US Patent 7335159 Endoscope having auto-insufflation and exsufflation

An endoscopic imaging system for examining a patient's body cavity includes an endoscope having a distal end, a proximal end and a number of lumens therein. One or more distal gas ports are disposed at or adjacent the distal end of the endoscope and one or more proximal gas ports are disposed proximal to the distal gas ports. Insufflation gas is delivered to the distal gas ports and withdrawn from the proximal gas ports or vice versa such that a gas bubble is formed in the body cavity and travels with the distal tip of the endoscope.