Patent ID: 8226774

Claim:
A method of cleaning an endoscope, comprising: causing a flow of a gas lengthwise along an interior surface of a passageway of the endoscope; and causing a flow of a liquid lengthwise along the interior surface of said passageway forming sliding liquid entities along the interior surface of said passageway, wherein said gas has a velocity at least somewhere along the interior surface of said passageway of approximately 2 m/s to approximately 80 m/s; wherein said flow of said liquid has a perimeter-normalized liquid flow rate of approximately 1 to approximately 5 milliliters per minute per millimeter of perimeter of said passageway; wherein said sliding liquid entities provide a moving three-phase interface on the interior surface of said passageway having an advancing contact angle on at least a portion of the interior surface of said passageway greater than approximately 50 degrees and has a receding contact angle greater than 0 degree so that a portion of the interior surface of said passageway is wetted by said liquid and an adjacent portion of the interior surface of said passageway is dry or nearly dry; and wherein said liquid comprises a surfactant that has a Ross Miles foam height measured at a surfactant concentration of 0.1% that is less than 50 mm.