# US 11,077,273 B2 · Patient interface with volume reducing member > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,077,273 B2 - Document ID: US11077273B2 - Status: Granted - Kind: B2 - Application number: 15/743,693 - Filed: 2016-07-18 - Published: 2018-07-19 - Granted: 2021-08-03 - Earliest claimed: 2015-07-20 - Assignees: ResMed Pty Ltd - Applicants: ResMed Pty Ltd - Inventors: Charles Harry Finch - Web page: https://patentgrep.com/patent/US11077273B2 ## CPC - A61M 16/0611: {with a gusset portion} - A61M 16/06: Respiratory or anaesthetic masks - A61M 16/0616: {with face sealing means comprising a flap or membrane projecting inwards, such that sealing increases with increasing inhalation gas pressure} - A61M 16/1045: {Devices for humidifying or heating the inspired gas by using recovered moisture or heat from the expired gas} - A61M 16/22: Carbon dioxide-absorbing devices {; Other means for removing carbon dioxide}(cartridges with absorbing substances for respiratory apparatus A62B19/00) - A61M 16/0683: {Holding devices therefor} - A61M 2202/0225: Carbon oxides, e.g. Carbon dioxide - A61M 2205/0216: Materials providing elastic properties, e.g. for facilitating deformation and avoid breaking - A61M 2205/42: Reducing noise - Y02A 90/10: Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation - 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)} - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE ## Abstract A patient interface includes a cushion assembly adapted to form a seal around the patient's nose and/or mouth and a gas washout vent configured to allow a flow of patient exhaled CO2 to an exterior of the patient interface to minimise rebreathing of exhaled CO2 by the patient. The cushion assembly defines a plenum chamber pressurised at a pressure above ambient pressure in use. At least one volume reducing member is provided within the plenum chamber to reduce an effective internal volume of the plenum chamber. The at least one volume reducing member is arranged to separate a main volume of the plenum chamber for delivery of the therapy pressure from deadspace volume provided at least superior the entrance to the patient's nasal passages. The main volume is adapted to be in direct fluid communication with the patient's nose and/or mouth and the vent. ## Claims ### Claim 1 A patient interface for sealed delivery of a flow of air at a continuously positive pressure with respect to ambient air pressure to an entrance to the patient's airways including the entrance of a patient's nares and a patient's mouth, wherein the patient interface is configured to maintain a therapy pressure in a range of 4 cmH2O to 30 cmH2O above the ambient air pressure in use, throughout the patient's respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered breathing; said patient interface comprising: a cushion assembly adapted to form a seal around the patient's nose and mouth, the cushion assembly defining a plenum chamber pressurised at the therapy pressure above the ambient air pressure in use, wherein the cushion assembly includes a seal forming structure adapted to form the seal at least along a portion of the patient's nose, wherein the seal and the plenum chamber is adapted to only surround the patient's nose and mouth of the patient's face; a gas washout vent configured to allow a flow of patient exhaled CO2 to an exterior of the patient interface to minimise rebreathing of exhaled CO2 by the patient; and one or more movable flaps or baffles provided within the plenum chamber to reduce an internal volume of the plenum chamber, wherein the one or more movable flaps or baffles is configured and arranged to separate a main volume of the plenum chamber for delivery of the therapy pressure from a deadspace volume of the plenum chamber, the main volume adapted to be in direct fluid communication with the entrance of the patient's nares, the entrance of the patient's mouth, and the gas washout vent, wherein the one or more movable flaps or baffles creates a flow bias such that all patient inhalation and patient exhalation throughout the patient's respiratory cycle occurs via the main volume. ### Claim 2 (depends on 1) The patient interface according to claim 1, wherein the one or more movable flaps or baffles is arranged to reduce a volume of CO2 that is rebreathed by the patient. ### Claim 3 (depends on 1) The patient interface according to claim 1, wherein the one or more movable flaps or baffles is arranged to reduce the internal volume of the plenum chamber without altering the seal. ### Claim 4 (depends on 1) The patient interface according to claim 1, wherein the one or more movable flaps or baffles includes the one or more movable flaps. ### Claim 5 (depends on 4) The patient interface according to claim 