title: Qualification of a quantitative laryngeal imaging system using videostroboscopy and videokymography.
abstract: OBJECTIVE
  We sought to determine whether full-cycle glottal width measurements could be obtained with a quantitative laryngeal imaging system using videostroboscopy, and whether glottal width and vocal fold length measurements were repeatable and reliable.
  
  
  METHODS
  Synthetic vocal folds were phonated on a laboratory bench, and dynamic images were obtained in repeated trials by use of videostroboscopy and videokymography (VKG) with an imaging system equipped with a 2-point laser projection device for measuring absolute dimensions. Video images were also obtained with an industrial videoscope system with a built-in laser measurement capability. Maximum glottal width and vocal fold length were compared among these 3 methods.
  
  
  RESULTS
  The average variation in maximum glottal width measurements between stroboscopic data and VKG data was 3.10%. The average variations in width measurements between the clinical system and the industrial system were 1.93% (stroboscopy) and 3.49% (VKG). The variations in vocal fold length were similarly small. The standard deviations across trials were 0.29 mm for width and 0.48 mm for length (stroboscopy), 0.18 mm for width (VKG), and 0.25 mm for width and 0.84 mm for length (industrial).
  
  
  CONCLUSIONS
  For stable, periodic vibration, the full extent of the glottal width can be reliably measured with the quantitative videostroboscopy system.
authors.affiliation: National Center for Voice and Speech, The Denver Center for the Performing Arts Denver, CO 80204, USA.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Popolo
authors.forename: Ingo R
authors.initials: IR
authors.lastname: Titze
mesh_terms: D005931:Glottis / Q000502:physiology*; D007734:Kymography; D007834:Lasers; D008954:Models, Biological; D010699:Phonation / Q000502:physiology; D049489:Stroboscopy; D014741:Video Recording; D014827:Vocal Cords / Q000502:physiology