The present invention relates generally to propulsion of objects within lumens, and specifically to methods and devices for propelling medical instruments through the colon.

It is an object of some aspects of the present invention to provide an improved system and method for propelling an object within a lumen.

It is a further object of some aspects of the present invention to provide an improved propulsion mechanism for advancing an endoscope within a body cavity of a patient for purposes of examination, diagnosis, and treatment.

In preferred embodiments of the present invention, a probe containing an endoscopic instrument is advanced through the lower gastrointestinal tract of a patient by inflation of a flexible sleeve coupled to the probe. One end of the sleeve is anchored, typically at or adjacent to the patient's anus. As the sleeve is inflated, preferably using a pressurized gas, the probe is propelled forward, and the sleeve is fed out gradually between the probe and the anus. The portion of the sleeve that is inflated expands radially outward and remains substantially stationary relative to the intestinal wall as long as it is inflated. Longitudinal motion of the sleeve relative to the wall generally occurs only at and adjacent to the probe itself. The probe is thus advanced easily, and trauma to the gastrointestinal tract is minimized. To remove the probe, the sleeve is deflated and is used to pull the probe back out through the anus. http://www.patentstorm.us/patents/6485409-description.html