Abstract
This paper presents a new technique for high-speed digital image recording for the observation of vocal cord vibration. Observation of the vocal cord vibration has generally been performed by using a high-speed motion picture and a stroboscopy. However, the high-speed motion picture requires special equipment and is not suited for practical clinical observations. Stroboscopy has inherent limitations in that irregular vibrations in the pathological cases can not be traced precisely. The system developed in the present study consists of an oblique-angled solid endoscope, a camera body containing an image sensor and an image processor. The output video signal from the image sensor is fed into the image processor through a high-speed A/D converter. Stored images are then displayed on a CRT monitor. Frame rates of 2000/sec and 4000/sec are realized for the images with 100×36 and 100×17 picture elements, respectively. A similar system using a fiberscope was also developed. Although images by the fiberscope are darker, a frame rate of 2000 per second was achieved for the images with 200×14 picture elements. The system makes it possible to observe vocal cord vibrations during the consonants. Compared to the ordinary high-speed motion picture system, the present systems are compact and enable flexible data collection including recording of pathological vocal cord vibrations. A compact unit for clinical use which consists of a small-sized image memory combined with an ordinary personal computer was also constructed.
