Patent ID: 8205615

Claim:
A system adapted to provide a regimen of respiratory therapy to a patient, the system comprising: a gas flow generator structured to produce a flow of breathing gas; a patient interface device structured to communicate the flow of breathing gas to an airway of such a patient; an exhaust port assembly; and a patient circuit structured to couple the gas flow generator to the patient interface device, wherein the exhaust port assembly comprises a mechanism structured to control the direction of a flow of exhaust gas discharged from the patient interface device, wherein the mechanism includes a moveable member structured to move relative to a component of the patient interface device responsive to a motive force, the moveable member including an opening structured to permit the exhaust gas to flow through the moveable member, and a counter weight spaced from the opening on the moveable member, wherein the moveable member and the patient interface device are structured to permit the exhaust gas to flow through the opening regardless of a position of the moveable member relative to the component of the patient interface device.