# US 12,594,397 B2 · Vent system for patient interface > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,594,397 B2 - Document ID: US12594397B2 - Status: Granted - Kind: B2 - Application number: 17/433,835 - Filed: 2020-02-26 - Published: 2022-05-12 - Granted: 2026-04-07 - Earliest claimed: 2019-02-26 - Assignees: ResMed Pty Ltd - Applicants: Resmed Pty Ltd - Inventors: Michael Christopher Hogg; Luke Andrew Stanislas - Web page: https://patentgrep.com/patent/US12594397B2 ## CPC - A61M 16/0816: {Joints or connectors} - A61M 16/208: {Non-controlled one-way valves, e.g. exhalation, check, pop-off non-rebreathing valves} - A61M 16/0666: {Nasal cannulas or tubing (devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02)} - A61M 16/0683: {Holding devices therefor} - A61M 16/06: Respiratory or anaesthetic masks - A61M 2202/0225: Carbon oxides, e.g. Carbon dioxide - A61M 2205/42: Reducing noise - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## Abstract A vent structure may include a vent housing comprising an inlet, an outlet, at least one exhaust gas orifice, and a membrane having a first end and a second end spaced apart, the membrane having a moveable portion between the first end and the second end. The moveable portion may be spaced radially from a membrane-facing surface inside of the vent housing to form an exhaust gas flow passage therebetween to allow exhaust gas to flow from the pressurised volume through the exhaust gas flow passage to atmosphere via the exhaust gas orifice. The moveable portion may be elastically deformable and configured to move radially relative to the membrane-facing surface in response to pressure differences between an interior side of the membrane and an exterior side of the membrane to change a cross-sectional area of the exhaust gas flow passage and regulate the vent flow of gas. ## Claims ### Claim 1 A patient interface comprising: a plenum chamber at least partially forming a volume pressurisable to a therapeutic pressure of at least 6 cmH2O above ambient air pressure throughout a patient's respiratory cycle in use, and the plenum chamber including a plenum chamber inlet port sized and structured to receive a therapy flow of gas for breathing by a patient, a seal-forming structure constructed and arranged to seal with a region of the patient's face surrounding an entrance to the patient's airways, the seal-forming structure having a hole to deliver the therapy flow of gas to the entrance to the patient's airways during use, and the seal-forming structure being constructed and arranged to maintain the therapeutic pressure in the plenum chamber throughout the patient's respiratory cycle in use; a positioning and stabilising structure comprising a strap configured to hold the seal-forming structure in a therapeutically effective position on the patient's head; a vent structure comprising: a vent housing comprising an inlet configured to be connected to a supply conduit to receive a flow of gas from a respiratory pressure therapy device, an outlet configured to supply the therapy flow of gas to the plenum chamber inlet port, and at least one exhaust gas orifice configured to discharge a vent flow of gas to atmosphere, and the at least one exhaust gas orifice being sized and shaped to discharge a vent flow of gas to atmosphere continuously throughout the patient's respiratory cycle and maintain the therapeutic pressure in the plenum chamber in use; and a membrane positioned within the vent housing and extending circumferentially around a longitudinal axis of the vent housing, the membrane having a first end and a second end spaced apart along a longitudinal axis of the membrane, and the membrane having a moveable portion positioned between the first end of the membrane and the second end of the membrane and surrounding the longitudinal axis of the membrane; wherein the moveable portion of the membrane is spaced radially, with respect to the longitudinal axis of the membrane, from a membrane-facing surface extending circumferentially around an inside of the vent housing to form an exhaust gas flow passage between the moveable portion of the membrane and the membrane-facing surface, and the exhaust gas flow passage being configured to allow gas to flow from the volume at least partially formed by the plenum chamber through the exhaust gas flow passage to atmosphere via the at least one exhaust gas orifice during use, wherein the moveable portion of the membrane is elastically deformable and is configured to move radially relative to the membrane-facing surface in response to differences in pressure throughout a therapeutic pressure range between an interior side of the membrane and an exterior side of the membrane to change a cross-sectional area of the exhaust gas flow passage; and wherein the patient interface is configured to allow the patient to breathe from ambient through their mouth in the absence of a flow of pressurised air through the plenum chamber inlet port, or the patient interface is configured to leave the patient's mouth uncovered. ### Claim 2 (depends on 1) The patient interface of claim 1, wherein the moveable portion of the membrane is an annulus that is substantially cylindrical or frustoconical in shape. ### Claim 3 (depends on 1) The patient interface of claim 1, wherein the vent housing comprises a first end and a second end aligned along