A self-propelled colonoscope comprises control part and an insertion tube including a distal part, a bending part, and a flexible part. The distal part is equipped with an image pickup element. Two or more endless belts each of which is circular in cross section extend along the surface of the flexible...http://www.google.es/patents/US6071234?utm_source=gb-gplus-sharePatente US6071234 - Self-propelled colonoscope
