Nasal interface

Abstract

The present application relates to a nasal interface (100) for delivering a flow of gas to a patient, as well as a patient interface and a respiratory therapy system. The nose interface (100) has a first fork (111), a second fork (112), and a gas manifold (120). The nasal interface (100) is configured to induce asymmetric flow at a nostril of a patient. At least one of the first fork (111), the second fork (112), or the gas manifold (120) includes a flow resistance positioned to increase a flow of gas traveling therethrough and thus reaching the at least one fork (111, 112).

Description

[0001] This application claims priority to U.S. Provisional Application No. 63 / 486,795, filed on February 24, 2023, and entitled "Patient Interface", the entire content of which is incorporated herein by reference. Technical Field

[0002] The present disclosure generally relates to a nasal interface, a patient interface, and a respiratory therapy system for delivering respiratory gases to a patient's airway. Background Art

[0003] Humidifiers are used to provide humidified respiratory gases to a patient. The gas is delivered to the patient via a patient interface. Examples of patient interfaces include masks, nasal masks, nasal cannulas, combinations of masks and nasal masks, etc.

[0004] A patient interface including a nasal interface can be used to deliver a high flow of gas to a patient. A nasal delivery prong or element is inserted into the patient's nose to deliver the desired treatment. To deliver the treatment, the nasal delivery prong may need to be sealed or semi-sealed at the nose, or may not need to be sealed at the nose. Nasal high flow is typically a non-sealed treatment that delivers a relatively high volume of flow to the patient through the nasal interface, which may be sufficient to meet or exceed the patient's inspiratory flow rate. Summary of the Invention

[0005] Disclosed herein is a nasal interface having features that allow the nasal interface to provide an asymmetric flow to a patient. The nasal interface can be configured to deliver nasal high flow. The asymmetric flow can provide increased dead space clearance in the patient's upper airway. One or more features of the disclosed nasal interface that allow the nasal interface to achieve an asymmetric flow at the patient's nostrils can reduce the (total) resistance to flow through the nasal interface, which can achieve a desired flow rate using a lower back pressure and / or a lower motor speed of a flow generating device.

[0006] According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface, comprising: a first prong having a first base and a first tip; a second prong having a second base and a second tip; a gas manifold including a manifold chamber and a gas inlet; and at least one element positioned within the first prong, the second prong, or the manifold chamber, wherein the at least one element is configured to increase the resistance to gas flow traveling through at least one of the first prong, the second prong, or the manifold chamber, and wherein the gas inlet is in fluid communication with, or is configured to be in fluid communication with, a gas delivery conduit.

[0007] In accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a nasal interface is provided that includes: a first prong having a first base and a first end; a second prong having a second base and a second end; a gas manifold including a manifold chamber and a gas inlet; and a second prong element positioned within the second prong, wherein the second prong element is configured to increase the flow resistance of a gas flow traveling through the second prong, and wherein the gas inlet is in fluid communication with, or is configured to be in fluid communication with, a gas delivery conduit.

[0008] In accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a nasal interface is provided that includes: a first prong having a first base and a first end; a second prong having a second base and a second end; a gas manifold including a manifold chamber and a gas inlet; and a manifold element positioned within the manifold chamber, wherein the manifold element is configured to increase the resistance of a gas flow traveling through the manifold chamber and reaching at least one of the first prong or the second prong, and wherein the gas inlet is in fluid communication with, or is configured to be in fluid communication with, a gas delivery conduit.

[0009] In some configurations, the increase in the flow resistance of the gas flow is configured to cause an asymmetric gas flow at the first prong and the second prong.

[0010] In some configurations, the first prong, the second prong, the manifold chamber, and the gas inlet are in fluid communication with each other.

[0011] In some configurations, the at least one element is a second prong element positioned within the second prong.

[0012] In some configurations, the second prong element is configured to increase the flow resistance of a gas flow traveling through the second prong.

[0013] In some configurations, the second prong element is positioned at the second base.

[0014] In some configurations, the second base of the second prong includes an inlet leading to a flow passage formed by the wall of the second prong.

[0015] In some configurations, the nasal interface includes a manifold element, wherein the manifold element is positioned within the manifold chamber of the gas manifold.

[0016] In some configurations, the manifold element is configured to increase the flow resistance of a gas flow traveling through the manifold chamber.

[0017] In some configurations, the gas flow is generally in a direction along a flow path from the gas manifold inlet, through the gas manifold chamber, and into the first prong and / or the second prong.

[0018] In some configurations, the manifold element is generally positioned at the center of the manifold chamber.

[0019] In some configurations, the nasal interface includes a first prong element, where the first prong element is positioned within a first fork.

[0020] In some configurations, the first prong element is configured to increase the flow resistance of the gas flow passing through the first fork.

[0021] In some configurations, the first prong element is positioned at the base of the first fork.

[0022] In some configurations, the first prong element provides a different resistance to gas flow compared to a second prong element.

[0023] In some configurations, the gas delivery conduit is located between the patient conduit and the gas inlet.

[0024] In some configurations, the gas manifold is integrally formed with, or coupled to, the gas delivery conduit.

[0025] In some configurations, the gas manifold includes a manifold width, and where the manifold width is as large as or larger than the inner diameter of at least one of the first fork or the second fork.

[0026] In some configurations, the nasal interface includes an insertion body that includes the first fork and the second fork, and where the outer surface of the insertion body between the first fork and the second fork includes a recess for receiving a portion of the patient's nose and reducing the pressure on the underside of the received portion.

[0027] In some configurations, the size of at least one of the first fork or the second fork is determined to maintain a sufficient gap between the outer surface of the at least one fork and the patient's skin to avoid sealing the gas path between the nasal interface and the patient.

[0028] In some configurations, at least the first fork or the second fork is made of an elastomeric material that enables the first fork to deform in response to temperature and contact with the patient's nostrils and set its shape in use.

[0029] In some configurations, at least one of the first fork or the second fork is not made of silicone.

[0030] In some configurations, at least one of the first fork or the second fork is made of a thermoplastic elastomer.

[0031] In some configurations, the nasal interface is configured to cause an asymmetric gas flow at the patient's nostrils.

[0032] In some configurations, the gas manifold includes a flow channel having a gas flow direction that is substantially perpendicular to the gas flow path through the first fork and the second fork.

[0033] In some configurations, the manifold element includes manifold holes for gas flow therethrough, wherein the holes have a smaller cross-sectional opening than the manifold chamber for gas flow.

[0034] In some configurations, the second prong includes a second hole for gas flow therethrough, wherein the second hole has a smaller cross-sectional opening than the second prong for gas flow.

[0035] In some configurations, the manifold holes and / or the second holes are formed in a plate or a wall.

[0036] In some configurations, the plate or the wall has an inlet surface and an outlet surface, and the manifold holes and / or the second holes are formed between the inlet surface and the outlet surface.

[0037] In some configurations, the gas flow is in a direction from the inlet surface through the manifold holes and / or the second holes to the outlet surface.

[0038] In some configurations, the transition between the outlet surface and the manifold holes and / or the second holes is tapered.

[0039] In some configurations, the transition between the inlet surface and the manifold holes and / or the second holes is substantially right-angled.

[0040] In some configurations, the transition between the inlet surface and the manifold holes and / or the second holes is tapered, wherein the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

[0041] In some configurations, the transition between the inlet surface and the manifold holes and / or the second holes is substantially sharp.

[0042] In some configurations, at least one of the manifold holes and / or the second holes is a gap, notch or slit that extends vertically longitudinally through the plate or the wall.

[0043] In some configurations, at least one of the manifold holes and / or the second holes is a gap, notch or slit that extends horizontally longitudinally through the plate or the wall.

[0044] In some configurations, at least one of the manifold holes and / or the second holes is a substantially circular perforation.

[0045] In some configurations, at least one of the manifold holes and / or the second holes includes a perforation pattern.

[0046] In some configurations, the plate or the wall of at least one of the manifold holes and / or the second holes includes a porous medium.

[0047] In some configurations, any one or more of the second prong element and / or the manifold element and / or the first prong element includes a valve.

[0048] In some configurations, the valve is configured to open only at a threshold pressure or a threshold flow rate.

[0049] In some configurations, the valve is configured to provide a defined pressure drop in the flow path.

[0050] In some configurations, the valve is a duckbill valve.

[0051] In some configurations, any one or more of the second fork element and / or the manifold element and / or the first fork element includes a nozzle.

[0052] In some configurations, the nozzle is configured to provide a defined pressure drop in the flow path.

[0053] In some configurations, the manifold element is configured to be adjusted via manual actuation to increase or decrease the degree of restriction imposed by the manifold element.

[0054] In some configurations, the manifold element is configured to be slidably movable in the upstream-downstream direction.

[0055] In some configurations, the manifold element includes a rotatable member having a helical thread.

[0056] In some configurations, the manifold element further includes an external portion located outside the gas manifold at the nasal interface.

[0057] In some configurations, the manifold element is configured to be rotatably movable such that when the external portion rotates, the manifold element vertically translates into or out of the manifold chamber flow path, thereby increasing or decreasing the degree of flow restriction in the flow path, respectively.

[0058] In some configurations, the gas manifold includes an opening at a wall that is generally opposite the gas inlet of the manifold and / or generally opposite the second base of the second fork.

[0059] In some configurations, the opening includes one or more holes.

[0060] In some configurations, the number and diameter of the holes are configured to provide a defined pressure drop.

[0061] In some configurations, the opening in the wall of the manifold is pneumatically connected to a member configured to provide a defined pressure drop.

[0062] In some configurations, the member is at least one of a porous medium, a nozzle, a pressure reducing valve, or a bubble CPAP bubbling chamber.

[0063] In some configurations, the axis of the gas inlet is coaxial with the axis of at least one of the first fork or the second fork.

[0064] In some configurations, the angle of the axis of the gas inlet is perpendicular to the axis of at least one of the first fork or the second fork.

[0065] In some configurations, the nasal interface includes an auxiliary gas inlet to induce or promote an asymmetric gas flow at the first and second forks.

[0066] In some configurations, the auxiliary gas inlet terminates in the first or second fork.

[0067] In some configurations, the auxiliary gas conduit includes an inlet and terminates at the inlet in the first or second fork.

[0068] In some configurations, the auxiliary gas inlet is in fluid communication with an auxiliary gas delivery conduit.

[0069] In some configurations, at least one of the gas inlet or the gas delivery conduit includes a lumen having a first internal cross-sectional area, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a lumen having a second internal cross-sectional area.

[0070] In some configurations, one or both of the first internal cross-sectional area and the second internal cross-sectional area are substantially circular.

[0071] In some configurations, the first internal cross-sectional area and the second internal cross-sectional area are different.

[0072] In some configurations, the second internal cross-sectional area is less than the internal cross-sectional area of the first or second fork.

[0073] In some configurations, the gas delivery conduit and the auxiliary gas delivery conduit are arranged on the same side of the manifold chamber.

[0074] In some configurations, the auxiliary gas delivery conduit is positioned within the gas delivery conduit.

[0075] In some configurations, at least one of the gas inlet or the gas delivery conduit includes a first length, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a second length.

[0076] In some configurations, the first length and the second length are not equal to induce or promote an asymmetric gas flow at the first and second forks.

[0077] In some configurations, the first length is longer than the second length to induce or promote an asymmetric gas flow at the first and second forks.

[0078] In some configurations, the first length is shorter than the second length to induce or promote an asymmetric gas flow at the first and second forks.

[0079] In some configurations, the gas delivery conduit is in communication with a first gas flow, and the auxiliary gas delivery conduit is in communication with a second gas flow.

[0080] In some configurations, the first gas flow has a different flow rate than the second gas flow.

[0081] In some configurations, the combined flow direction between the gas manifold and the first gas flow is a different flow direction than the combined flow direction between the gas manifold and the second gas flow.

[0082] In some configurations, one of the first gas flow or the second gas flow is an inhalation flow.

[0083] In some configurations, the gas pressure of the first gas flow is different from the gas pressure of the second gas flow.

[0084] In some configurations, a negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

[0085] According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a nasal interface is provided that includes: a first prong having a first base and a first tip; a second prong having a second base and a second tip; and a gas manifold including: a manifold chamber; a first gas inlet; and a second gas inlet, wherein the first gas inlet and the second gas inlet are disposed at opposite ends of the manifold chamber and are in fluid communication with a first gas delivery conduit and a second gas delivery conduit, respectively.

[0086] According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a nasal interface is provided that includes: a first prong having a first base and a first tip; a second prong having a second base and a second tip; and a gas manifold including: a manifold chamber; a first gas inlet; a second gas inlet, wherein the first gas inlet and the second gas inlet are in fluid communication with a first gas delivery conduit and a second gas delivery conduit, respectively, wherein the nasal interface is configured to cause an asymmetric gas flow at the first prong and the second prong.

[0087] In some configurations, the first gas inlet and the second gas inlet are disposed on opposite sides of the manifold chamber.

[0088] In some configurations, the first gas inlet is closer to the first prong than the second inlet, and wherein the second gas inlet is closer to the second prong than the first gas inlet.

[0089] In some configurations, at least one of the first gas inlet and the first gas delivery conduit is formed as an integral structure, or the second gas inlet and the second gas delivery conduit are formed as an integral structure.

[0090] In some configurations, the first gas delivery conduit is in communication with the first gas flow, and the second gas delivery conduit is in communication with the second gas flow.

[0091] In some configurations, the first gas flow has a different flow rate than the second gas flow.

[0092] In some configurations, the combined flow direction between the gas manifold and the first gas flow is a different flow direction than the combined flow direction between the gas manifold and the second gas flow.

[0093] In some configurations, one of the first gas flow or the second gas flow is an inhalation flow.

[0094] In some configurations, the gas pressure of the first gas flow is different from the gas pressure of the second gas flow.

[0095] In some configurations, a negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

[0096] In some configurations, the first fork, the second fork, the manifold chamber, the first gas inlet, and the second gas inlet are in fluid communication with each other.

[0097] In some configurations, the nasal interface includes flow-altering features configured to cause an asymmetric gas flow at the first fork and the second fork.

[0098] In some configurations, the first inlet and / or the first gas delivery conduit includes a lumen having a first internal cross-sectional area, and the second inlet and / or the second gas delivery conduit includes a lumen having a second internal cross-sectional area to cause an asymmetric gas flow at the first fork and the second fork.

[0099] In some configurations, one or both of the first internal cross-sectional area and the second internal cross-sectional area are substantially circular.

[0100] In some configurations, one or both of the first internal cross-sectional area and the second internal cross-sectional area are substantially non-circular.

[0101] In some configurations, the first internal cross-sectional area and the second internal cross-sectional area are not equal to cause an asymmetric gas flow at the first fork and the second fork.

[0102] In some configurations, the first internal cross-sectional area is greater than the second internal cross-sectional area to cause an asymmetric gas flow at the first fork and the second fork.

[0103] In some configurations, the first internal cross-sectional area is less than the second internal cross-sectional area to cause an asymmetric gas flow at the first fork and the second fork.

[0104] In some configurations, the first inlet and / or the first gas delivery conduit includes a first length, and the second inlet and / or the second gas delivery conduit includes a second length to cause an asymmetric gas flow at the first fork and the second fork.

[0105] In some configurations, the first length and the second length are not equal to cause an asymmetric gas flow at the first fork and the second fork.

[0106] In some configurations, the first length is longer than the second length to cause an asymmetric gas flow at the first fork and the second fork.

[0107] In some configurations, the first length is shorter than the second length to cause an asymmetric gas flow at the first fork and the second fork.

[0108] In some configurations, the inner surface of the first inlet and / or the first gas delivery conduit includes a first embossed feature pattern.

[0109] In some configurations, the inner surface of the second inlet and / or the second gas delivery conduit includes a second embossed feature pattern.

[0110] In some configurations, the first embossed feature pattern is substantially rougher than the second embossed feature pattern to cause an asymmetric gas flow at the first fork and the second fork.

[0111] In some configurations, the first embossed feature pattern is substantially smoother than the second embossed feature pattern to cause an asymmetric gas flow at the first fork and the second fork.

[0112] In some configurations, the embossed feature pattern includes one or more of the following: pits, protrusions, ribs, and / or fins.

[0113] In some configurations, the axis of one or both of the first gas inlet and the second gas inlet is coaxial with the axis of at least one of the first fork or the second fork.

[0114] In some configurations, the angle of the axis of the first gas inlet and / or the second gas inlet is perpendicular to the axis of at least one of the first fork or the second fork.

[0115] In some configurations, the nasal interface includes at least one of the following: (i) a first fork element positioned within the first fork; (ii) a second fork element positioned within the second fork; (iii) a manifold element positioned within the manifold chamber and between a first base of the first fork and a second base of the second fork; (iv) a first gas inlet element positioned at the first gas inlet leading to the gas manifold; or (v) a second gas inlet element positioned at the second gas inlet leading to the gas manifold, wherein the first fork element, the second fork element, the manifold element, the first gas inlet element, and / or the second gas inlet element are each configured to increase the flow resistance of the gas flow entering the corresponding element to cause an asymmetric gas flow at the first fork and the second fork.

[0116] In some configurations, the nasal interface includes the first gas inlet element and the second gas inlet element, each of which is configured to increase the flow resistance of the gas flow entering the gas manifold through the first gas inlet and the second gas inlet, respectively.

[0117] In some configurations, the nasal interface includes the first fork element and the second fork element, each of which is configured to increase the flow resistance of the gas flow entering the first fork and the second fork, respectively.

[0118] In some configurations, the nasal interface includes the manifold element and the first gas inlet element, each of which is configured to increase the flow resistance of the gas flow in the manifold chamber and entering the gas manifold through the manifold element and the first gas inlet element, respectively.

[0119] In some configurations, the nasal interface includes the manifold element and the second gas inlet element, each of which is configured to increase the flow resistance of the gas flow in the manifold chamber and entering the gas manifold through the manifold element and the second gas inlet element, respectively.

[0120] In some configurations, at least one of the first fork element, the second fork element, the manifold element, the first gas inlet element, or the second gas inlet element includes a hole for reducing the passage of the gas flow.

[0121] In some configurations, the hole has a smaller cross-sectional opening than at least one of the flow channels for the first fork, the second fork, or the manifold chamber, or the first inner cavity or the second inner cavity for the gas flow.

[0122] In some configurations, the hole is formed in a plate or a wall.

[0123] In some configurations, the plate or the wall has an inlet surface and an outlet surface, and the hole is formed between the inlet surface and the outlet surface.

[0124] In some configurations, the gas flow is in a direction from the inlet surface through the hole to the outlet surface.

[0125] In some configurations, the transition between the outlet surface and the hole is tapered.

[0126] In some configurations, the transition between the inlet surface and the hole is substantially right-angled.

[0127] In some configurations, the transition between the inlet surface and the hole is tapered, wherein the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

[0128] In some configurations, the transition between the inlet surface and the hole is substantially a sharp corner.

[0129] In some configurations, the at least one hole is a clearance, notch, or slit that extends vertically longitudinally through the plate or wall.

[0130] In some configurations, the at least one hole is a clearance, notch, or slit that extends horizontally longitudinally through the plate or wall.

[0131] In some configurations, the at least one hole is a substantially circular perforation.

[0132] In some configurations, the at least one hole includes a perforation pattern.

[0133] In some configurations, the plate or wall of the at least one hole includes a porous medium.

[0134] In some configurations, at least one of the first fork element, the second fork element, the manifold element, the first gas element, or the second gas element includes a valve.

[0135] In some configurations, the valve is configured to open only at a threshold pressure or a threshold flow rate.

[0136] In some configurations, the valve is configured to provide a defined pressure drop in the flow path.

[0137] In some configurations, the valve is a duckbill valve.

[0138] In some configurations, at least one of the first fork element, the second fork element, the manifold element, the first gas element, or the second gas element includes a nozzle.

[0139] In some configurations, the nozzle is configured to provide a defined pressure drop in the flow path.

[0140] In some configurations, at least one of the first fork element, the second fork element, the manifold element, the first gas element, or the second gas element is configured to be adjusted via manual actuation to increase or decrease the degree of restriction imposed by the element.

[0141] In some configurations, the element is configured to be slidably movable in the upstream-downstream direction.

[0142] In some configurations, the element includes a rotatable member having a helical thread.

[0143] In some configurations, the element further includes an external portion located outside the nose interface.

[0144] In some configurations, the element is configured to be rotatably movable such that when the external portion is rotated, the element vertically translates into or out of the flow path, thereby increasing or decreasing, respectively, the degree of flow restriction in the flow path.

[0145] According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a nasal interface is provided that includes: a first prong and a second prong; a gas manifold that includes a manifold chamber and a gas inlet, the gas inlet being in fluid communication with a gas delivery conduit or being configured to be in fluid communication with a gas delivery conduit; and at least one flow guiding element, wherein the at least one flow guiding element is configured to direct a gas flow from the gas inlet to one of the first prong or the second prong to produce an asymmetric gas flow.

[0146] In some configurations, the at least one flow guiding element is the gas inlet.

[0147] According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a nasal interface is provided that includes: a first prong and a second prong; a gas manifold that includes a manifold chamber and a gas inlet, the gas inlet being in fluid communication with a gas delivery conduit or being configured to be in fluid communication with a gas delivery conduit; and at least one flow guiding element that is formed as part of at least one of the manifold chamber, the gas inlet, or the gas delivery conduit, wherein the at least one flow guiding element is configured to direct a gas flow to one of the first prong or the second prong to produce an asymmetric gas flow.

[0148] In some configurations, the first prong, the second prong, the manifold chamber, and the first gas inlet are in fluid communication with each other.

[0149] In some configurations, the flow guiding element is configured to provide a greater dynamic pressure at the first prong during use and a smaller dynamic pressure at the second prong during use to produce an asymmetric gas flow.

[0150] In some configurations, the size of at least one of the first prong or the second prong is determined to maintain a sufficient gap between the outer surface of the at least one prong and the skin of the patient to avoid sealing the gas path between the nasal interface and the patient.

[0151] In some configurations, the first prong and the second prong are in fluid communication with the manifold chamber.

[0152] In some configurations, the gas inlet is positioned in the manifold chamber, opposite at least one of the first prong or the second prong.

[0153] In some configurations, the at least one flow guiding element is positioned within the gas manifold chamber.

[0154] In some configurations, the at least one flow guiding element is positioned within the gas delivery conduit.

[0155] In some configurations, the at least one flow guiding element is positioned within the gas delivery conduit at the point where the gas delivery conduit meets the gas inlet.

[0156] In some configurations, the at least one flow guiding element includes at least one angled protrusion, wherein the protrusion is configured to direct a gas flow from the gas inlet towards one of the first fork or the second fork.

[0157] In some configurations, the at least one flow guiding element further includes an angled second protrusion, which is oppositely positioned to the first protrusion in the flow path and is similarly configured to direct a gas flow from the gas inlet towards one of the first fork or the second fork.

[0158] In some configurations, the nasal interface includes a second flow guiding element, which is positioned at an inlet leading to one of the first fork or the second fork in the gas manifold.

[0159] In some configurations, the second flow guiding element is configured to direct a gas flow from the gas inlet towards one of the first fork or the second fork.

[0160] In some configurations, the second flow guiding element is configured to direct an exhaled gas flow from one of the first fork or the second fork to the opposite fork.

[0161] In some configurations, the second flow guiding element includes at least one angled protrusion, wherein the protrusion is configured to direct a gas flow from the gas inlet towards one of the first fork or the second fork, and is configured to direct an exhaled gas flow from one of the first fork or the second fork to the opposite fork.

[0162] In some configurations, the axis of the gas inlet is coaxial with the axis of at least one of the first fork or the second fork.

[0163] In some configurations, the angle of the axis of the gas inlet is perpendicular to the axis of at least one of the first fork or the second fork.

[0164] In some configurations, the gas inlet is positioned at a substantially central position between the first fork and the second fork in the manifold chamber.

[0165] In some configurations, the at least one flow guiding element is positioned within the gas manifold chamber and adjacent to the first fork.

[0166] In some configurations, the at least one flow guiding element is configured to direct a gas flow from the gas delivery conduit towards the inlet of the first fork.

[0167] In some configurations, the second flow guiding element is configured to direct a gas flow from the inlet of the first fork into the flow path of the first fork.

[0168] In some configurations, the at least one flow guiding element is positioned within the gas manifold chamber and adjacent to the second fork.

[0169] In some configurations, the at least one flow guiding element is configured to direct a gas flow from a gas delivery conduit toward an inlet of the second prong.

[0170] In some configurations, a second flow guiding element is configured to direct a gas flow from the inlet of the second prong into a flow path of the second prong.

[0171] In some configurations, the nasal interface includes at least one of the following: (i) a first prong element positioned within the first prong; (ii) a second prong element positioned within the second prong; (iii) a manifold element positioned within a manifold chamber and between a first base of the first prong and a second base of the second prong; wherein the first prong element, the second prong element, and / or the manifold element are each configured to increase a flow resistance of a gas flow entering the corresponding element.

[0172] In some configurations, the nasal interface includes a first prong element and a second prong element, each configured to increase a flow resistance of a gas flow entering the first prong and the second prong, respectively.

[0173] In some configurations, the nasal interface includes a manifold element and a second prong element, each configured to increase a flow resistance of a gas flow entering the second prong through the second prong element and within the manifold chamber, respectively.

[0174] In some configurations, at least one of the first prong element, the second prong element, and / or the manifold element includes an aperture for reducing a gas flow passage.

[0175] In some configurations, the aperture has a cross-sectional opening that is smaller than a cross-section of a flow channel for at least one of the first prong, the second prong, or the manifold chamber.

[0176] In some configurations, the first prong has a first prong length and the second prong has a second prong length, and wherein the first prong length is different from the second prong length.

[0177] In some configurations, the first prong length is longer than the second prong length to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0178] In some configurations, the first prong length is shorter than the second prong length to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0179] In some configurations, the first prong has a first prong cross-sectional width and the second prong has a second prong cross-sectional width, and wherein the first prong cross-sectional width is different from the second prong cross-sectional width.

[0180] In some configurations, the first prong cross-sectional width is greater than the second prong cross-sectional width to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0181] In some configurations, the width of the cross-section of the first prong is less than the width of the cross-section of the second prong to induce or facilitate an asymmetric gas flow at the first and second prongs.

[0182] In some configurations, the first prong has a first end and the second prong has a second end, and wherein the geometry of the first end and the geometry of the second end are different to induce or facilitate an asymmetric gas flow at the first and second prongs.

[0183] In some configurations, at least one of the first end or the second end tapers or converges to form a nozzle shape.

[0184] In some configurations, at least one of the first end or the second end widens or flares to form a diffuser shape.

[0185] In some configurations, the first prong has a first inner surface and the second prong has a second inner surface, wherein at least one of the first inner surface or the second inner surface has surface features configured to affect the internal flow resistance of at least one of the first or second prongs.

[0186] In some configurations, the surface features are ridges formed in a concentric pattern around the first inner surface or the second inner surface as rings, helices, or bands.

[0187] In some configurations, the surface features are fins formed in a substantially axial direction pattern along the first inner surface or the second inner surface as lines, bands, or strips.

