Tubes for delivering gases and / or patient interfaces

Abstract

Tubes 174 for delivery of gas to the patient interface and for treatment of exhaled gas. The tubes include an inhalation conduit 170 for directing the flow of gas towards the patient interface, an exhalation conduit 173 for directing the flow of gas from the patient interface 100, and a filter 140 in fluid communication with or part of the exhalation conduit 140. The filter 140 is configured to filter the flow of exhaled gas from the patient interface 100 before the flow of exhaled gas leaves the patient interface and into the ambient air.

Description

[Technical field]

[0001] The present disclosure relates to tubes for patient interfaces for delivering gas to a patient, and related patient interfaces, and in particular, but not exclusively, to tubes or patient interfaces for directing or processing exhaled gas from a patient. [Background technology]

[0002] In various medical procedures, respiratory support is required to achieve adequate gas exchange in the patient. Respiratory support involves the delivery of respiratory gas to the patient's airway via a patient interface, such as a nasal cannula, an endotracheal tube (ETT), a tracheotomy tube, a laryngeal mask (LMA), a nasal mask, a face mask, etc. Respiratory support may be provided to an apneic patient or to a patient who is spontaneously breathing. In many cases, it is desirable to provide a high flow rate of respiratory gas to the patient to achieve effective oxygenation and remove CO2 to reduce the respiratory dead space.

[0003] Patients receiving respiratory assistance are generally very ill, and the delivery of respiratory assistance is a significant factor in the chances and rates of recovery. Advances in respiratory assistance delivery systems and patient interfaces have therefore focused on features for the safe and effective delivery of respiratory gases to the patient, with little attention paid to the management of exhaled gases.

[0004] The background discussion contained herein, including references to documents, acts, materials, equipment, articles and the like, is included to explain the context of the present disclosure and is not to be considered as an admission or suggestion that any of the referred material was published, publicly known, or part of the common general knowledge in any jurisdiction as of the priority date of any of the claims. Summary of the Invention [Means for solving the problem]

[0005] Many respiratory diseases are known to be transmitted by infectious droplets of respiratory gases entering the respiratory system of an uninfected subject. The 2009 "swine flu" A(H1N1) began in Mexico and spread rapidly to over 200 countries and regions. Coronaviruses form a large family of viruses that can cause illnesses ranging from the common cold to more severe diseases. SARS (severe acute respiratory syndrome), MERS (Middle East respiratory syndrome), and more recently, respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of the disease COVID-19, have reached pandemic status due to their high transmissibility. According to the World Health Organization (WHO), at the priority date of this application, transmission of severe acute SARS-CoV-2 is believed to occur mainly by droplets and fomites between infecting and infectees. Subsequent research and evidence now suggests that infection can occur when aerosols or droplets containing the virus are inhaled or come into direct contact with the eyes, nose, or mouth.

[0006] Aerosols, which are very small particles or droplets suspended in the air, can be generated by a variety of mechanisms, including the interaction of a high velocity air stream with a relatively slow moving liquid stream or liquid from a liquid source. Humans routinely generate respirable particles ranging in size from activities such as speaking, breathing, exercising, sneezing, and coughing, including droplets, aerosols, and intermediate particles. These very small particles or droplets may contain substances and / or contaminants that are undesirable for humans to come into contact with. Aerosols may be infectious and / or contain pathogens, which can cause adverse health effects if inhaled or come into contact with fluids from the eyes.

[0007] It is recognized that managing exhaled gases can be particularly difficult, at least during the delivery of high-flow therapy using non-sealing patient interfaces.

[0008] The risk of transmission of infection depends on the amount of viable pathogens that make it to the site of infection in the infected person, which in turn depends on the amount of pathogens in the gases expelled by the respiratory tract or otherwise exhaled, and on the survival rate of the pathogens during transmission. Similarly, the risk of exposure to substances or contaminants in the patient's exhaled gases, such as nebulised drugs, depends on the amount of drug that makes it to an unintended recipient, which in turn depends on the amount of drug expelled by the respiratory gases, and on the viability of the drug in the unintended recipient.

[0009] It is desirable to reduce one or more risks associated with exhaled gases from patients receiving respiratory assistance.

[0010] In a first aspect, in accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a tube for delivery of gas to a patient interface and for treatment of exhaled gas is disclosed, the tube comprising: an inspiratory conduit for directing gas flow towards the patient interface; an expiratory conduit for directing the flow of expiratory gas from the patient interface; and a filter in fluid communication with or part of the exhalation conduit, the filter configured to filter the flow of exhaled gas from the patient interface before the flow of exhaled gas enters the ambient air from the patient interface; Includes.

[0011] In some configurations, the inhalation and exhalation conduits are coaxial or substantially parallel.

[0012] In some forms, the inhalation and exhalation conduits are on a single limb such that both the inhalation and exhalation conduits extend in one direction from the patient interface during use.

[0013] In some embodiments, the inhalation conduit is an inner conduit and the exhalation conduit is an outer conduit.

[0014] In some embodiments, the wall of the expiratory conduit comprises a filter.

[0015] In some forms, the filter comprises one or more filter materials selected from the group including: N95 or higher (e.g., N99) rated or HEPA filter material, fibrous, porous knit, mesh, woven foam, textile, non-textile, or foam filter material.

[0016] In some forms, the length of the filter within the wall is configured to reduce resistance to gas flow through the filter.

[0017] In some forms, the portion of the exhalation conduit upstream of the filter has a wall that is substantially impermeable.

[0018] In some embodiments, the length of the portion of the expiratory conduit upstream of the filter is at least about 80 mm.

[0019] In some forms, the exhalation conduit is coupled to a filter component that includes a filter.

[0020] In some forms, the filter comprises one or more filter materials selected from the group including: N95 or higher (e.g., N99) rated or HEPA filter material, fibrous, porous knit, mesh, woven foam, textile, non-textile, or foam filter material.

[0021] In some embodiments, the expiratory conduit includes structure to prevent or minimize collapse or narrowing of the expiratory lumen in the expiratory conduit.

[0022] In some embodiments, the structures include one or more of: corrugations, pleats, helical wraps, ribs, and support features.

[0023] In some forms, the inhalation conduit is configured to direct a flow of gas toward at least one inhalation lumen of the patient interface, and the exhalation conduit is configured to direct a flow of gas from at least one exhalation lumen of the patient interface.

[0024] In a further aspect, in accordance with certain features, aspects and advantages of at least one of the embodiments disclosed herein, a combination of a patient interface and a tube as outlined herein is disclosed, the patient interface including: at least one inspiratory element for directing a flow of gas to the patient's airway, the or each inspiratory element including at least one inspiratory lumen through which the flow of gas is directed; and at least one expiratory element including an expiratory lumen providing an expiratory gas flow path.

[0025] In some forms, the patient interface includes first and second nasal elements configured to direct gases into and / or from one nostril of the patient.

[0026] In some configurations, the at least one inspiratory element includes one or both of a first and second nasal element, and the at least one exhalation element includes one or both of a first and second nasal element.

[0027] In some configurations, the first nasal element includes a first nasal prong and the second nasal element includes a second nasal prong.

[0028] In some forms, the patient interface includes a flow directing member for directing gas flow from the inhalation conduit to one of the first and second nasal elements and for directing gas flow from the other of the first and second nasal elements to the exhalation conduit.

[0029] In some forms, the patient interface includes a partition or other physical separator to provide mechanical fluid disconnection between the fluid flow path of the first nasal element and the fluid flow path of the second nasal element.

[0030] In some forms, the patient interface includes a gas port for entrainment of exhaled gases from the patient's nose and / or the patient's mouth that are not directed into the exhalation nose element.

[0031] In a further aspect, in accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, an exhalation tube for treatment of exhaled gases is disclosed, the exhalation tube comprising: an expiratory conduit for directing the flow of expiratory gas from the patient interface; and a filter in fluid communication with or part of the exhalation conduit, the filter configured to filter the flow of exhaled gas from the patient interface before the flow of exhaled gas enters the ambient air from the patient interface; Includes.

