A ligation device includes (1) a flexible outer tube which can be inserted through a channel of an insertion tube of the endoscope, (2) a flexible inner tube provided in the outer tube, (3) a ring which is made of an elastic material and is provided to a periphery of the inner tube, and (4) an manipulator...http://www.google.se/patents/US5980537?utm_source=gb-gplus-sharePatent US5980537 - Ligation device for endoscope
