title: Estimation of inferior-superior vocal fold kinematics from high-speed stereo endoscopic data in vivo.
abstract: Despite being an indispensable tool for both researchers and clinicians, traditional endoscopic imaging of the human vocal folds is limited in that it cannot capture their inferior-superior motion. A three-dimensional reconstruction technique using high-speed video imaging of the vocal folds in stereo is explored in an effort to estimate the inferior-superior motion of the medial-most edge of the vocal folds under normal muscle activation in vivo. Traditional stereo-matching algorithms from the field of computer vision are considered and modified to suit the specific challenges of the in vivo application. Inferior-superior motion of the medial vocal fold surface of three healthy speakers is reconstructed over one glottal cycle. The inferior-superior amplitude of the mucosal wave is found to be approximately 13 mm for normal modal voice, reducing to approximately 3 mm for strained falsetto voice, with uncertainty estimated at σ ≈ 2 mm and σ ≈ 1 mm, respectively. Sources of error, and their relative effects on the estimation of the inferior-superior motion, are considered and recommendations are made to improve the technique.
authors.affiliation: Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: David E
authors.initials: DE
authors.lastname: Sommer
authors.affiliation: Department of Mechanical Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan.
authors.forename: Isao T
authors.initials: IT
authors.lastname: Tokuda
authors.affiliation: Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Peterson
authors.affiliation: Department of Communication Disorders, Health Sciences University of Hokkaido, 2-5 Ainosato, Hokkaido 002-8072, Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Sakakibara
authors.affiliation: Department of Otolaryngology, University of Tokyo Hospital, 7-3-1 Hongo, Tokyo 113-8655, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imagawa
authors.affiliation: Department of Otolaryngology, University of Tokyo Hospital, 7-3-1 Hongo, Tokyo 113-8655, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Yamauchi
authors.affiliation: Department of Otolaryngology, University of Tokyo Hospital, 7-3-1 Hongo, Tokyo 113-8655, Japan.
authors.forename: Takaharu
authors.initials: T
authors.lastname: Nito
authors.affiliation: Department of Otolaryngology, University of Tokyo Hospital, 7-3-1 Hongo, Tokyo 113-8655, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Yamasoba
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, National Center for Global Health and Medicine Hospital, 1-21-1 Toyama, Tokyo 162-8655, Japan.
authors.forename: Niro
authors.initials: N
authors.lastname: Tayama
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology*; D004867:Equipment Design; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D007828:Laryngoscopy / Q000295:instrumentation / Q000379:methods*; D008297:Male; D010699:Phonation / Q000502:physiology*; D010700:Phonetics; D012016:Reference Values; D013018:Sound Spectrography; D014827:Vocal Cords / Q000502:physiology*; D014833:Voice Quality / Q000502:physiology