4, wherein the one or more movable flaps separate or divide the plenum chamber into a main chamber and at least one peripheral chamber separate and distinct from the main chamber, the main chamber comprising the main volume. ### Claim 6 (depends on 5) The patient interface according to claim 5, wherein the at least one peripheral chamber comprises the deadspace volume within the plenum chamber. ### Claim 7 (depends on 5) The patient interface according to claim 5, wherein the internal volume of the plenum chamber is reduced to the main volume of the main chamber. ### Claim 8 (depends on 5) The patient interface according to claim 5, wherein the one or more movable flaps includes an upper or superior movable flap arranged to establish the at least one peripheral chamber adapted to be positioned above the patient's nares. ### Claim 9 (depends on 5) The patient interface according to claim 5, wherein the one or more movable flaps includes a lower or inferior movable flap arranged to establish the at least one peripheral chamber adapted to be positioned below the patient's lower lip. ### Claim 10 (depends on 4) The patient interface according to claim 4, wherein each of the one or more movable flaps includes a free end portion adapted to be oriented towards the patient's face. ### Claim 11 (depends on 10) The patient interface according to claim 10, wherein each of the one or more movable flaps is flexible and is adapted to allow each of the one or more movable flaps to deform and/or flex to conform to the patient's face. ### Claim 12 (depends on 1) The patient interface according to claim 1, further comprising a heat and moisture exchanger within the plenum chamber. ### Claim 13 (depends on 1) The patient interface according to claim 1, wherein the cushion assembly includes a front wall portion and the seal forming structure. ### Claim 14 (depends on 13) The patient interface according to claim 13, wherein the front wall portion comprises the gas washout vent. ### Claim 15 (depends on 13) The patient interface according to claim 13, wherein the one or more movable flaps or baffles is provided to the front wall portion. ### Claim 16 (depends on 1) The patient interface according to claim 1, wherein the one or more movable flaps or baffles is arranged to separate the main volume from the deadspace volume provided inferior the entrance to the patient's mouth. ### Claim 17 (depends on 1) The patient interface according to claim 1, wherein the one or more movable flaps or baffles is constructed of an elastomeric material. ### Claim 18 (depends on 1) The patient interface according to claim 1, wherein the deadspace volume is pressurised via the flow of air at the continuously positive pressure and provides pneumatic sealing of the cushion assembly. ### Claim 19 (depends on 1) The patient interface according to claim 1, wherein the one or more movable flaps or baffles is structured and arranged to obstruct flow between the main volume and the deadspace volume. ### Claim 20 (depends on 1) The patient interface according to claim 1, wherein the one or more movable flaps or baffles separates or divides the plenum chamber into a main chamber and at least one peripheral chamber separate and distinct from the main chamber, the main chamber comprising the main volume. ### Claim 21 (depends on 20) The patient interface according to claim 20, further comprising one or more pressurisation ports arranged to allow pressurisation via the flow of air at the continuously positive pressure of the at least one peripheral chamber. ### Claim 22 (depends on 21) The patient interface according to claim 21, further comprising a heat and moisture exchanger within the plenum chamber, and the one or more pressurisation ports are positioned on an anterior side of the heat and moisture exchanger. ### Claim 23 (depends on 1) The patient interface according to claim 1, wherein the one or more movable flaps or baffles comprises an end portion adapted to sealingly engage with the patient's face. ### Claim 24 (depends on 1) The patient interface according to claim 1, wherein the seal forming structure is adapted to form the seal along a nasal bridge region of the patient's nose. ### Claim 25 (depends on 24) The patient interface according to claim 24, wherein the seal forming structure is adapted to form the seal along the nasal bridge region, sides of nose regions, cheek regions, side of mouth regions, and a below the lower lip region. ### Claim 26 (depends on 1) The patient interface according to claim 1, wherein the deadspace volume is provided superior the main volume and the entrance to the patient's nares. ### Claim 27 (depends on 1) The patient interface according to claim 1, wherein the flow bias is directed away from the deadspace volume.