[0188] In some configurations, when the surface features are present on both the first inner surface and the second inner surface, the surface features are different to induce an asymmetric gas flow at the first and second prongs.

[0189] In some configurations, at least one of the first and second prongs has a non-circular cross-sectional shape configured to affect the internal flow resistance of at least one of the first or second prongs.

[0190] In some configurations, the non-circular cross-sectional shape is reduced by the size of the circular cross-sectional shape removed therefrom.

[0191] In some configurations, the non-circular cross-sectional shape is substantially U-shaped.

[0192] In some configurations, the non-circular cross-sectional shape is substantially polygonal.

[0193] In some configurations, when the non-circular cross-sectional shape is present on each of the first and second prongs, the non-circular cross-sectional shapes are different to induce or facilitate an asymmetric gas flow at the first and second prongs.

[0194] In some configurations, at least one of the first prong and the second prong includes a base restriction at the base of the prong, the base restriction being configured to affect the internal flow resistance of at least one of the first prong or the second prong.

[0195] In some configurations, the base restriction is a nozzle or diffuser formed at the base of the prong.

[0196] In some configurations, when base restrictions are present on the first prong and the second prong, the base restrictions are different to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0197] In some configurations, at least one of the first prong and the second prong includes a valve located within the prong, the valve being configured to affect the internal flow resistance of at least one of the first prong or the second prong.

[0198] In some configurations, the valve is configured to restrict or block gas flow therethrough until the gas flow exceeds a defined pressure.

[0199] In some configurations, the valve is a duckbill valve.

[0200] In some configurations, the valve is a one-way valve.

[0201] In some configurations, when valves are present in each of the first prong and the second prong, the valves have different characteristics to cause an asymmetric gas flow at the first prong and the second prong.

[0202] In some configurations, the nasal interface further includes a third prong, wherein the first prong, the second prong, and the third prong are spaced apart to be engagable as adjacent pairs into the nostrils of a patient, and wherein at least one of the first prong, the second prong, or the third prong has different flow characteristics than the other prongs to cause or promote an asymmetric gas flow at each prong.

[0203] In some configurations, the nasal interface further includes a closure for releasably blocking gas flow through the first prong, the second prong, or the third prong.

[0204] According to certain features, aspects, and advantages of at least one of the embodiments disclosed herein, there is provided a nasal interface including: a first prong having a first base and a first end; a second prong having a second base and a second end; a gas manifold; a first gas inlet; and an auxiliary gas inlet; wherein the first gas inlet and the second gas inlet are in fluid communication with a first gas delivery conduit and a second gas delivery conduit, respectively; and wherein the nasal interface is configured to cause an asymmetric gas flow at the first prong and the second prong.

[0205] In some configurations, the first gas inlet terminates in the gas manifold.

[0206] In some configurations, the auxiliary gas inlet terminates in either the first fork or the second fork.

[0207] In some configurations, the auxiliary gas inlet is in fluid communication with an auxiliary gas delivery conduit.

[0208] In some configurations, at least one of the first gas inlet or the gas delivery conduit includes a lumen having a first internal cross-sectional area, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a lumen having a second internal cross-sectional area.

[0209] In some configurations, one or both of the first internal cross-sectional area and the second internal cross-sectional area are substantially circular.

[0210] In some configurations, the first internal cross-sectional area and the second internal cross-sectional area are different.

[0211] In some configurations, the second internal cross-sectional area is less than the internal cross-sectional area of either the first fork or the second fork.

[0212] In some configurations, the gas delivery conduit and the auxiliary gas delivery conduit are disposed on the same side of the gas manifold.

[0213] In some configurations, the auxiliary gas delivery conduit is located within the gas delivery conduit.

[0214] In some configurations, at least one of the first gas inlet or the gas delivery conduit includes a first length, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a second length.

[0215] In some configurations, the first length and the second length are not equal to cause an asymmetric gas flow at the first fork and the second fork.

[0216] In some configurations, the first length is longer than the second length to cause or promote an asymmetric gas flow at the first fork and the second fork.

[0217] In some configurations, the first length is shorter than the second length to cause or promote an asymmetric gas flow at the first fork and the second fork.

[0218] In some configurations, the gas delivery conduit is in communication with a first gas flow, and the auxiliary gas delivery conduit is in communication with a second gas flow.

[0219] In some configurations, the first gas flow has a different flow rate than the second gas flow.

[0220] In some configurations, the resultant flow direction between the gas manifold and the first gas flow is a different flow direction than the resultant flow direction between the gas manifold and the second gas flow.

[0221] In some configurations, one of the first gas flow or the second gas flow is an inhalation flow.

[0222] In some configurations, the gas pressure of the first gas flow is different from the gas pressure of the second gas flow.

[0223] In some configurations, a negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

[0224] In accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a patient interface is provided that includes the nasal interface described herein.

[0225] In some configurations, the patient interface further includes a headgear to hold the nasal interface on the patient's face.

[0226] In some configurations, the patient interface further includes a gas delivery conduit in fluid communication with the gas inlet.

[0227] In some configurations, the gas delivery conduit is a breathable tube.

[0228] In some configurations, the gas manifold is integrally formed with or coupled to the gas delivery conduit.

[0229] In some configurations, the gas delivery conduit couples the gas inlet to a patient conduit that supplies gas from a flow generator.

[0230] In some configurations, the patient interface further includes a gas delivery conduit retaining clip.

[0231] In accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a respiratory therapy system is provided that includes: a respiratory therapy device that includes: a controller; a blood oxygen saturation sensor; an ambient air inlet; an oxygen inlet; a valve in fluid communication with the oxygen inlet to control the oxygen flow through the oxygen inlet; and a gas outlet; wherein the controller is configured to control the valve based on at least one measurement of the oxygen saturation from the blood oxygen saturation sensor; and a patient interface as described herein.

[0232] Features from one or more embodiments or configurations may be combined with features from one or more other embodiments or configurations. Additionally, during a patient's respiratory support process, more than one embodiment or configuration may be used together in a respiratory support system.

[0233] As used herein, the term "(s)" following a noun refers to the plural and / or singular form of that noun.

[0234] As used herein, the term "and / or" means "and" or "or", or both where the context permits.

[0235] As used in this specification, the term "comprising" means "consisting at least in part of". When interpreting each statement in this specification that includes the term "comprising", there may also be features other than the one or those features preceded by that term. Related terms such as "including" and "having" will be interpreted in the same manner.

[0236] References to numerical ranges disclosed herein (e.g., 1 to 10) are also intended to include references to all rational numbers within that range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10), as well as references to any range of rational numbers within that range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7), so all sub-ranges of all ranges explicitly disclosed herein are also explicitly disclosed. These are merely examples of specific intents, and all possible combinations of values between the lowest and highest values listed are considered to be stated explicitly in this application in a similar manner.

[0237] The present disclosure may also be broadly stated as consisting of the parts, elements, and features individually or jointly referred to or pointed out in the specification of this application, and any or all combinations of any two or more of said parts, elements, or features.

[0238] Where specific entities are mentioned herein that have known equivalents in the field to which the present disclosure pertains, such known equivalents are considered to be incorporated herein as if individually set forth.

[0239] The present disclosure includes the foregoing and also contemplates the following constructions given by way of example only. BRIEF DESCRIPTION OF THE DRAWINGS

[0240] From the following detailed description with reference to the accompanying drawings, specific embodiments and their modifications will become apparent to those skilled in the art, wherein:

[0241] Figure 1A is a left front perspective view of a patient interface of an exemplary construction of the present disclosure, the patient interface including a nasal interface.

[0242] Figure 1B is a right front perspective view of the patient interface.

[0243] Figure 1C is a left front exploded perspective view of the patient interface.

[0244] Figure 1D is a front view of the nasal interface.

[0245] Figure 2 is a front view of the nasal interface according to the present disclosure, schematically showing the elements.

[0246] Figure 3A isFigure 2 Schematic perspective view of the elements of the nasal interface.

[0247] Figure 3B is Figure 3A Schematic front view of the elements in a possible configuration.

[0248] Figure 3C is Figure 3A Schematic front view of the elements in a possible configuration.

[0249] Figure 4 Front view of a modification of the nasal interface according to the present disclosure.

[0250] Figure 5 Front view of a modification of the nasal interface according to the present disclosure.

[0251] Figure 6 Front view of a modification of the nasal interface according to the present disclosure.

[0252] Figure 7 is Figure 6 Front view of a modification of the nasal interface.

[0253] Figure 8 is Figure 6 Front view of a modification of the nasal interface.

[0254] Figure 9 Front view of a modification of the nasal interface according to the present disclosure.

[0255] Figure 10 is Figure 9 Front view of a modification of the nasal interface.

[0256] Figure 11 is Figure 9 Front view of the nasal interface, schematically showing the elements.

[0257] Figure 12 Front view of a modification of the nasal interface according to the present disclosure.

[0258] Figure 13 Front view of a modification of the nasal interface according to the present disclosure.

[0259] Figure 14 Front view of a modification of the nasal interface according to the present disclosure.

[0260] Figure 15 is Figure 14 Front view of a modification of the nasal interface.

[0261] Figure 16 is according to Figure 1D Front view of a modification of the fork of the nasal interface.

[0262] Figure 17 is a front view of a modification of the fork of the nasal interface according to Figure 1D the fork of the nasal interface according to

[0263] Figure 18 is a front view of a modification of the fork of the nasal interface according to Figure 1D the fork of the nasal interface according to

[0264] Figure 19 is a front view of a modification of the fork of the nasal interface according to Figure 1D the fork of the nasal interface according to

[0265] Figure 20 is a front view of a modification of the fork of the nasal interface according to Figure 1D the fork of the nasal interface according to

[0266] Figure 21 is a front view of a modification of the fork of the nasal interface according to Figure 1D the fork of the nasal interface according to

[0267] Figure 22 is a front view of a modification of the fork of the nasal interface according to Figure 1D the fork of the nasal interface according to

[0268] Figure 23 is a front view of a modification of the nasal interface according to Figure 1D the nasal interface according to

[0269] Figure 24 Illustrates a respiratory therapy system incorporating the patient interface and nasal interface of the present disclosure.

[0270] Figure 25 Illustrates the control loop of a respiratory therapy system for closed-loop blood oxygen saturation (SpO2) control.

[0271] Figure 26 Illustrates an alternative respiratory therapy system incorporating the patient interface and nasal interface of the present disclosure.

[0272] Figure 27 Illustrates a cross-sectional view of a patient conduit that can be used in the respiratory therapy system of the present disclosure and / or with the nasal interface.

[0273] Figure 28 Illustrates a cross-sectional view of an alternative patient conduit that can be used in the respiratory therapy system of the present disclosure and / or with the nasal interface. DETAILED DESCRIPTION

[0274] A patient interface can be used to deliver respiratory gases to a patient's airway. The patient interface can include a nasal interface, which can be used to deliver a gas flow to the patient. A nasal delivery element (e.g., a nasal fork or nasal pillow) is inserted into the patient's nose to deliver the desired therapy. The nasal delivery fork may need to be sealed at the nose to deliver the therapy. One or more nasal delivery elements can include a nasal pillow to seal at the nose.

[0275] A system for delivering gas to a patient via a nasal interface is disclosed.

[0276] The system provides an asymmetric gas flow to each nostril, for example creating a pressure difference at a first nasal prong and a second nasal prong of the nasal interface. Asymmetric flow as described herein refers to different flows within the nasal interface (e.g., nasal prongs) or within the nose (e.g., different flows between the nostrils). In this way, different flows can be delivered by each nasal prong. Asymmetric flow can also include partially unidirectional flow.

[0277] Delivery of asymmetric flow can improve dead space clearance in the upper airway. The described nasal interface is configured to create such asymmetric flow through a flow restriction element.

[0278] The flow generated by respiratory therapy depends on the flow through the nasal interface, which depends on the pressure at each nasal prong. If the pressure at each nasal prong is different, an asymmetric gas flow will be generated.

[0279] If the flow through the nasal interface, leakage, or a combination of flow and leakage is asymmetric, the flow through the nose may become asymmetric during respiration. Partially unidirectional flow can be a type of asymmetric flow. When air is flushed out of the upper airway, partially unidirectional flow can provide improved clearance of the anatomical dead space. Partially unidirectional flow may be more comfortable than fully unidirectional flow. Fully unidirectional flow as described herein includes all flow entering one nostril through a nasal delivery prong and exiting through the other nostril. Partially unidirectional flow as described herein includes flows that can enter the nose via both nostrils and exit the nose through one nostril, flows that can enter the nose through one nostril and exit the nose through both nostrils, or different proportions of flows that can enter the nose through both nostrils and / or different proportions of flows that can exit the nose through both nostrils, and can be flows that can enter the nose via both nostrils and exit the nose through both nostrils or one nostril and optionally exit the nose via the mouth. If there is a pressure difference between the first nasal prong and the second nasal prong, during inhalation, the first nasal prong will receive more gas flow from the gas inlet than the second nasal prong. During exhalation, the second nostril associated with the second nasal prong will expel more gas flow than the first nostril associated with the first nasal prong. The pressure difference between the first nasal prong and the second nasal prong can change depending on whether the patient's respiratory cycle is in the inhalation phase or the exhalation phase.

[0280] Asymmetric flow assessment can be applied over an appropriate time period. For example, asymmetric flow assessment can be applied over one respiratory cycle of the patient or alternatively over a different number of respiratory cycles of the patient.

[0281] Partially unidirectional flow can reduce turbulence in the patient's nasal cavity, which can improve comfort.

[0282] Figures 1A to 1DAn exemplary patient interface 10 is shown, which includes a nasal interface 100 having a first nasal prong 111 and a second nasal prong 112. The nasal interface includes a gas manifold 120, which includes a gas inlet 121.

[0283] The first nasal prong 111 and the second nasal prong 112 are in fluid communication with the gas inlet 121 through the manifold 120. The gas inlet 121 is located at the manifold 120 such that the first nasal prong 111 is closer to the gas inlet 121 and the second nasal prong 112 is farther from the gas inlet 121. The gas manifold 120 forms a manifold chamber 125 to allow gas to pass therethrough. Thus, in some configurations, the gas inlet 121 is located on one side of the gas manifold 120 or otherwise biased to one side.

[0284] The first nasal prong 111 and the second nasal prong 112 have flow paths to allow gas to flow therethrough. The flow paths of the first nasal prong 111 and the second nasal prong 112 are formed by their respective inner walls. The gas manifold 120 is in fluid communication with a gas delivery conduit 300 connected through the gas inlet 121. The gas manifold 120 can be removably attached to or integrally molded onto the gas delivery conduit 300.

[0285] In the illustrated configuration, the gas flow travels from the gas delivery conduit 300 through the gas inlet 121, through the manifold chamber 125 to the first nasal prong 111 and the second nasal prong 112, and through their respective flow channels to the patient's nostrils. Thus, the direction of the gas flow from the gas delivery conduit 300 defines an upstream direction and a downstream direction. However, it should be emphasized that the gas flow is not limited to one direction. For example, the patient's exhalation can provide a gas flow in the opposite direction, such as through the first nasal prong 111 and the second nasal prong 112 into the gas manifold 120. However, the upstream and downstream definitions as defined above are used herein.

[0286] In the illustrated configuration, the first nasal prong 111 and the second nasal prong 112 can be formed as part of an interface body 118. The interface body 118 is a face mount for engaging with the patient's face. The first nasal prong 111 and the second nasal prong 112 are integrally molded or removably attached to the interface body 118.

[0287] The interface body 118 component can be connectable or engagable to a gas manifold component 120a, or can be integrally formed or permanently joined with the gas manifold component 120a. The interface body 118 and the gas manifold portion 120a form the gas manifold 120.

[0288] The interface body 118 can be formed of a soft, flexible material such as silicone, thermoplastic elastomer, or other polymers known in the art. The first nasal prong 111 and the second nasal prong 112 can be soft and can be formed of a sufficiently thin layer of silicone or other suitable material to achieve this property. The interface body 118 and the nasal prongs 111, 112 can be formed, for example, of an elastomeric material that is capable of conforming to the geometry of a patient's nostrils and / or cheeks and providing an effective pneumatic seal.

[0289] The interface body 118 includes two side arms that extend laterally outward from either side.

[0290] In the illustrated configuration, the side arms include wings 113 and 114 that extend laterally from either side of the interface body 118. The wings 113 and 114 are integrally formed with the interface body 118 but can alternatively be separate components.

[0291] In some configurations, the first nasal prong 111 and the second nasal prong 112 extend generally upward and rearward from the interface body 118.

[0292] In some configurations, the second nasal prong 112 is closer to the gas inlet 121, while the first nasal prong 111 is farther from the gas inlet 121.

[0293] The gas inlet 121 is an opening, hole, or port in the gas manifold 120 for releasably or permanently connecting to a conduit such as a gas delivery conduit 300. In some arrangements, the gas inlet 121 can form a tube or passage that extends from or is part of the gas manifold 120. In some arrangements, the gas inlet 121 has fastening or connecting means for securing to the conduit.

[0294] The gas manifold 120 can include a single gas inlet 121.

[0295] In the illustrated configuration, the first nasal prong 111 has an opening at its tip or end 131 for delivering gas from the gas manifold 120. The gas delivered through the first nasal prong 111 exits the first nasal prong 111 via the first end 131. The first nasal prong 111 has a first base 135 at the end of the first nasal prong 111 opposite the first end 131. The first base 135 is another opening and is connected to the gas manifold 120 and allows gas to flow from the manifold chamber 125 to the first nasal prong 111. The first base 135 can be integrally formed with or removably connected to the interface body 118.

[0296] The second nasal prong 112 has an opening at its tip or end 132 for delivering gas from the gas manifold 120. The gas delivered through the second nasal prong 112 exits the first nasal prong 112 via the second end 132. The second nasal prong 112 has a second base 136 at an end of the second nasal prong 112 opposite the second end 132. The second base 136 is another opening that is connected to the gas manifold 120 and allows gas to flow from the manifold chamber 125 into the second nasal prong 112 and through the second nasal prong. The second base 136 may be integrally formed with or removably connected to the interface body 118.

[0297] The first nasal prong 111 and the second nasal prong 112 may have any suitable shape to seal or insert into the patient's nostrils. For example, in one configuration, the first nasal prong 111 and the second nasal prong 112 may be substantially tubular and may be sized to be larger than the patient's nostrils, but may be soft or flexible to deform when inserted into the nostrils and seal against the nostrils. In one example, the first nasal prong 111 and / or the second nasal prong 112 are curved and optionally curved to point posteriorly towards the patient's head during use. The first nasal prong 111 and / or the second nasal prong 112 may also be configured such that their outlets point towards the midline plane of the nasal interface 100. When the nasal interface 100 is in use, this midline position may be parallel to the sagittal plane of the patient. In other words, when the nasal interface 100 is in use, the outlets of the first nasal prong 111 and / or the second nasal prong 112 may point towards the sagittal plane of the patient. In one configuration, the first nasal prong 111 and the second nasal prong 112 may be soft or flexible to deform and are sized to form a non-sealing arrangement with the nostrils. In one configuration, the first nasal prong 111 and the second nasal prong 112 may not enter the nostrils but be located proximally. In some configurations, the nasal prongs 111, 112 are softer or more flexible than the interface body 118.

[0298] The nasal interface 100 provides a patient interface adapted to deliver a high airflow, high humidity gas flow to the patient's nasal cavity / nostrils. In some configurations, the nasal interface 100 is adapted to deliver a high flow of gas over a wide flow range (e.g., about 8 lpm, or higher depending on other treatment applications, possibly such as 10 - 50 lpm or higher). In some configurations, the nasal interface 100 is adapted to deliver relatively low pressure gas.

[0299] The gas manifold component 120a may be inserted into the interface body 118 to form the gas manifold 120. The interface body 118 may include at least one substantially horizontal side entry passage 118a, 118b that leads to the base or the interior of the interface body 118 for releasably receiving the outlet of the gas manifold component 120a passing therethrough.

[0300] The gas manifold component 120a can optionally be inserted into the interface body 118 from either of two opposite horizontal directions, i.e., from the left or the right. In this way, the orientation of the gas flow manifold component 120a can be reconfigured relative to the interface body 118. In other words, depending on the most convenient situation, e.g., depending on which side of the user the gas source or the breathing apparatus is located, the user can choose to have the gas inlet 121 (and the conduit 300 extending therefrom) of the manifold component 120a extend from the left or the right side of the interface body 118 of the nasal interface 100.

[0301] The interface body 118 can include a pair of opposite side access passages 118a, 118b leading to the interior of the base or the interface body 118, each side access passage being adapted to releasably receive the outlet of the gas manifold component 120a passing therethrough.

[0302] The interface body 118 is shaped to generally follow the contour of the patient's face around the upper lip region. The interface body 118 is molded or preformed to be conformable and / or flexible in the facial region where the intubation will be located to adapt to, accommodate, and / or correspond to the contour of the user's face. In some configurations, the interface body 118 includes a portion or recess that houses a part of the patient's nose and reduces the pressure on the lower side of the housed portion.

[0303] The nasal interface 100 can be held on the patient's face using a headgear. The headgear includes a headband 200. The headband 200 can be of a single continuous length and is adapted to extend along the patient's cheeks, over the ears, and around the back of the head during use, can be adjustable, and / or can extend around other parts of the patient's head.

[0304] In the illustrated exemplary configuration, the main ends 2011 and 2021 of the headband 200 are adapted to releasably connect to corresponding structures 101 and 102 located on either side of the nasal interface 100 to hold the nasal interface 100 in place during use.

[0305] In one configuration, clip members that can be received and held within the corresponding structures 101, 102 are provided at each end 2011, 2021. The clip members can be coupled to the band at the respective main ends. Additionally, the length of the headband 200 is adjustable to assist in adjusting the band according to the wearer's head. The headband 200 can be formed of a soft and stretchable / elastic material, such as an elastic textile material / fabric that is comfortable for the wearer. Alternatively, the headband 200 can be formed of a substantially more rigid or less flexible material, such as a hard plastic material.

[0306] The headgear may also include additional straps or other headgear components that, in use, connect the headband 200 to extend over the patient's head. The overhead strap or overhead member may have the benefit of pulling the strap 200 up and over the patient's ears in use to improve fit and comfort.

[0307] Generally, but also referring to Figures 1A to 1C , in an exemplary configuration of the adjustable strap 200, the adjustment mechanism is provided in the form of one or more insertable / removable strap segments or strap extensions 2201.

[0308] The fixed-length strap segment 2201 is capable of being releasably connected to the main strap 210 to extend the length of the main strap. In this configuration, the main strap 210 includes a pair of intermediate or secondary ends 2031, 2041 that are releasably connected to each other and are also releasably connected to the respective ends 2211 and 2221 of the strap segment 2201. When the secondary ends 2031 and 2041 are connected to each other, the main strap 210 has an initial length / dimension that is continuous for the wearer. To extend the length of the strap 200 beyond this initial length, the main strap 210 can be disconnected at the secondary ends 2031 / 2041, and one or more additional strap segments 2201 are connected between the secondary ends.

[0309] Multiple strap segments 2201 having different predetermined lengths can be provided to provide optional adjustment lengths. For example, one or more strap segments 2201 can have a length in the range of from about 1 cm to about 10 cm, or in the range of from about 2 cm to about 6 cm. The strap segment 220 has a length of, for example, about 2 cm, about 4 cm, or about 6 cm. It should be understood that these examples are not intended to be limiting, and the length of each strap segment can be any size as it depends on the user and / or application.

[0310] In addition, each end 2211, 2221 of each strap segment 2201 can be connected to the respective ends 2211, 2221 of another strap segment 2201 and / or to the respective secondary ends 2031, 2041 of the main strap 210, such that the user can combine one or more strap segments 2201 having the same or varying lengths to adjust the total extended length as needed.

[0311] The additional strap segments can be formed of a soft and stretchable / elastic material, such as an elastic textile material / fabric that is comfortable for the wearer. For example, a tubular knitted headband or a portion of the headband 210 can be adjusted, particularly for comfort on the user's ears.

[0312] It should be understood that particular comfort can be obtained with a headband that is capable of providing proper positioning of the nasal interface 100 at a relatively stable position on the user's face while also providing a relatively loose fit or a low-tension fit around the user's head.

[0313] Alternatively, the additional strap segments may be formed from a substantially rigid material, such as a hard plastic material.

[0314] A strap connector 2301 is provided at each of the secondary ends 2031, 2041 of the main strap 210 and the corresponding ends 2031, 2041 of the strap segment 2201.

[0315] Each strap connector 2301 is provided at one end with a strap connection mechanism for coupling to the strap material, and at the opposite end with a coupling mechanism for releasably coupling the corresponding ends of similar connectors 2301.

[0316] In an alternative, the strap connector 2301 may be a buckle of various different forms that is adapted to adjust the length or tension of the head strap segment 210 that holds the patient interface in place around the user's head.

[0317] It should also be understood that the connector 2301 may be positioned offset from the midpoint at the rear of the user's head, or may be offset to one side of the user's head. This may be advantageous in order to avoid bumping a part of the user's head that may be uncomfortable for the user in some positions, such as when sleeping.

[0318] In yet another configuration, the strap segments may have different lengths in order to be set asymmetrically or to assist in operation in the case of an offset connector 2301 position. Additionally, in the two strap segments 210, the length of one of these straps may be adjustable while the length of the other may not be adjustable. For example, one strap segment 210 may have a constant length or be permanently connected to the connector 2301.

[0319] In an exemplary configuration, the strap connection mechanism may include a series of internal teeth located within the body of the connector for establishing a friction fit engagement with the corresponding end of the strap. Hinged jaws of the body are provided and the hinged jaws close over the teeth to securely hold the end of the strap on the teeth. The releasable connection mechanism at the other end includes a pair of convex and concave members, such as a projection and a hole respectively, both of which are adapted to connect to corresponding convex and concave members of a similar connector 230. A lug on the projection may connect with a recess in the concave member to provide a snap fit engagement between the members. It should be understood that in alternative configurations, any other suitable connector configuration may be used to releasably connect the secondary ends of the strap to each other and to the ends of additional strap segments.

[0320] The cannula connectors 2401 are provided at the main ends 2011 and 2021 of the main bands 210. These connectors 2401 have a band connection mechanism similar to the band connectors 2301 of the secondary ends 2031 and 2041, but include a clip member such as a push - fit clip 2411 at the end of the connector 2401 opposite the band end. The clip 2411 is configured to releasably couple to corresponding structures 101, 102 at the sides of the nasal interface 100. The clip member 2411 can be a bendable member that forms a hinge relative to the band, such as a plastic member. The clip 2411 can be pre - formed to have a curved shape along its length. In one example, the clip 2411 can be pre - formed with two or more portions angled relative to each other, for example, an angle between 0 degrees and 20 degrees. This curvature and / or angle allows the clip 2411 to conform to the contour of the patient's face in the area of the clip 2411.

