Objectives To develop an objective analysis of laryngeal videostroboscopy (VSS) movies in the space-time domain for quantitative determination of the true vocal folds (TVFs) vibratory pattern to allow for detection of local pathologies at early stages of development. Methods Contours of the TVF and false vocal folds (FVFs) were tracked on each frame of a VSS movie. A registration algorithm was used with respect to the centerline of the FVF to eliminate movements not related to TVF vibration. The registered contours of the TVF were analyzed in time and frequency domains. Results The TVF vibration demonstrated a sinusoidal pattern with the same fundamental frequency at every section along the folds of healthy subjects, as well as detection of an abnormal area with a different fundamental frequency in TVF with local pathologies. Analysis of the TVF vibration time delay of healthy subject revealed a posterior-to-anterior longitudinal wave that was not detected by visual observation. Conclusions An objective analysis of laryngeal VSS movies was developed for quantitative determination of the TVF vibration. This analysis was able to detect and quantify TVF characteristics in normal subjects as well as in patients with pathologies beyond the ability of examinee's naked eyes.
- Active contours
- Vocal folds vibration