Patent ID: 11896761
Assignee: RESMED PTY LTD
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 16:
17. A patient interface configured to deliver a supply of gas at positive pressure to an entrance of a patient's airways for respiratory therapy, the patient interface comprising:
a plenum chamber pressurizable to a therapeutic pressure above ambient air pressure;
a seal-forming structure constructed and arranged to form a seal with a region of a patient's face surrounding an entrance to a patient's airways; and
a vent assembly configured to provide a vent flow of gas to discharge gas exhaled by the patient from the plenum chamber to ambient, the vent assembly comprising:
a base including at least one first orifice extending through the base to allow gas to be discharged from the plenum chamber to ambient along a primary vent flow path and at least one second orifice to allow gas to be discharged from the plenum chamber to ambient along a secondary vent flow path;
a diffusing member provided to the base, the diffusing member configured and arranged such that the at least one first orifice is covered by the diffusing member along the primary vent flow path and the at least one second orifice is not covered by the diffusing member along the secondary vent flow path; and
a vent component provided to the at least one second orifice of the base, the vent component including a plurality of vent orifices;
wherein the vent component comprises an expanding polymer material structured and arranged to regulate the vent flow of gas along the secondary vent flow path throughout respiratory therapy, and
wherein the vent component s configured to expand and contract due to presence of water or humidity.