[0321] The nasal interface 100 can include sleeves 270. Each sleeve 270 can be pre - formed to have a curved shape along its length. In one example, each sleeve 270 can be pre - formed with two or more portions angled relative to each other, for example, an angle between 0 degrees and 20 degrees. This curvature and / or angle allows the sleeve to conform to the contour of the patient's face or cheek in the area of the sleeve during use. Alternatively, the sleeve 270 can assume the shape of a curved sleeve when engaged with the main ends 2011, 2021 of the headband 200 or the connector 2401.

[0322] The sleeve 270 provides a surface area with a relatively high - friction surface material for frictionally engaging with the user's face or facial skin. This surface area is positioned to frictionally engage with the user's facial cheek skin. This surface area is at least localized to the band or band segment that will be positioned on the user's cheek. The surface area provided with the relatively high - friction surface material can be a material that is smooth and comfortable for the patient's skin. Thus, the sleeve 270 or at least the surface area 271 is formed of a material that is relatively softer than the connector 2401.

[0323] In one configuration, the surface area 271 or the sleeve 270 is formed of a soft thermoplastic elastomer (TPE), but can alternatively be formed of other plastic materials such as silicone or any other biocompatible material.

[0324] The surface area 271 can be a surface of a relatively wider surface area that is closer to the patient interface compared to a surface area further away from the patient interface. In one configuration, the sleeve 270 tapers from a relatively wide surface area 273 to a relatively small surface area 274 in a direction extending away from the connection point between the connector 2401 and the nasal interface 100. The width of the sleeve at the end 273 can be the same as or similar to the width of the tapered distal ends of the corresponding wings 113, 114 of the interface body 118. This provides a smooth transition between the nasal interface 100 and the headcap.

[0325] The sleeve 270 can be colored to provide identification of the nasal interface 100. As described herein, the nasal interface can be provided in different sizes, such as small, medium, and large. The sleeve 270 for each of these sizes can include a different color to indicate the different sizes. Alternatively or additionally, the cannula can be colored in a specific manner to indicate that the nasal forks 111, 112 have an asymmetric nasal flow rather than a symmetric nasal flow.

[0326] A headgear for other forms of interfaces other than nasal cannulas can include a cheek support 270 as described or similar at or near either side end of the strap of the headgear of the interface, the cheek support being connected to the nasal interface for frictionally engaging with the user's face to stabilize the mask at the cheek on the face. Such a headgear can also include a single headband adapted to extend along the patient's cheek, over the ear, and around the back of the head during use, and the ends thereof include clips in any suitable form that are coupled to the nasal interface (or permanently attached to the nasal interface) at either side.

[0327] Referring Figures 1A to 1C , in the illustrated construction, the patient interface 10 includes a tube retaining clip 280. The tube retaining clip 280 can support a patient conduit 300 or other gas supply tube from a portion of the patient interface 10. By supporting the patient conduit 300 or other gas supply tube from the nasal interface 100 or near it, the bending moment applied to the patient conduit 300 or other gas supply tube 300 due to the asymmetric flow through the first fork 111 and the second fork 112 and / or the movement of the patient's head will be blocked by the tube retaining clip 280, thereby enhancing patient comfort.

[0328] In the illustrated construction, the tube retaining clip 280 includes a tubular body 281 for receiving and accommodating a portion of the patient conduit 300 or other gas supply tube therein.

[0329] In the illustrated construction, the tube retaining clip 280 supports the patient conduit 300 or other gas supply tube from the headgear of the patient interface. In an alternative construction, the tube retaining clip 280 can support the patient conduit 300 or other gas supply tube from a portion of the nasal interface 100 of the patient interface. For example, the tube retaining clip 280 can support the patient conduit 300 or other gas supply tube from the interface body 118. In some constructions, the tube retaining clip 280 can support the patient interface from one or either of the wings 114, 115 of the nasal interface 100.

[0330] The hook portion 282 projects from the tubular body 281 to couple to a strap or other component of the headgear. In this way, the conduit 300 can be coupled or tethered to the headband 210 or headgear during use. If the conduit 300 is pulled, the force will be applied to the headband 210 rather than directly to the cannula 100. This repositioning of the force will reduce the likelihood that the forks 111 and 112 of the nasal interface 100 will pop out of the patient's nostrils.

[0331] One or more tethering points for attaching the tube retention clip 280 can be located on the headgear, preferably having at least two symmetric tethering points on either side of the headgear to increase usability.

[0332] It should also be understood that the tube retention clip 280 can be removed from the patient conduit 300 or other gas supply tube, or can be a permanent fitting on the patient conduit or other gas supply tube.

[0333] The tube retention clip 280 can be connected (removably or permanently) or attached to a portion of the patient interface 10, such as an interface portion that provides a relatively more rigid area (e.g., to support the patient conduit 300). The tube retention clip can also be positioned or fixed at a specific location on the patient conduit 300, e.g., a predetermined location that will hold the retention clip in place.

[0334] In some configurations, one or both of the first fork 111 and the second fork 112 ensure that a gap is maintained between the outer surface of the fork and the patient's skin to avoid a seal between the nasal interface 100 and the patient. This provides a gas path for the gas flow around the outer surface of the nasal forks 111, 112.

[0335] The patient interface 10 can have any one or more of the features and functions described in PCT Publication No. WO2014 / 182179 or U.S. Patent No. 10,406,311. The contents of these specifications are incorporated herein by reference in their entirety.

[0336] As an alternative to the headgear, the patient interface can include a fixation system of the type described in PCT Publication No. WO2012 / 053910 or U.S. Patent No. 10,238,828. The contents of these specifications are incorporated herein by reference in their entirety.

[0337] The nasal interface can have any one or more of the features described in relation to the nostril locator of U.S. Patent No. 10,918,818. The contents of this specification are incorporated herein by reference in their entirety.

[0338] Referring Figure 2 ,, there is shown a patient interface 10 having a nasal interface 100 as described in reference Figures 1A to 1D . Additionally, at least one element is provided that is configured or arranged to increase the resistance to gas flow through the nasal interface or a portion thereof.

[0339] Figure 2 Figure 2 schematically shows a first fork element 201, a second fork element 202, and a manifold element 203, which are configured or arranged to increase the resistance to gas flow through the respective first fork 111, second fork 112, and manifold 120.

[0340] The elements 201, 202, 203 used throughout the text may also be referred to as flow restrictors or flow limiters.

[0341] Although Figure 2 Figure 2 shows the first fork element 201, the second fork element 202, and the manifold element 203, in a plurality of configurations as described in detail below, there may be a single element 201, 202, 203 in the nasal interface 100, or any combination of two elements (e.g., the second fork element 202 and the manifold element 203).

[0342] When present, the second fork element 202 is located within the second fork 112 and is configured to increase the flow resistance of the gas flow through the second fork 112. The second fork element 202 may be located at or near the second base 136, at or near the second end 132, or at any position between the second end 132 and the second base 136.

[0343] In some configurations, the flow resistance provided by any of the elements 201, 202, 203 described herein may be such that very little flow (negligible flow) or no flow is allowed through the element.

[0344] When present, the manifold element 203 is positioned within the manifold chamber 125 and is configured to increase the flow resistance of the gas flow through the gas manifold 120. The manifold element 203 is positioned between the inlets of the flow channels for the respective first fork 111 and second fork 112, e.g., between the first base 135 and the second base 136. Thus, in a configuration where the gas inlet 121 is located on one side of the gas manifold 120, the gas flow through the manifold chamber 125 from the gas inlet 121 will be restricted for one proximal fork and not restricted for the other fork. Specifically, in the case where the first fork 111 is close to the gas inlet 121, the gas flow is not restricted by the manifold element 203 to reach the first base 135 because the gas inlet 121 and the first base 135 are in fluid communication without gas passing through the manifold element 203. The gas flow from the gas inlet 121 through the manifold chamber 125 to the second base 136 is restricted by the manifold element 203 because the gas inlet 121 and the second base 136 are in fluid communication with the gas having to pass through the manifold element 203.

[0345] When present, the manifold element 203 divides the manifold chamber 125 into an upstream portion 141 and a downstream portion 142 located on either side of the manifold element 203. The upstream portion 141 is located on the side of the gas inlet 121 of the gas manifold 120.

[0346] When present, the first prong element 201 is positioned within the first prong 111 and serves to increase the flow resistance of the gas flow through the first prong 111. The first prong element 201 can be located at or near the first base 135, at or near the first end 131, or at any position between the first end 131 and the first base 135.

[0347] When present individually in the nasal interface 100, each of the elements 201, 202, 203 causes an asymmetric gas flow at the first prong 111 and the second prong 112 and thus at each nostril. The asymmetric flow results in a pressure difference between the first nasal prong 111 and the second nasal prong 112, and thus in a pressure difference between the patient's nostrils. Thus, a single first prong element 201, second prong element 202, or manifold element 203 can provide flow restriction to cause an asymmetric gas flow at each prong 111, 112 accordingly. Similarly, a combination of the second prong element 202 and the manifold element 203 (in the absence of the first prong element 201) will result in a restriction of the flow to the second prong 112, which will result in an asymmetric flow. However, the presence of the first prong element 201 and the second prong element 202 (or the manifold element 203) that restrict the gas flow in a similar manner at each of the first prong 111 and the second prong 112 will not produce an asymmetric gas flow. However, in some configurations, the elements 201, 202, 203 can be configured to restrict the flow in different magnitudes so as to provide an asymmetric flow even when there is a combination that restricts the flow to the first prong 111 and the second prong 112.

[0348] In some configurations, the nasal prong closest to the gas inlet 121 has no restriction because the gas flow is least disturbed by the geometry from the gas inlet 121 to the corresponding nasal prong. Thus, as Figure 2In the case where there is no first element 201 in the first nasal fork 111. In some configurations, when there is a first fork element 201, at least one of the second fork 112 and the gas manifold 120 has no elements or flow restrictions. In some configurations, when there is a second fork element 202, at least one of the first fork 111 and the gas manifold 120 has no elements or flow restrictions. In some configurations, when there is a manifold element 203, at least one of the first fork 111 and the second fork 112 has no elements or flow restrictions. Each of the at least one element as described herein causes an asymmetric flow at the patient's nostrils. In an example, when providing a gas flow to the patient, optionally during the patient's inhalation phase, the patient's exhalation phase, or during the patient's respiratory cycle, each of the at least one element causes an asymmetric flow at the patient's nostrils. In some configurations, the elements 201, 202, 203 passively cause flow restrictions.

[0349] Although the elements 201, 202, 203 are shown as rectangles, these elements 201, 202, 203 can take any suitable form. Examples in this regard are provided below.

[0350] The flow restrictions provided by the elements 201, 202, 203 can take various forms depending on the desired flow differences between the forks. Referring to Figures 3A to 3C , the elements 201, 202, 203 take the form of a plate or wall 205. The plate 205 is positioned or formed in the forks 111, 112 or the manifold chamber 125. The plate 205 is positioned across the passage through which the gas flows. The plate 205 includes holes 207 to allow the gas to flow through it. The holes 207 formed in the first fork element 201, the second fork element 202 or the manifold element 203 provide an opening smaller than the flow channel and restrict the gas flow through it.

[0351] In some configurations, the plate 205 is positioned substantially centrally across the passage through which the gas flows.

[0352] The holes 207 can be located at the center of the plate 205 or can be eccentric within the plate.

[0353] Referring to Figure 3B , the plate 205 has a surface facing the gas flow from the gas inlet 121 (e.g., the upstream direction). This is the inlet surface 211. The plate 205 has a surface facing the direction opposite to the gas flow from the gas inlet 121 (e.g., the downstream direction). This is the outlet surface 213. The holes 207 are formed to extend between the surfaces such that the plate 205 has a thickness.

[0354] The inlet surface 211 transitions between the surface facing the flow and the formation of the holes 207 (e.g., the walls of the holes 207). InFigure 3B In Figure 3B , the transition portion 214 between the inlet surface 211 and the orifice surface 207 is a sharp-corner transition portion 214. The sharp-corner transition portion 214 can be substantially a right angle formed between the two surfaces. Alternatively, the transition portion can be formed as a rounded corner or a chamfered edge. The equivalent rounded or chamfered angle of the sharp-corner transition portion 214 from the inlet surface 211 to the chamfer has an angle between approximately 75° and 110°. The sharp corner 214 causes disruption to the gas flow, such as causing turbulence. This results in additional disruption to the flow caused by the elements 201, 202, 203.

[0355] The outlet surface 213 transitions between the orifice 207 and the wake. In Figure 3B In Figure 3B , the transition portion 216 between the orifice 207 and the outlet surface 213 is a smooth-angle transition portion 216 with a rounded or chamfered edge. The equivalent rounded or chamfered angle of the smooth-angle transition portion 216 from the outlet surface 213 to the chamfer has an angle between approximately 30° and 75°. The smooth angle 216 allows the gas flow to leave the orifice 207 to fill the flow channels passing through the elements 201, 202, 203.

[0356] Referring to Figure 3C , the transition portion 215 between the inlet surface 211 and the orifice surface 207 is a smooth-angle inlet transition portion 215. Thus, it is similar to the smooth-angle outlet transition portion 216. The equivalent rounded or chamfered angle of the smooth-angle transition portion 215 from the inlet surface 211 to the chamfer has an angle between approximately 30° and 75°.

[0357] In some configurations, the sharp-angle inlet transition portion 214 or the smooth-angle inlet transition portion 215 has a greater angle or chamfer angle than the smooth-angle outlet transition portion 216. This ensures that the gas flow is disrupted when entering the orifice 207.

[0358] The variations in the smooth and sharp transition portions 214, 215, 216 result in the elements 201, 202, 203 having a higher discharge coefficient than the equivalent plate 205 of the orifice 207 with the same inner diameter.

[0359] The smooth-angle transition 216 at the outlet surface 213 can ensure that, for example, during a patient's exhalation, the gas flow towards the manifold chamber 125 through the first fork 111 or the second fork 112 having the first fork element 201 or the second fork element 202 is less restricted. Thus, the accumulation of gas in either nostril of the patient is avoided.

[0360] In some configurations, the diameter of the aperture 207 can be reduced at one location, such as near the exit surface 213, such that the change in cross-section creates an increased pressure drop relative to the larger-diameter inlet surface 211 and thus enters the elements 201, 202, 203 more smoothly. This change in the diameter of the aperture 207 can be formed as a nozzle.

[0361] When formed as an orifice, the aperture 207 can be any shape, such as circular, or can be triangular, square, or any polygonal shape. Multiple apertures 207 can be formed in the plate 205. In some examples, a non-perforated but non-adjacent plate 205 with one or more small gaps can be provided, or an adjacent wall with a perforation pattern can be provided. A porous medium such as a filter can be used as the plate 205. Gaps, slits, or cuts can be formed in the plate 205, extending longitudinally either vertically or horizontally relative to the plate 205 itself. A perforated wall or plate 205 can have the benefit of reducing acoustic noise generation.

[0362] In some configurations, the elements 201, 202, 203 can have a varying surface texture in the gas flow path to provide a pressure drop across the elements 201, 202, 203. A substantially rougher area can have an increased pressure drop.

[0363] In some configurations, the first fork element 201, the second fork element 202, or the manifold element 203 can be in the form of a valve to cause a pressure drop to restrict flow. Referring Figure 4 , there is shown a patient interface 10, which has a nasal interface 100 as described in Figures 1A to 1D and Figure 2 . The manifold element 203 includes a manually adjustable flow restrictor 220.

[0364] In this configuration, the gas manifold 120 has a manifold element 203 that is connected to or forms with an adjustment mechanism for the flow restrictor 220, which can be actuated from outside the gas manifold 120.

[0365] In some configurations, the flow restrictor 220 has a slider 221 disposed on the exterior of the gas manifold 120 for adjusting the position of the body 222 of the flow restrictor 220 within the manifold chamber 125. The body 222 of the flow restrictor provides a variable opening through the manifold chamber 125 by varying how much of the flow path cross-sectional area is "open" or effective and how much gas flow passes through the manifold element 203 to the second fork 112. In some configurations, the manifold chamber 125 tapers between a first base 135 and a second base 136. The flow restrictor 220 is movable along the manifold chamber 125, e.g., in a direction toward or away from the gas inlet 121, such that the passage between the first base 135 and the second base 136 in the manifold chamber 125 varies. In use, by actuating the slider 221 along the exterior of the gas manifold 120, the flow restrictor 220 is moved closer to the first fork 111 to block flow to the second fork 112. The degree of restriction can be greater / lesser depending on the size or height of the body 222. Conversely, moving the element toward the second fork 112 reduces the restrictive effect on the flow to the second fork 112 since the gas flow path in the manifold chamber 125 is less restricted.

[0366] In some arrangements, the flow restrictor 220 can be further moved into the manifold chamber 125 to provide a smaller opening, e.g., a vertical movement. Thus, the cross-sectional area of the flow path varies through the body 222, leaving a smaller effective orifice for flow. These movements can all be applied to a single flow restrictor 220.

[0367] Referring Figure 5 , the patient interface 10 is shown as having the nasal interface 100 described with reference Figures 1A to 1D , Figure 2 and 4 . The flow restrictor 220 of the manifold element 203 is replaced by a rotatable restrictor 225.

[0368] The rotatable restrictor 225 is arranged to extend through the gas manifold 120 such that an inner portion is within the manifold chamber 125 and an outer portion is outside the gas manifold 120. The rotatable restrictor 225 is adjustable to increase or decrease the gas flow through the manifold chamber 125 located downstream of the manifold element 203. The rotatable restrictor 225 is a helix to allow rotation to move the rotatable restrictor 225 further into the manifold chamber 125 to effectively reduce the orifice through which flow passes, or increase the orifice through which gas flows. The adjustment is made by rotating the outer portion of the rotatable restrictor located outside the gas manifold 120. Thus, the gas flow from the gas inlet 121 is restricted at the second fork 112 by the rotatable regulator 225, and the amount of restriction can be varied.

[0369] The threads of the rotatable limiter 225 help to hold the manifold element 203 in place, allowing the clinician to safely construct the nasal interface 100 as needed without the risk of the manifold element 203 being struck or displaced at a later point in time.

[0370] The valves of the manifold element 203 (such as the flow limiter 220 or the rotatable limiter 225) can be manually or electronically controlled.

[0371] Although reference is made to the manifold element 203 in Figure 4 and Figure 5 either the first fork element 201 or the second fork element 202 can utilize such a valve. Additionally, the sliding or rotational functions of the flow limiter 220 or rotatable limiter 225 valves can be combined.

[0372] Referring to Figure 6 a patient interface 10 with a nasal interface 100 is shown. This arrangement is as described in reference Figures 1A to 1D and can optionally be combined with other configurations described herein.

[0373] In this configuration, a manifold opening 230 is formed in the wall of the gas manifold 120. The manifold opening 230 allows a portion of the gas to pass through it and thus exit the manifold chamber 125. The manifold opening 230 can include one or more holes.

[0374] In this configuration, there is a manifold element 203 as described elsewhere herein. Thus, the manifold chamber 125 is divided into an upstream portion 141 and a downstream portion 142 on either side of the manifold element 203. The upstream portion 141 is on the gas inlet 121 side of the manifold chamber 125. The manifold opening 230 is positioned in the downstream portion 142.

[0375] In some configurations, the manifold opening 230 is positioned on a wall of the gas manifold 120 that is generally opposite the gas inlet 121. In other configurations, the manifold opening 230 is positioned on a wall of the gas manifold 120 that is generally opposite the second base 136. In some configurations, these can be the same location.

[0376] As described above with reference to Figure 2 the manifold element 203 is a restriction to the gas flow. Thus, the upstream portion 141 is generally at a higher pressure because the gas flow is restricted by the manifold element 203 into the downstream portion 142. This is especially true during patient inhalation. Thus, more gas flow will travel through the unobstructed / unrestricted first fork 111 compared to the second fork 112.

[0377] During exhalation by the patient, gas may leak into the surrounding environment where the second prong 112 is unsealed. Gas can also flow back into the gas manifold 120 by flowing back through the second prong 112. In the presence of the manifold element 203, this causes an increase in pressure in the downstream portion 142 because the gas flow through the manifold element 203 is restricted. The manifold opening 230 allows some gas to be discharged into the environment. Thus, in some configurations, the amount of pressure experienced in the nasal interface 100 can be prevented from reaching an undesirable level.

[0378] Factors that can cause an increase in pressure within the downstream portion 142 also include excessive blockage of the patient's nostrils. In some cases, this may be caused by incorrect interface sizing.

[0379] The manifold opening 230 can be used as an exhalation outlet.

[0380] During inhalation, some gas flow through the manifold opening 230 may occur such that not all of the gas that flows from the upstream portion 141 to the downstream portion 142 passes through the second prong 112. However, even if a certain amount of gas flow does not enter the second prong 112 but is discharged into the environment through the manifold opening 230, the increased pressure will have the effect of reducing the exhaled gas flow exhaled from the nostril associated with the second prong 112. This has the advantage of increasing the asymmetry, which is also achieved by positioning the manifold element 203.

[0381] Reference Figure 7 shows a patient interface 10 with a nasal interface 100. The arrangement, as described in reference Figure 6 includes a manifold opening 230 formed in the wall of the gas manifold 120.

[0382] In this configuration, the manifold opening 230 is configured to be connected to a pressure drop member 232. The pressure drop member 232 is configured to prevent overpressure from occurring. This helps with possible overpressure in the downstream portion 142 of the manifold chamber 125, as described above with reference to the manifold opening 230 itself.

[0383] For the pressure drop member 232, a variety of configurations are possible. In one configuration, the pressure drop member 232 is a porous medium, such as a filter. In another configuration, the pressure drop member 232 is a nozzle. Other members 232 that cause a generally known pressure drop can also be used.

[0384] In some configurations, the pressure drop member 232 is an auxiliary tube. The auxiliary tube can be a nasogastric tube, i.e., extending into at least one of the first prong 111 or the second prong 112.

[0385] In another configuration, the pressure drop member 232 is a valve. The valve can be a pressure reducing valve with a defined pressure threshold at which the valve opens. In other configurations, the valve depends on the flow rate to increase the flow rate based on a flow - pressure relationship. Thus, the pressure in the downstream portion 142 is controlled and allowed to be released in a controlled manner while maintaining an asymmetric flow.

[0386] For clarity, in some configurations, the manifold opening 230 and the pressure drop member 232 can be combined such that the manifold opening 230 is a nozzle, valve, porous medium, auxiliary tube, or other member itself rather than an opening leading to such a member. In one example, the manifold opening 230 and the pressure drop member 232 are one - way valves that allow insertion of an auxiliary tube (such as a nasogastric tube). The one - way valve can be a flexible valve.

[0387] The pressure drop member 232 can be manually or electronically controllable. For example, with the aid of a valve, it can be controllable to open or close in response to a pressure threshold.

[0388] In some configurations, the pressure drop member 232 is a bubble CPAP (BCPAP) bubbling chamber, which is configured to control pressure. The use of bubble CPAP allows an indication of the minimum pressure observed. For example, if bubbling occurs when set to 2 cmH 2 O, this indicates positive end - expiratory pressure (PEEP). Thus, a clinician or caregiver can configure the pressure drop member 232 to vary the pressure or flow rate. The flow rate and pressure can be configured independently.

[0389] In some configurations, leakage or venting of gas to the surrounding environment at the unsealed forks 111, 112 and / or at the manifold opening 230 reduces the positive end - expiratory pressure (PEEP). Thus, the therapy profile changes due to the exhaust function.

[0390] In Figure 6 and 7 configurations, the manifold element 203 has been described. However, it is not necessary for the manifold element 203 to be present as described. Instead, in some configurations, the manifold opening 230 can still be implemented to assist with pressure while maintaining an asymmetric flow in cases where preferential flow is provided to the first fork 111 or the second fork 112. Additionally, in some configurations including the manifold opening 230, there can be a first fork element 201 or a second fork element 202, or other features to cause an asymmetric flow as described throughout this document. The manifold opening 230 and the optional pressure drop member 232 reduce the risk of pressure damage, for example, due to improper fitting.

[0391] Referring to Figure 8 shows a patient interface 10 with a nasal interface 100. The arrangement is as shown in reference Figure 2as described.

[0392] In this arrangement, the manifold element 203 is formed as a one-way valve 204. Thus, when the one-way valve 204 is closed, a portion of the flow restriction serves to prevent flow from the downstream portion 142 from flowing into the upstream portion 141 through the manifold element 203.

[0393] The one-way valve 204 can also serve as a flow restriction, for example as described elsewhere herein with reference to the manifold element 203. Thus, the valve can provide a restriction to flow, for example having an opening smaller than the cross-section of the manifold chamber 125, to reduce the gas flow from the upstream portion 141 to the downstream portion 142. Thus, an asymmetric flow is provided between the first fork 111 and the second fork 112.

[0394] In some configurations, the one-way valve 204 is a duckbill valve.

[0395] Due to the possible pressure build-up within the downstream portion 142 of the manifold chamber 125 by implementing the one-way valve 204, this arrangement can be combined with the manifold opening 230 as Figure 8 shown and described above with reference to Figure 6 Likewise, the pressure drop member 232 described with reference to Figure 7 can also be implemented.

[0396] Figure 9 An exemplary patient interface 10 is shown, which includes a nasal interface 100 having a first nasal fork 111 and a second nasal fork 112. The components of the patient interface 10 are similar to those described with reference to Figures 1A to 1D and like reference numerals are used herein for like features.

[0397] The nasal interface includes a gas manifold 120, which includes a first gas inlet 121 and a second gas inlet 122. The gas manifold 120 forms a manifold chamber 125 to allow gas to pass therethrough. The nasal interface 100 includes a flow-altering feature to provide an asymmetric flow at one of the forks 111, 112.

[0398] The first nasal fork 111 and the second nasal fork 112 are in fluid communication with the first gas inlet 121 and the second gas inlet 122 through the gas manifold 120. The first gas inlet 121 is positioned at the gas manifold 120 such that the first nasal fork 111 is closer to the first gas inlet 121, while the second nasal fork 112 is farther from the first gas inlet 121. The second gas inlet 122 is positioned at the gas manifold 120 such that the second nasal fork 112 is closer to the second gas inlet 122, while the first nasal fork 111 is farther from the second gas inlet 122.

[0399] In some configurations, the positions of these forks are reversed such that the second nasal fork 112 is closer to the first gas inlet 121 and the first nasal fork 111 is closer to the second gas inlet 122.

[0400] In some configurations, the first gas inlet 121 and the second gas inlet 122 are located at opposite sides of the gas manifold 120. In other configurations, the first gas inlet 121 and the second gas inlet 122 are arranged adjacent to each other.

[0401] The first fork 111 and the second fork 112 have flow passages to allow gas to flow therethrough. The flow passages of the first fork 111 and the second fork 112 are formed by their respective inner walls.

[0402] The gas manifold 120 is in fluid communication with a gas delivery conduit 300 that is connected to the gas manifold 120 through the first gas inlet 121 and the second gas inlet 122.

[0403] In some configurations, the gas delivery conduit 300 has a first gas delivery conduit 301 connected to the first gas inlet 121 and a second gas delivery conduit 302 connected to the second gas inlet 122. The gas delivery conduit 300 can be divided into the first delivery conduit 301 and the second delivery conduit 302, for example, by a Y-piece. In some other configurations, the first gas delivery conduit 301 and the second gas delivery conduit 302 are directly connected to one or more flow generators. The gas manifold 120 can be removably attached to or integrally molded with the gas delivery conduit 300, the first gas delivery conduit 301, or the second gas delivery conduit 302.