[0032] In some embodiments, the wall of the expiratory conduit comprises a filter.

[0033] In some forms, the filter comprises one or more filter materials selected from the group including: N95 or higher (e.g., N99) rated or HEPA filter material, fibrous, porous knit, mesh, woven foam, textile, non-textile, or foam filter material.

[0034] In some forms, the length of the filter within the wall is configured to reduce resistance to gas flow through the filter.

[0035] In some forms, the portion of the exhalation conduit upstream of the filter has a wall that is substantially impermeable.

[0036] In some embodiments, the length of the portion of the expiratory conduit upstream of the filter is at least about 80 mm.

[0037] In some forms, the exhalation conduit is coupled to a filter component that includes a filter.

[0038] In some forms, the filter comprises one or more filter materials selected from the group including: N95 or higher (e.g., N99) rated or HEPA filter material, fibrous, porous knit, mesh, woven foam, textile, non-textile, or foam filter material.

[0039] In some embodiments, the expiratory conduit includes structure to prevent or minimize collapse or narrowing of the expiratory lumen in the expiratory conduit.

[0040] In some embodiments, the structures include one or more of: corrugations, pleats, helical wraps, ribs, and support features.

[0041] In some forms, the exhalation conduit is configured to direct a flow of gas from at least one exhalation lumen of the patient interface.

[0042] In a further aspect, in accordance with certain features, aspects and advantages of at least one of the embodiments disclosed herein, a combination of a patient interface and an exhalation tube as outlined herein is disclosed, the patient interface including: at least one inhalation element for directing a flow of gases to the patient's airway, the or each inhalation element including at least one inhalation lumen through which the flow of gases is directed; and at least one exhalation element including an exhalation lumen providing an exhalation gas flow path.

[0043] In some forms, the patient interface includes first and second nasal elements configured to direct gases into and / or from one nostril of the patient.

[0044] In some configurations, the at least one inspiratory element includes one or both of a first and second nasal element, and the at least one exhalation element includes one or both of a first and second nasal element.

[0045] In some configurations, the first nasal element includes a first nasal prong and the second nasal element includes a second nasal prong.

[0046] In a further aspect, in accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a patient interface for delivery of gas to a patient is disclosed, the patient interface comprising: at least one inspiratory lumen for directing the flow of gas to the patient's airway; at least one exhalation lumen including an exhalation gas flow path for directing the flow of exhalation gas from the patient; and a filter in fluid communication with or part of the exhaled gas flow path, the filter configured to filter the flow of exhaled gas from the patient interface before the flow of exhaled gas enters the ambient air from the patient interface; Includes.

[0047] In some forms, the patient interface includes an inhalation conduit in fluid communication with the inhalation lumen, and an exhalation conduit in fluid communication with the exhalation lumen.

[0048] In some forms, the inhalation and exhalation conduits are integrally formed with or coupled to the patient interface.

[0049] In some configurations, the inhalation and exhalation conduits are coaxial or substantially parallel.

[0050] In some forms, the inhalation and exhalation conduits are on a single limb such that both the inhalation and exhalation conduits extend in one direction from the patient interface.

[0051] In some embodiments, the inhalation conduit is an inner conduit and the exhalation conduit is an outer conduit.

[0052] In some embodiments, the wall of the expiratory conduit comprises a filter.

[0053] In some forms, the filter comprises one or more filter materials selected from the group including: N95 or higher (e.g., N99) rated or HEPA filter material, fibrous, porous knit, mesh, woven foam, textile, non-textile, or foam filter material.

[0054] In some forms, the length of the filter within the wall is configured to reduce resistance to gas flow through the filter.

[0055] In some forms, the portion of the exhalation conduit upstream of the filter has a wall that is substantially impermeable.

[0056] In some embodiments, the length of the portion of the expiratory conduit upstream of the filter is at least about 80 mm.

[0057] In some forms, the exhalation conduit is coupled to a filter component that includes a filter.

[0058] In some forms, the filter comprises one or more filter materials selected from the group including: N95 or higher (e.g., N99) rated or HEPA filter material, fibrous, porous knit, mesh, woven foam, textile, non-textile, or foam filter material.

[0059] In some embodiments, the expiratory conduit includes structure to prevent or minimize collapse or narrowing of the expiratory lumen in the expiratory conduit.

[0060] In some embodiments, the structures include one or more of: corrugations, pleats, helical wraps, ribs, and support features.

[0061] In some forms, the patient interface includes first and second nasal elements configured to direct gases into and / or from one nostril of the patient.

[0062] In some configurations, the first nasal element includes a first nasal prong and the second nasal element includes a second nasal prong.

[0063] In some forms, the patient interface includes a flow directing member for directing the flow of gases towards one of the first and second nasal elements and for directing the flow of gases from the other of the first and second nasal elements.

[0064] In some forms, the patient interface includes a partition or other physical separator to provide a mechanical fluid separation between the fluid flow path of the first nasal element and the fluid flow path of the second nasal element.

[0065] In some forms, the patient interface includes a gas port for drawing exhaled gases from the patient's nose and / or the patient's mouth that are not directed into the exhalation nose element.

[0066] In a further aspect, in accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a patient interface for respiratory therapy is disclosed, the patient interface comprising: a cannula body including a first nasal element and a second nasal element; and A cannula manifold including a manifold inhalation lumen, a manifold exhalation lumen, and a flow directing member, the cannula manifold being reconfigurable with respect to the cannula body such that in a first configuration, the flow directing member is positioned to direct gas flow from the manifold inhalation lumen to a first nasal element and to direct gas flow from the second nasal element to the manifold exhalation lumen, and in a second configuration, the flow directing member is positioned to direct gas flow from the manifold inhalation lumen to the second nasal element and to direct gas flow from the first nasal element to the manifold exhalation lumen. Includes.

[0067] In some embodiments, the cannula manifold is configured to be inserted into the cannula body.

[0068] In some forms, the patient interface includes or is coupled to an inhalation conduit in fluid communication with the inhalation lumen, and includes or is coupled to an exhalation conduit in fluid communication with the exhalation lumen.

[0069] In some configurations, the inhalation and exhalation conduits are coaxial or substantially parallel.

[0070] In some forms, the inhalation and exhalation conduits are on a single limb such that both the inhalation and exhalation elements extend in one direction from the cannula body.

[0071] In some embodiments, the inhalation conduit is an inner conduit and the exhalation conduit is an outer conduit.

[0072] In some forms, the flow directing members are positioned such that the first and second nasal elements distal to the manifold inlet and manifold outlet are inhalation nasal elements for directing gas flow towards the patient, and the first and second nasal elements proximal to the manifold inlet and manifold outlet are exhalation nasal elements for directing exhalation gas flow away from the patient.

[0073] In some forms, the flow directing members are positioned such that the first and second nasal elements proximal to the manifold inlet and manifold outlet are inhalation nasal elements for directing gas flow towards the patient, and the first and second nasal elements distal to the manifold inlet and manifold outlet are exhalation nasal elements for directing exhalation gas flow away from the patient.

[0074] In some forms, the patient interface includes a gas port for drawing exhaled gases from the patient's nose and / or the patient's mouth that are not directed into the exhalation nose element.

[0075] In some configurations, the cannula manifold includes a body portion and the flow directing member includes a proximal portion extending substantially longitudinally of the body portion and a distal portion extending laterally from a distal end of the proximal portion and contacting the body portion.

[0076] In some forms, a cavity defined between the proximal portion, the distal portion, and the body portion defines a cavity for forming one of the exhalation gas receiving opening and the inhalation gas delivery opening.

[0077] In some forms, the other of the inhalation gas delivery opening and the exhalation gas receiving opening is located on an opposite side of the distal portion of the flow directing member from the cavity.

[0078] In some configurations, the first and second nasal elements are configured to direct gases into and / or from one nostril of the patient.

[0079] In some configurations, the first nasal element includes a first nasal prong and the second nasal element includes a second nasal prong.

[0080] In some configurations, the cannula manifold is configured to be inserted into the cannula body in a first configuration and a second configuration.

