Endoscopy: Developments in Optical Instrumentation

Optical fibers transmit high-intensity illumination for viewing internal organs and tissue. Remote viewing is obtained by relays of lenses or graded-index-of-refraction rods in rigid endoscopes and by precisely aligned fiber-optic bundles in flexible fiberscopes. Endoscopy is considered for routine examinations, such as in colonoscopy. Lasers are used as surgical tools through endoscopes for cutting and coagulation. They may also be used to provide illumination for the efficient transmission of light through thin optical fibers.