[0404] The first gas inlet 121 and the second gas inlet 122 are openings, holes, or ports in the gas manifold 120 for releasably or permanently connecting to a conduit, such as the first gas delivery conduit 301 or the second gas delivery conduit 302. In some arrangements, the first gas inlet 121 and the second gas inlet 122 can form a tube or channel extending from or as part of the gas manifold 120. In some arrangements, the first gas inlet 121 and the second gas inlet 122 have fastening or connecting devices for securing to a conduit.

[0405] In the illustrated configuration, the gas flow travels from the first gas delivery conduit 301 through the gas inlet 121, through the manifold chamber 125 to the first prong 111 and the second prong 112, and through their respective flow channels to the patient's nostrils. The gas flow also travels from the second gas delivery conduit 302 through the gas inlet 122, through the manifold chamber 125 to the second prong 112 and the first prong 111, and through their respective flow channels to the patient's nostrils. However, in some configurations, the gas can flow in the opposite direction, such as during exhalation, where the gas flow from the patient's nostrils can flow through the first prong 111 and the second prong 112 into the gas manifold 120.

[0406] In the illustrated configuration, the first nasal prong 111 and the second nasal prong 112 can be formed as part of the interface body 118. The interface body 118 is a face mount for engaging with the patient's face. The first nasal prong 111 and the second nasal prong 112 are integrally molded with the interface body 118 or removably attached to the interface body.

[0407] The interface body 118 component can be connected to or engaged with the gas manifold 120 component, or can be integrally formed or permanently joined with the gas manifold 120 component.

[0408] The interface body 118 can be formed of a soft, flexible material such as silicone, thermoplastic elastomer, or other polymers known in the art. The first nasal prong 111 and the second nasal prong 112 can be soft and can be formed of a sufficiently thin layer of silicone or other suitable material to achieve this property. The interface body 118 and the prongs 111, 112 can be formed of an elastomeric material, for example, that is capable of conforming to the geometry of the patient's nostrils and / or cheeks and providing an effective pneumatic seal.

[0409] The interface body 118 includes two side arms that extend laterally outward from either side. In the illustrated configuration, the side arms include wings 113 and 114 that extend laterally from either side of the interface body 118. The wings 113 and 114 are integrally formed with the interface body 118, but can alternatively be separate components.

[0410] In some configurations, the first nasal prong 111 and the second nasal prong 112 extend generally upward and rearward from the interface body 118.

[0411] In the illustrated configuration, the first nasal prong 111 has an opening at its tip or end 131 for delivering gas from the gas manifold 120. The gas delivered through the first nasal prong 111 exits the first nasal prong 111 via the first end 131. The first nasal prong 111 has a first base 135 at an end of the first nasal prong 111 opposite the first end 131. The first base 135 is another opening and is connected to the gas manifold 120 and allows gas to flow from the manifold chamber 125 to the first prong 111. The first base 135 may be integrally formed with the interface body 118 or removably connected to the interface body.

[0412] The second nasal prong 112 has an opening at its tip or end 132 for delivering gas from the gas manifold 120. The gas delivered through the second nasal prong 112 exits the first nasal prong 112 via the second end 132. The second nasal prong 112 has a second base 136 at an end of the second nasal prong 112 opposite the second end 132. The second base 136 is another opening connected to the gas manifold 120 and allows gas to flow from the manifold chamber 125 to the second prong 112 and through the second prong. The second base 136 may be integrally formed with the interface body 118 or removably connected to the interface body.

[0413] The first nasal prong 111 and the second nasal prong 112 may have any suitable shape to seal or insert into a patient's nostrils. For example, in one configuration, the first nasal prong 111 and the second nasal prong 112 may be substantially tubular and may be sized to be larger than a patient's nostrils, but may be soft or flexible to deform when inserted into the nostrils and seal with the nostrils. In another configuration, the first nasal prong 111 and the second nasal prong 112 may be soft or flexible to deform and are sized to form a non-sealing arrangement with the nostrils. For example, the first nasal prong 111 and the second nasal prong 112 may not enter the nostrils but be located proximally. In some configurations, the nasal prongs 111, 112 are softer or more flexible than the interface body 118.

[0414] The first gas delivery conduit 301 and the second gas delivery conduit 302, or the first gas inlet 121 or the second gas inlet 122 may be configured to provide an asymmetric flow to the first prong 111 and the second prong 112.

[0415] In some configurations, such as when the passage is circular, the flow-altering features that provide an asymmetric flow include conduits 301, 302 or inlets 121, 122 having different (unequal) internal passage diameters (lumen). The difference in diameter results in different characteristics of the gas flow through the first gas inlet 121 and the second gas inlet 122 and thus to the respective proximal nasal prongs 111, 112.

[0416] In some configurations, the diameter of the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 is greater than the diameter of the internal passage of the second gas delivery conduit 302 or the second gas inlet 122. Alternatively, the diameter of the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 is less than the diameter of the internal passage of the second gas delivery conduit 302 or the second gas inlet 122.

[0417] In some configurations, such as when the passage is a non-circular shape, flow-altering features that provide asymmetric flow include conduits 301, 302 or inlets 121, 122 having different internal passage cross-sections (lumen). While not limited thereto, non-circular shapes include oval, straight-sided shapes or any polygonal shape. A combination of a circular internal passage for one of the conduits 301, 302 or inlets 121, 122 and a non-circular shape for the other of the conduits 301, 302 or inlets 121, 122 can also be provided. The difference in cross-sections between the conduits 301, 302 or inlets 121, 122 results in different characteristics of the gas flow through the first gas inlet 121 and the second gas inlet 122 and thus to the respective proximal nasal prongs 111, 112.

[0418] In some configurations, the cross-section of the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 is greater than the cross-section of the internal passage of the second gas delivery conduit 302 or the second gas inlet 122. Alternatively, the cross-section of the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 is less than the cross-section of the internal passage of the second gas delivery conduit 302 or the second gas inlet 122.

[0419] In some configurations, flow-altering features that provide asymmetric flow include conduits 301, 302 or inlets 121, 122 having internal passages (lumen) of different lengths. For example, the gas delivery conduit 300 can be split at different sections to provide the first gas delivery conduit 301 and the second gas delivery conduit 302. Alternatively or additionally, in some configurations, the lengths of the tubes from the Y-piece can be different for the first gas delivery conduit 301 and the second gas delivery conduit 302. Alternatively or additionally, the first gas inlet 301 and the second gas inlet 302 can also be formed as tubes having different lengths extending from the gas manifold 120 (which is connected to the gas delivery conduits 301, 301). The difference in lengths results in different characteristics of the gas flow through the first gas inlet 121 and the second gas inlet 122 and thus to the respective proximal nasal prongs 111, 112.

[0420] In some configurations, the length of the first gas delivery conduit 301 or the first gas inlet 121 is longer than the length of the second gas delivery conduit 302 or the second gas inlet 122. Alternatively, the length of the first gas delivery conduit 301 or the first gas inlet 121 is shorter than the length of the second gas delivery conduit 302 or the second gas inlet 122.

[0421] In some configurations, flow-altering features that provide an asymmetric flow include conduits 301, 302 or inlets 121, 122 having internal flow-modifying elements or relief features. These elements can include, but are not limited to, fins, baffles, protrusions, dividers, vanes, or any other constrictions. The flow-modifying elements can be different between the conduits 301, 302 or inlets 121, 122, or can be present in only one of the conduits 301, 302 or inlets 121, 122. The flow-modifying elements result in different characteristics of the gas flow through the first gas inlet 121 and the second gas inlet 122 and thus to the respective proximal nasal forks 111, 112. The flow-modifying elements can be the elements described elsewhere herein, such as those for the first fork 111 and the second fork 112.

[0422] In some configurations, the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 includes an internal flow-modifying element (or relief feature), while the internal passage of the second gas delivery conduit 302 or the second gas inlet 122 does not include an internal flow-modifying element (or relief feature). Alternatively, the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 does not include an internal flow-modifying element, while the internal passage of the second gas delivery conduit 302 or the second gas inlet 122 includes an internal flow-modifying element. Alternatively, the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 includes an internal flow-modifying element that has a greater effect on the flow of the internal flow-modifying element of the internal passage of the second gas delivery conduit 302 or the second gas inlet 122. Alternatively, the internal passage of the first gas delivery conduit 301 or the first gas inlet 121 includes an internal flow-modifying element that has a lesser effect on the flow of the internal flow-modifying element of the internal passage of the second gas delivery conduit 302 or the second gas inlet 122.

[0423] Reference is made to Figure 10 , which shows a patient interface 10 having a nasal interface 100. The arrangement is as described with reference to Figure 9 and includes a first gas inlet 121 and a second gas inlet 122.

[0424] In addition, in this configuration, the first gas delivery conduit 301 and the second gas delivery conduit 302 are connected to different gas flows. Thus, the first gas delivery conduit 301 and the second gas delivery conduit 302 do not branch off from a single gas delivery conduit 300.

[0425] The first gas delivery conduit 301 is connected to a first gas flow 303 (i.e., in fluid communication therewith), and the second gas delivery conduit 302 is connected to a second gas flow 304 (i.e., in fluid communication therewith). The first gas flow 303 and the second gas flow 304 have different flow characteristics as flow-altering features, such as different flow rates or even flow directions. Thus, due to the different flows entering the gas manifold 120 near the first fork 111 and the second fork 112, the different flow characteristics of the first gas flow 303 and the second gas flow 304 cause an asymmetric flow at the first fork 111 and the second fork 112. For example, different gas pressures are formed near the inlets (bases 135, 136) of each fork 111, 112. In the case where one of the first gas flow 303 or the second gas flow 304 has a negative pressure (e.g., is a suction), different gas pressures are formed near the inlets (bases 135, 136) of each fork 111, 112, resulting in an asymmetric flow.

[0426] In some configurations, the flow-altering features that provide an asymmetric flow include the first gas flow 303 delivering a gas flow at a higher rate than the second gas flow 304 and thus delivering it to the corresponding proximal forks 111, 112. Alternatively, the first gas flow 303 delivers a gas flow at a lower rate than the second gas flow 304 and thus delivers it to the corresponding proximal forks 111, 112.

[0427] In some configurations, the flow-altering features that provide an asymmetric flow include the first gas flow 303 having a gas flow at a positive pressure with respect to ambient pressure and the second gas flow 304 having a gas flow at a negative pressure. Alternatively, the first gas flow 303 has a gas flow at a negative pressure, while the second gas flow 304 has a gas flow at a positive pressure.

[0428] In some configurations, to prevent excessive mixing of the first gas flow 303 with the second gas flow 304, a manifold element 203 as described elsewhere herein may be provided between the first fork 111 and the second fork 112 and thus between the first inlet 121 and the second inlet 122. The manifold element 203 may partially restrict the flow or may completely restrict the flow.

[0429] Referring Figure 11 , a patient interface 10 with a nasal interface 100 is shown. This arrangement, as described with reference to Figure 9 , includes a first gas inlet 121 and a second gas inlet 122.

[0430] Additionally, in this configuration, a first fork element 201, a second fork element 202, a manifold element 203, a first gas inlet element 209, and a second gas inlet element 208 are provided as flow-altering features for increasing the resistance of the gas flow passing therethrough. The first fork element 201, the second fork element 202, and the manifold element 203 can be the same as those described elsewhere herein, for example, with reference to Figure 2 .

[0431] Although Figure 11 a first fork element 201, a second fork element 202, a manifold element 203, a first (gas) inlet element 209, and a second (gas) inlet element 208 are shown having the configuration detailed below, there can be a single element 201, 202, 203, 208, 209 in the nasal interface 100, or any combination of elements can be present.

[0432] The elements 201, 202, 203, 208, 209 used throughout the text can also be referred to as flow restrictors or flow restricting portions.

[0433] When present, the second fork element 202 is positioned within the second fork 112 and is configured to increase the resistance of the gas flow passing through the second fork 112. The second fork element 202 can be positioned at or near the second base 136, at or near the second end 132, or at any position between the second end 132 and the second base 136.

[0434] In some configurations, the flow resistance provided by any of the elements 201, 202, 203, 208, 209 described herein can be such that very little flow (e.g., negligible flow) or no flow is allowed to pass through the element.

[0435] When present, the manifold element 203 is positioned within the manifold chamber 125 and serves to increase the flow resistance of the gas flow through the gas manifold 120. The manifold element 203 is positioned between the inlets between the flow channels for the respective first prong 111 and second prong 112, for example, between the first base 135 and the second base 136. Similarly, the manifold element 203 is positioned between the first gas inlet 121 and the second gas inlet 122. Thus, since the first gas inlet 121 is substantially positioned on the side of the gas manifold 120 adjacent to the first prong 111, the gas flow through the manifold chamber 125 from the first gas inlet 121 will be restricted for the second prong 112 positioned on the opposite side of the manifold element 203, but not restricted for the other first prong 111 adjacent to the first gas inlet 121. Likewise, since the second gas inlet 122 is substantially positioned on the other side of the gas manifold 120 adjacent to the second prong 112, the gas flow through the manifold chamber 125 from the second gas inlet 122 will be restricted for the first prong 111 positioned on the opposite side of the manifold element 203, but not restricted for the second prong 112 adjacent to the second gas inlet 122.

[0436] When present, the first prong element 201 is positioned within the first prong 111 and serves to increase the flow resistance of the gas flow through the first prong 111. The first prong element 201 may be positioned at or adjacent to the first base 135, at or adjacent to the first tip 131, or at any position between the first tip 131 and the first base 135.

[0437] When present, the first gas inlet element 209 is positioned adjacent to the first inlet 121 and serves to increase the flow resistance of the gas flow through the first inlet 121 (e.g., from the first gas delivery conduit 201 into the manifold chamber 125). The first inlet element 209 may be positioned at any position between the position of the first gas delivery conduit 301 into the gas manifold 120 before the first base 135. In some arrangements, where the first gas inlet 121 is a tube or a channel, the first inlet element 209 is positioned within the channel or at the end of the channel.

[0438] When present, the second gas inlet element 208 is positioned adjacent to the second inlet 122 and serves to increase the flow resistance of the gas flow through the second inlet 122 (e.g., from the second gas delivery conduit 302 into the manifold chamber 125). The second inlet element 208 may be positioned at any position between the position of the second gas delivery conduit 302 into the gas manifold 120 before the second base 136. In some arrangements, where the second gas inlet 122 is a tube or a channel, the second inlet element 208 is positioned within the channel or at the end of the channel.

[0439] Each of components 201, 202, 203, 208, 209 individually or in combination causes an asymmetric gas flow through first prong 111 and second prong 112 and thus at each nostril. Thus, a single first prong component 201, second prong component 202, manifold component 203, second inlet component 208, or first inlet component 209 can provide a flow restriction to correspondingly cause an asymmetric gas flow through each prong 111, 112. In the case of second inlet component 208 or first inlet component 209, the flow restriction caused by a single component 208, 209 has effects similar to and different from those of gas delivery conduits 301, 302 or gas inlets 121, 122 having similar characteristics as described with reference to Figure 9 and causes a flow through first gas inlet 121 or second gas inlet 122 that is different from that of the other gas inlets and thus causes a different flow to proximal nasal prongs 111, 112.

[0440] In some configurations, there is a single component 201, 202, 203, 208, 209 and no other components. Thus, at least one of first prong 111, second prong 112, manifold chamber 125, first inlet 121, or second inlet 122 is not flow restricted by, for example, components 201, 202, 203, 208, 209.

[0441] A combination of two or more components 201, 202, 203, 208, 209 will also result in a restriction of the flow to at least one of first prong 111 or second prong 112, which will cause an asymmetric flow.

[0442] Although the magnitude of the flow restriction through each of components 201, 202, 203, 208, 209 varies in various combinations to allow for an asymmetric flow at prongs 111, 112, some non-limiting explanations of combinations are as follows:

[0443] 1) The first inlet component 209 is combined with the second inlet component 208, each being configured to increase the flow resistance of the gas flow entering the gas manifold 120 through the first gas inlet 121 and the second gas inlet 122, respectively. Each of the first inlet component 209 and the second inlet component 208 has different characteristics so as to affect the flow in different ways. Thus, the flow to each prong 111, 112 and thus to each nostril is asymmetric.

[0444] In this arrangement, in some configurations, there is no first prong component 201, second prong component 202, or manifold component 203.

[0445] 2) The first inlet element 209 is combined with the manifold element 203, each being configured to increase the flow resistance of the gas flow passing therethrough. Thus, the flow through the first gas inlet 121 to the first fork 111 is restricted by the first inlet element 209. However, the manifold element 203 also ensures that the flow through the second gas inlet 122 across the manifold chamber 125 to the first fork 111 is also restricted. The flow from the second gas inlet 122 to the second fork 112 has no (or less) resistance. Thus, the flow to each fork 111, 112 and thus to each nostril is asymmetric.

[0446] In this arrangement, in some configurations, there is no first fork element 201, second fork element 202, or second inlet element 208.

[0447] 3) The second inlet element 208 is combined with the manifold element 203, each being configured to increase the flow resistance of the gas flow passing therethrough. Thus, the flow through the second gas inlet 122 to the second fork 112 is restricted by the second inlet element 208. However, the manifold element 203 also ensures that the flow through the first gas inlet 121 across the manifold chamber 125 to the second fork 112 is also restricted. The flow from the first gas inlet 121 to the first fork 111 has no (or less) resistance. Thus, the flow to each fork 111, 112 and thus to each nostril is asymmetric.

[0448] In this arrangement, in some configurations, there is no first fork element 201, second fork element 202, or first inlet element 209.

[0449] 4) The first fork element 201 and the second fork element 202 are combined, each being configured to increase the flow resistance of the gas flow entering the first fork 111 and the second fork 112 respectively. Each of the first fork element 201 and the second fork element 202 has different characteristics so as to affect the flow in different ways. Thus, the flow to each fork 111, 112 and thus to each nostril is asymmetric.

[0450] In this arrangement, in some configurations, there is no first inlet element 209, second inlet element 208, or manifold element 209.

[0451] 5) The first inlet element 209 is combined with the manifold element 203 and the first fork element 201, each being configured to increase the flow resistance of the gas flow passing therethrough. Accordingly, the flow from the first gas inlet 121 to the first fork 111 is restricted by the first inlet element 209 and the first fork element 201. However, the manifold element 203 ensures that the flow across the manifold chamber 125 from the second gas inlet 122 to the first fork 111 is also restricted. The flow from the second gas inlet 122 to the second fork 112 has no (or less) resistance. Thus, the flow to each fork 111, 112 and thus to each nostril is asymmetric.

[0452] In this arrangement, in some configurations, there is no second fork element 202 or second inlet element 208. In some arrangements, the manifold element 203 can be removed in the case where the first fork element 201 performs a similar function.

[0453] 6) The combination of the second inlet element 208 with the manifold element 203 and the second fork element 202, each being configured to increase the flow resistance of the gas flow passing therethrough. Accordingly, the flow from the second gas inlet 122 to the second fork 112 is restricted by the second inlet element 208 and the second fork element 202. However, the manifold element 203 also ensures that the flow across the manifold chamber 125 from the first gas inlet 121 to the second fork 112 is restricted. The flow from the first gas inlet 121 to the first fork 111 has no (or less) resistance. Thus, the flow to each fork 111, 112 and thus to each nostril is asymmetric.

[0454] In this arrangement, in some configurations, there is no first fork element 201 or first inlet element 209. In some arrangements, the manifold element 203 can be removed and the second fork element 202 performs a similar function of restricting the flow from the first gas inlet 121 to the second fork 112.

[0455] Although the elements 201, 202, 203 are shown as rectangular, these elements 201, 202, 203, 208, 209 can take any suitable form. For example, these elements can be orifice plates with a single hole, orifice plates with multiple holes, Venturi throats or nozzles. Other examples are provided in the present disclosure.

[0456] As referred to Figure 11 The present configuration described can be combined with any other part of the present disclosure. For example, the form of the elements (e.g., the holes 207 formed in the plate or wall 205 as referred to Figures 3A to 3C described) can be applied to the elements 201, 202, 203, 208, 209 of the present configuration. Similarly, for as referred to Figure 4 and 5The described rotatable restrictor 225 or the manual flow restrictor 220 with the slider 221 can equally be applied to the elements 201, 202, 203, 208, 209 of this construction. The flow rate variations of the first gas flow 303 and the second gas flow 304 can be applied in combination with this construction. Refer to Figures 6 to 8 The described manifold opening 230 and the optional pressure drop member 232 can equally be applied to this construction.

[0457] Refer to Figure 12 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is as described with reference to FIG. 1.

[0458] Additionally, in this construction, the gas delivery conduit 300 is in fluid communication with the first gas flow 303, as referred to Figure 10 and described with the first gas delivery conduit 301. The first gas flow 303 provides a gas flow with a specific set of characteristics (e.g., flow rate or velocity).

[0459] The nasal interface 100 of this construction also includes an auxiliary gas delivery conduit 305. The auxiliary gas delivery conduit 305 is smaller than the gas delivery conduit 300. For example, the inner diameter of the lumen of the auxiliary gas delivery conduit 305 is smaller than the inner diameter of the lumen of the gas delivery conduit 300. The auxiliary gas delivery conduit 305 is smaller than the first fork 111. For example, the inner diameter of the lumen of the auxiliary gas delivery conduit 305 is smaller than the inner diameter of the flow path of the first fork 111.

[0460] The auxiliary gas delivery conduit 305 is connected (in fluid communication) to the second gas flow 304 as referred to Figure 10 and described. Thus, the second gas flow 304 has characteristics different from those of the first gas flow 303.

[0461] The auxiliary gas delivery conduit 305 is located within the gas delivery conduit 300 and extends into the manifold chamber 125. The auxiliary gas delivery conduit 305 terminates within the first nasal fork 111 and thus has a gas outlet leading into the first nasal fork 111. Since the auxiliary gas delivery conduit 305 is smaller than the first fork 111 and the gas delivery conduit 300, it does not block the conduit and also allows the first gas flow 303 to flow through the conduit.

[0462] The second gas flow 304 through the auxiliary gas delivery conduit 305 causes an asymmetric flow at the first fork 111 and the second fork 112 because the different gas characteristics are only directed to the first fork 111 and thus to a single nostril of the patient. The gas flow from the first gas flow 303 is directed to the second fork 112 without any flow restriction.

[0463] The different gas characteristics of the first gas flow 303 and the second gas flow 304 can also be as referred to Figure 10The negative pressure described above. Therefore, a lower dynamic pressure is provided at one of the nasal forks 111, 112.

[0464] In some configurations, the auxiliary gas delivery conduit 305 is positioned outside and / or extends parallel to the gas delivery conduit 300. In some configurations, the auxiliary gas delivery conduit 305 is in fluid communication with the flow generator at the input end. In other configurations, the auxiliary gas delivery conduit 305 is in fluid communication with the gas delivery conduit 300 at the input end, where the characteristics of the auxiliary gas delivery conduit 305 cause a different flow at its output end compared to the gas delivery conduit 300. In some configurations, the auxiliary gas delivery conduit 305 has its outlet at the first end 131 of the first fork 111. Alternatively, the auxiliary gas delivery conduit 305 extends to the second fork 112 and has its outlet there, thus causing an asymmetric flow between the forks 111, 112.

[0465] Referring to Figure 13 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is similar to the arrangement described with reference to FIG. 1.

[0466] In this configuration, the nasal interface 100 includes a flow guiding element 240 to provide an asymmetric gas flow to the first fork 111 and the second fork 112.

[0467] The flow guiding element 240 is formed at or near the gas inlet 121. The flow guiding element 240 is formed as a sub-channel to guide the gas flow to the first fork 111. The flow guiding element 240 guides the gas flow from the gas delivery conduit 300 into the first fork guiding flow 243. Thus, most of the gas flow from the gas delivery conduit 300 is guided into the first fork 111 and into the patient's nostril.

[0468] In this configuration, the flow guiding element 240 is formed as a curved channel with an inlet end 246 facing the gas delivery conduit 300 and an outlet end 247 facing the first end 131 of the first fork 111. The inlet end 246 is positioned in the gas manifold 120, between the gas inlet 121 and the first base 135. The outlet end 247 is positioned in the first fork 111, at or between the first base 135 and the first end 131.

[0469] In some configurations, the inlet end 246 of the flow guiding element 240 is positioned in the gas delivery conduit 300 or in the gas inlet 121. In some configurations, the outlet end 247 of the flow guiding element 240 is positioned in the gas manifold 120 and faces the first base 135 of the first fork 111.

[0470] The flow guiding element 240 is positioned to provide a first fork gap 242 between itself and the inner wall of the first fork 111. Thus, the outer dimension of the portion of the flow guiding element 240 positioned within the first fork 111 (e.g., the outlet end 247) is smaller than the inner dimension of the first fork 111. The first fork gap 242 provides a first manifold guiding flow 245. The first manifold guiding flow 245 allows the flow along the first fork 111, i.e., in the direction from the first end 131 to the first base 135, to be partially guided through the first fork gap 242. Thus, the patient exhaled gas entering the first fork 111 can be at least partially guided as the first manifold guiding flow 245 through the first fork gap 242 and flow into the gas manifold 120 in the direction of the second fork 112.

[0471] The shape of the flow guiding element 240 can be said to have angled protrusions.

[0472] The turbulent gas flow or the flow interacting with the patient exhaled flow emerging from the outlet end 247 of the flow guiding element 240 can also be the first manifold guiding flow 245 before reaching the patient's nostrils.

[0473] The cross-sectional area of the first fork gap 242 is smaller than the cross-sectional area of the outlet end 247 of the flow guiding element 240. However, in some configurations, the cross-sectional area of the first fork gap 242 is larger than the cross-sectional area of the outlet end 247 of the flow guiding element 240.

[0474] In some configurations, the flow guiding element 240 is positioned to provide a manifold gap 241 between itself and the inner wall of the gas manifold 120. The manifold gap 241 provides a second manifold guiding flow 244. The second manifold guiding flow 244 allows the gas flow entering the gas manifold 120, i.e., from the gas delivery conduit 300, to be partially guided through the manifold gap 241. Thus, a portion of the gas flow entering the gas manifold 120 is guided as the second manifold guiding flow 244 through the manifold gap 241 and flows into the gas manifold 120 in the direction of the second fork 112.

[0475] The cross-sectional area of the manifold gap 241 is smaller than the cross-sectional area of the inlet end 246 of the flow guiding element 240. However, in some configurations, the cross-sectional area of the manifold gap 241 is larger than the cross-sectional area of the inlet end 246 of the flow guiding element 240.

[0476] Thus, the flow guiding element 240 guides all or most of the gas flow as a first fork guiding flow 243 from the gas delivery conduit 300 into the first fork 111. The gas flow towards the second fork 112 is the first manifold guiding flow 245 through the first fork gap 242 and / or the second manifold guiding flow 244 through the manifold gap 241.

