Abstract
A new type of forward-viewing upper gastrointestinal fiberscope "GIF type D3" was made by Olympus Optical Company. This new fiberscope has the strong upward angulation of the apical portion with the intention to make easy observation of the lesser curvature side of the stomach mainly the gastric angulus, and is equipped with the mec-hanism by which it is possible to change the direction of the biopsy forceps about 20° aiming at easier and more precise biopsy. Diameter and effective length of the scope, length of the apical rigid portion, image of optics and structure of the control part are almost the same as the previous GIF type D2. The upward angulation of the tip gains about 180° and 200° if combined with the lateral angulation, however the downward angulation is only 80°. By this strong upward angulation, it becomes very easy to observe the cardia. But it is not sufficient for complete observation of the gastric angulus because the apical rigidd part is not short enough even having strong upward angulation. Biopsy forceps comes out in the left lower side of the visual field, which can be turned toward the right upper direction by the direction changing mechanism of the biopsy forceps. Thus, the tip of biopsy forceps turns to the center of the visual field easily, and it becomes possible to take precise biopsies from the right side of the wall. But, it is difficult or even impossible to take biopsy from the left side, because the biopsy forceps is apt to run parallel to this side of the wall.
