title: Imaging and Analysis of Human Vocal Fold Vibration Using Two-Dimensional (2D) Scanning Videokymography.
abstract: OBJECTIVE
  Laryngeal videokymography and high-speed digital kymography are the currently available techniques for studying aperiodic vibration of the vocal folds. However, videokymography has a fundamental limitation that only linear portions of the vocal fold mucosa can be visualized, whereas high-speed digital kymography has the disadvantages of lack of immediate feedback during examination and considerable waiting time before kymographic visualization. We developed a new system, two-dimensional (2D) scanning videokymography, that provides a possible alternative for evaluation of the vibratory pattern of the vocal folds. Herein, we report the application of 2D scanning videokymography for visualization of vocal fold vibration in humans and an analysis of its parameters.
  
  
  METHODS
  Two young healthy volunteers (one man and one woman) took part in this study. The vibratory patterns of their vocal folds were evaluated using 2D scanning videokymography and laryngeal stroboscopy.
  
  
  RESULTS
  Two-dimensional scanning videokymography provided a high-definition image of the vibratory movements of the vocal folds. In analysis of the images acquired by the device, various parameters including fundamental frequency; ratio of the vibratory phases; phase, amplitude, and glottal area symmetry; and cycle-to-cycle variability were extracted.
  
  
  CONCLUSIONS
  Our results indicate that 2D scanning videokymography is a useful and promising tool for visualization of the vibratory movement of the vocal folds. This new technique might improve our understanding of the mechanism of vocal fold vibration and contribute to voice research as well as clinical practice.
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Pusan National University, Yang-san, Gyeongsangnam-do, South Korea; Department of Speech Rehabilitation, Choonhae College of Health Sciences, Ulsan, South Korea.
authors.forename: Hee-June
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Department of Otorhinolaryngology and Head and Neck Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea.
authors.forename: Wonjae
authors.initials: W
authors.lastname: Cha
authors.affiliation: Department of Otorhinolaryngology and Head and Neck Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea.
authors.forename: Geun-Hyo
authors.initials: GH
authors.lastname: Kim
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Pusan National University, Yang-san, Gyeongsangnam-do, South Korea.
authors.forename: Gye-Rok
authors.initials: GR
authors.lastname: Jeon
authors.affiliation: Department of Otolaryngology, School of Medicine, Pusan National University, Yang-san, Gyeongsangnam-do, South Korea.
authors.forename: Byung Joo
authors.initials: BJ
authors.lastname: Lee
authors.affiliation: Department of Applied IT and Engineering, Pusan National University, Miryang, Gyeongsangnam-do, South Korea.
authors.forename: Bum-Joo
authors.initials: BJ
authors.lastname: Shin
authors.affiliation: Department of Language Therapy, Daegu University, Daegu, South Korea.
authors.forename: Yang-Gyu
authors.initials: YG
authors.lastname: Choi
authors.affiliation: Department of Otolaryngology, School of Medicine, Pusan National University, Yang-san, Gyeongsangnam-do, South Korea. Electronic address: wangsg@pusan.ac.kr.
authors.forename: Soo-Geun
authors.initials: SG
authors.lastname: Wang
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007734:Kymography; D007828:Laryngoscopy; D008297:Male; D010699:Phonation; D049489:Stroboscopy; D013997:Time Factors; D014732:Vibration; D014741:Video Recording; D014827:Vocal Cords / Q000033:anatomy & histology / Q000502:physiology*; D014831:Voice; D055815:Young Adult
keywords: Human; Two-Dimensional; Vibration; Videokymography; Vocal folds