Patent ID: 7481764

Claim:
A device which includes an elongate body with a movable mass arranged to decelerate toward an end of the body in order to impart forward movement thereto, via momentum transfer, and to accelerate away from said end in order to further drive the body forward, again using momentum transfer, wherein the device defines a first flow path for applying pressurized fluid to a rear of the moveable mass and a second flow path for allowing the fluid to be discharged from between a front of the moveable mass and the end of the body, wherein fluid flow along the second flow path is reduced as the moveable mass approaches the end of the body, in order to provide a fluid cushion to dampen impact between the moveable mass and the body and wherein a third flow path is provided to inject fluid between the moveable mass and the end of the body, in order to accelerate the moveable mass in a rearward direction relative to the end of the body, wherein the device is a self advancing probe, and wherein the self advancing probe is an endoscope.