[0477] The gas flow reaching the first fork 111 has less directional change as it passes through the flow guiding element 240.

[0478] This arrangement results in a greater dynamic pressure at the first fork and a smaller dynamic pressure at the second fork 112. Thus, an asymmetric flow is provided to the forks 111, 112.

[0479] Referring Figure 14 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is similar to the arrangement described with reference to FIG. 1 and has a different configuration from the flow guiding element 240 described with reference to Figure 13 .

[0480] In this configuration, the flow guiding element 240 provides an asymmetric gas flow to the first fork 111 and the second fork 112.

[0481] The flow guiding element 240 is formed at or near the gas inlet 121. The flow guiding element 240 includes a first angled protrusion 248 to direct the gas flow to the first fork 111. The first angled protrusion 248 is formed as a plate or a wall. The gas flow from the gas inlet 121 enters the flow guiding element 240, and the first angled protrusion 248 directs the flow as a first fork guiding flow 243 towards the first fork 111. Thus, the flow guiding element 240 and the first angled protrusion 248 generally direct the gas flow from the gas delivery conduit 300 to the first fork 111. The greater dynamic pressure at the first fork 111 compared to the second fork 112 creates an asymmetric flow.

[0482] The first angled protrusion 248 is located within the gas manifold 120 near the gas inlet 121. Thus, the flow guiding element 240 and the first angled protrusion 248 do not impede or (fully) restrict the flow in the manifold chamber 125, but rely on guiding the flow to provide an asymmetric flow to one of the forks 111, 112.

[0483] The flow provided to the second fork 112 through the first manifold guiding flow 245 allows the exhaled air from the patient to be directed back to the first fork 111 and can be directed by the opposite side of the first angled protrusion 248. Additionally, some of the flow may not be fully directed from the gas inlet 121 to the first nasal fork 111, but instead flows into the manifold chamber 125 and to the second fork 112.

[0484] In some configurations, to assist in guiding the flow, the gas inlet 121 is positioned on a wall of the gas manifold 120 that is generally opposite the first prong 111 (or the second prong 112, as required). Thus, the flow guiding element 240 and the first angled protrusion 248 assist in guiding the flow through the inlet into the manifold chamber 125 itself to the associated prong 111, 112. This may also be referred to as the front inlet 121.

[0485] In some configurations, the flow guiding element includes a second angled protrusion 249. The second angled protrusion 249 assists the first angled protrusion 248 in guiding the flow from the gas inlet 121. The first angled protrusion 248 and the second angled protrusion 249 are formed on opposite sides of the gas inlet 121. The first angled protrusion 248 and the second angled protrusion 249 may be formed in a nozzle shape.

[0486] The flow guiding element 240 may be positioned to direct the flow to the second prong 112 rather than the first prong 111 to provide an asymmetric flow.

[0487] Reference Figure 15 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to Figure 14 and includes a flow guiding element 240.

[0488] In this configuration, the nasal interface 100 further includes an additional flow guiding element 250 or a second flow guiding element 250.

[0489] The second flow guiding element 250 is disposed within the manifold chamber 125 at or near the inlet of the first prong 111, i.e., near the first base 135.

[0490] In addition to the flow guiding element 240, the additional flow guiding element 250 directs the gas flow from the gas delivery conduit 300 into the first prong 111. Thus, the first prong guide flow 243 through the manifold chamber 125 is further urged by the additional flow guiding element 250 into the first prong 111. This ensures that most of the gas flow from the gas delivery conduit 300 is directed into the first prong 111 and into the patient's nostril, thus providing an asymmetric flow compared to the second prong 112.

[0491] The additional flow guiding element 250 is formed as an angled plate or wall, optionally having a wedge shape, so as to form another nozzle shape at the inlet of the first fork 111 to guide the flow therein. The gas flow from the gas inlet 121 enters the flow guiding element 240 and is guided as the first fork guiding flow 243 towards the first fork 111, and the additional flow guiding element 250 guides any flow that has been diverted into the first fork 111. A greater dynamic pressure at the first fork 111 as compared to the second fork 112 results in an asymmetric flow.

[0492] The flow provided to the second fork 112 by the first manifold guiding flow 245 causes the exhaled breath from the patient to be guided back to the first fork 111. The additional flow guiding element 250 forms a guiding channel for the first manifold guiding flow 245 into the manifold chamber 125. Thus, the exhaled flow is more guided into the manifold chamber 125 and thus towards the second fork 112. Additionally, some gas flow may not be fully guided from the gas inlet 121 into the first nasal fork 111 but instead flows into the manifold chamber 125 and into the second fork 112. The additional flow guiding element 250 also guides a portion of this flow as the second manifold guiding flow 244.

[0493] The additional flow guiding element 250 can be positioned to direct the flow to the second fork 112 rather than the first fork 111 to provide an asymmetric flow. This can be combined with the flow guiding element 240 that directs flow to the second fork 112.

[0494] The flow guiding element 240 and the additional flow guiding element 250 can be combined with other configurations discussed herein. For example, the first fork element 201, the second fork element 202, the manifold element 203, the first inlet element 209, and the second inlet element 208 can be used to further restrict the flow. Similarly, multiple gas delivery conduits 300 can also be used in conjunction with one or more of the flow guiding element 240 and the additional flow guiding element 250 as needed to create an asymmetric flow at the forks 111, 112.

[0495] The flow guiding elements 240, 250 as described herein can be formed as part of the gas inlet 121, the gas manifold 120, or the gas delivery conduit 300. That is, the flow guiding elements 240, 250 can be formed as walls, components, or features of the gas inlet 121, the gas manifold 120, or the gas delivery conduit 300. Such a structure can be a separate structure that is later integrated with the gas inlet 121, the gas manifold 120, or the gas delivery conduit 300, or can be formed together (e.g., by an extrusion or molding process), or can be part of the overall structure (e.g., the nozzle shape for the gas inlet 121). The term "formed together" can also be considered to mean that the flow guiding elements 240, 250 are not removable or are permanently integrated with the gas inlet 121, the gas manifold 120, or the gas delivery conduit 300.

[0496] Referring Figure 16 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to FIG. 1 and, as will be readily understood, can optionally be combined with any of the disclosures herein without any modification to the described features.

[0497] In this configuration, the first prong 111 and the second prong 112 are modified to have different lengths. Accordingly, a long first prong 111a is provided, where the distance between the first end 131 and the first base 135 is longer than the distance between the second end 132 and the second base 136 of the short second prong 112a.

[0498] By providing a long first prong 111a and a short second prong 112a, the prongs 111a, 112a are modified to have different internal flow resistances (relative to each other). Thus, when the gas flow has to travel further, the amount of flow through each prong 111a, 112a is different and thus the resulting flow is asymmetric. One way is to make the prongs of different lengths, noting that the flow resistance also depends on the length of the flow path.

[0499] In some configurations, the long first prong 111a is made longer relative to the second prong 112 such that the short second prong 112a has the same length as the second prong 112 described elsewhere in this document. Alternatively, the short second prong 112a is made shorter relative to the first prong 111 such that the long first prong 111a has the same length as the first prong 111 described elsewhere herein. However, in other arrangements, the lengths of both the first prong 111a and the second prong 112a are changed. The change in relative lengths can vary to provide the desired asymmetric flow.

[0500] Changes in the lengths of the tines 111a, 112a can be assumed to have the same inner diameter. In some configurations, the inner diameter can be different, which results in different tines 111a, 112a requiring different lengths. In the infant patent interface 10, the effect of tine length is more significant when both the height and inner diameter of the tines are small. Thus, a relatively small difference in tine length will have a relatively large effect on flow resistance and thus on asymmetric flow.

[0501] In some configurations, the second tine 112 is relatively longer than the first tine 111. The variations in the tine lengths 111a, 112a can be combined with any of the disclosures herein. For example, the first tine element 201, the second tine element 202, the manifold element 203, the first inlet element 209, and the second inlet element 208 can be used to further restrict flow.

[0502] Tines of varying lengths, such as a long first tine 111a and a short second tine 112a or any variation in the lengths of the tines 111, 112, can be combined with any of the configurations described herein, such as in a non-limiting example with other features that provide asymmetric flow.

[0503] Reference Figure 17 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to FIG. 1 and can be combined with any of the disclosures herein. As will be readily understood, any optional combination with the disclosures herein will not require any modification to the described features.

[0504] In this configuration, the first tine 111 and the second tine 112 are modified to have different end geometries. Thus, a nozzle-type first tine 111b is provided, where the first end 131 tapers or narrows at its tip to form a nozzle. A diffuser-type second tine 112b is provided at a position where the second end 132 expands at its tip to form a diffuser.

[0505] In some configurations, one of a nozzle-type first tine 111b or a diffuser-type second tine 112b is provided.

[0506] By providing a nozzle-type first tine 111b and a diffuser-type second tine 112b, the tines 111b, 112b are modified to have different internal flow resistances (relative to each other). Thus, the amount of flow through each tine 111b, 112b is different because the gas flow has different exit profiles determined by the ends 131, 132.

[0507] The nozzle-type first tine 111b behaves like a nozzle, resulting in a higher velocity and a narrower profile of the flow leaving the nozzle-type first tine 111b compared to the unmodified tines 111, 112. Thus, a higher gas velocity at one tine will result in asymmetric flow.

[0508] The diffuser-style second prong 112b acts like a diffuser, thereby causing the flow leaving the diffuser-style second prong 112b to have a wider profile and a lower exit velocity. Thus, the lower gas velocity at one prong will result in an asymmetric flow.

[0509] While the effect of the diffuser is to result in a lower exit velocity, in some configurations, another effect of using the diffuser-style second prong 112b is that the diffuser end may block the patient's nostril into which the end extends to fill the nostril. This may lead to an increase in flow resistance. However, compared to the unmodified prongs 111, 112, this has the advantage of creating a different gas flow. Thus, an asymmetric flow is formed at the prong.

[0510] Another advantage of the diffuser-style second prong 112b is that noise can be attenuated compared to the unmodified prongs 111, 112 or the nozzle-style first prong 111b. The same gas flow leaving through a larger opening has a lower velocity and thus makes less sound.

[0511] In some configurations, a nozzle may be provided at the second prong 112 and / or a diffuser may be provided at the first prong 111. The nozzle-style first prong 111b and the diffuser-style second prong 112b described herein can be combined with any other configuration described herein, and optionally also with prongs of different lengths as described in reference Figure 16 as described.

[0512] Referring to Figure 18 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to FIG. 1 and can be combined with any disclosure herein. It will be understood that no other features need to be modified to be combined with the embodiments described herein.

[0513] In this configuration, the first prong 111 is modified to have an internal ridge. Thus, a ridged first prong 111c is provided, where the ridge 260 is formed on the inner surface of the ridged first prong 111c.

[0514] With the ridged first prong 111c and the unmodified second prong 112, the prongs 111c, 112 have different internal flow resistances (relative to each other) due to different inner surface areas. Thus, the amount of flow through each prong 111c, 112 is different because the gas flow varies, is obstructed, or is disturbed in the ridged first prong 111c, and the resulting flow is asymmetric.

[0515] To increase the surface area, the ridge 260 is either formed as a groove in the inner surface of the ridged first prong 111c or as a protrusion on the inner surface of the ridged first prong 111c. In some configurations, the ridge 260 is formed by adding material from the ridged first prong 111c, and in other configurations, the ridge 260 is formed by removing material from the ridged first prong 111c.

[0516] The ridge 260 can be formed as a ring, a helix, or a band in a substantially concentric pattern on the interior of the ridged first prong 111c. Any number of ridges 260 can be formed, such as a single ridge 260 or multiple ridges 260. The ridges 260 can be equally spaced or have a varying spacing. The dimensions (e.g., the protruding dimension) of the ridges 260 can be the same for all ridges 260 or can vary.

[0517] In some configurations, the ridge 260 can be formed in the second prong 112. When formed in the second prong 112, either there is no ridge 260 in the first prong 111 or the ridged first prong 111c has different ridges 260 to create different internal flow resistances, thus providing an asymmetric flow at the prong.

[0518] The ridged first prong 111c can be combined with other configurations described herein and also optionally with configurations such as different lengths of prongs as described with reference to Figure 16 and / or with configurations such as the nozzle - type first prong 111b / diffuser - type second prong 112b as described with reference to Figure 17

[0519] Referring to Figure 19 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to FIG. 1 and can be combined with any disclosure herein. It will be understood that no other features need to be modified to be combined with the embodiments described herein.

[0520] In this configuration, the first prong 111 is modified to have internal fins 261. Thus, a finned first prong 111d is provided, where the fins 261 are formed on the inner surface of the finned first prong 111d.

[0521] The combination of the finned first prong 111d and the unmodified second prong 112 results in the prongs 111d, 112 having different internal flow resistances (relative to each other) due to different inner surface areas. Thus, the amount of flow through each prong 111d, 112 is different because the gas flow varies, is obstructed, or is disturbed in the finned first prong 111d, and the resulting flow is asymmetric.

[0522] To increase the surface area, the fin 261 is either formed as a groove in the inner surface of the finned first prong 111d or as a protrusion on the inner surface of the finned first prong 111d. In some configurations, the fin 261 is formed by adding material to the finned first prong 111d, and in other configurations, the fin 261 is formed by removing material from the finned first prong 111d.

[0523] The fin 261 can be formed as a line, strip, or band in a generally axial direction pattern within the finned first prong 111d. Any number of fins 261 can be formed, such as one fin 261 or multiple fins 261. The fins 261 can be equally spaced or have a varying spacing. The dimensions of the fins 261 (such as the protrusion dimension) can be the same for all fins 261 or can vary.

[0524] In some configurations, the fin 261 can be formed in the second prong 112. When formed in the second prong 112, the fin 261 is either absent in the first prong 111 or the finned first prong 111d has differently configured fins 261, such as different dimensions, arrangements, or quantities, to create different internal flow resistances and thereby provide asymmetric flow at the prong.

[0525] Referring Figure 18 and Figure 19 The features of the ridges 260 or fins 261 described can be collectively referred to as surface features.

[0526] The finned first prong 111d can be combined with other configurations described herein and optionally can also be combined with configurations such as differently lengthed prongs as described with reference to Figure 16 or nozzle - type first prong 111b / diffuser - type second prong 112b as described with reference to Figure 17 or ridges 260 in either the first prong 111 or the second prong 112 as described with reference to Figure 18 or any one of the first prong 111 or the second prong 112.

[0527] Referring Figure 20 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to FIG. 1 and can be combined with any disclosure herein. As will be readily understood, any optional combination with the disclosures herein will not require any modification of the described features.

[0528] In this configuration, the first prong 111 is modified to have a non - circular cross - section or non - circular cross - sectional shape. Thus, a non - circular first prong 111e is provided, where the shape of the lumen of the non - circular first prong 111e is different from that of a cylindrical or substantially cylindrical shape (which is the usual shape of a conduit).

[0529] The combination of the non-circular first prong 111e and the unmodified second prong 112 results in the prongs 111e, 112 having different internal flow resistances (relative to each other) due to different internal surface areas. Thus, compared to the substantially circular cross-section of the second prong 112, the amount of flow through each prong 111e, 112 is different because the gas flow is altered, obstructed, or disturbed in the non-circular first prong 111e, and the resulting flow is asymmetric.

[0530] To increase or alter the surface area, the profile of the non-circular first prong 111e can take various forms. In non-limiting examples, when viewed in the axial direction, the first profile 111f has a circular profile with additional smaller-diameter circular profiles formed in its walls. Thus, the flow area of the first profile is reduced by the size of the smaller-diameter circles. In another non-limiting example, when viewed in the axial direction, the second profile 111g has a circular profile with additional smaller-equivalent-diameter U-shaped profiles formed in its walls. The curved portion of the U-shape protrudes into the center of the circular profile. Thus, the flow area of the first profile is reduced by the profile of the U-shape dimensions. In another non-limiting example, when viewed in the axial direction, the third profile 111h has a triangular profile with curved corners. Thus, the flow area of the first profile varies according to the size of the third profile 111h, or the shape of the channel formed by the third profile 111h itself results in flow characteristics different from a circular profile. In some configurations, any profile other than a circular cross-section can be used.

[0531] The non-circular first prong 111e can be formed along the length of the prong, or can be formed partially along the prong, such as at or between one of the first end 131 and the first base 135. The dimensions and variations of the profile shape can vary along the length of the prong.

[0532] In some configurations, a non-circular profile (e.g., the first profile 111f, the second profile 111g, or the third profile 111h) can be formed in the second prong 112. When formed in the second prong 112, the non-circular first prong 111e can be replaced with an unmodified first prong 111, or the non-circular first prong 111e has a cross-sectional profile different from the cross-sectional profile of the second prong 112. This results in different internal flow resistances to provide an asymmetric flow at the prong.

[0533] The first profile 111f, the second profile 111g, and the third profile 111h can be oriented in any direction like the nasal prongs 111, 112. Thus, any feature (e.g., the protruding U-shape of the first profile 111f or the second profile 111g or the flat face of the triangle of the third profile 111h) can face inward towards the patient's face, outward away from the patient's face, or laterally across the patient's face - or any other orientation.

[0534] In some configurations, the protruding portions of the fork profile (such as the U-shaped shape of the first profile 111f or the second profile 111g) are used to accommodate an auxiliary tube, such as a nasogastric tube. Such an auxiliary tube can be positioned inside or outside the forks 111, 112.

[0535] In some configurations, such as with reference to Figure 20 the varying profiles of the forks 111, 112 described or any other variations of the profiles can exist only at the ends 131, 132 of the forks 111, 112. Such profiles can include gaps or protrusions to accommodate an auxiliary tube as described elsewhere. Such an auxiliary tube can be provided on the outer or inner side of the forks 111, 112. The auxiliary tube itself may block the nostrils, increasing the flow resistance and thus providing an asymmetric flow at (at least one of) the forks 111, 112.

[0536] The non-circular first fork 111e can be combined with any of the other configurations described herein and optionally with forks of different lengths such as with reference to Figure 16 described, nozzles-type first forks 111b / diffuser-type second forks 112b such as with reference to Figure 17 described, ridges 260 in at least one of the first fork 111 or the second fork 112, and / or fins 261 formed in at least one of the first fork 111 or the second fork 112 such as with reference to Figure 19 described. Figure 20 The non-circular first fork 111e can be combined with any of the other configurations described herein and optionally with forks of different lengths such as with reference to

[0537] In some configurations, the first fork 111 or the second fork 112 can be further modified to modify the surface area or the flow rate therethrough, such as with reference to Figure 2 , 11 or as described in paragraphs 16 to 20. Such modifications can be provided as an alternative or in addition to those embodiments described herein. In one configuration, at least one of the first fork 111 or the second fork 112 has an increased wall thickness relative to the other. The increased wall thickness causes at least one of the first fork 111 or the second fork 112 to have a reduced cross-sectional flow area and thus less gas flow can pass therethrough. Due to the difference in the internal flow resistance of the forks 111, 112, this results in an asymmetric flow.

[0538] In another configuration, at least one of the first fork 111 or the second fork 112 has a restriction at the ends 131, 132 of the forks 111, 112. The restriction is an alternative or addition to the first fork element 201 or the second fork element 202. For example, in some configurations, the restriction is formed as part of the ends 131, 132 of the forks 111, 112 themselves, such as having a partial closure formed thereon.

[0539] In another configuration, at least one of the first prong 111 or the second prong 112 has a base restriction 262 at the first base 135 or the second base 136 of the prongs 111, 112. The restriction is an alternative or addition to the first prong element 201 or the second prong element 202. Figure 21 Exemplary configurations of the proximal end restriction 262 are provided. In Figure 21 it shows that a proximal end restriction 262 is formed at the second base 136 of the second prong 112. The proximal end restriction 262 is formed to have a flow interference inlet leading to the second prong 112, for example having a flat flow-facing surface, where a sharp edge leads upward into the flow channel of the second prong 112. This arrangement provides flow interference to reduce the gas flow through the proximal end restriction 262 relative to the first prong 111 that does not have any proximal end restriction 262. Thus, an asymmetric flow is provided at the prong.

[0540] The proximal end restriction 262 has a flow guiding surface for reverse flow through the second prong 112. Thus, the exhaled gas is not restricted in the same way through the proximal end restriction 262 to ensure no pressure build-up at the patient's nostrils.

[0541] In some configurations, the proximal end restriction 262 can be formed in the first prong 111. When formed in the first prong 111, the second prong 112 can be an unmodified second prong 112 or can have a proximal end restriction 262 that provides different flow characteristics. Although examples of the proximal end restriction 262 are provided, other variations are possible.

[0542] Referring to Figure 22 it shows a patient interface 10 having a nasal interface 100. This arrangement is the same as the arrangement described with reference to FIG. 1 and can be combined with any of the disclosures herein. As will be readily understood, any optional combination disclosed herein will not require any modification of the described features.

[0543] In this configuration, the first prong 111 is modified to have a valve. Thus, a valved first prong 111i is provided, where a duckbill valve 263 is formed within the valved first prong 111i.

[0544] The duckbill valve 263 is positioned in the direction in the first forked member 111i with valve to allow gas flow from the manifold chamber 125 through the first forked member 111i with valve to the patient's nostrils in a variable amount based on the pressure differential across the duckbill valve 263. In some configurations, the duckbill valve 263 may only allow flow to pass through when above a defined pressure, after which the gas flow increases based on that pressure differential. To function in this manner, the duckbill valve 263 is in a closed position 265 until the defined pressure is achieved, at which point the duckbill valve 263 begins to open to allow flow. The flow rate / flow volume causes a pressure differential that further opens the duckbill valve 263 until the duckbill valve reaches a fully open position 264. Alternatively, the duckbill valve 263 only allows flow in the case of a low pressure differential, and the flow varies as a function of that pressure differential, increasing as the pressure differential increases. The duckbill valve 263 functions as a one-way valve to prevent backflow of gas flow from the patient. Thus, a greater pressure differential between the first end 131 of the first forked member 111i with valve and the first base 135 of the first forked member 111i with valve forces the duckbill valve 263 to the closed position 265. At this point, the first forked member 111i with valve is a non-sealing forked member to ensure that there is no pressure build-up in the patient's nostrils. The pressure requirements to allow flow through the first forked member 111i with valve and the duckbill valve 263 result in an asymmetric flow relative to the unmodified second forked member 112.

[0545] In some configurations, the duckbill valve 263 may be formed in the second forked member 112. When formed in the second forked member 112, the first forked member 111 may be an unmodified first forked member 111, or may have a duckbill valve 263 configured to result in different flow characteristics. While an example of a duckbill valve 263 is provided, other valves may also be used.

[0546] The duckbill valve 263 may be combined with any of the other configurations described herein.

[0547] In some configurations, at least one of the first forked member 111 or the second forked member 112 is angled relative to the midline plane of the nasal interface 100, optionally angled relative to the patient's nasal septum in use. Thus, the axis of the first forked member 111 may be at a different relative angle to the axis of the second forked member 112 (with reference to the midline plane of the nasal interface 100). For example, one of the forked members 111, 112 may be unmodified while the other forked member 111, 112 is angled "outwardly", e.g., towards the near sidewall of the gas manifold 120 (or away from the opposing forked member 111, 112), such that the forked members 111, 112 abut the nasal cavity wall. The gas flow exiting the angled forked members 111, 112 may encounter resistance from the nasal cavity wall and create different pressures at the ends 131, 132 of each forked member, thereby causing an asymmetric flow.

[0548] In some configurations, at least one of the first prong 111 or the second prong 112 is angled "inwardly" towards the opposite prong 111, 112 for example. This can result in a less restricted flow depending on the degree of the angle.

[0549] Referring Figure 23 , a patient interface 10 with a nasal interface 100 is shown. This arrangement is the same as the arrangement described with reference to FIG. 1 and can be combined with any disclosure herein. As will be readily understood, any optional combination disclosed herein will not require any modification to the described features.

[0550] In this configuration, the nasal interface 100 includes a first nasal prong 111, a second nasal prong 112, and a third nasal prong 115. The third nasal prong 115 is formed in the same manner as the first nasal prong 111 or the second nasal prong 112 and has a flow passage that allows gas to flow therethrough.

[0551] In addition to the first nasal prong 111 and the second nasal prong 112, the third nasal prong is also in fluid communication with a gas inlet 121 via a manifold 120. The gas inlet 121 is located at the manifold 120 such that the first nasal prong 111 is closer to the gas inlet 121, the third nasal prong 115 is farther from the gas inlet 121, and the second nasal prong 112 is positioned between the first and second nasal prongs.

[0552] The first nasal prong 111, the second nasal prong 112, and the third nasal prong 115 are spaced apart so as to be engagable as adjacent pairs of nasal prongs into a patient's nostrils. Thus, the first prong 111 and the second prong 112 can be engaged with the patient's nostrils as described for the two-prong 111, 112 configuration described elsewhere in this disclosure, or the second prong 112 and the third prong 115 can be engaged with the patient's nostrils.

[0553] Thus, the nasal interface 100 of this construction has a first prong 111 or a third prong 115 that is not engaged and leads to the atmosphere during use. To avoid pressure loss and gas flow through the unengaged prongs 111, 115 within the gas manifold, a closure 119 is releasably engaged within the unused prongs 111, 115. Thus, the nasal interface 100 can be reconfigured by moving the closure 119 between a first configuration in which the first prong 111 and the second prong 112 allow gas to pass through to the patient's nostrils and a second configuration in which the second prong 112 and the third prong 115 allow gas to pass through to the patient's nostrils. The closure 119 is engaged to prevent gas flow through the third prong 115 or the first prong 111 respectively between the first and second configurations.

[0554] The closure 119 can be of any suitable form, such as a plug or a cap. Additionally, in some configurations, the closure 119 can be engaged by other parts of the nasal interface 100. For example, the inlet 121 or the gas delivery conduit 300 can be inserted into the gas manifold 120 to block at least one of the forks 111, 112, 115. Thus, flow is provided to the unblocked forks 111, 112, 115. In such a configuration, the closure 119 is formed at the base of the forks 111, 112, 115. The closure 119 can be movable by inserting, for example, the gas delivery conduit 300 into the opposite side of the gas manifold 120 (e.g., the location where there is a second inlet 122). Thus, the forks near the respective inlets 121, 122 are blocked by the gas delivery conduit 300. Alternatively, the closure 119 is formed by the distance that the gas delivery conduit 300 is inserted into the gas manifold 120, for example, by having an opening in the conduit that aligns with an opening in the fork opening or within the gas manifold 120 at a different location. Other parts of the nasal interface 10 can be reconfigurable to block at least one of the forks 111, 112, 115 as described herein.

[0555] The first fork 111, the second fork 112, and the third fork 115 are configured to have different gas flows passing therethrough to create an asymmetric flow as described throughout this document. Thus, as a non-limiting example, at least one of the first fork 111, the second fork 112, or the third fork 115 has a flow restriction in the form of a first fork element 201, a second fork element 202, a manifold element 203, a first inlet element 209 and a second inlet element 208, a flow guiding element 240, an additional flow guiding element 250, forks of different lengths as described with reference to Figure 16 as described, nozzles and diffusers as described with reference to Figure 17 as described, ridges 260 as described with reference to Figure 19 as described, fins 261 as described with reference to Figure 20 as described, base end restrictions 262 as described with reference to Figure 21 as described, or duckbill valves 263 as described with reference to Figure 22 as described. Additionally, in some configurations, the second inlet 122 as described with reference to Figure 9 is combined with the first fork 111, the second fork 112, and the third fork 115 to allow gas to flow on either side of the gas manifold 120. This provides additional control over the asymmetric flow.