[0081] In some configurations, the first configuration corresponds to the cannula manifold being inserted into the cannula body from a first side of the cannula body, and the second configuration corresponds to the cannula manifold being inserted into the cannula body from a second side of the cannula body.

[0082] In some configurations, the cannula body includes an elastomeric component.

[0083] In some configurations, the cannula manifold comprises a rigid polymer component.

[0084] In some embodiments, the cannula manifold includes a pressure monitoring port that is in fluid communication with the manifold inhalation lumen and the manifold exhalation lumen.

[0085] In some forms, the pressure monitoring port is configured to provide a gas flow for pressure monitoring through the pressure monitoring port, the gas flow comprising an average of an inhalation gas flow and an exhalation gas flow.

[0086] In some forms, the patient interface includes a filter in fluid communication with the manifold exhalation lumen, the filter configured to filter the flow of exhaled gas from the patient interface before the flow of exhaled gas enters the ambient air from the patient interface.

[0087] In a further aspect, in accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a patient interface for respiratory therapy is disclosed, the patient interface comprising: a cannula body including a first nasal element configured to direct gases into one nostril of the patient and a second nasal element configured to direct gases from another nostril of the patient; and a cannula manifold including a manifold inlet lumen for inhaled gas flow in fluid communication with a manifold inlet, a manifold outlet lumen for exhaled gas flow in fluid communication with a manifold outlet, flow directing members arranged to direct gas flow from the manifold inlet lumen to a first nasal element and to direct gas flow from a second nasal element to the manifold outlet lumen, and a pressure monitoring port in fluid communication with the manifold inlet lumen and the manifold outlet lumen, the manifold inlet and the manifold outlet being on a single rim such that both the manifold inlet and the manifold outlet extend in one direction from a patient interface in use. Includes.

[0088] In some forms, the patient interface includes a lumen in fluid communication with the pressure monitoring port, an inspiratory gas port in fluid communication with the manifold inspiratory lumen, and an expiratory gas port in fluid communication with the manifold expiratory lumen, the lumens providing fluid communication between the inspiratory gas port, the expiratory gas port, and the pressure monitoring port.

[0089] In some configurations, the manifold inlet and the manifold outlet are coaxial or substantially parallel.

[0090] In some forms, the patient interface includes an inhalation conduit in fluid communication with the manifold inhalation lumen, and an exhalation conduit in fluid communication with the manifold exhalation lumen.

[0091] In some forms, the inhalation and exhalation conduits are integrally formed with or coupled to the cannula manifold.

[0092] In some forms, the pressure monitoring port is configured to provide a gas flow for pressure monitoring through the pressure monitoring port, the gas flow comprising an average of an inhalation gas flow and an exhalation gas flow.

[0093] In some embodiments, the cannula manifold is configured to be inserted into the cannula body.

[0094] In some configurations, the cannula manifold is configured to be inserted into the cannula body in a first configuration and a second configuration, the first configuration corresponding to the cannula manifold being inserted into the cannula body from a first side of the cannula body, and the second configuration corresponding to the cannula manifold being inserted into the cannula body from a second side of the cannula body.

[0095] In a further aspect, in accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a patient interface for respiratory therapy is disclosed, the patient interface comprising: a cannula body including a first nasal element and a second nasal element; and A cannula manifold including a manifold inhalation lumen, a manifold exhalation lumen, and a flow directing member, the flow directing member positioned to direct gas flow from the manifold inhalation lumen to a first nasal element and to direct gas flow from a second nasal element to the manifold exhalation lumen. Includes.

[0096] In some embodiments, the cannula manifold is configured to be inserted into the cannula body.

[0097] In some forms, the patient interface includes or is coupled to an inhalation conduit in fluid communication with the inhalation lumen, and includes or is coupled to an exhalation conduit in fluid communication with the exhalation lumen.

[0098] In some configurations, the inhalation and exhalation conduits are coaxial or substantially parallel.

[0099] In some forms, the inhalation and exhalation conduits are on a single limb such that both the inhalation and exhalation elements extend in one direction from the cannula body.

[0100] In some embodiments, the inhalation conduit is an inner conduit and the exhalation conduit is an outer conduit.

[0101] In some forms, the flow directing members are positioned such that the first and second nasal elements distal to the manifold inlet and manifold outlet are inhalation nasal elements for directing gas flow towards the patient, and the first and second nasal elements proximal to the manifold inlet and manifold outlet are exhalation nasal elements for directing exhalation gas flow away from the patient.

[0102] In some forms, the flow directing members are positioned such that the first and second nasal elements proximal to the manifold inlet and manifold outlet are inhalation nasal elements for directing gas flow towards the patient, and the first and second nasal elements distal to the manifold inlet and manifold outlet are exhalation nasal elements for directing exhalation gas flow away from the patient.

[0103] In some forms, the patient interface includes a gas port for drawing exhaled gases from the patient's nose and / or the patient's mouth that are not directed into the exhalation nose element.

[0104] In some configurations, the cannula manifold includes a body portion and the flow directing member includes a proximal portion extending substantially longitudinally of the body portion and a distal portion extending laterally from a distal end of the proximal portion and contacting the body portion.

[0105] In some forms, a cavity defined between the proximal portion, the distal portion, and the body portion defines a cavity for forming one of the exhalation gas receiving opening and the inhalation gas delivery opening.

[0106] In some forms, the other of the inhalation gas delivery opening and the exhalation gas receiving opening is located on an opposite side of the distal portion of the flow directing member from the cavity.

[0107] In some configurations, the first and second nasal elements are configured to direct gases into and / or from one nostril of the patient.

[0108] In some configurations, the first nasal element includes a first nasal prong and the second nasal element includes a second nasal prong.

[0109] In some embodiments, the cannula manifold is configured to be inserted into the cannula body.

[0110] In some configurations, the cannula body includes an elastomeric component.

[0111] In some configurations, the cannula manifold comprises a rigid polymer component.

[0112] In some embodiments, the cannula manifold includes a pressure monitoring port that is in fluid communication with the manifold inhalation lumen and the manifold exhalation lumen.

[0113] In some forms, the pressure monitoring port is configured to provide a gas flow for pressure monitoring through the pressure monitoring port, the gas flow comprising an average of an inhalation gas flow and an exhalation gas flow.

[0114] In some forms, the patient interface includes a filter in fluid communication with the manifold exhalation lumen, the filter configured to filter the flow of exhaled gas from the patient interface before the flow of exhaled gas enters the ambient air from the patient interface.

[0115] In a further aspect, in accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a respiratory assistance or support system is disclosed, the respiratory assistance or support system including: a patient interface as outlined herein, and at least one of a humidifier and a respiratory gas source.

[0116] In some forms, the respiratory assistance or support system includes an inhalation conduit for delivering gas from a humidifier or respiratory gas source to a patient interface.

[0117] In a further aspect, in accordance with certain features, aspects, and advantages of at least one of the embodiments disclosed herein, a kit is disclosed, the kit including: a tube as outlined herein or an exhalation tube as outlined herein, and a patient interface.

[0118] In some forms, the patient interface is as outlined herein.

[0119] It should be noted that any one of the aspects described above may include any of the features of any of the other aspects, and may include any of the features of any of the embodiments in the following section.

[0120] It should be understood that each of the various embodiments described herein may incorporate features, modifications, and alternatives described in the context of one or more other embodiments, such as, for example, not limited to the various features of the tubing, filter, and patient interface embodiments, and may incorporate any one or more of the various features of the tubing, filter, and patient interface as described in the context of the various patient interface embodiments. In the interest of efficiency, such features, modifications, and alternatives have not been repeatedly disclosed for each and every embodiment, but one of ordinary skill in the art will recognize that such combinations of features, modifications, and alternatives disclosed for some embodiments may be applied to other embodiments as well, and are within the scope of, and form a part of, the subject matter of the present disclosure.

[0121] As used herein, the term "one or more" before a noun refers to the plural and / or the singular form of that noun.

