Application of the Home Video Camera for Laryngo-stroboscopy

Ever since the successful visualization of the vibratory mode of the vocal folds by Oertel in 1895, laryngostroboscopy has been widely applied in the clinical management of dysphonias. However, in order to keep a record of the observed stroboscopic images, a very highly sensitive video camera was needed, and such cameras were considerably heavy and expensive. The purpose of this paper is to introduce a method of videotaping the vocal fold vibration obtained by the newly developed laryngo-stroboscope (Nagashima LS-3A) using a rigid telescope (Nagashima SFT-1) or a flexible fiberscope (Machida FLT-6) and a reasonably priced color video camera for family usage (JVC GX-N7). Thanks to recent technological advances, compact and lightweight color cameras with sufficient sensitivity and capable of producing suitable afterimages for video laryngo-stroboscopy have been available. Besides, this new stroboscope provides continuous slow-motion images of the vocal fold vibration with quantitatively constant slow-motion ratio generated by the digital phase shift circuit, and those stroboscopic images simultaneously follow the voice pitch fluctuations. Magnified color slow-motion images of the vocal fold vibration obtained by this method are of high quality and of great value for evaluation and documentation of various laryngeal disorders in the field of phono-surgery.