US Patent 6988986 Self-propelled imaging system

An imaging system comprising an imaging device assembled on a carrier tube, and a first outwardly expandable element and a second outwardly expandable element mounted on the carrier tube, wherein the second expandable element is expandable both radially and axially, the imaging system comprising a mode of operation, wherein during expansion of the second expandable element, obstruction of the radial expansion of the second expandable element causes the axial expansion of the second expandable element to propel the carrier tube and the imaging device axially.