Instrument with an optical system. Used for microinvasive diagnosis or surgery to examine body cavities, hollow organs or joints. A distinction is made between rigid and flexible endoscopes. Rigid endoscopes transmit the image of the examined object to the eyepiece through a lens system within the endoscope shaft. The necessary light to illuminate the object under inspection is transmitted to the tip of the endoscope via a fibre-optic light guide, which is also in the shaft. With flexible endoscopes, image and light are transmitted via a fibre-optic bundle. Generally, the instruments have working channels allowing the insertion of micromechanical devices such as forceps and sampling accessories.

Reprocessing of endoscopes and their accessory instruments must be carried out in accordance with the joint recommendation of the Commission for Hospital Hygiene and Infection Prevention at the Robert Koch-Institute (RKI) and the Federal Institute for Drugs and Medical Devices (“Hygienic requirements for the reprocessing of medical devices”).