[0122] As used herein, the term "and / or" means "and," or "or," or both, where the context permits.

[0123] As used herein, the term "comprising" means "consisting at least in part of." In interpreting each statement herein containing the term "comprising," there may be other features present than those preceding the term. Related words such as "comprise" and "comprises" are to be interpreted in the same manner.

[0124] The present disclosure may also be broadly described as being in the parts, elements and features referred to or shown in the specification of this application, individually or collectively, and in any or all combinations of any two or more of said parts, elements or features, and where specific integers known to be equivalent in the industry to which this disclosure pertains are set forth herein, such known equivalents are deemed to be incorporated herein as if they were individually set forth.

[0125] This disclosure contemplates configurations as described above and also as given below by way of example only.

[0126] Specific embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein, which refers to the drawings. [Brief description of the drawings]

[0127] [Figure 1] 1 is a schematic diagram of an overall respiratory support or assistance system; [Diagram 2] FIG. 2 is a schematic diagram of a first form of patient interface having nasal elements and in which filtration is provided by a filter located remotely from the nasal elements. [Diagram 3] 3A-3C show schematic cross-sectional views of exemplary configurations of inhalation and exhalation conduits for use with the patient interfaces described herein or for other uses, where FIG. 3(a) shows a coaxial configuration in which the inhalation conduit is within the exhalation conduit, FIG. 3(b) shows separate, side-by-side inhalation and exhalation conduits, which may be parallel, and FIG. 3(c) shows combined inhalation and exhalation conduits. [Figure 4A] FIG. 13 is a schematic diagram of a second embodiment of a patient interface and tubing. [Figure 4B] FIG. 13 is a schematic diagram of a third embodiment of a patient interface and tubing. [Figure 4C] FIG. 11 is a schematic diagram of a fourth embodiment of a patient interface and tubing. [Figure 4D] FIG. 13 is a schematic diagram of a fifth embodiment of a patient interface and tubing. [Figure 4E] FIG. 13 is a schematic diagram of a sixth embodiment of a patient interface and tubing. [Figure 4F] FIG. 13 is a schematic diagram of a seventh embodiment of a patient interface and tubing. [Figure 4G] FIG. 13 is a schematic diagram of an eighth embodiment of a patient interface and tubing. [Figure 4H] FIG. 13 is a schematic diagram of a ninth embodiment of a patient interface and tubing. [Figure 5A] 13 is a front view of the patient interface illustrating an alternative insertion orientation of the cannula manifold into the cannula body of the patient interface. [Figure 5B] FIG. 4B is a perspective front view from above of the patient interface of FIG. 4A. [Figure 5C] FIG. 4B is a top view of the patient interface of FIG. 4A. [Figure 5D] FIG. 2 is a perspective view from below of the body of the patient interface, without showing the manifold; [Figure 5E] FIG. 5E is a cross-sectional view of the front of the body of FIG. 5D. [Figure 5F] FIG. 5B is a top view of the cannula manifold of the patient interface of FIG. 5A. [Figure 5G] FIG. 5F is a left-side cross-sectional view of the cannula manifold of FIG. 5F. [Figure 5H] FIG. 5F is a top view of the cannula manifold of FIG. 5F. [Figure 5I] FIG. 5F is a perspective front view from above of the cannula manifold of FIG. 5F. [Figure 5J] FIG. 13 is a cross-sectional view of the front of the patient interface and cannula manifold assembly. [Figure 5K] FIG. 2 is a cross-sectional view from above of the patient interface and the cannula manifold. [Figure 5L] FIG. 1 is a perspective front cross-sectional view from above of the patient interface and cannula manifold; [Figure 5M] FIG. 13 is another perspective, top, front cross-sectional view of the patient interface and cannula manifold. [Figure 5N] FIG. 13 is a perspective rear view from above of the patient interface and cannula manifold, not showing the overmolded section. [Figure 5O] FIG. 13 is another top perspective rear view of the patient interface and cannula manifold, not showing the overmolded section. [Figure 6A]FIG. 2 is a schematic diagram of the gas flow paths in a first configuration of the patient interface and cannula manifold. [Figure 6B] FIG. 13 is a schematic diagram of the gas flow paths in a second configuration of the patient interface and cannula manifold. [Figure 6C] FIG. 13 is a schematic diagram of a patient interface and gas flow paths in a first configuration of an alternative cannula manifold; [Figure 6D] FIG. 13 is a schematic diagram of the patient interface and gas flow paths in a second configuration of an alternative cannula manifold; [Figure 7A] FIG. 13 is a top view of an alternative cannula manifold for use with a patient interface. [Figure 7B] FIG. 13 is a front view of an alternative cannula manifold. [Figure 7C] FIG. 13 is a view from below of an alternative cannula manifold. [Figure 7D] FIG. 13 is a left sectional view of an alternative cannula manifold. [Figure 7E] FIG. 13 is a perspective front cross-sectional view from above of an alternative cannula manifold, with inhalation gas flow represented by solid arrows and exhalation gas flow represented by dashed-dotted arrows. [Figure 8A] FIG. 13 is a top view of an alternative cannula manifold with a pressure monitoring port. [Figure 8B] FIG. 13 is a front view of an alternative cannula manifold. [Figure 8C] FIG. 13 is a view from below of an alternative cannula manifold. [Figure 8D] FIG. 13 is a rear view of an alternative cannula manifold. [Figure 8E] FIG. 13 is a top perspective front view of an alternative cannula manifold; [Figure 8F] FIG. 13 is a left sectional view of an alternative cannula manifold showing details of the pressure monitoring port. [Figure 8G] FIG. 13 is another left cross-sectional view of the alternative cannula manifold showing details of the pressure monitoring port. [Figure 9A] FIG. 13 is a top view of another alternative cannula manifold with pressure monitoring ports and pressure tubing. [Figure 9B] FIG. 13 is a front view of an alternative cannula manifold. [Figure 9C] FIG. 13 is a view from below of an alternative cannula manifold. [Figure 9D] FIG. 13 is a top perspective front view of an alternative cannula manifold; [Figure 9E] FIG. 13 is a top perspective rear view of an alternative cannula manifold showing pressure monitoring ports. [Figure 9F] FIG. 13 is a cross-sectional view of an alternative cannula manifold showing details of the pressure monitoring port. [Figure 10A] 1 shows a patient interface in use on a patient, the patient interface having an external fluid guide in the cannula body for capturing and redirecting the exhaled air flow. [Figure 10B] FIG. 2 is a perspective front view of the external fluid guide. [Figure 10C] 1 shows a cross-sectional view of the front of the external fluid guide. [Figure 10D] 1 shows an alternative form of external fluid guide. [Figure 10E] 1 shows an alternative form of external fluid guide. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0128] It should be understood that the illustrated embodiments are examples only and are not to be taken as limiting the scope of the present disclosure.

[0129] Embodiments of the present disclosure relate to patient interfaces used in respiratory assistance that provide features for directing or processing exhaled gases from a patient. Processing of exhaled gases can reduce the risk of environmental transmission when those gases may contain infectious or pathogenic particles, as well as reducing the risk associated with the presence of other substances in the exhaled gases, such as nebulized medications. Some embodiments of the present disclosure relate specifically to reducing the risk of transmission resulting from aerosols in exhaled gases during the administration of respiratory therapy, although it should be understood that the scope of the present disclosure is not limited to such applications. The present disclosure provides embodiments for intercepting / capturing and / or slowing the velocity of aerosols and other particles in the exhaled gases to reduce the concentration of particles in the exhaled gas stream and the likelihood that those particles will either travel a sufficient distance to enter another person's airway or fall onto a surface that may pose a risk of transmission upon touch.

