title: Particle image velocimetry measurements for the study of nasal airflow.
abstract: CONCLUSIONS
  Particle image velocimetry (PIV) permits investigation of the distribution and velocity of the airflow in the nasal cavity. During breathing, the main laminar flow stream passes through the middle meatus and turbulent flow can be detected under physiologic conditions.
  
  
  OBJECTIVE
  Physical models or casts of the nasal cavity have been utilized in several studies in an effort to understand its aerodynamics. PIV is a new technique for measuring the aerodynamic properties of tubular structures. In this article we evaluate nasal airflow characteristics during physiologic breathing under normal conditions and the usefulness of PIV.
  
  
  METHODS
  A nasal model cast obtained by a combination of rapid prototyping and solidification of clear silicone was connected to a pump which simulated the physiological pressure in the upper airway system. A glycerol-water mixture was used as the flow material. The airstream was marked with spherical polyvinyl particles, observed through solidified clear silicone and analyzed using PIV.
  
  
  RESULTS
  The main flow within the cavity, which was mostly laminar, passed through the middle meatus. Turbulence was clearly visible in the anteroinferior part of the middle turbinate. The flow rate was highest at the middle meatus during inspiration and expiration.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Konkuk University College of Medicine, Seoul, Korea. jkkimmd@kuh.ac.kr
authors.forename: Jin Kook
authors.initials: JK
authors.lastname: Kim
authors.forename: Joo-Heon
authors.initials: JH
authors.lastname: Yoon
authors.forename: Chang Hoon
authors.initials: CH
authors.lastname: Kim
authors.forename: Tae Wook
authors.initials: TW
authors.lastname: Nam
authors.forename: Dae Bo
authors.initials: DB
authors.lastname: Shim
authors.forename: Hyang Ae
authors.initials: HA
authors.lastname: Shin
mesh_terms: D000403:Airway Resistance; D000465:Algorithms; D045853:Exhalation / Q000502:physiology; D006801:Humans; D001239:Inhalation / Q000502:physiology; D008953:Models, Anatomic; D009296:Nasal Cavity / Q000502:physiology*; D010316:Particle Size; D015203:Reproducibility of Results; D012212:Rheology; D025363:Rhinomanometry / Q000379:methods*; D012680:Sensitivity and Specificity