title: Power loss mechanisms in pathological tracheas.
abstract: The effort required to inhale a breath of air is a critically important measure in assessing airway function. Although the contribution of the trachea to the total flow resistance of the airways is generally modest, pathological alterations in tracheal geometry can have a significant negative effect. This study investigates the mechanisms of flow energy loss in a healthy trachea and in four geometries affected by retrosternal goitre which can cause significant distortions of tracheal geometry including constriction and deviation with abnormal curvature. By separating out the component of energy loss related to the wall shear (frictional loss), striking differences are found between the patterns of energy dissipation in the normal and pathological tracheas. Furthermore the ratio of frictional to total loss is dramatically reduced in the pathological geometries.
authors.affiliation: Department of Aeronautics, Imperial College London.
authors.forename: A J
authors.initials: AJ
authors.lastname: Bates
authors.affiliation: Department of Aeronautics, Imperial College London.
authors.forename: A
authors.initials: A
authors.lastname: Comerford
authors.affiliation: Department of Aeronautics, Imperial College London; Department of Otolaryngology, St. Mary׳s Hospital, Imperial College Healthcare Trust.
authors.forename: R
authors.initials: R
authors.lastname: Cetto
authors.affiliation: Department of Bioengineering, Imperial College London.
authors.forename: R C
authors.initials: RC
authors.lastname: Schroter
authors.affiliation: Department of Otolaryngology, St. Mary׳s Hospital, Imperial College Healthcare Trust.
authors.forename: N S
authors.initials: NS
authors.lastname: Tolley
authors.affiliation: Department of Aeronautics, Imperial College London. Electronic address: d.doorly@imperial.ac.uk.
authors.forename: D J
authors.initials: DJ
authors.lastname: Doorly
mesh_terms: D017276:Friction; D006801:Humans; D057446:Hydrodynamics; D008954:Models, Biological; D014132:Trachea / Q000473:pathology / Q000502:physiology / Q000503:physiopathology*
keywords: Airflow; CFD; Energy; Power; Trachea; Work of breathing