[0130] One factor that determines whether respiratory droplets pose a risk of becoming airborne is the size of the droplet. Respiratory droplets fall into a range of sizes characterized by diameters up to a few hundred microns. Droplets evaporate depending on their size, velocity, chemical composition, and how they cluster in the exhaled "jet". These dependencies arise because evaporation is driven by the difference in temperature and partial pressure at the surface of the evaporating material compared to its environment. External influences on evaporation include room temperature, humidity, and ventilation patterns. Large droplets fall to the ground or another surface before they evaporate completely. These form the droplet transmission route. Small droplets evaporate to very small sizes and remain in the air for several minutes. These are called droplet nuclei and represent the airborne transmission route. In general, the larger the droplet, the faster it falls. As the droplets get smaller, at some point they reach a size that will allow them to evaporate before hitting the ground. Humidity can affect how long droplets can remain suspended in the air, with high humidity environments slowing evaporation and low humidity environments accelerating evaporation and therefore the risk of airborne transmission.

[0131] Embodiments of the present disclosure provide a tube and / or patient interface that may reduce the likelihood that aerosols containing pathogens and / or contaminants in the exhaled gases will become dispersed from the patient's airways by physically filtering the exhaled gas flow through a filter before the exhaled gas flow leaves the patient interface and into the ambient air. This feature is intended to reduce the likelihood of aerosolization of particles and / or reduce the likelihood of spread by slowing the exit rate of unfiltered pathogens in the exhaled gases.

[0132] Referring initially to Figure 1, there is shown a respiratory assistance or support system 500 that may be used with the patient interfaces and tubing of the present disclosure. In such a system, a patient 600 is provided with a flow of gas through a patient interface 100. The flow of gas may be humidified. The patient interface 100 is held in an operative position on the patient's face using an associated retainer, headgear, or the like. The retainer provides a retention mechanism configured to hold the patient interface 100 on the patient's face during use.

[0133] The patient interface 100 is connected to a humidified gas delivery passageway or inhalation conduit 170. The inhalation conduit 170 defines an inhalation lumen that directs the flow of gases towards the patient interface 100. The inhalation conduit 170 is connected at one end to the patient interface 100 and at an opposite end to an outlet of the humidifier 510. The inhalation conduit 170 may be connected to the humidifier 510 by an extension tube 175. The extension tube 175 and / or the inhalation conduit 170 form a patient conduit adapted to be connected to a gas source to deliver a flow of gas to the patient 600.

[0134] The patient interface 100 is connected to an expiratory conduit 173 (FIG. 2) that defines an expiratory lumen for directing the flow of expiratory gases from the patient. The expiratory conduit 173 is connected at one end to the patient interface 100.

[0135] The inhalation conduit 170 and the exhalation conduit 173 are both part of a tube 174 for delivery of gas to the patient interface 100 and for processing of exhaled gas from the patient interface. In an alternative form, the inhalation conduit 170 may be provided by a first tube and the exhalation conduit 173 may be provided by a separate second tube.

[0136] The inhalation conduit 170 is configured to direct the flow of gas toward at least one inhalation lumen 120 of the patient interface, and the exhalation conduit 173 is configured to direct the flow of gas from at least one exhalation lumen 130 of the patient interface.

[0137] The extension tube 175, tube 174, and / or conduits 170, 173 may be part of the patient interface 100. Thus, a "patient interface" as used herein may refer not only to the portion of the interface that contacts and / or interfaces with the patient, but also to the tube 174, extension tube 175, including the inhalation conduit 170 that delivers a flow of gas to the patient interface and the exhalation conduit 173 that receives exhaled gases from the patient interface.

[0138] The humidifier 510 receives and humidifies gas supplied from a flow generator or breathing gas source 520, which may include a blower 530. Alternatively or additionally, other gas sources may be used, such as a wall source with a flow meter. The humidifier 510 and the gas source 520 may be integrated or in separate modules. The humidifier 510 may include a humidification chamber 570 filled with water or other liquid 540, and a heating means 550 for heating the water 540 to humidify the gas path through the humidifier 510. A controller 560 may be provided to control and possibly vary one or more characteristics of the supplied gas, including but not limited to the pressure profile of the gas, the flow rate profile of the gas at the patient interface 100, the temperature and / or humidity of the gas. It will be appreciated that the control capabilities depend on the purpose and application of the respiratory assistance system 500.

[0139] The respiratory system 500 may be a high-flow therapy device or system. High-flow therapy as described 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 targeted flow of humidified respiratory gas through an intentionally unsealed patient interface at a flow rate generally intended to meet or exceed the patient's inspiratory flow rate. Exemplary patient interfaces include, but are not limited to, nasal or oral patient interfaces. Typical flow rates in adults often range from about 15 liters per minute (LPM) to about 70 LPM or more. Typical flow rates in pediatric patients (e.g., neonates, infants, and children) often range from about 1 liter per minute per kilogram of patient weight to about 3 liters per minute per kilogram of patient weight or more. High-flow therapy may also optionally include administration of therapeutic medications and / or gas mixture compositions including supplemental oxygen. High flow therapy includes nasal high flow (NHF), humidified high flow nasal cannula (HHFNC), high flow nasal oxygen (HFNO), and high flow therapy (HFT), among other common names. The flow rates used to achieve "high flow" can be any of the flow rates listed below.

[0140] For example, in some embodiments, for an adult patient, "high flow therapy" refers to the delivery of gas to the patient at a flow rate of about 10 LPM or greater, e.g., from about 10 LPM to about 120 LPM, or from about 10 LPM to about 100 LPM, or from about 15 LPM to about 95 LPM, or from about 20 LPM to about 90 LPM, or from 25 LPM to about 75 LPM, or from about 25 LPM to about 85 LPM, or from about 30 LPM to about 80 LPM, or from about 35 LPM to about 75 LPM, or from about 40 LPM to about 70 LPM, or from about 45 LPM to about 65 LPM, or from about 50 LPM to about 60 LPM. In some embodiments, for neonatal, infant, or pediatric patients, "high flow therapy" can refer to delivery of gas to a patient at a flow rate of 1 LPM or greater, such as from about 1 LPM to about 25 LPM, or from about 2 LPM to about 25 LPM, or from about 2 LPM to about 5 LPM, or from about 5 LPM to about 25 LPM, or from about 5 LPM to about 10 LPM, or from about 10 LPM to about 25 LPM, or from about 10 LPM to about 20 LPM, or from about 10 LPM to 15 LPM, or from about 20 LPM to 25 LPM. High flow therapy devices for adult, neonatal, infant, or pediatric patients can deliver gas to a patient at a flow rate of from about 1 LPM to about 100 LPM, or any of the subranges outlined above. The flow therapy device 10 may deliver any concentration of oxygen (e.g., fraction of delivered oxygen, FdO2) up to 100% at any flow rate from about 1 LPM to about 100 LPM. In some forms, any of the flow rates may be combined with oxygen concentrations (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, flow rates may be between about 25 LPM and 75 LPM in combination with oxygen concentrations (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 forms, the flow therapy device 10 may include safety thresholds that prevent a user from delivering too much oxygen to the patient when operating in manual mode.

[0141] High-flow therapy may be administered to the user's nares and / or orally. High-flow therapy may deliver gas to the user at a rate that is at or above the intended user's maximum inspiratory flow conditions. High-flow therapy may create a flushing effect in the nasopharynx, causing the high inlet gas flow to flush the anatomical dead space of the upper airway. This may create a reservoir of fresh gas available with every breath, while minimizing nitrogen and carbon dioxide rebreathing. Meeting inspiratory demand and flushing the airway is also important when trying to control the patient's fraction of inhaled oxygen, FiO2. High-flow therapy may be implemented using a non-sealing patient interface, such as a nasal cannula. The nasal cannula may be configured to deliver respiratory gas to the user's nares at a rate that is above the intended user's maximum inspiratory flow conditions.

[0142] The term "non-sealing patient interface" as used herein may refer to an interface that provides a pneumatic link between a patient's airway and a gas flow source and does not completely occlude the patient's airway. A non-sealing pneumatic link may include less than about 95% occlusion of the patient's airway. A non-sealing pneumatic link may include less than about 90% occlusion of the patient's airway. A non-sealing pneumatic link may include between about 40% and about 80% occlusion of the patient's airway. The airway may include one or both of the patient's nostrils. In a nasal cannula, the airway passes through one or both of the nostrils.