[0556] The flow restriction of at least one of the first fork 111, the second fork 112, and the third fork 115 allows the user to move their nostrils between engagement with the first fork 111 and the second fork 112 to engagement with the second fork 112 and the third fork 115, thus having an asymmetric flow with different configurations.

[0557] In some configurations, the first prong 111 and the third prong 115 are configured to have the same gas flow therethrough, while the second prong 112 is configured to have a different gas flow therethrough to allow switching of an asymmetric flow between the left and right nostrils. Thus, a greater dynamic pressure is provided at the second prong 112 and a lesser dynamic pressure is provided at the first prong 111 and the third prong 115, or a greater dynamic pressure is provided at the first prong 111 and the third prong 115 and a lesser dynamic pressure is provided at the second prong 112.

[0558] In an alternative configuration, the first prong 111 and the second prong 112 are modular to allow removal and replacement of prong types having different flow restrictors.

[0559] As described above, the patient interface 10 having the nasal interface 100 according to the configurations described herein can be used in methods of delivering gas to the airway of a patient in need, improving ventilation of a patient in need, reducing the volume of anatomic dead space within the airway of a patient in need, and / or treating a respiratory condition of a patient in need.

[0560] A patient interface 10 including a nasal interface 100 of the type disclosed herein can be used in a respiratory therapy system for delivering gas to a patient.

[0561] In some configurations, the respiratory therapy system 1000 includes a respiratory therapy device 1100 and a patient interface 10, the patient interface including the nasal interface 100.

[0562] Figure 24 An exemplary respiratory therapy device 1100 is shown.

[0563] The respiratory therapy device 1100 includes a main housing 1101 that houses a flow generator 1011 in the form of a motor / impeller device (e.g., a blower), an optional humidifier 1012, a controller 1013, and a user interface 1014 (including, for example, a display and input devices such as buttons, touchscreens, etc.).

[0564] The controller 1013 can be configured or programmed to control the operation of the device. For example, the controller can control the components of the device, including but not limited to: operating the flow generator 1011 to generate a gas flow (airflow) for delivery to the patient, operating the humidifier 1012 (if present) to humidify and / or heat the generated gas flow, controlling the oxygen flow into the flow generator blower, receiving user input from the user interface 1014 for reconfiguration and / or user-defined operation of the device 1000, and outputting information to the user (e.g., on a display).

[0565] The user can be a patient, a healthcare professional, or any other person interested in using the device. As used herein, "gas flow" can refer to any gas flow that can be used in a respiratory assistance or respiratory device, such as an ambient air flow, a flow comprising substantially 100% oxygen, a flow comprising a certain combination of ambient air and oxygen, and / or the like.

[0566] The patient breathing conduit 300 is connected at one end to a gas flow outlet 1021 in the housing 1100 of the respiratory therapy device 1100. The patient breathing conduit 300 is connected at the other end to the nasal interface 100 via a gas manifold 120 and nasal forks 111, 112.

[0567] The gas flow generated by the respiratory therapy device 1100 can be humidified and delivered to the patient via the patient conduit 300 through the nasal interface 100. The patient conduit 300 can have a heater to heat the gas flow passing therethrough to the patient. For example, the patient conduit 300 can have a heating wire 300a to heat the gas flow passing therethrough to the patient. The heating wire 300a can be under the control of the controller 1013. The patient conduit 300 and / or the nasal interface 100 can be considered part of the respiratory therapy device 1100 or alternatively can be considered its peripheral device. The respiratory therapy device 1100, the patient breathing conduit 300, and the patient interface 10 including the nasal interface 10 together can form a respiratory therapy system 1000.

[0568] The controller 1013 can control the flow generator 1011 to generate a gas flow at a desired flow rate. The controller 1013 can also control the supplemental oxygen inlet to allow the delivery of supplemental oxygen, and the humidifier 1012 (if present) can humidify the gas flow and / or heat the gas flow to an appropriate level, and so on. The gas flow is directed to the patient through the patient conduit 300 and the nasal interface 100. The controller 1013 can also control the heating element in the humidifier 1012 and / or the heating element 300a in the gas delivery conduit 300 to heat the gas to a desired temperature for a desired treatment level and / or patient comfort level. The controller 1013 can be programmed with or can determine a suitable target temperature for the gas flow. In some configurations, a gas mixture composition including supplemental oxygen and / or therapeutic drug administration can be provided through the supplemental oxygen inlet. The gas mixture composition can include oxygen, heliox, nitrogen, nitric oxide, carbon dioxide, argon, helium, methane, sulfur hexafluoride, and combinations thereof, and / or the supplemental gas can include aerosolized drugs.

[0569] The oxygen inlet port 1028 may include a valve 1028a through which pressurized gas may enter the flow generator or blower. The valve may control the flow of oxygen into the flow generator blower. The valve may be any type of valve, including a proportional valve or a bistable valve. The oxygen source may be an oxygen tank or the oxygen supply of a hospital. The purity of medical grade oxygen is typically between 95% and 100%. Oxygen sources of lower purity may also be used. Examples of valve modules and filters are disclosed in PCT Publication No. WO2018 / 074935 and U.S. Patent Application Publication No. 2019 / 0255276, both of which have the title "Valve Module and Filter". The contents of these specifications are incorporated herein by reference in their entirety.

[0570] The respiratory therapy device 1100 may measure and control the oxygen content of the gas delivered to the patient and thus measure and control the oxygen content of the gas inhaled by the patient. During high-flow therapy, the high flow rate of gas delivered may meet or exceed the patient's peak inspiratory flow rate. This means that the volume of gas delivered to the patient by the device during inspiration meets or exceeds the volume of gas inhaled by the patient during inspiration. Thus, high-flow therapy helps prevent entrainment of ambient air during patient inhalation and flushes the exhaled gas from the patient's airway. If the flow rate of the delivered gas reaches or exceeds the patient's peak inspiratory flow rate, entrainment of ambient air may be prevented and the gas delivered by the device will be substantially the same as the gas inhaled by the patient. In this way, the oxygen concentration measured in the device, the fraction of delivered oxygen (FdO2), will be substantially the same as the oxygen concentration breathed by the user, the fraction of inhaled oxygen (FiO2), and thus these terms may be considered equivalent.

[0571] Operating sensors 1003a, 1003b, 1003c (such as flow, temperature, humidity, and / or pressure sensors) may be placed at various locations within the respiratory therapy device 1100. Additional sensors (e.g., sensors 1020, 1025) may be placed at various locations on the patient conduit 300 and / or nasal interface 100 (e.g., a temperature sensor 1029 may be present at or near the end of the inspiratory tube). The output from the sensors may be received by the controller 1013 to assist the controller in operating the respiratory therapy device 1100 in a manner that provides appropriate therapy. In some configurations, providing appropriate therapy includes meeting the patient's peak inspiratory flow rate. The device 1100 may have a transmitter and / or receiver 1015 to enable the controller 1013 to receive signals 1008 from the sensors and / or control various components of the respiratory therapy device 1100, including but not limited to the flow generator 1011, the humidifier 1012, and the heating wire 300a, or accessories or peripherals associated with the respiratory therapy device 1100. Additionally or alternatively, the transmitter and / or receiver 1015 may transfer data to a remote server or enable remote control of the device 1100.

[0572] Oxygen can be measured by placing one or more gas component sensors (such as an ultrasonic transducer system, also known as an ultrasonic sensor system) after the oxygen and ambient air are completely mixed. The measurement can be performed within the device, the delivery catheter, the patient interface, or at any other suitable location.

[0573] The respiratory therapy device 1100 can include a patient sensor 1026, such as a pulse oximeter or a patient monitoring system, to measure one or more physiological parameters of the patient, such as the patient's blood oxygen saturation (SpO2), heart rate, respiratory rate, perfusion index, and provide a measurement of the signal quality.

[0574] The patient sensor 1026 can communicate with the controller 1013 via a wired connection or via communication through a wireless transmitter on the patient sensor 1026.

[0575] The patient sensor 1026 can be a disposable adhesive sensor designed to be attached to the patient's finger. The patient sensor 1026 can be a non-disposable sensor.

[0576] Sensors designed for different age groups and attached to different locations on the patient are available and can be used with the respiratory therapy device 1100.

[0577] A pulse oximeter is typically attached to the user at the user's finger, although other locations such as the earlobe are also optional. The pulse oximeter will be connected to a processor in the device and will continuously provide a signal indicating the patient's blood oxygen saturation. The patient sensor 1026 can be a thermally exchangeable device that can be attached or exchanged during the operation of the respiratory therapy device 1100. For example, the patient sensor 1026 can use a USB interface or use a wireless communication protocol (such as, for example, near field communication, WiFi or ) to connect to the respiratory therapy device 1100. When the patient sensor 1026 is disconnected during operation, the respiratory therapy device 1100 can continue to operate in its previous operating state for a defined period of time. After the defined period of time, the respiratory therapy device 1100 can trigger an alarm, transition from an automatic mode to a manual mode, and / or completely exit the control mode (such as an automatic mode or a manual mode). The patient sensor 1026 can be a bedside monitoring system or other patient monitoring system that communicates with the respiratory therapy device 1100 via a physical or wireless interface.

[0578] The respiratory therapy device 1100 may include a high-flow therapy device. High-flow therapy, as discussed herein, is intended to be given its typical ordinary meaning as understood by those skilled in the art, which generally refers to a respiratory assistance system that delivers a target flow of humidified breathing gas at a flow rate that is typically intended to meet or exceed the patient's inspiratory flow rate via a patient interface that is not intentionally sealed. Typical patient interfaces include, but are not limited to, nasal or tracheal patient interfaces. Typical flow rates for adults are generally in the range from about fifteen liters per minute (lpm) to about seventy liters per minute or greater, but are not limited thereto. Typical flow rates for pediatric patients (e.g., neonates, infants, and children) are generally in the range from about one liter per kilogram of patient body weight per minute to about three liters per kilogram of patient body weight per minute or greater, but are not limited thereto. High-flow therapy may also optionally include the administration of a gas mixture composition that includes supplemental oxygen and / or a therapeutic agent. High-flow therapy is commonly referred to as nasal high-flow (NHF), humidified high-flow nasal cannula (HHFNC), high-flow nasal oxygen (HFNO), high-flow therapy (HFT), or tracheal high-flow (THF), among other common names. The flow rate used to achieve the "high flow rate" can be any of the flow rates listed below. For example, in some configurations, for an adult patient, "high-flow therapy" may refer to delivering gas to the patient at a flow rate greater than or equal to about 10 liters per minute (10 lpm), such as between about 10 lpm and about 100 lpm, or between about 15 lpm and about 95 lpm, or between about 20 lpm and about 90 lpm, or between 25 lpm and 75 lpm, or between about 25 lpm and about 85 lpm, or between about 30 lpm and about 80 lpm, or between about 35 lpm and about 75 lpm, or between about 40 lpm and about 70 lpm, or between about 45 lpm and about 65 lpm, or between about 50 lpm and about 60 lpm. In some configurations, for a neonate, infant, or child patient, "high-flow therapy" may refer to delivering gas to the patient at a flow rate greater than 1 lpm, such as between about 1 lpm and about 25 lpm, or between about 2 lpm and about 25 lpm, between about 2 lpm and about 5 lpm, or between about 5 lpm and about 25 lpm, or between about 5 lpm and about 10 lpm, or between about 10 lpm and about 25 lpm, or between about 10 lpm and about 20 lpm, or between about 10 lpm and 15 lpm, or between about 20 lpm and 25 lpm. A high-flow therapy device for an adult patient, neonate, infant, or child patient may deliver gas to the patient at a flow rate between about 1 lpm and about 100 lpm or at any flow rate within any of the sub-ranges described above. The flow therapy device 1000 may deliver any concentration of oxygen (e.g., FdO2), up to 100%, at any flow rate between about 1 lpm and about 100 lpm.In some configurations, any flow rate can be combined with an oxygen concentration (FdO2) of about 20%-30%, 21%-30%, 21%-40%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 70%-80%, 80%-90%, and 90%-100%. In some combinations, the flow rate can be between about 25 lpm and 75 lpm, combined with an oxygen concentration (FdO2) of about 20%-30%, 21%-30%, 21%-40%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 70%-80%, 80%-90%, and 90%-100%. In some configurations, the respiratory therapy device 1100 can include a safety threshold that prevents a user from delivering a large amount of oxygen to a patient when operating in a manual mode.

[0579] In some configurations, the respiratory therapy device 1100 includes a controller 1013; a blood oxygen saturation sensor 1026; an ambient air inlet 1027; an oxygen inlet 1028; a valve 1028a fluidly connected to the oxygen inlet 1028 to control the oxygen flow through the oxygen inlet 1028; and a gas outlet 1021; wherein the controller 1013 is configured to control the valve 1028a based on at least one measurement of the oxygen saturation from the blood oxygen saturation sensor 1026.

[0580] The patient interface 10 used in the respiratory therapy system 1000 having the respiratory therapy device 1100 includes a nasal interface 100, which includes: a first prong 111 and a second prong 112 that are asymmetric with each other; and a gas manifold 120 including a gas inlet 121, wherein the first prong 111 and the second prong 112 are fluidly connected to the gas inlet 121. The nasal interface 100 is configured to cause an asymmetric gas flow at the patient's nostrils.

[0581] The first prong 111 and the second prong 112 are asymmetric with each other, or are asymmetric to each other, or are different in shape and configuration from each other, or are asymmetric when compared to each other.

[0582] In some configurations, the nasal interface 100 includes an interface body 118, which includes the first prong 111 and the second prong 112.

[0583] In some configurations, the gas manifold 120 is integral with the interface body 118, or is separate from and connectable to the interface body 118.

[0584] In some configurations, the first prong 111 and the second prong 112 are configured to engage the nasal passages in a non-sealed manner.

[0585] In some configurations, the first prong 111 and the second prong 112 allow exhaled gas to escape around the first and second prongs.

[0586] In some configurations, the first prong 111 and the second prong 112 are configured to deliver gas to a patient without interfering with the patient's spontaneous breathing.

[0587] The nasal interface 100 can have any one or more of the features and / or functions described herein for the nasal interface 100.

[0588] In some configurations, the respiratory therapy device 1000 includes a flow generator 1011 and a humidifier 1012.

[0589] In some configurations, the respiratory therapy system includes a patient conduit 300 having a heater 300a.

[0590] In some configurations, the patient interface includes a breathable tube in fluid communication with the gas inlet 121, and the patient interface further includes a headgear to hold the nasal interface on the patient's face.

[0591] Patients with various health conditions and diseases can benefit from oxygen therapy. For example, patients with chronic obstructive pulmonary disease (COPD), pneumonia, asthma, bronchopulmonary dysplasia, heart failure, cystic fibrosis, sleep apnea, lung disease, respiratory trauma, acute respiratory distress, receiving pre- and post-operative oxygen delivery, and other conditions or diseases can benefit from oxygen therapy. A common way to treat these problems is to provide supplemental oxygen to the patient to prevent their blood oxygen saturation (SpO2) from dropping too low (e.g., below about 90%). However, supplying too much oxygen to the patient can over-oxidize their blood and is also considered dangerous. Generally, a patient's SpO2 is maintained in the range of about 80% to about 99%, preferably about 92% to about 96%, although these ranges may vary depending on the patient's condition. Due to various factors, such as respiratory rate, tidal volume, heart rate, activity level, height, weight, age, gender, and other factors, there is no one prescribed level of supplemental oxygen that can consistently achieve an SpO2 response within the target range for every patient. Each patient will periodically require that the fraction of oxygen delivered to them (FdO2) be monitored and adjusted to ensure they receive the correct FdO2 to achieve the target SpO2. Achieving the correct and consistent SpO2 is an important factor in treating patients with various health conditions or diseases. Additionally, patients with these health problems can benefit from a system that automatically controls oxygen saturation. The present disclosure is applicable to a wide range of patients who require rapid and accurate oxygen saturation control.

[0592] Referring to Figure 24 , the controller 1013 can be programmed with or configured to execute a closed-loop control system for controlling the operation of the respiratory therapy device 1100. The closed-loop control system can be configured to ensure that the patient's SpO2 reaches a target level and remains at or near that level at all times.

[0593] The controller 1013 can receive input from a user, which can be used by the controller 1013 to perform a closed-loop control system. The target SpO2 value can be a single value or a range of values. The value can be pre-set, selected by a clinician, or determined based on the type of patient, where the type of patient can refer to the current ailment, and / or information about the patient such as age, weight, height, gender, and other patient characteristics. Similarly, the target SpO2 can be two values, each selected in any of the above ways. These two values represent the range of acceptable values of the patient's SpO2. The controller can use the values within the said range as the target. The target value can be the mid-value of the range, or any other value within the range, which can be pre-set or selected by the user. Alternatively, the range can be automatically set based on the target value of SpO2. The controller can be configured to have one or more set responses when the patient's SpO2 value moves outside the range. The responses can include an alarm, changing to manual control of FdO2, changing FdO2 to a specific value, and / or other responses. The controller can have one or more ranges, where one or more different responses occur when moving outside each range.

[0594] Typically, SpO2 will be controlled between about 80% and about 100%, or between about 80% and about 90%, or between about 88% and about 92%, or between about 90% and about 99%, or between about 92% and about 96%. SpO2 can be controlled between any two suitable values from any two of the above ranges. The target SpO2 can be between about 80% and about 100%, or between about 80% and about 90%, or between about 88% and about 92%, or between about 90% and about 99%, or between about 92% and about 96%, or about 94%, or 94%, or about 90%, or 90%, or about 85%, or 85%. The SpO2 target can be any value between any two appropriate values from any two of the above ranges. The SpO2 target can correspond to the median of the SpO2 defining the range.

[0595] FdO2 can be configured to be controlled within a range. If the flow rate reaches or exceeds the patient's peak inspiratory flow rate, the oxygen concentration measured in the device (FdO2) can be substantially the same as the oxygen concentration (FiO2) that the patient is breathing, and thus these terms can be considered equivalent. Each limit value of the range can be preset, user-selected, or determined based on the type of patient, where the type of patient can refer to the current ailment and / or information about the patient such as age, weight, height, gender, and / or other patient characteristics. Alternatively, a single value of FdO2 can be selected, and the range can be determined at least in part based on that value. For example, the range can be a set amount above and below the selected FdO2. The selected FdO2 can be used as the starting point for the controller. If the controller attempts to move FdO2 outside the range, the system can have one or more responses. These responses can include an alarm, preventing FdO2 from moving outside the range, switching to manual control of FdO2, and / or switching to a specific FdO2. The device can have one or more ranges, where one or more different responses occur when the limit value of each range is reached.

[0596] Reference Figure 25 , shows a schematic diagram of a closed-loop control system 1500. The closed-loop control system can utilize two control loops. The first control loop can be implemented by an SpO2 controller. The SpO2 controller can determine a target FdO2 based in part on a target SpO2 and / or a measured SpO2. As described above, the target SpO2 value can be a single value or a range of acceptable values. This value can be pre-set, clinician-selected, or automatically determined based on customer characteristics. Typically, the target SpO2 value is received or determined before or at the start of the treatment period, although the target SpO2 value can be received at any time during the treatment period. During the treatment period, the SpO2 controller can also receive the following as inputs: the measured FdO2 readings from the gas composition sensor, and the measured FdO2 readings and signal quality readings from the patient sensor. In some configurations, the SpO2 controller can receive the target FdO2 as an input, in which case the output of the SpO2 controller can be provided directly back to the SpO2 controller as an input. Based at least in part on this input, the SpO2 controller can output the target FdO2 to the second control loop.

[0597] During the treatment period, the SpO2 and FdO2 controllers can continue to automatically control the operation of the respiratory treatment device 1100 until the end of the treatment period or an event triggers a change from the automatic mode to the manual mode.

[0598] Increased flushing caused by the asymmetry of the tines 111, 112 in the nasal interface 100 can improve the effectiveness of supplemental oxygenation. Closed-loop SpO2 control with an asymmetric nasal interface 100 can allow a patient's SpO2 to be maintained at or near a target value with a reduced amount of oxygen used compared to symmetric nasal high flow. This can result in oxygen conservation.

[0599] The respiratory therapy system can have any one or more of the features and functions described in PCT Publication No. WO2021 / 049954 and U.S. Provisional Application No. 62 / 898,464. The contents of these specifications are incorporated herein by reference in their entirety.

[0600] Figure 26 An alternative exemplary respiratory therapy system 2000 is shown that can utilize a patient interface 10 including a nasal interface 100.

[0601] In the illustrated configuration, the respiratory therapy system 2000 includes a respiratory therapy device 2100. The respiratory therapy device can include a flow generator 2101.

[0602] The illustrated flow generator 2101 includes a gas inlet 2102 and a gas outlet 2104. The flow generator 2101 can include a blower 2106. The blower 2106 can draw in gas from the gas inlet 2102. In some configurations, the flow generator 2101 can include a source or container of compressed gas (e.g., air, oxygen, etc.). The container can include a valve that can be adjusted to control the gas flow leaving the container. In some configurations, the flow generator 2101 can use such a compressed gas source and / or other gas sources in place of the blower 2106. In some configurations, the blower 2106 can be used in combination with another gas source. In some configurations, the blower 2106 can include a motorized blower or can include a bellows device or some other structure capable of generating a gas flow. In some configurations, the flow generator 2101 draws in ambient gas through the gas inlet 2102. In some configurations, the flow generator 2101 is adapted to draw in ambient gas through the gas inlet 2102 and receive other gases (e.g., oxygen, nitric oxide, carbon dioxide, etc.) through the same gas inlet 2102 or a different gas inlet. Other configurations are possible.

[0603] The illustrated flow generator 2101 includes a user control interface 2108. The user control interface 2108 can include one or more buttons, knobs, dials, switches, control levers, touchscreens, speakers, displays, and / or other input or output modules that a user can use to input commands into the flow generator 2101 to view data and / or control the operation of the flow generator 2101 and / or control the operation of other aspects of the respiratory therapy system 2000.

[0604] The flow generator 2101 can direct gas through the gas outlet 2104 to the first conduit 2110. In the illustrated configuration, the first conduit 2110 directs the gas to the gas humidifier 2112. The gas humidifier is optional.

[0605] The gas humidifier 2112 is used to entrain moisture in the gas to provide a humidified gas stream. The illustrated gas humidifier 2112 includes a humidifier inlet 2116 and a humidifier outlet 2118. The gas humidifier 2112 can include, be configured to contain, or contain water or other humidifying or moisture - enhancing agents (hereinafter referred to as water).

[0606] In some configurations, the gas humidifier 2112 includes a heating element (not shown). The heating element can be used to heat the water in the gas humidifier 2112 to facilitate water evaporation and / or entrainment in the gas stream and / or increase the temperature of the gas passing through the gas humidifier 2112. The heating element can include, for example, a resistive metal heating plate. However, other heating elements are also conceivable. For example, the heating element can include a plastic conductive heating plate or a chemical heating system with a controllable heat output.

[0607] In the illustrated configuration, the gas humidifier 2112 includes a user control interface 2120. The user control interface 2120 includes one or more buttons, knobs, dials, switches, joysticks, touchscreens, speakers, displays, and / or other input or output modules that a user can use to input commands into the gas humidifier 2112 to view data, and / or control the operation of the gas humidifier 2112, and / or control the operation of other aspects of the respiratory therapy system 2000.

[0608] In some configurations, the flow generator 2101 and the gas humidifier 2112 can share a housing 2126. In some configurations, the gas humidifier 2112 can share only a portion of the housing 2126 with the flow generator 2101. Other configurations are also possible.

[0609] In the illustrated configuration, the gas travels from the humidifier outlet 2118 to the second conduit 300. The second conduit 300 can include as described with respect to Figure 24The catheter heater described above. The catheter heater can be used to add heat to the gas passing through the second catheter 300. The heat can reduce or eliminate the possibility of water entrained in the gas stream condensing along the wall of the second catheter 300. The catheter heater can include one or more resistance wires located in, on, around, or near the wall of the second catheter 300. In one or more configurations, one or more such resistance wires can be located outside any gas passage. In one or more configurations, one or more such resistance wires are not in direct contact with the gas passing through the second catheter 300. In one or more configurations, the wall or surface of the second catheter 300 intercedes between one or more resistance wires and the gas passing through the second catheter 300.

[0610] The gas passing through the second catheter 300 can be delivered to the nasal interface 100. The nasal interface 100 can pneumatically connect the respiratory therapy system 100 to the patient's airway. In some configurations, the respiratory therapy system 2000 utilizes a dual-branch system that includes separate inspiratory gas passages and expiratory gas passages that engage with one or more of the patient's airways.

[0611] In some configurations, a short length of tubing connects the nasal interface 100 to the second catheter 300. In some configurations, the short length of tubing can have a smooth bore. For example, a flexible short length of tubing can connect the nasal interface to the second catheter 300. The short length of tubing connecting the nasal interface to the second catheter 300 can be breathable such that it allows vapor to transmit through the tube wall. In some configurations, the short length of tubing can incorporate one or more heating wires as described elsewhere herein. Whether heated or not, a smooth bore can improve the efficiency of delivering the nebulized substance as described elsewhere herein.

[0612] The respiratory therapy device 2100 includes a nebulizer 2128. In some configurations, if the nebulizer 2128 is used, the flow generator 2101, the gas humidifier 2112, and the nebulizer 2128 can share the housing 2126. In some configurations, the nebulizer 2128 is separate from the housing 2126.

[0613] The nebulizer 2128 can be connected to a portion of the gas passage that extends between the flow generator 2101 (which can include a gas inlet 2102) and the nasal interface 100, although other arrangements of the nebulizer 2128 or another nebulizer can be used. In some configurations, the nebulizer 2128 is not linearly positioned anywhere between the humidifier outlet 2118 and the nasal interface 100. Instead, the nebulizer 2128 is positioned upstream of the humidifier outlet 2118 or upstream of the inlet of the second catheter 2122. In some configurations, the nebulizer 2128 can be positioned upstream of the inlet to the humidifier. In some configurations, the nebulizer 2128 can be positioned between the gas flow source and the chamber.

[0614] The nebulizer 2128 can include a substance (e.g., a drug, a tracer gas, etc.) that can be introduced into the gas stream. The substance can be entrained in the gas stream and delivered to the patient's airway along with the breathing gas. The nebulizer 2128 can be connected to a portion of the gas passageway via a delivery device 2130, which can include a conduit or an adapter. Alternatively, the nebulizer 2128 can be directly engaged with the gas passageway, which may obviate the need for the delivery device 2130.