a longitudinal axis of the vent housing, the longitudinal axis of the membrane being aligned with the longitudinal axis of the vent housing. ### Claim 4 (depends on 3) The patient interface of claim 3, wherein the moveable portion of the membrane comprises one or more walls aligned parallel to the flow of gas through the vent housing from the first end of the vent housing to the second end of the vent housing. ### Claim 5 (depends on 3) The patient interface of claim 3, wherein the vent housing comprises a first housing member at the first end of the vent housing and a second housing member at the second end of the vent housing, and the first housing member and the second housing member being configured to connect together. ### Claim 6 (depends on 5) The patient interface of claim 5, wherein the first housing member comprises an inlet connection portion configured to fluidly connect the vent structure to the supply conduit. ### Claim 7 (depends on 5) The patient interface of claim 5, wherein the second housing member comprises an outlet connection portion configured to fluidly connect the vent structure to the patient interface or to a tube configured to be connected to the patient interface. ### Claim 8 (depends on 1) The patient interface of claim 1, wherein the membrane is joined to a membrane support at the first end of the membrane. ### Claim 9 (depends on 1) The patient interface of claim 1, wherein the moveable portion of the membrane is formed from silicone rubber. ### Claim 10 (depends on 1) The patient interface of claim 1, wherein the vent structure comprises a damping structure comprising a damping chamber within the vent housing configured to damp vibration of the moveable portion of the membrane. ### Claim 11 (depends on 10) The patient interface of claim 10, wherein the vent housing at least partially forms the damping chamber. ### Claim 12 (depends on 10) The patient interface of claim 10, wherein one of the interior side and the exterior side of the membrane faces the membrane-facing surface and the other of the interior side and the exterior side of the membrane at least partially forms the damping chamber. ### Claim 13 (depends on 10) The patient interface of claim 10, wherein the damping chamber is in fluid communication with the volume at least partially formed by the plenum chamber. ### Claim 14 (depends on 10) The patient interface of claim 10, wherein the vent structure is configured such that movement of the moveable portion of the membrane increases or decreases a volume of the damping chamber. ### Claim 15 (depends on 14) The patient interface of claim 14, wherein the vent housing and damping chamber are configured to damp vibration of the moveable portion of the membrane by restricting gas exchange between the damping chamber and the volume at least partially formed by the plenum chamber. ### Claim 16 (depends on 1) The patient interface of claim 1, wherein the exhaust gas flow passage comprises a restriction region having a smaller cross-sectional area than adjacent regions of the exhaust gas flow passage. ### Claim 17 (depends on 16) The patient interface of claim 16, wherein the membrane-facing surface is closest to the moveable portion of the membrane at the restriction region. ### Claim 18 (depends on 16) The patient interface of claim 16, wherein the membrane-facing surface comprises a restrictor portion forming the restriction region in the exhaust gas flow passage. ### Claim 19 (depends on 18) The patient interface of claim 18, wherein the membrane-facing surface comprises contoured surfaces forming the restrictor portion. ### Claim 20 (depends on 18) The patient interface of claim 18, wherein the restrictor portion comprises a rib in the membrane-facing surface. ### Claim 21 (depends on 18) The patient interface of claim 18, wherein the restrictor portion is located centrally between the first end of the membrane and the second end of the membrane. ### Claim 22 (depends on 18) The patient interface of claim 18, comprising a damping chamber within the vent housing configured to damp vibration of the moveable portion of the membrane, wherein the damping chamber comprises a first end proximal to the first end of the membrane and a second end proximal to the second end of the membrane, and the restriction region in the exhaust gas flow passage being aligned centrally between the first end of the damping chamber and the second end of the damping chamber. ### Claim 23 (depends on 1) The patient interface of claim 1, wherein the vent housing is configured to reduce vibration of the moveable portion of the membrane in modes of vibration higher than a first mode of vibration. ### Claim 24 (depends on 1) The patient interface of claim 1, wherein the vent housing is configured to limit movement of the moveable portion of the membrane towards the membrane-facing surface during use. ### Claim 25 (depends on 24) The patient interface of claim 24, wherein the vent housing is configured to contact an end of the membrane and prevent the end of the membrane from moving towards the membrane-facing surface during use. ### Claim 26 (depends on 25) The patient interface of claim 25, wherein the vent housing comprises at least one projection configured to contact the end of the membrane to limit movement of the end of the membrane during use. ### Claim 27 (depends on 26) The patient