The rectoscope comprises a short, wide tube having a proximal coupling housing or a coupling housing which may be coupled at its distal side to a tube of optional length and width. The coupling housing may be coupled at its proximal side to a mandrel or an instrument carrier which is equipped with axially...http://www.google.co.uk/patents/US4538594?utm_source=gb-gplus-sharePatent US4538594 - Rectoscope