[0615] The respiratory treatment device 2100 can include a controller 2113. The controller 2113 can be configured or programmed to control the operation of the device. For example, the controller 2113 can control the components of the device, including but not limited to: operating the flow generator 2101 to generate a gas stream (airflow) for delivery to the patient, operating the humidifier 2112 (if present) to humidify and / or heat the generated gas stream, controlling the oxygen flow into the flow generator blower, receiving user input from the user interfaces 2108 and / or 2120 for reconfiguration and / or user-defined operation of the device 2100, and outputting information to the user (e.g., on a display).

[0616] The controller 2113 can control the flow generator 2101 to generate a gas stream at a desired flow rate. The controller 2113 can also control the supplemental oxygen inlet to allow delivery of supplemental oxygen, and the humidifier 2112 (if present) can humidify the gas stream and / or heat the gas stream to an appropriate level, etc. The controller 2113 can also control the operation of the nebulizer 2128. The gas stream is directed to the patient through the patient conduit 300 and the nasal interface 100. The controller 2113 is also capable of controlling the heating element in the humidifier 2112 and / or the heating element in the patient conduit 300 to heat the gas to a desired temperature for a desired treatment level and / or patient comfort level. The controller 2113 can be programmed or can determine a suitable target temperature for the gas stream. In some configurations, a gas mixture composition including supplemental oxygen and / or therapeutic drug administration can be provided through the supplemental oxygen inlet. The gas mixture composition can include oxygen, heliox, nitrogen, nitric oxide, carbon dioxide, argon, helium, methane, sulfur hexafluoride, and combinations thereof, and / or the supplemental gas can include an aerosolized drug from the nebulizer 2128.

[0617] In some configurations, a respiratory therapy device 2100 includes a gas inlet 2102, a gas outlet 2118, and an atomizer 2128 for delivering one or more substances into a gas stream. A nasal interface 100 used in a respiratory therapy system 2000 having the respiratory therapy device 2100 includes: a gas inlet 121 that is in fluid communication with the gas outlet 2118 to receive gas and one or more substances from the respiratory therapy device; a first prong 111 and a second prong 112; and a gas manifold 120 that includes the gas inlet 121. The first prong 111 and the second prong 112 are in fluid communication with the gas inlet 121. The nasal interface 100 is configured to cause an asymmetric gas flow at a patient's nostrils.

[0618] The respiratory therapy system 2000 may include conduits 300, 320 (examples of which are described below) to receive gas and one or more substances from the respiratory therapy device 2100 and to deliver the gas and one or more substances to the gas inlet 121 of the nasal interface 100.

[0619] In the illustrated configuration, the respiratory therapy system 2000 may operate as follows. Due to the rotation of the impeller of the motor of the blower 2106, gas may be drawn into the flow generator 2101 through the gas inlet 2102. The gas is pushed out of the gas outlet 2104 and through the first conduit 2110. The gas enters the gas humidifier 2112 through the humidifier inlet 2116. Once inside the gas humidifier 2112, the gas entrain moisture as it passes over or near water in the gas humidifier 2112. The water is heated by a heating element, which helps to humidify and / or heat the gas passing through the gas humidifier 2112. The gas leaves the gas humidifier 2112 through the humidifier outlet 2118 and enters the second conduit 300. Before entering the second conduit 300, the gas receives one or more substances from the nebulizer 128. The gas passes from the second conduit 300 to the nasal interface 100, where the gas is inhaled into the patient's airway to assist in treating a respiratory disorder.

[0620] Figure 27Illustrated is an exemplary type of tube or conduit 300 that can be used to deliver gas to the nasal interface 100. The tube or conduit 300 is shown as having a smooth bore 3021 or a non-corrugated bore. This type of tube is best described and illustrated in, for example, U.S. Patent Application Publication No. 2014 / 0202462 (also published as PCT Publication No. WO2012 / 164407A1) and PCT Publication No. WO2014 / 088430. The contents of these specifications are incorporated herein by reference in their entirety. As described therein, the tube is formed by beads 3041 and small tubes or bubbles 3061. Generally, the peak-to-valley surface roughness of such a tube is on the order of 0.15 - 0.25 mm. In one configuration, the conduit or tube has an inner bore diameter of 13 - 14 mm. The two members 3041, 3061 combine to define a conduit or tube with a lumen having minimal surface deviation. In some configurations, the beads 304 include wires 3081. One or more wires can be used to heat the conduit wall rather than being positioned within the flow conveyed by the conduit or tube 300. In the illustrated configuration, the beads 3041 include four wires 3081. In some configurations, the beads 304 can include two wires 3081. Other numbers of wires can also be used.

[0621] Figure 28 Illustrated is an alternative exemplary type of tube or conduit 320 that can be used to deliver gas to the nasal interface 100. Referring to Figure 28 , the illustrated conduit or tube 320 is a corrugated tube. In one configuration, the conduit or tube 320 has an inner bore diameter of 20 - 21 mm. The corrugated tube 320 includes deep grooves 322 along the wall 324 of the tube 320. In many cases, the grooves 322 result in one or more helical interruptions extending along the length of the lumen defined by the wall 324. Thus, the inner surface of the conduit or tube is significantly rougher than Figure 26 the smooth bore tube 300 illustrated. Generally, the peak-to-valley surface roughness of a corrugated conduit or tube is approximately 1.5 - 2.5 mm. In Figure 28 the illustrated configuration, one or more heating wires 326 can also be coiled and positioned in direct contact with the gas flow through the lumen. When the wire is located within the gas flow path, the heating wire increases the "surface roughness" by 2 - 3 mm, although this is only an estimate of the effect of the heating wire positioned within the gas flow path.

[0622] Compared to using a more traditional heated breathing tube 320 as illustrated in Figure 28 , using a Figure 27The smooth-bore heating tube 300 shown is used to deliver medication from the nebulizer 2128 described above, resulting in a significant increase in medication delivery efficiency. The increased efficiency is thought to be due to a substantial reduction in the amount of atomized medication trapped within the grooves 322 and exposed heating wires 326 of more traditional heating breathing tubes 320. For example, it has been estimated that, by way of example and not limitation, 300% more atomized medication is captured by the surface as compared to medication retained within the smooth-bore heating breathing tube 300 as shown in Figure 27 . It is believed that due to smaller vortices and fewer obstacles (which present effective roughness) in the flow, deposition processes such as impingement are reduced.

[0623] In some configurations, when the flow rate exceeds the optimal flow rate, it has been found that the delivery efficiency decreases. In other words, at some high flow rates above 30 lpm, the flow rate is inversely proportional to the atomization efficiency to a degree (i.e., high flow rates result in more medication being trapped within the circuit rather than being delivered to the patient).

[0624] By using the nasal cannula 100 with nasal forks 111, 112, a reduction in flow rate is possible for an equivalent dead space clearance, which can improve the delivery of respiratory therapy using atomized medication. Due to a smoother flow transition, atomized medication is less likely to "crash out," in which a portion of the medication deposits on the inner surface of the flow path rather than being delivered to the patient or otherwise lost due to impingement on the surface. Using the partial unidirectional flow provided by the nasal interface 100, less medication is wasted when the patient exhales against the flow than otherwise might be wasted. Other aspects of the nasal cannula 100 with nasal forks 111, 112 (including the cross-sectional areas of the forks and the relationship of these cross-sectional areas) can improve the delivery of respiratory therapy using atomized medication.

[0625] The patient interface 10 and nasal interface 100 used in the respiratory therapy system 2000 can have any one or more of the features and / or functions described herein for the nasal interface 100.

[0626] The respiratory therapy system 2000 can have any one or more of the features and / or functions of the systems described in PCT Publication No. WO2016 / 085354 or U.S. Patent Application Publication No. 2017 / 0312472. The contents of these specifications are incorporated herein by reference in their entirety.

[0627] Although the present disclosure has been described with respect to certain embodiments, other embodiments that are obvious to a person of ordinary skill in the art are also within the scope of the present disclosure. Accordingly, various changes and modifications may be made without departing from the spirit and scope of the present disclosure. For example, various components may be repositioned as needed. Features from any of the described embodiments may be combined with one another and / or the device may include one, more than one, or all of the features of the above-described embodiments. Additionally, not all features, aspects, and advantages are necessary for the practice of the present disclosure. Accordingly, the scope of the present disclosure is intended to be defined only by the appended claims.

[0628] For clarity, in the present disclosure, like reference numerals are used in the figures to identify like elements. However, for convenience, some features that are present in or annotated with reference numerals in some of the figures of the present disclosure are not shown or annotated with reference numerals in other figures of the present disclosure. Unless the context clearly requires otherwise, these omissions should not be construed to mean that features omitted from the figures of one drawing cannot be equivalently incorporated or implemented in the construction of the disclosed methods, devices, and systems associated with or embodied in other drawings. Conversely, unless the context clearly requires otherwise, the presence of some features in some figures of the present disclosure should not be assumed to mean that the disclosed methods, devices, and systems associated with or embodied in those figures must include those features.

[0629] Clause

[0630] Additional embodiments are included in the following clauses or numbered statements.

[0631] 1. A nasal interface, comprising:

[0632] i. A first prong having a first base and a first end;

[0633] ii. A second prong having a second base and a second end;

[0634] iii. A gas manifold including a manifold chamber and a gas inlet; and

[0635] iv. At least one element positioned within the first prong, the second prong, or the manifold chamber;

[0636] b. wherein the at least one element is configured to increase the resistance of the gas flow traveling through at least one of the first prong, the second prong, or the manifold chamber, and

[0637] c. wherein the gas inlet is in fluid communication with, or is configured to be in fluid communication with, a gas delivery conduit.

[0638] 2. The nasal interface according to clause 1, wherein the increase in the resistance of the gas flow is configured to cause an asymmetric gas flow at the first prong and the second prong.

[0639] 3. A nasal interface according to Clause 1 or Clause 2, wherein the at least one element is a second prong element positioned within the second prong.

[0640] 4. A nasal interface according to Clause 3, wherein the second prong element is configured to increase the resistance of the gas flow passing through the second prong.

[0641] 5. A nasal interface according to Clause 3 or Clause 4, wherein the second prong element is positioned at the second base.

[0642] 6. A nasal interface according to any one of Clauses 1 to 5, wherein the second base of the second prong includes an inlet leading to a flow passage formed by the walls of the second prong.

[0643] 7. A nasal interface according to any one of Clauses 1 to 6, wherein the at least one element is a manifold element, and the manifold element is positioned within a manifold chamber of a gas manifold.

[0644] 8. A nasal interface according to Clause 7, wherein the manifold element is configured to increase the resistance of the gas flow passing through the manifold chamber.

[0645] 9. A nasal interface according to any one of Clauses 1 to 8, wherein the gas flow is generally in a direction from the gas manifold inlet, through the gas manifold chamber, and into the flow passage within the first prong and / or the second prong.

[0646] 10. A nasal interface according to Clause 7 or Clause 8, wherein the manifold element is generally positioned at the center of the manifold chamber.

[0647] 11. A nasal interface according to any one of Clauses 3 to 5, wherein the nasal interface includes a first prong element, and the first prong element is positioned within the first prong.

[0648] 12. A nasal interface according to Clause 11, wherein the first prong element is configured to increase the resistance of the gas flow passing through the first prong.

[0649] 13. A nasal interface according to Clause 11 or Clause 12, wherein the first prong element is positioned at the first base of the first prong.

[0650] 14. A nasal interface according to Clause 12, wherein the first prong element provides a different resistance to the gas flow compared to the second prong element.

[0651] 15. A nasal interface according to any one of Clauses 1 to 14, wherein a gas delivery conduit is located between the patient conduit and the gas inlet.

[0652] 16. A nasal interface according to any one of Clauses 1 to 15, wherein the gas manifold is integrally formed with or coupled to the gas delivery conduit.

[0653] 17. The nasal interface according to any one of clauses 1 to 16, wherein the gas manifold includes a manifold width, and wherein the manifold width is as large as or larger than the inner diameter of at least one of the first fork or the second fork.

[0654] 18. The nasal interface according to any one of clauses 1 to 17, wherein the nasal interface includes an intubation body, the intubation body includes the first fork and the second fork, and wherein the outer surface of the intubation body between the first fork and the second fork includes a recess to accommodate a part of the patient's nose and reduce the pressure on the lower side of the accommodated part.

[0655] 19. The nasal interface according to any one of clauses 1 to 18, wherein the size of at least one of the first fork or the second fork is determined to maintain a sufficient gap between the outer surface of the at least one fork and the patient's skin to avoid sealing the gas path between the nasal interface and the patient.

[0656] 20. The nasal interface according to any one of clauses 1 to 19, wherein at least the first fork or the second fork is made of an elastomeric material, and the elastomeric material enables the first fork to deform in response to temperature and contact with the patient's nostril and set its shape in use.

[0657] 21. The nasal interface according to any one of clauses 1 to 20, wherein at least one of the first fork or the second fork is not made of silicone.

[0658] 22. The nasal interface according to any one of clauses 1 to 21, wherein at least one of the first fork or the second fork is made of a thermoplastic elastomer.

[0659] 23. The nasal interface according to any one of clauses 1 to 22, wherein the gas manifold includes a flow channel, and the flow channel has a gas flow direction substantially perpendicular to the gas flow path through the first fork and the second fork.

[0660] 24. The nasal interface according to clause 7 or 8, wherein the manifold element includes a manifold hole for gas to flow through, and wherein the manifold hole has a smaller cross-sectional opening than the manifold chamber for gas flow.

[0661] 25. The nasal interface according to any one of clauses 3 to 5, wherein the second fork element includes a second hole for gas to flow through, and wherein the second hole has a smaller cross-sectional opening than the second fork for gas flow.

[0662] 26. The nasal interface according to clause 24 or clause 25, wherein the manifold hole and / or the second hole are formed in a plate or a wall.

[0663] 27. The nasal interface according to clause 26, wherein the plate or wall has an inlet surface and an outlet surface, and the manifold holes and / or the second holes are formed between the inlet surface and the outlet surface.

[0664] 28. The nasal interface according to clause 27, wherein the gas flow is in a direction from the inlet surface through the manifold holes and / or the second holes to the outlet surface.

[0665] 29. The nasal interface according to clause 27 or clause 28, wherein the transition between the outlet surface and the manifold holes and / or the second holes is tapered.

[0666] 30. The nasal interface according to any one of clauses 27 to 29, wherein the transition between the inlet surface and the manifold holes and / or the second holes is substantially right-angled.

[0667] 31. The nasal interface according to any one of clauses 27 to 29, wherein the transition between the inlet surface and the manifold holes and / or the second holes is tapered, and the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

[0668] 32. The nasal interface according to any one of clauses 27 to 29, wherein the transition between the inlet surface and the manifold holes and / or the second holes is substantially a sharp corner.

[0669] 33. The nasal interface according to any one of clauses 26 to 32, wherein at least one of the manifold holes and / or the second holes is a gap, notch or slit that extends vertically longitudinally through the plate or wall.

[0670] 34. The nasal interface according to any one of clauses 26 to 32, wherein at least one of the manifold holes and / or the second holes is a gap, notch or slit that extends horizontally longitudinally through the plate or wall.

[0671] 35. The nasal interface according to any one of clauses 24 to 34, wherein at least one of the manifold holes and / or the second holes is a substantially circular perforation.

[0672] 36. The nasal interface according to any one of clauses 24 to 35, wherein at least one of the manifold holes and / or the second holes includes a perforation pattern.

[0673] 37. The nasal interface according to any one of clauses 26 to 34, wherein the plate or wall of at least one of the manifold holes and / or the second holes includes a porous medium.

[0674] 38. The nasal interface according to any one of clauses 1 to 37, wherein the at least one element includes a valve.

[0675] 39. The nasal interface according to clause 38, wherein the valve is configured to open only at a threshold pressure or a threshold flow rate.

[0676] 40. A nasal interface according to clause 38 or clause 39, wherein the valve is configured to provide a defined pressure drop in the flow path.

[0677] 41. A nasal interface according to any one of clauses 38 to 40, wherein the valve is a duckbill valve.

[0678] 42. A nasal interface according to any one of clauses 1 to 41, wherein the at least one element includes a nozzle.

[0679] 43. A nasal interface according to clause 42, wherein the nozzle is configured to provide a defined pressure drop in the flow path.

[0680] 44. A nasal interface according to clause 7 or clause 8, wherein the manifold element is configured to be adjusted via manual actuation to increase or decrease the degree of restriction imposed by the manifold element.

[0681] 45. A nasal interface according to clause 44, wherein the manifold element is configured to be slidably movable in the upstream-downstream direction.

[0682] 46. A nasal interface according to clause 44, wherein the manifold element includes a rotatable member having a helical thread.

[0683] 47. A nasal interface according to clause 45 or clause 46, wherein the manifold element further includes an external portion located outside the gas manifold of the nasal interface.

[0684] 48. A nasal interface according to clause 47, wherein the manifold element is configured to be rotatably movable such that when the external portion rotates, the manifold element vertically translates into or out of the manifold chamber flow path, thereby increasing or decreasing the degree of flow restriction in the flow path, respectively.

[0685] 49. A nasal interface according to any one of clauses 1 to 48, wherein the gas manifold includes an opening at a wall that is generally opposite the gas inlet of the gas manifold and / or generally opposite the second base of the second fork.

[0686] 50. A nasal interface according to clause 49, wherein the opening includes one or more holes.

[0687] 51. A nasal interface according to clause 50, wherein the number and diameter of the holes are configured to provide a defined pressure drop.

[0688] 52. A nasal interface according to any one of clauses 49 to 51, wherein the opening in the wall of the manifold is pneumatically connected to a member configured to provide a defined pressure drop.

[0689] 53. The nasal interface according to clause 52, wherein the component is at least one of a porous medium, a nozzle, a pressure reducing valve, an auxiliary tube, or a bubble CPAP bubbling chamber.

[0690] 54. The nasal interface according to any one of clauses 1 to 53, wherein the axis of the gas inlet is coaxial with the axis of at least one of the first fork or the second fork.

[0691] 55. The nasal interface according to any one of clauses 1 to 53, wherein the angle of the axis of the gas inlet is perpendicular to the axis of at least the first fork or the second fork.

[0692] 56. The nasal interface according to any one of clauses 1 to 55, wherein the gas manifold includes a second gas inlet.

[0693] 57. The nasal interface according to any one of clauses 1 to 56, wherein the nasal interface includes an auxiliary gas inlet to cause or promote an asymmetric gas flow at the first fork and the second fork.

[0694] 58. The nasal interface according to clause 57, wherein the auxiliary gas inlet terminates in the first fork or the second fork.

[0695] 59. The nasal interface according to clause 57 or 58, wherein the auxiliary gas inlet is in fluid communication with an auxiliary gas delivery conduit.

[0696] 60. The nasal interface according to any one of clauses 57 to 59, wherein at least one of the gas inlet or the gas delivery conduit includes a lumen having a first internal cross-sectional area, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a lumen having a second internal cross-sectional area.

[0697] 61. The nasal interface according to clause 60, wherein one or both of the first internal cross-sectional area and the second internal cross-sectional area are substantially circular.

[0698] 62. The nasal interface according to clause 61 or clause 62, wherein the first internal cross-sectional area and the second internal cross-sectional area are different.

[0699] 63. The nasal interface according to clause 63, wherein the second internal cross-sectional area is smaller than the internal cross-sectional area of the first fork or the second fork.

[0700] 64. The nasal interface according to clause 59, wherein the gas delivery conduit and the auxiliary gas delivery conduit are arranged on the same side of the manifold chamber.

[0701] 65. The nasal interface according to clause 59, wherein the auxiliary gas delivery conduit is positioned within the gas delivery conduit.

[0702] 66. The nasal interface according to clause 59, wherein at least one of the gas inlet or the gas delivery conduit includes a first length, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a second length.

[0703] 67. The nasal interface according to clause 66, wherein the first length and the second length are not equal to cause an asymmetric gas flow at the first fork and the second fork.

[0704] 68. The nasal interface according to clause 66 or clause 67, wherein the first length is longer than the second length to cause or promote an asymmetric gas flow at the first fork and the second fork.

[0705] 69. The nasal interface according to clause 66 or clause 67, wherein the first length is shorter than the second length to cause or promote an asymmetric gas flow at the first fork and the second fork.

[0706] 70. The nasal interface according to clause 59, wherein the gas delivery conduit is in communication with a first gas flow, and the auxiliary gas delivery conduit is in communication with a second gas flow.

[0707] 71. The nasal interface according to clause 70, wherein the first gas flow has a flow rate different from that of the second gas flow.

[0708] 72. The nasal interface according to clause 70 or clause 71, wherein the resultant flow direction between the gas manifold and the first gas flow is a flow direction different from the resultant flow direction between the gas manifold and the second gas flow.

[0709] 73. The nasal interface according to any one of clauses 70 to 72, wherein one of the first gas flow or the second gas flow is an inhalation flow.

[0710] 74. The nasal interface according to any one of clauses 70 to 73, wherein the gas pressure of the first gas flow is different from the gas pressure of the second gas flow.

[0711] 75. The nasal interface according to clause 74, wherein a negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

[0712] 76. A nasal interface, comprising:

[0713] i. A first fork having a first base and a first end;

[0714] ii. A second fork having a second base and a second end; and

[0715] iii. A gas manifold, comprising:

[0716] 1. A manifold chamber;

[0717] 2. A first gas inlet; and

[0718] 3. Second gas inlet,

[0719] b. wherein the first gas inlet and the second gas inlet are in fluid communication with a first gas delivery conduit and a second gas delivery conduit respectively,

[0720] i. wherein the nasal interface is configured to cause an asymmetric gas flow at the first fork and the second fork.

[0721] 77. The nasal interface according to clause 76, wherein the first gas inlet and the second gas inlet are arranged on opposite sides of the manifold chamber.

[0722] 78. The nasal interface according to clause 76 or clause 77, wherein the first gas inlet is closer to the first fork than the second gas inlet, and wherein the second gas inlet is closer to the second fork than the first gas inlet.

[0723] 79. The nasal interface according to any one of clauses 76 to 78, wherein at least one of the first gas inlet and the first gas delivery conduit is formed as an integral structure, or the second gas inlet and the second gas delivery conduit are formed as an integral structure.

[0724] 80. The nasal interface according to any one of clauses 76 to 79, wherein the first gas delivery conduit is in communication with a first gas flow, and the second gas delivery conduit is in communication with a second gas flow.

[0725] 81. The nasal interface according to clause 80, wherein the first gas flow has a different flow rate from the second gas flow.

[0726] 82. The nasal interface according to clause 80 or clause 81, wherein the combined flow direction between the gas manifold and the first gas flow is a different flow direction from the combined flow direction between the gas manifold and the second gas flow.

[0727] 83. The nasal interface according to any one of clauses 80 to 82, wherein one of the first gas flow or the second gas flow is an inhalation flow.

[0728] 84. The nasal interface according to any one of clauses 80 to 83, wherein the gas pressure of the first gas flow is different from the gas pressure of the second gas flow.

[0729] 85. The nasal interface according to clause 84, wherein a negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

[0730] 86. A nasal interface according to any one of clauses 76 to 85, wherein at least one of the first gas inlet or the first gas delivery conduit includes a lumen having a first internal cross-sectional area, and at least one of the second gas inlet or the second gas delivery conduit includes a lumen having a second internal cross-sectional area.

[0731] 87. The nasal interface according to clause 86, wherein one or both of the first internal cross-sectional area and the second internal cross-sectional area are substantially circular.

[0732] 88. The nasal interface according to clause 86, wherein one or both of the first internal cross-sectional area and the second internal cross-sectional area are substantially non-circular.

[0733] 89. The nasal interface according to any one of clauses 86 to 88, wherein the first internal cross-sectional area and the second internal cross-sectional area are not equal to cause an asymmetric gas flow at the first fork and the second fork.

[0734] 90. The nasal interface according to any one of clauses 86 to 89, wherein the first internal cross-sectional area is greater than the second internal cross-sectional area to cause an asymmetric gas flow at the first fork and the second fork.

[0735] 91. The nasal interface according to any one of clauses 86 to 89, wherein the first internal cross-sectional area is less than the second internal cross-sectional area to cause an asymmetric gas flow at the first fork and the second fork.

[0736] 92. The nasal interface according to any one of clauses 76 to 91, wherein at least one of the first gas inlet or the first gas delivery conduit includes a first length, and at least one of the second gas inlet or the second gas delivery conduit includes a second length.

[0737] 93. The nasal interface according to clause 92, wherein the first length and the second length are not equal to cause an asymmetric gas flow at the first fork and the second fork.

[0738] 94. The nasal interface according to clause 92 or clause 93, wherein the first length is longer than the second length to cause an asymmetric gas flow at the first fork and the second fork.

[0739] 95. The nasal interface according to clause 92 or clause 93, wherein the first length is shorter than the second length to cause an asymmetric gas flow at the first fork and the second fork.

[0740] 96. The nasal interface according to any one of clauses 76 to 95, wherein the inner surface of at least one of the first gas inlet or the first gas delivery conduit includes a first embossed feature pattern.

[0741] 97. A nasal interface according to any one of clauses 76 to 96, wherein the inner surface of at least one of the second gas inlet or the second gas delivery conduit includes a second embossed feature pattern.

[0742] 98. A nasal interface according to clause 97 when dependent on clause 96, wherein the first embossed feature pattern is substantially rougher than the second embossed feature pattern to cause an asymmetric gas flow at the first and second forks.

[0743] 99. A nasal interface according to clause 97 when dependent on clause 96, wherein the first embossed feature pattern is substantially smoother than the second embossed feature pattern to cause an asymmetric gas flow at the first and second forks.

[0744] 100. A nasal interface according to any one of clauses 96 to 99, wherein the embossed feature pattern includes one or more of the following: pits, protrusions, ribs, and / or fins.

[0745] 101. A nasal interface according to any one of clauses 76 to 100, wherein the axis of at least one of the first gas inlet or the second gas inlet is coaxial with the axis of at least one of the first fork or the second fork.

[0746] 102. A nasal interface according to any one of clauses 76 to 100, wherein the axis of the first gas inlet and / or the second gas inlet is perpendicular to the axis of at least one of the first fork or the second fork.

[0747] 103. A nasal interface according to any one of clauses 76 to 102, comprising at least one of the following:

[0748] (i) A first fork element positioned within the first fork;

[0749] (ii) A second fork element positioned within the second fork;

[0750] (iii) A manifold element positioned within the manifold chamber and between the first base of the first fork and the second base of the second fork;

[0751] (iv) A first gas inlet element positioned at the first gas inlet leading to the gas manifold; or

[0752] (v) A second gas inlet element positioned at the second gas inlet leading to the gas manifold,

[0753] a. wherein each of the first fork element, the second fork element, the manifold element, the first gas inlet element, and / or the second gas inlet element is configured to increase the resistance of the gas flow entering the corresponding element to cause an asymmetric gas flow at the first and second forks.

[0754] 104. The nasal interface according to clause 103, including the first gas inlet element and the second gas inlet element, each of which is configured to increase the flow resistance of the gas flow entering the gas manifold through the first gas inlet and the second gas inlet, respectively.

[0755] 105. The nasal interface according to clause 103, including the first fork element and the second fork element, each of which is configured to increase the flow resistance of the gas flow entering the first fork and the second fork, respectively.

