Abstract

Rigid endoscopes are widely used instruments for least invasive surgery of various parts of the body, including the abdomen, urinary system, and knee. The rigid endoscope should be distinguished from the flexible fiberoptic endoscope which is generally of larger diameter and is comprised of a two-dimensional array of closely-packed optical fibers. Medical endoscopes using GRIN optics are always rigid endoscopes. The diameter of rigid endoscopes generally range between 1.7mm and 5mm. A typical rigid endoscope may contain up to 50 spherical surfaces. Because of the difficulty in fabricating very small lenses, gradient-index lenses are preferred for the smaller diameter endoscopes.

© 1984 Optical Society of America