[0143] Referring to Figure 2, a patient interface 100 for delivery of gas to a patient is shown. The patient interface 100 has at least one inspiratory element 155 including an inspiratory lumen 120 defining an inspiratory gas flow path that directs the flow of gas to the patient's airway via at least one of the nostrils. At least one expiratory element 155 including an expiratory lumen 130 defining an expiratory gas flow path directs the flow of expiratory gas from the patient. A gas permeable body including a filter 140 is disposed in or in fluid communication with the expiratory gas flow path.

[0144] The filter 140 may be provided in any suitable location or component of the patient interface, provided that it is configured such that exhaled gas in the exhalation flow path is directed through the filter before exiting the patient interface and before the flow of exhaled gas from the patient interface and tubing 140 enters the surrounding environment, including ambient air, some examples of which are described in more detail below. The configuration may be such that the filter 140 at least partially treats the exhaled gas before it exits the patient interface 100 and tubing 174. In some embodiments, treating the exhaled gas may include reducing the emission and / or reducing the rate and / or concentration of aerosols and other particulate contaminants into the surrounding air.

[0145] The patient interface 100 may include a device for donning or otherwise attaching the device to the patient. In some embodiments, a securement device (not shown) is provided for securing the patient interface to the patient and may include elastic or resilient straps, ties, or adhesive dermal pads for temporarily attaching at least a portion of the patient interface to the patient's skin, thereby holding the patient interface in an operable position. Alternatively, the securement device may include a cap / skull type headgear. Such headgear may include a continuous or mesh fabric or nonwoven sheet forming multiple straps or a cap. Alternatively or in addition, such headgear may include a combination of rigid or substantially rigid members and straps. The patient interface may include one or more connection features for coupling any of the listed securement devices. The one or more connection features may allow for permanent coupling of the securement device or may be removable or detachable.

[0146] As outlined above, the inhalation conduit 170 is configured to direct the flow of gas toward at least one inhalation lumen 120 of the patient interface, and the exhalation conduit 173 is configured to direct the flow of gas from at least one exhalation lumen 130 of the patient interface.

[0147] In the form shown in FIG. 2, the patient interface includes at least one inspiratory element 155 for directing the flow of gas to the patient's airway, the or each inspiratory element including at least one inspiratory lumen 120 through which the flow of gas is directed, and at least one expiratory element 155, the or each expiratory element including at least one expiratory lumen 130 providing an expiratory gas flow path.

[0148] Depending on the configuration of the patient interface 100, the at least one inspiratory element includes one or both of a first and second nasal element 155, and the at least one exhalation element includes one or both of a first and second nasal element 155. These alternatives are described below with reference to Figures 4A-4H.

[0149] 2, the patient interface 100 includes first and second nasal elements 155, both of which are configured to direct gases into and out of one nostril of the patient. Each nasal element 155 thus has an inhalation lumen 120 and an exhalation lumen 130.

[0150] In the illustrated embodiment, the first nasal element includes a first nasal prong and the second nasal element includes a second nasal prong.

[0151] 2, the exhalation lumen 130, which defines the gas flow path of the exhalation element, is provided through a head portion or cover 160 that covers a portion of the nasal element 155 that defines the inhalation lumen 120. In some embodiments, this portion of the nasal element 155 may be described as a nasal prong, and the head portion or cover 160 is in the shape of a cap or pillow. Although the illustrated embodiment provides the head portion or cover 160 as a separate element, it should be understood that the head portion or cover may be integral with or part of the nasal element.

[0152] The head piece or cover 160 is sized and / or shaped to occlude the nostrils such that exhaled gases E from the nostrils are directed primarily through the exhalation lumen 130 of the nasal element and through the exhalation conduit 173 to the filter 140. The outer surface of the head piece or cover 160 abuts the inner wall of the nostril such that the exhaled gases are directed therethrough. If the nostrils are not sufficiently occluded by the head piece or cover 160, some exhaled gases may flow around the nasal element. However, a significant proportion of the exhaled gases are directed through the exhalation conduit 173 and filtered by the filter 140.

[0153] In some embodiments, the head portion or cover 160 may be removable from the nasal prongs and replaceable.

[0154] In some embodiments, the head portion or cover 160 includes a skirt 166 configured to rest over the opening to the nostrils to enhance occlusion and ensure that substantially all exhaled gas from the nostrils is directed through the exhalation lumen 130.

[0155] In some configurations, the nasal prongs are configured to substantially seal within the patient's nares and have an acceptable amount of leakage from the patient's mouth, hi some configurations, the nasal prongs do not seal with the patient's nares and have an acceptable amount of leakage from the patient's nares and mouth.

[0156] 2 also shows, in schematic form, a cannula manifold 150 providing a gas inflow path through the manifold inlet lumen 125 from an inhalation conduit 170 of an inhalation tube in fluid communication with a source of breathing gas to the inhalation lumen 120. However, it should be understood that the cannula manifold 150 may be omitted and the flow R of breathing gas may be provided by a conduit 170 directly connected or coupled to the inhalation lumen 120 of the nasal prongs 155. Alternatively, a head piece or cover 160 may provide the inhalation lumen 120 instead of the nasal prongs for delivery of breathing gas from the cannula manifold 150. In such an arrangement, the head piece or cover 160 has an inner membrane defining the inhalation lumen 120 and is configured to mate with the cannula manifold 150 such that the inhalation lumen within the cover is in fluid communication with the manifold inhalation lumen 125.

[0157] The cannula manifold 150 may be co-operatively operatively received in a cannula body that includes nasal prongs 155. Example cannula body configurations are described below.

[0158] 2, each nasal prong provides both an inhalation lumen and an exhalation lumen, and the exhalation lumen may be parallel or coaxial with the inhalation lumen. Each nasal prong is in fluid communication with a manifold inhalation lumen 125 and a manifold exhalation lumen 135 within the cannula manifold 150.

[0159] A head portion or cover 160 is configured to mate with the nasal prongs 155, and the cannula manifold 150 is configured to mate with the cannula body such that the exhalation lumen 130 in the cover is in fluid communication with the manifold exhalation lumen 135, together forming an exhalation gas flow path that directs the exhalation gas through the filter 140 before exiting the patient interface 100 and the tube 174. In some embodiments of the patient interface 100, the filter 140 may be located distal to the nasal elements.

[0160] The head piece or cover 160 may occlude the nares, limiting or preventing the escape of exhaled gases that do not first pass through the filter 140. The head piece or cover 160 may be formed in part or in its entirety from any suitable material, such as silicone, foam, or other materials. The head piece or cover 160 may be configured to be used to cover the top of the nasal prongs, or may be integrally formed with the nasal prongs to occlude or block the nares. In some embodiments, the head piece or cover 160 includes a skirt 166 configured to rest over the openings to the nares to enhance occlusion and ensure that all exhaled gases from the nares are directed through the filter 140. The filter 140 is located further along the exhalation flow path and further distal to the patient than the head piece or cover 160. The filter is therefore downstream of the exhalation flow path.

[0161] While embodiments of the present disclosure are described in connection with a nasal cannula device that directs gas flow into both of a patient's nostrils, it should be understood that the present disclosure also contemplates patient interfaces that direct gas flow into a single nostril and allow exhaled gas flow to exit the other nostril.

[0162] 2, filter 140 is configured as a sheath formed around at least a portion or all of an expiratory conduit 173 that is in fluid communication with manifold expiratory lumen 135. In alternative configurations, filter 140 may form or part of expiratory conduit 173, or filter 140 may be a separate component in fluid communication with expiratory conduit 173. Expiratory conduit 173 may be integrally formed with a patient interface, such as cannula manifold 150, or may be coupled to a patient interface.

[0163] The filter 140 may include a filter tube and a filter member. The filter tube, and thereby the filter 140, may be provided as a separate component that may be utilized as a breathing circuit if desired. For example, the filter tube may be connectable to an expiratory port of the cannula manifold 150 or to an expiratory conduit 173 that receives expiratory gas from the cannula manifold 150. The filter tube may be provided as a separate consumable item that may be connected to any breathing circuit that has the ability to channel at least a portion of the expiratory gas.