[0756] 106. The nasal interface according to clause 103, including the manifold element and the first gas inlet element, each of which is configured to increase the flow resistance of the gas flow in the manifold chamber and entering the gas manifold through the manifold element and the first gas inlet element, respectively.

[0757] 107. The nasal interface according to clause 103, including the manifold element and the second gas inlet element, each of which is configured to increase the flow resistance of the gas flow in the manifold chamber and entering the gas manifold through the manifold element and the second gas inlet element, respectively.

[0758] 108. The nasal interface according to any one of clauses 103 to 107, wherein at least one of the first fork element, the second fork element, the manifold element, the first gas inlet element or the second gas inlet element, when present, includes holes for reducing the passage of the gas flow.

[0759] 109. The nasal interface according to clause 108, wherein the holes are formed in a plate or a wall.

[0760] 110. The nasal interface according to clause 109, wherein the plate or the wall has an inlet surface and an outlet surface with holes formed therebetween.

[0761] 111. The nasal interface according to clause 110, wherein the gas flow is in a direction from the inlet surface through the holes to the outlet surface.

[0762] 112. The nasal interface according to clause 109 or clause 110, wherein the transition between the outlet surface and the holes is tapered.

[0763] 113. The nasal interface according to any one of clauses 109 to 112, wherein the transition between the inlet surface and the holes is substantially right-angled.

[0764] 114. The nasal interface according to any one of clauses 109 to 112, wherein the transition between the inlet surface and the holes is tapered, and the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

[0765] 115. A nasal interface according to any one of clauses 109 to 112, wherein the transition between the inlet surface and the orifice is substantially a sharp corner.

[0766] 116. A nasal interface according to any one of clauses 109 to 115, wherein at least one orifice is a gap, cut, or slit that extends vertically longitudinally through the plate or wall.

[0767] 117. A nasal interface according to any one of clauses 109 to 115, wherein at least one orifice is a gap, cut, or slit that extends horizontally longitudinally through the plate or wall.

[0768] 118. A nasal interface according to any one of clauses 108 to 115, wherein at least one orifice is a substantially circular perforation.

[0769] 119. A nasal interface according to any one of clauses 108 to 115, wherein at least one orifice includes a perforation pattern.

[0770] 120. A nasal interface according to any one of clauses 109 to 115, wherein the plate or wall of at least one orifice includes a porous medium.

[0771] 121. A nasal interface according to any one of clauses 103 to 108, wherein when present, at least one of the first fork element, second fork element, manifold element, first gas inlet element, or second gas inlet element includes a valve.

[0772] 122. A nasal interface according to clause 121, wherein the valve is configured to open only at a threshold pressure or threshold flow rate.

[0773] 123. A nasal interface according to clause 121 or clause 122, wherein the valve is configured to provide a defined pressure drop in the flow path.

[0774] 124. A nasal interface according to any one of clauses 121 to 123, wherein the valve is a duckbill valve.

[0775] 125. A nasal interface according to any one of clauses 103 to 124, wherein when present, at least one of the first fork element, second fork element, manifold element, first gas inlet element, or second gas inlet element includes a nozzle.

[0776] 126. A nasal interface according to clause 125, wherein the nozzle is configured to provide a defined pressure drop in the flow path.

[0777] 127. A nasal interface according to any one of clauses 103 to 126, wherein, when present, at least one of the first fork element, the second fork element, the manifold element, the first gas inlet element or the second gas inlet element is configured to be adjusted by manual actuation to increase or decrease the degree of restriction imposed by the element.

[0778] 128. A nasal interface according to clause 127, wherein the element is configured to be slidably movable in the upstream-downstream direction.

[0779] 129. A nasal interface according to clause 128, wherein the element includes a rotatable member having a helical thread.

[0780] 130. A nasal interface according to clause 129, wherein the element further includes an external portion located outside the nasal interface.

[0781] 131. A nasal interface according to clause 130, wherein the element is configured to be rotatably movable such that when the external portion is rotated, the element is vertically translated into or out of the flow path, thereby increasing or decreasing the degree of flow restriction in the flow path, respectively.

[0782] 132. A nasal interface comprising:

[0783] i. a first fork and a second fork;

[0784] ii. a gas manifold including a manifold chamber and a gas inlet, the gas inlet being in fluid communication with or configured to be in fluid communication with a gas delivery conduit; and

[0785] iii. at least one flow guiding element formed as a part of at least one of the manifold chamber, the gas inlet or the gas delivery conduit;

[0786] b. wherein the at least one flow guiding element is configured to direct a gas flow to one of the first fork or the second fork to produce an asymmetric gas flow.

[0787] 133. A nasal interface according to clause 132, wherein the flow guiding element is configured to provide a greater dynamic pressure at the first fork in use and a smaller dynamic pressure at the second fork in use to produce an asymmetric gas flow.

[0788] 134. A nasal interface according to clause 132 or clause 133, wherein at least one of the first fork or the second fork is sized to maintain a sufficient gap between the outer surface of the at least one fork and the patient's skin to avoid sealing the gas path between the nasal interface and the patient.

[0789] 135. The nasal interface according to any one of clauses 132 to 134, wherein the first prong and the second prong are in fluid communication with the manifold chamber.

[0790] 136. The nasal interface according to any one of clauses 132 to 135, wherein the gas inlet is positioned in the manifold chamber relative to at least one of the first prong or the second prong.

[0791] 137. The nasal interface according to any one of clauses 132 to 137, wherein the axis of the gas inlet is coaxial with the axis of at least one of the first prong or the second prong.

[0792] 138. The nasal interface according to any one of clauses 132 to 136, wherein the angle of the axis of the gas inlet is perpendicular to the axis of at least one of the first prong or the second prong.

[0793] 139. The nasal interface according to any one of clauses 134 to 138, wherein the at least one flow guiding element is positioned within the gas manifold chamber.

[0794] 140. The nasal interface according to any one of clauses 134 to 138, wherein the at least one flow guiding element is positioned within the gas delivery conduit.

[0795] 141. The nasal interface according to clause 140, wherein the at least one flow guiding element is positioned within the gas delivery conduit at the point where the gas delivery conduit meets the gas inlet.

[0796] 142. The nasal interface according to any one of clauses 134 to 141, wherein the at least one flow guiding element includes at least one angled protrusion, and the protrusion is configured to direct the gas flow from the gas inlet towards one of the first prong or the second prong.

[0797] 143. The nasal interface according to clause 142, wherein the at least one flow guiding element further includes an angled second protrusion, the second protrusion is positioned opposite the first protrusion in the flow path, and is similarly configured to direct the gas flow from the gas inlet towards one of the first prong or the second prong.

[0798] 144. The nasal interface according to any one of clauses 134 to 143, including a second flow guiding element positioned at the entrance to one of the first prong or the second prong in the gas manifold.

[0799] 145. The nasal interface according to clause 144, wherein the second flow guiding element is configured to direct the gas flow from the gas inlet towards one of the first prong or the second prong.

[0800] 146. A nasal interface according to clause 144 or clause 145, wherein the second flow guiding element is configured to guide the exhaled gas flow from the first fork or the second fork to the opposite fork.

[0801] 147. A nasal interface according to clause 144 or clause 145, wherein the second flow guiding element includes at least one angled protrusion, wherein the protrusion is configured to guide the gas flow from the gas inlet towards one of the first fork or the second fork, and is configured to guide the exhaled gas flow from the first fork or the second fork to the opposite fork.

[0802] 148. A nasal interface according to any one of clauses 134 to 147, wherein the gas inlet is positioned at a substantially central position between the first fork and the second fork in the manifold chamber.

[0803] 149. A nasal interface according to any one of clauses 134 to 148, wherein the at least one flow guiding element is positioned within the gas manifold chamber and near the first fork.

[0804] 150. A nasal interface according to any one of clauses 134 to 149, wherein the at least one flow guiding element is configured to guide the gas flow from the gas delivery conduit towards the inlet of the first fork.

[0805] 151. A nasal interface according to any one of clauses 144 to 147, wherein the second flow guiding element is configured to guide the gas flow from the inlet of the first fork into the flow path of the first fork.

[0806] 152. A nasal interface according to any one of clauses 134 to 151, wherein the at least one flow guiding element is positioned within the gas manifold chamber and near the second fork.

[0807] 153. A nasal interface according to any one of clauses 134 to 148, wherein the at least one flow guiding element is configured to guide the gas flow from the gas delivery conduit towards the inlet of the second fork.

[0808] 154. A nasal interface according to any one of clauses 144 to 147, wherein the second flow guiding element is configured to guide the gas flow from the inlet of the second fork into the flow path of the second fork.

[0809] 155. A nasal interface according to any one of clauses 134 to 154, comprising at least one of the following:

[0810] (i) A first fork element positioned within the first fork;

[0811] (ii) A second fork element positioned within the second fork;

[0812] (iii) A manifold element positioned within a manifold chamber and between a first base of the first prong and a second base of the second prong;

[0813] b. wherein the first prong element, the second prong element, and / or the manifold element are each configured to increase the flow resistance of the gas flow entering the respective element.

[0814] 156. The nasal interface according to clause 155, comprising the first prong element and the second prong element, each of which is configured to increase the flow resistance of the gas flow entering the first prong and the second prong, respectively.

[0815] 157. The nasal interface according to clause 155, comprising the manifold element and the second prong element, each of which is configured to increase the flow resistance of the gas flow entering the second prong and the manifold chamber through the second prong element and the manifold element, respectively.

[0816] 158. The nasal interface according to any one of clauses 155 to 157, wherein at least one of the first prong element, the second prong element, and / or the manifold element, when present, includes holes for reducing the passage of the gas flow.

[0817] 159. The nasal interface according to clause 158, wherein the holes are formed in a plate or a wall.

[0818] 160. The nasal interface according to clause 159, wherein the plate or the wall has an inlet surface and an outlet surface between which the holes are formed.

[0819] 161. The nasal interface according to clause 160, wherein the gas flow is in a direction from the inlet surface through the holes to the outlet surface.

[0820] 162. The nasal interface according to clause 160 or clause 161, wherein the transition between the outlet surface and the holes is tapered.

[0821] 163. The nasal interface according to any one of clauses 160 to 162, wherein the transition between the inlet surface and the holes is substantially right-angled.

[0822] 164. The nasal interface according to any one of clauses 160 to 162, wherein the transition between the inlet surface and the holes is tapered, and the taper angle of the outlet surface is greater than the taper angle of the inlet surface.

[0823] 165. The nasal interface according to any one of clauses 160 to 162, wherein the transition between the inlet surface and the holes is substantially a sharp corner.

[0824] 166. The nasal interface according to any one of clauses 159 to 165, wherein at least one hole is a gap, notch, or slit vertically and longitudinally extending through the plate or the wall.

[0825] 167. The nasal interface according to any one of clauses 159 to 165, wherein at least one hole is a gap, notch or slit that extends horizontally longitudinally through the plate or wall.

[0826] 168. The nasal interface according to any one of clauses 158 to 167, wherein at least one hole is a substantially circular perforation.

[0827] 169. The nasal interface according to any one of clauses 158 to 167, wherein at least one hole includes a perforation pattern.

[0828] 170. The nasal interface according to any one of clauses 159 to 169, wherein the plate or wall of at least one hole includes a porous medium.

[0829] 171. The nasal interface according to any one of clauses 155 to 170, wherein when present, at least one of the first fork element, the second fork element and / or the manifold element includes a valve.

[0830] 172. The nasal interface according to clause 171, wherein the valve is configured to open only at a threshold pressure or a threshold flow rate.

[0831] 173. The nasal interface according to clause 171 or clause 172, wherein the valve is configured to provide a defined pressure drop in the flow path.

[0832] 174. The nasal interface according to any one of clauses 171 to 173, wherein the valve is a duckbill valve.

[0833] 175. The nasal interface according to any one of clauses 155 to 174, wherein when present, at least one of the first fork element, the second fork element and / or the manifold element includes a nozzle.

[0834] 176. The nasal interface according to clause 175, wherein the nozzle is configured to provide a defined pressure drop in the flow path.

[0835] 177. The nasal interface according to any one of clauses 155 to 176, wherein when present, at least one of the first fork element, the second fork element and / or the manifold element is configured to be adjusted by manual actuation to increase or decrease the degree of restriction through the element.

[0836] 178. The nasal interface according to clause 177, wherein the element is configured to be slidably movable in the upstream-downstream direction.

[0837] 179. The nasal interface according to clause 177, wherein the element includes a rotatable member having a helical thread.

[0838] 180. The nasal interface according to clause 179, wherein the element further includes an external portion located outside the nasal interface.

[0839] 181. The nasal interface according to clause 180, wherein the element is configured to be rotatably movable such that when the external portion rotates, the element vertically translates into or out of the flow path, thereby increasing or decreasing the degree of flow restriction in the flow path, respectively.

[0840] 182. The nasal interface according to any one of clauses 1 to 181, wherein the first prong has a first prong length and the second prong has a second prong length, and the first prong length is different from the second prong length.

[0841] 183. The nasal interface according to clause 182, wherein the first prong length is longer than the second prong length to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0842] 184. The nasal interface according to clause 182 or 183, wherein the first prong length is shorter than the second prong length to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0843] 185. The nasal interface according to any one of clauses 1 to 184, wherein the first prong has a first prong cross-sectional width and the second prong has a second prong cross-sectional width, and wherein the first prong cross-sectional width is different from the second prong cross-sectional width.

[0844] 186. The nasal interface according to clause 185, wherein the first prong cross-sectional width is greater than the second prong cross-sectional width to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0845] 187. The nasal interface according to clause 185, wherein the first prong cross-sectional width is less than the second prong cross-sectional width to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0846] 188. The nasal interface according to any one of clauses 1 to 187, wherein the first prong has a first end and the second prong has a second end, and wherein the geometry of the first end is different from the geometry of the second end to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0847] 189. The nasal interface according to clause 188, wherein at least one of the first end or the second end tapers or converges to form a nozzle shape.

[0848] 190. The nasal interface according to clause 188 or clause 189, wherein at least one of the first end or the second end widens or flares to form a diffuser shape.

[0849] 191. The nasal interface according to any one of clauses 1 to 190, wherein the first prong has a first inner surface and the second prong has a second inner surface, and at least one of the first inner surface or the second inner surface has surface features configured to affect the internal flow resistance of at least one of the first prong or the second prong.

[0850] 192. The nasal interface according to clause 191, wherein the surface features are ridges formed in a concentric pattern as rings, helices, or bands around the first inner surface or the second inner surface.

[0851] 193. The nasal interface according to clause 190 or 191, wherein the surface features are fins formed in a substantially axial direction pattern as lines, bands, or strips along the first inner surface or the second inner surface.

[0852] 194. The nasal interface according to any one of clauses 191 to 193, wherein when the surface features are present on both the first inner surface and the second inner surface, the surface features are different to cause an asymmetric gas flow at the first prong and the second prong.

[0853] 195. The nasal interface according to any one of clauses 1 to 194, wherein at least one of the first prong and the second prong has a non-circular cross-sectional shape configured to affect the internal flow resistance of at least one of the first prong or the second prong.

[0854] 196. The nasal interface according to clause 195, wherein the non-circular cross-sectional shape is reduced by the size of the circular cross-sectional shape removed therefrom.

[0855] 197. The nasal interface according to clause 195, wherein the non-circular cross-sectional shape is substantially U-shaped.

[0856] 198. The nasal interface according to clause 195, wherein the non-circular cross-sectional shape is substantially polygonal.

[0857] 199. The nasal interface according to any one of clauses 195 to 198, wherein when the non-circular cross-sectional shape is present on each of the first prong and the second prong, the non-circular cross-sectional shapes are different to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0858] 200. The nasal interface according to any one of clauses 1 to 199, wherein at least one of the first prong and the second prong includes a base restriction at the base of the prong, the base restriction being configured to affect the internal flow resistance in at least one of the first prong or the second prong.

[0859] 201. The nasal interface according to clause 200, wherein the base restriction is a nozzle or diffuser formed at the base of the prong.

[0860] 202. A nasal interface according to clause 200 or clause 201, wherein when there are base restriction portions on the first prong and the second prong, the base restriction portions are different to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0861] 203. A nasal interface according to any one of clauses 1 to 202, wherein at least one of the first prong and the second prong includes a prong valve located within the prong, the prong valve being configured to affect the internal flow resistance of at least one of the first prong or the second prong.

[0862] 204. A nasal interface according to clause 203, wherein the prong valve is configured to restrict or block the gas flow therethrough until the gas flow exceeds a defined pressure.

[0863] 205. A nasal interface according to clause 203 or clause 204, wherein the prong valve is a duckbill valve.

[0864] 206. A nasal interface according to any one of clauses 203 to 205, wherein the prong valve is a one-way valve.

[0865] 207. A nasal interface according to any one of clauses 203 to 206, wherein when there is a prong valve in each of the first prong and the second prong, the prong valves have different characteristics to cause an asymmetric gas flow at the first prong and the second prong.

[0866] 208. A nasal interface according to any one of clauses 1 to 207, further comprising a third prong, wherein the first prong, the second prong and the third prong are spaced apart to be able to engage into the patient's nostrils as adjacent pairs, and wherein at least one of the first prong, the second prong or the third prong has different flow characteristics from the other prongs to cause or promote an asymmetric gas flow at each prong.

[0867] 209. A nasal interface according to clause 208, further comprising a closure for releasably blocking the gas flow through the first prong, the second prong or the third prong.

[0868] 210. A nasal interface, comprising:

[0869] i. A first prong having a first base and a first end;

[0870] ii. A second prong having a second base and a second end;

[0871] iii. A gas manifold;

[0872] iv. A first gas inlet; and

[0873] v. An auxiliary gas inlet;

[0874] vi. wherein the first gas inlet and the second gas inlet are in fluid communication with a first gas delivery conduit and a second gas delivery conduit respectively;

[0875] viii. wherein the nasal interface is configured to cause an asymmetric gas flow at the first and second forks.

[0876] 211. The nasal interface according to clause 210, wherein the first gas inlet terminates in a gas manifold.

[0877] 212. The nasal interface according to clause 201 or 211, wherein the auxiliary gas inlet terminates in the first or second fork.

[0878] 213. The nasal interface according to any one of clauses 210 to 212, wherein the auxiliary gas inlet is in fluid communication with an auxiliary gas delivery conduit.

[0879] 214. The nasal interface according to any one of clauses 210 to 213, wherein at least one of the first gas inlet or the gas delivery conduit includes a lumen having a first internal cross-sectional area, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a lumen having a second internal cross-sectional area.

[0880] 215. The nasal interface according to clause 214, wherein one or both of the first internal cross-sectional area and the second internal cross-sectional area are substantially circular.

[0881] 216. The nasal interface according to clause 214 or 215, wherein the first internal cross-sectional area and the second internal cross-sectional area are different.

[0882] 217. The nasal interface according to clause 216, wherein the second internal cross-sectional area is smaller than the internal cross-sectional area of the first or second fork.

[0883] 218. The nasal interface according to clause 213, wherein the gas delivery conduit and the auxiliary gas delivery conduit are arranged on the same side of the gas manifold.

[0884] 219. The nasal interface according to any one of clause 213, wherein the auxiliary gas delivery conduit is located within the gas delivery conduit.

[0885] 220. The nasal interface according to clause 213, wherein at least one of the first gas inlet or the gas delivery conduit includes a first length, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a second length.

[0886] 221. The nasal interface according to clause 220, wherein the first length and the second length are not equal to cause an asymmetric gas flow at the first and second forks.

[0887] 222. The nasal interface according to clause 220 or clause 221, wherein the first length is longer than the second length to cause or promote an asymmetric gas flow at the first and second forks.

[0888] 223. A nasal interface according to clause 220 or clause 221, wherein the first length is shorter than the second length to cause or promote an asymmetric gas flow at the first prong and the second prong.

[0889] 224. A nasal interface according to clause 214, wherein the gas delivery conduit is in communication with the first gas flow and the auxiliary gas delivery conduit is in communication with the second gas flow.

[0890] 225. A nasal interface according to clause 224, wherein the first gas flow has a different flow rate from the second gas flow.

[0891] 226. A nasal interface according to clause 224 or clause 225, wherein the combined flow direction between the gas manifold and the first gas flow is a different flow direction from the combined flow direction between the gas manifold and the second gas flow.

[0892] 227. A nasal interface according to any one of clauses 224 to 226, wherein one of the first gas flow or the second gas flow is an inhalation flow.

[0893] 228. A nasal interface according to any one of clauses 224 to 227, wherein the gas pressure of the first gas flow is different from the gas pressure of the second gas flow.

[0894] 229. A nasal interface according to clause 228, wherein a negative gas pressure relative to the environment is formed by the first gas flow or the second gas flow.

[0895] 230. A patient interface comprising a nasal interface according to any one of clauses 1 to 229.

[0896] 231. The patient interface according to clause 230, further comprising a headgear for holding the nasal interface on the patient's face.

[0897] 232. The patient interface according to clause 230 or 231, further comprising a gas delivery conduit in fluid communication with the gas inlet.

[0898] 233. The patient interface according to clause 232, wherein the gas delivery conduit is a breathing tube.

[0899] 234. The patient interface according to clause 233, wherein the gas manifold is integrally formed with or coupled to the gas delivery conduit.

[0900] 235. The patient interface according to any one of clauses 232 to 234, wherein the gas delivery conduit couples the gas inlet to a patient conduit that provides gas from a flow generator.

[0901] The patient interface according to any one of clauses 232 to 235 further includes a gas delivery conduit retaining clip.

[0902] 237. A respiratory therapy system comprising:

[0903] i. A respiratory therapy device comprising:

[0904] ii. A controller;

[0905] iii. A blood oxygen saturation sensor;

[0906] iv. An ambient air inlet;

[0907] v. An oxygen inlet;

[0908] vi. A valve in fluid communication with the oxygen inlet to control the flow of oxygen through the oxygen inlet; and

[0909] vii. A gas outlet;

[0910] b. wherein the controller is configured to control the valve based on at least one oxygen saturation measurement from the blood oxygen saturation sensor; and

[0911] i. The patient interface according to any one of clauses 230 to 236.

Claims

1. A nasal interface, characterized in that: The nasal interface includes: a first prong having a first base and a first distal end; a second prong having a second base and a second end; a gas manifold comprising a manifold chamber and a gas inlet; and at least one element positioned within the first tine, the second tine, or the manifold chamber; wherein the at least one element is configured to increase resistance to gas flow traveling through at least one of the first prong, the second prong, or the manifold chamber, and The gas inlet is in fluid communication with the gas delivery conduit, or is configured to be in fluid communication with the gas delivery conduit.

2. The nasal interface according to claim 1, characterized in that The increase in resistance to gas flow is configured to induce asymmetric gas flow at the first fork and the second fork.

3. A nasal interface according to claim 1 or claim 2, characterized in that The at least one element is a second fork element positioned within the second fork.

4. The nasal interface according to claim 3, characterized in that The second prong element is configured to increase resistance to gas flow traveling through the second prong.

5. A nasal interface according to claim 3 or claim 4, characterized in that: The second fork element is positioned at the second base.

6. A nasal interface according to any one of claims 1 to 5, characterized in that The second base of the second tine includes an inlet to a flow passage formed by a wall of the second tine.

7. A nasal interface according to any one of claims 1 to 6, characterized in that The at least one element is a manifold element, wherein the manifold element is positioned within a manifold chamber of the gas manifold.

8. The nasal interface according to claim 7, characterized in that The manifold element is configured to increase resistance to gas flow traveling through the manifold chamber.

9. A nasal interface according to any one of claims 1 to 8, characterized in that The gas flow is in a direction from the gas manifold inlet, through the gas manifold chamber, and into the flow passage of the first fork and / or the second fork.

10. A nasal interface, characterized in that: The nasal interface includes: a first prong having a first base and a first distal end; a second prong having a second base and a second end; and Gas manifold, comprising: Manifold chamber; a first gas inlet; and Second gas inlet, The first gas inlet and the second gas inlet are respectively in fluid communication with the first gas delivery conduit and the second gas delivery conduit. Therein, the nasal interface is configured to induce asymmetric gas flow at the first fork and the second fork.

11. The nasal interface of claim 10, wherein: The first gas inlet and the second gas inlet are arranged on opposite sides of the manifold chamber.

12. A nasal interface according to claim 10 or claim 11, characterized in that The first gas inlet is closer to the first prong than the second gas inlet, and wherein the second gas inlet is closer to the second prong than the first gas inlet.

13. A nasal interface, characterized in that: The nasal interface includes: First fork and second fork; a gas manifold comprising a manifold chamber and a gas inlet, the gas inlet being in fluid communication with the gas delivery conduit or being configured to be in fluid communication with the gas delivery conduit; and at least one flow directing element formed as part of at least one of the manifold chamber, the gas inlet, or the gas delivery conduit; The at least one flow directing element is configured to direct the gas flow to one of the first fork or the second fork to generate an asymmetric gas flow.

14. The nasal interface of claim 13, wherein: The flow directing element is configured to provide, in use, a greater dynamic pressure at the first fork and, in use, a lesser dynamic pressure at the second fork to produce an asymmetric gas flow.

15. A nasal interface according to claim 13 or claim 14, characterized in that At least one of the first or second prongs is sized to maintain sufficient clearance between an outer surface of the at least one prong and the patient's skin to avoid sealing a gas path between the nasal interface and the patient.

16. A nasal interface according to any one of claims 13 to 15, characterized in that The first prong and the second prong are in fluid communication with the manifold chamber.

17. A nasal interface according to any one of claims 13 to 16, characterized in that A gas inlet is positioned in the manifold chamber opposite at least one of the first prong or the second prong.

18. A nasal interface according to any one of claims 13 to 17, characterized in that The axis of the gas inlet is coaxial with respect to the axis of at least one of the first prong or the second prong.

19. A nasal interface, characterized in that: The nasal interface includes: a first prong having a first base and a first distal end; a second prong having a second base and a second end; Gas manifold; a first gas inlet; and Auxiliary gas inlet; wherein the first gas inlet and the second gas inlet are fluidly connected to the first gas delivery conduit and the second gas delivery conduit, respectively; Therein, the nasal interface is configured to induce asymmetric gas flow at the first fork and the second fork.

20. The nasal interface of claim 19, wherein: A first gas inlet terminates in the gas manifold.

21. The nasal interface according to claim 19 or 20, characterized in that The auxiliary gas inlet terminates in the first fork or the second fork.

22. A nasal interface according to any one of claims 19 to 21, characterized in that The auxiliary gas inlet is in fluid communication with the auxiliary gas delivery conduit.

23. A nasal interface according to any one of claims 19 to 22, characterized in that At least one of the first gas inlet or the gas delivery conduit includes a lumen having a first interior cross-sectional area, and at least one of the auxiliary gas inlet or the auxiliary gas delivery conduit includes a lumen having a second interior cross-sectional area.

24. The nasal interface of claim 23, wherein: One or both of the first interior cross-sectional area and the second interior cross-sectional area are circular.

25. A nasal interface according to claim 23 or 24, characterized in that The first interior cross-sectional area and the second interior cross-sectional area are different.

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