An endoscope has a control section and a tube section connected to the control section to be conducted into the body cavity, wherein a channel running through the tube section contains a guide tube which is made flexible along the entire length or near the distal end portion, and reciprocates through...http://www.google.fr/patents/US4245624?utm_source=gb-gplus-shareBrevet US4245624 - Endoscope with flexible tip control