[0164] In some forms, the filter tube provides an inhalation lumen 170 and an exhalation lumen 173a. The filter tube may have a first open end and a second open end. The first open end may be connectable to a gas source or a humidified gas source, and the second open end may be connectable to the patient interface 100, for example, to the cannula manifold 150. The connection or connections may be via any suitable form, such as a standard medical taper or any suitable form of proprietary connector.

[0165] 2, the portion of the filter tube upstream of filter 140 may include a substantially impermeable wall that, during use, is adjacent to the patient's face and is closer to the patient's face than filter 140, thereby minimizing discomfort from exhaled gas flow through the filter contacting the patient's skin.

[0166] An inhalation conduit 170 is in fluid communication with the manifold inhalation lumen 125. The inhalation conduit 170 may be integrally formed with a patient interface, such as the cannula manifold 150, or may be coupled to the cannula manifold.

[0167] 2, the inhalation conduit 170 and the exhalation conduit 173 may be on a single limb such that both the inhalation conduit 170 and the exhalation conduit 173 extend in one direction from the patient interface 100 during use. For example, the inhalation conduit 170 and the exhalation conduit 173 may both extend from the right side of the patient interface during use, or alternatively, both extend from the left side of the patient interface during use. As described in more detail below, the cannula manifold 150 may be reconfigurable with respect to the cannula body such that the inhalation conduit 170 and the exhalation conduit 173 can extend from both sides of the patient interface during use.

[0168] 2, the inhalation conduit 170 and the exhalation conduit 173 are coaxial. In alternative configurations, the inhalation conduit 170 and the exhalation conduit 173 may be substantially parallel, or alternatively, may both extend at a non-parallel angle from one side of the patient interface during use.

[0169] FIG. 3 shows exemplary configurations of inhalation conduit 170 and exhalation conduit 173 that may be used, including a coaxial configuration in which inhalation conduit 170 is within exhalation conduit 173 (FIG. 3(a)), separate side-by-side inhalation conduit 170 and exhalation conduit 173, which may be parallel, for example, and provided by a separate inhalation tube and a separate exhalation tube (FIG. 3(b)), and combined inhalation conduit 170 and exhalation conduit 173 (FIG. 3(c)).

[0170] When a separate exhalation tube is provided, the exhalation tube may be connected to any system capable of directing or diverting at least a portion of the exhalation gas flow into the exhalation tube, filtering the exhalation gas flow before it enters the ambient air.

[0171] In the coaxial configuration, the inhalation conduit 170 is generally the inner conduit and the exhalation conduit 173 is generally the outer conduit. The inner conduit may be sealed from the outer conduit or, alternatively, the inner conduit may be breathable. Throughout the following description, a material that allows the passage of water molecules through a monolithic wall of the material by a solution diffusion mechanism without allowing bulk passage of liquid water or bulk flow of respiratory gases across the wall is described as a "breathable" material. Those skilled in the art should recognize that the water molecules in the wall do not have a state (solid, liquid, or gas) because they are molecularly dispersed in a medium, but are sometimes referred to in the art as vapor (e.g., the rate of transport is often referred to as water vapor transmission rate, etc.). Furthermore, it should be recognized that the monolithic wall does not include open channels or through-holes from one major surface to another, allowing viruses to be prevented from being carried along with air and liquid water droplets through such channels or pores via a pore flow mechanism. The outer lumen may act to insulate the inner lumen to reduce the occurrence of condensation within the inner inhalation conduit.

[0172] The manifold exhalation lumen 135 is in fluid communication with the pores of the gas permeable body that provides the filter 140 to direct exhaled gases E from the nostrils through the manifold body 150 and then through the gas permeable body 140 such that treated or filtered exhaled gases F are released from the patient interface 100 directly into the ambient air. Alternatively or additionally, the filter 140 may be a component within the exhalation conduit 173 or may be integral with and formed from the tube. For example, the wall of the exhalation conduit 173 may include a filter. In one example, the wall of the exhalation conduit 173 within the filter region 140 may be formed from, e.g., extruded from, a gas permeable filter material, with an internal breathing gas delivery channel or lumen defined by an internal gas impermeable membrane that maintains the separation of inhaled and exhaled gases.

[0173] Filter 140 is configured to trap aerosols entrained within the exhaled gas stream, and may further be configured to trap and substantially remove pathogens.

[0174] In some embodiments, it is envisioned that the filter 140 is provided by a gas permeable body that includes a filter material that is porous, i.e., permeable to exhaled gas. Thus, as used throughout the description of the illustrated embodiment, "pores" refers to spaces or gaps in the filter material through which exhaled gas travels. In some cases, the porosity or roughness of the filter material is sufficient to allow normal breathing. However, in situations where the patient is receiving NHF through the patient interface 100, the filter material ideally provides a higher exhaled gas flow rate to avoid causing a decrease in therapy or harm to the patient. Thus, the filter material is ideally sufficiently coarse to limit the increase in resistance to flow caused by the exhaled gas being directed through the gas permeable body, as well as to be effective in filtering or blocking particles to reduce their concentration in the exhaled gas flow, or at least to reduce the velocity of particles in the exhaled gas.

[0175] To reduce the risk of transmission, it may be desirable to use a filter material formed of or including a gas permeable body, including N95 or higher (e.g., N99) rating or HEPA filter material. The filter material may include one or more materials selected from the group including, but not limited to, fibrous, porous knitted, mesh, woven foam, textile, non-textile, foam, or another filter material.

[0176] The length and / or surface area of ​​the filter 140 within the wall of the expiratory conduit 173 may be configured to reduce resistance to the flow of gas through the filter 140. For example, the length of the filter 140 within the wall of the expiratory conduit 173 may be from about 160 mm to about 295 mm. The surface area of ​​the filter may be, for example, about 13,270 mm. 2In some embodiments, the filter 140 surface area can be, for example, up to about 6,535 mm 2 ~Approx. 12,050mm 2 It is possible.

[0177] In some configurations, the length of the exhalation conduit may be between about 325mm and 390mm. In some configurations, the inner diameter of the exhalation conduit 173 may be about 13mm. Any other suitable configuration may be used.

[0178] In some embodiments, filter materials having a larger surface area of ​​filtration media may provide lower resistance to flow due to exhaled gases being directed through the gas permeable body.

[0179] The portion of the exhalation conduit 173 upstream of the filter 140 (ie, closer to the patient interface than the filter) may have a substantially impermeable wall.

[0180] The length of the portion of the exhalation conduit 173 upstream of the filter may be at least about 80 mm to avoid contact of the filter with the patient's face to minimize discomfort from exhalation gas flow through the filter contacting the patient's skin, and the length of that portion of the exhalation conduit 173 may be up to about 195 mm.

[0181] An end 173 a of the exhalation conduit 173 downstream of the filter 140 is generally closed and gas impermeable to restrict the flow of exhaled gases therethrough and direct the exhaled gases through the filter 140 .

[0182] In various embodiments, at least a portion of the patient interface may be thermally conductive. For example, the inspiratory lumen that directs gases into the patient's airway, such as through the nasal elements 155, may include a thermally conductive material and be configured to facilitate warming the gases delivered to the patient. The gas permeable body that provides the filter 140 may be thermally conductive, which may reduce resistance to flow through the gas permeable body, especially when moist or as it becomes moist with use.

[0183] The tubing 174 and conduits 170, 173 described herein provide gas to the patient interface 100 and / or are in fluid communication or connection with the cannula manifold 150, 1150, 2150, 3150, 4150 or cannula manifold assembly.

[0184] Such tubes and / or conduits may be made of a breathable and flexible type.

[0185] Such tubes or conduits, and in particular at least the exhalation conduit 173, may include structure to prevent or minimize collapse or narrowing of the exhalation lumen 135 in the exhalation conduit. The structure may include one or more of: corrugations, pleats, helical wraps, ribs, or support features.

