Synchronizing videostroboscopic images of human laryngeal vibration with physiological signals

This report describes a new system that permits the precise correlation of videostroboscopic images with corresponding physiological measures, such as glottography and subglottic pressure.

A healthy volunteer had unilateral vocal cord paralysis induced by infiltrating local anesthesia into the recurrent and superior laryngeal nerve. Vocal-fold vibrations were monitored by photoglottography (PGG) and electroglottography (EGG). Analog signals from the EGG and PGG were synchronized with the video and correlated.

The method described permits images to be sampled throughout sustained phonation. This technique allows study of events during glottic vibration. Results obtained have been in close agreement with previous studies that correlate the vocal-fold morphology to glottographic signal using other methods. This technique is inexpensive in comparison with high-speed filming. The main disadvantage of this method is related to the limitations of stroboscopy.