Patent ID: 8096944

Claim:
A method of maintaining an imager clear of debris during a procedure on a body tissue where the debris would otherwise obscure an optical input of the imager, comprising: using a pressurized gas to form an annular envelope of a stream of the pressurized gas; embedding the optical input of the imager in the annular envelope of gas so that the optical input of said imager is surrounded with the annular envelope of gas, directing the annular gas stream downstream from the optical input, without the use of a deflector apparatus that deflects the gas stream toward the optical input of said imager, to form an annular gas shield around the optical input of said imager so that the debris initially directed from any angle toward the optical input is redirected by the annular gas shield away from the optical input, said pressurized annular envelope of gas directed downstream from the optical input forming a turbulent flow of gas directly in front of the optical input to thereby remove liquids that collect on the optical input of said imager, whereby debris is prevented from accumulating on the optical input of the imager, and preventing movement of apparatus in the annular envelope of the pressurized gas at a location that spoils the annular envelope of gas and obstructs viewing through the imager to thereby provide an uninterrupted annular gas shield and thus uninterrupted shielding of debris generated by the procedure from obscuring the optical input of said imager.