Abstract
The three dimentional (3D) laryngostroboscopy was newly developed in cooperation with Shinko Optical Co., Ltd. and Flovel Co., Ltd. The system is composed of a 3D laryngotelescope with two TV cameras, a control unit, a monitor display, a wireless liquid crystal shutter eyewear, and a laryngostroboscope.
The specifications of the 3D laryngotelescope which has the two lines of vision are as follows. The diameter of the telescope is 15mm. The angled view is 70°. The field of view is 35°. The distance between the centers of the two object lenses is 6mm. The angular parallax is 7°. The diameter of the field is 25mm at the standard focal distance of 50mm, and 15mm at the nearest focal distance of 35mm.
The time multiplexed stereopsis is adopted in this system. Each field from the right and left TV cameras is mixed alternately and written in the pair of the two field memories in sequence in the frequency of 60 Hz, while it is read out and displayed on the monitor display in a high frequency of 120 Hz in order to avoid flicker.
Stereoscopic views with sufficient depth perception of wave crests rising from the medial/lower surface and travelling toward the lateral/upper surface of the vocal cords were obtained through the three dimensional (3D) laryngostroboscopy.
