A surgical instrument has a channel dimensioned to receive a viewing instrument and enable the viewing instrument to be moved to or from a position near an optically transparent portion of a blunt, enclosed distal end of a shaft to provide unobstructed viewing through the distal end, and a position to...http://www.google.sh/patents/US7794393?utm_source=gb-gplus-sharePatent US7794393 - Resectoscopic device and method
