Quantifying the Subharmonic Mucosal Wave in Excised Larynges via Digital Kymography.
OBJECTIVE
In this paper, a nonlinear least squares fitting method was proposed to quantify subharmonic mucosal waves.


METHODS
Subharmonic mucosal waves from 10 excised canine larynges were recorded using digital kymography and analyzed using nonlinear least squares and linear least squares methods. Amplitudes of fundamental and subharmonic mucosal wave components of right-upper, right-lower, left-upper, and left-lower vocal fold lips were calculated. Lastly, phase differences of fundamental and subharmonic components of the left and right vocal folds were compared.


RESULTS
The results showed that the nonlinear least squares analysis method provides a more effective complement to the linear fitting method for subharmonic mucosal wave extraction. There was a significant difference in amplitudes between the subharmonic and the fundamental components of mucosal waves (P < 0.05). The phase differences of the fundamental and the subharmonic components of the right and left vocal folds were not significantly different.


CONCLUSIONS
The application of the nonlinear least squares analysis method in digital kymography is useful for the characterization of subharmonic mucosal waves.
Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen, China; State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing, China. Electronic address: yuzhang@xmu.edu.cn.
Yu
Y
Zhang
Department of Applied Marine Physics & Engineering, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, China.
Nanmu
N
Huang
Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
William
W
Calawerts
Department of Applied Marine Physics & Engineering, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, China.
Lin
L
Li
Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
Allison L
AL
Maytag
Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
Jack J
JJ
Jiang
D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D066298:In Vitro Techniques; D007734:Kymography; D007820:Laryngeal Mucosa / Q000033:anatomy & histology / Q000502:physiology* / Q000601:surgery; D016018:Least-Squares Analysis; D016014:Linear Models; D017711:Nonlinear Dynamics; D010699:Phonation; D012815:Signal Processing, Computer-Assisted; D014732:Vibration; D014827:Vocal Cords / Q000033:anatomy & histology / Q000502:physiology* / Q000601:surgery; D014828:Vocalization, Animal
digital kymography; excised larynx experiment; mucosal wave; nonlinear least-squares method; subharmonics