interface of claim 26, wherein the at least one projection is positioned outside of the exhaust gas flow passage. ### Claim 28 (depends on 26) The patient interface of claim 26, wherein the vent housing comprises a plurality of projections, and wherein a plurality of damping orifices are formed between the plurality of projections, the plurality of damping orifices being configured to allow gas to flow therethrough and into and out of a damping chamber from the volume at least partially formed by the plenum chamber, and plurality of damping orifices being configured to resist gas exchange between the damping chamber and the volume at least partially formed by the plenum chamber to damp vibration of the moveable portion of the membrane. ### Claim 29 (depends on 1) The patient interface of claim 1, wherein the vent housing comprises a rounded surface at or proximal to an entrance to the exhaust gas flow passage to facilitate a change in direction of the vent flow of gas proximal to the entrance to the exhaust gas flow passage. ### Claim 30 (depends on 1) The patient interface of claim 1, wherein the vent housing comprises a plurality of exhaust gas orifices. ### Claim 31 (depends on 30) The patient interface of claim 30, wherein the vent housing comprises at least one diffused exhaust gas orifice and at least one undiffused exhaust gas orifice. ### Claim 32 (depends on 31) The patient interface of claim 31, wherein the at least one diffused exhaust gas orifice is located at or proximal to a first end of the vent housing and the at least one undiffused exhaust gas orifice is located between the first end of the vent housing and a second end of the vent housing. ### Claim 33 (depends on 31) The patient interface of claim 31, wherein the at least one diffused exhaust gas orifice opens in a lateral direction and the at least one undiffused exhaust gas orifice opens in at an oblique angle relative to the lateral direction partially towards the second end of the vent housing. ### Claim 34 (depends on 31) The patient interface of claim 31, comprising a diffuser member comprising a network of fibres and configured to diffuse and/or audibly muffle noise from gas that contacts the diffuser member during use. ### Claim 35 (depends on 31) The patient interface of claim 31, wherein the vent structure is configured to allow gas to flow through the at least one undiffused exhaust gas orifice if the gas is unable to flow through the at least one diffused exhaust gas orifice. ### Claim 36 (depends on 35) The patient interface of claim 35, wherein the vent structure is shaped such that the flow of gas changes direction to a greater extent to flow through the at least one undiffused exhaust gas orifice than to flow through the at least one diffused exhaust gas orifice. ### Claim 37 (depends on 31) The patient interface of claim 31, comprising an exhaust gas orifice member at least partly forming the at least one exhaust gas orifice, and the exhaust gas orifice member being configured to connect to a first housing member of the vent housing. ### Claim 38 (depends on 37) The patient interface of claim 37, wherein the at least one diffused exhaust gas orifice is positioned at or proximal to a first end of the exhaust gas orifice member and the at least one undiffused exhaust gas orifice is provided at or proximate a second end of the exhaust gas orifice member opposite the first end of the exhaust gas orifice member. ### Claim 39 (depends on 37) The patient interface of claim 37, comprising a diffuser member comprising a network of fibres and configured to be retained in the vent structure by the exhaust gas orifice member. ### Claim 40 (depends on 1) The patient interface of claim 1, wherein the moveable portion of the membrane is positioned radially outward from the membrane-facing surface, with respect to the longitudinal axis of the membrane. ### Claim 41 (depends on 1) The patient interface of claim 1, wherein the moveable portion of the membrane is configured to be constricted to move radially inwardly towards the membrane-facing surface. ### Claim 42 (depends on 1) The patient interface of claim 1, wherein the membrane-facing surface is provided on an outer surface of a first housing member of the vent housing, and the outer surface is located within the vent housing. ### Claim 43 (depends on 42) The patient interface of claim 42, wherein the first housing member comprises a shaft configured to project from a first end of the first housing member into an interior of the vent structure, and the membrane-facing surface being positioned on an outside surface of the shaft at or proximal to the second end of the first housing member. ### Claim 44 (depends on 43) The patient interface of claim 43, wherein the first housing member comprises a rounded surface on the shaft at the second end of the first housing member at or proximal to an entrance to the exhaust gas flow passage. ### Claim 45 (depends on 1) The patient interface of claim 1, wherein the exhaust gas flow passage extends contiguously around an entire circumference in the vent housing. ### Claim 46 (depends on 1) The patient interface of claim 1, further comprising a swivel elbow or a vent connector tube, wherein the outlet of the vent housing and the plenum chamber inlet port are configured to be fluidly connected by the swivel elbow or the vent connector tube.