ENT Department, La Timone Hospital, 13385, Marseille, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Giovanni
mesh_terms: D000328:Adult; D000392:Air Movements; D005260:Female; D005931:Glottis / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D008297:Male; D008954:Models, Biological; D009038:Motion; D012123:Pulmonary Ventilation; D012119:Respiration; D014732:Vibration; D055815:Young Adult
keywords: Airflow rate; Glottis; Inhalation; Laryngoscopy; Respiration; Unsteadiness