[0186] In one form, the tube may be formed by spirally winding a filter material film onto the former. A helical support rib, applied in a semi-molten state, is placed in the overlap between adjacent turns. Heat from the helical support rib bonds the two adjacent strips, and once cooled, the rib forms a flexible, resilient conduit. The helical support rib may be selected from a range of thermoplastics that provide sufficient structural and processing properties. The melting temperatures of the helical support rib and the filter material film should be similar to aid processing when formed in this manner. An exemplary polymer is Arnitel® EM550, a thermoplastic co-polyester. Otherwise, the formation may be as described in U.S. Pat. No. 6,769,431, the entire contents of which are incorporated herein by reference.

[0187] The tube 174 and / or the conduit may be made of a material that may be crush resistant and / or reduce or minimize noise generation when the conduit is moved or bent, sometimes referred to as a "rustling" sound. For example, the tube may include an elongated film that is spirally wrapped with an elongated reinforcing member to form the lumen of the tube. The tube may also be of the type that is extruded to form the conduit. In various embodiments, one or more breathable materials may be used in the construction of the inhalation conduit to help expel any condensation that builds up in the conduit (e.g., from "rain-out").

[0188] In various embodiments, the reinforcing members may help prevent or reduce the collapse and / or kinking of the tube, or at least the likelihood of collapse and / or kinking during use. The lumen of the conduit may include a substantially smooth bore to reduce resistance to flow and / or minimize surface features on which condensation may accumulate or pool.

[0189] The tubing used for the inhalation conduit 170 and exhalation conduit 173 preferably: resists crushing, resists flow restriction when bent (e.g., <50% increased resistance to flow when bent around a 1 inch cylinder), resists kinking, resists change in length / volume under varying internal pressure (e.g., resistance to elastic compliance), resists leaking (e.g., <25 ml / min at 6 kPa), has low flow resistance (e.g., <0.2 kPa increase in pressure at maximum rated flow rate), and is electrically safe (e.g., resistant to sparks in the tubing), even in operating environments that may be oxygen-rich.

[0190] The patient interface 100 and tubing 174 for delivering gas to the patient interface 100 and for processing exhaled gases may have many different configurations, some of which are shown, for example, diagrammatically in Figures 4A-4H. Unless otherwise described below, features, functions, and options are the same as in the configuration of Figure 2, and like reference numbers indicate like parts. Any of the patient interfaces and tubing described herein may be used in a respiratory assistance or support system, such as that described with reference to Figure 1.

[0191] As discussed above in relation to FIG. 3, the inhalation conduit 170 and exhalation conduit 173 in the configurations of FIGS. 4A-4H may have any suitable configuration, for example a coaxial configuration in which the inhalation conduit 170 is inside the exhalation conduit 173 (FIG. 3(a)), separate side-by-side inhalation conduit 170 and exhalation conduit 173 which may be parallel (FIG. 3(b)), and combined inhalation conduit 170 and exhalation conduit 173 (FIG. 3(c)).

[0192] In each configuration, the tube 174 includes an inhalation conduit 170 that defines a flow of gases toward the patient interface 100, and an exhalation conduit 173 for directing the flow of gases away from the patient interface 100. The filter 140 is in fluid communication with or is part of the exhalation conduit 173, and is configured to filter the flow of exhaled gases from the patient interface 100 before the flow of exhaled gases leaves the patient interface 100 and enters the ambient air. In some configurations, the exterior surface of the filter 140 is in direct communication with the ambient air to deliver filtered exhaled gases to the ambient air.

[0193] In some configurations, the exhaled gas flow may be passively directed, filtered, and transferred to ambient air; i.e., no active suction is applied to the exhaled conduit 173. In other configurations, active suction may be provided to pull the gas flow through the exhaled conduit 173 and / or filter 140. In some configurations, simultaneous positive and negative flows may be used. For example, in addition to using a positive gas flow source to deliver gas to the patient's airway, a negative gas flow source may be provided to generate a gas flow that travels substantially through the exhaled conduit 173 and / or filter 140 in a direction away from the patient's airway. The negative gas flow source may include a flow generator, e.g., a blower. The features and functions of the simultaneous positive and negative flows may be as described in PCT / NZ2015 / 050044 (published as WO2015 / 156690) and U.S. Pat. No. 10,610,653. The entire contents of those specifications are incorporated herein by reference.

[0194] The tubing 174 may be provided in combination with the patient interface 100 or alternatively, may be provided separately for retrofit, repair, or replacement purposes. The components described herein may be provided in kit form such that one or more of the patient interface, tubing, and / or filter can be assembled.

[0195] In some forms, the inhalation conduit 170 may be provided as a separate inhalation tube from the exhalation tube forming the exhalation conduit 173 .

[0196] The tube 174, filter 174, and patient interface 100 may be used in a respiratory assistance or support system 500, such as that of FIG.

[0197] In the configuration of FIG. 4A, rather than being on a single limb, an inhalation conduit 170 extends from one side of the patient interface 100 during use, and an exhalation conduit 173 extends from the opposite side of the patient interface during use.

[0198] 2, each nasal element 155 provides both a nasal element inhalation lumen 120 and a nasal element exhalation lumen 130. Alternatively, the patient interface 100 may be configured to provide unidirectional flow, where only one nasal element provides a nasal element inhalation lumen 120 and only the other nasal element provides a nasal element exhalation lumen 130. Both alternative configurations (unidirectional and bidirectional) are possible for any of the configurations described herein.

[0199] In the configuration of Figure 4A, the exhalation conduit 173 is coupled to a filter component that includes a filter 140. The filter component includes a filter housing 140a in fluid communication with a downstream portion of the exhalation conduit 173 and a filter member 140b. The filter member 140b may be any of the materials described above with respect to Figure 2.

[0200] Alternatively, the wall of the exhalation conduit 173 may include a filter 140 as described above.

[0201] The portion of the exhalation conduit 173 upstream of the filter 140 and proximal to the patient interface may include a wall that is substantially impermeable to minimize discomfort from the exhalation gas flow through the filter contacting the patient's skin.

[0202] In the configuration of FIG. 4B, the patient interface 100 is configured to provide unidirectional flow, where only one nasal element 155a provides the nasal element inhalation lumen 120, and only the other nasal element 155b provides the nasal element exhalation lumen 130.

[0203] In this configuration, the exhalation conduit 173 is coupled to a filter component including filter 140 as in the configuration of Figure 4A. The wall of the portion of the exhalation conduit upstream of the filter and proximal to the patient interface may be substantially impermeable, which is the portion of the exhalation conduit that may come into contact with the patient during use.

[0204] In the configuration of FIG. 4C, the patient interface 100 is configured to provide unidirectional flow, where only one nasal element 155a provides the nasal element inhalation lumen 120, and only the other nasal element 155b provides the nasal element exhalation lumen 130.

[0205] In this configuration, as in the configuration of Figure 2, the wall of the expiratory conduit 173 includes a filter 140. The wall of the expiratory conduit upstream of the filter may be substantially impermeable.

[0206] In the configuration of Figures 4B and 4C, the patient interface 100 includes a first nasal element 155a provided for fluid communication with a first nostril of the patient, and an associated first conduit 170 provided for separate and / or dedicated fluid connection with the first nasal element 155a. The patient interface 100 includes a second nasal element 155b provided for fluid communication with a second nasal element of the patient, and an associated second conduit 173 provided for separate and / or dedicated fluid connection with the second nasal element 155b. Either the first nasal element 155a with said associated first conduit 170, or the second nasal element 155b with said associated second conduit 173, is configured as the only inhalation line or conduit for delivering gas from a gas source to one or the first patient's nostril. The other of the first nasal element 155a with the associated first conduit 170, or the second nasal element 155b with the associated second conduit 173, is configured as the only exhalation line or conduit for receiving gases from the other or second patient nostril. The patient interface 100 includes a partition or other physical separator between the first nasal element 155a and the second nasal element 155b. The partition or other physical separator provides a mechanical fluidic decoupling between the fluid flow paths of the first nasal element 155a and the second nasal element 155b.

[0207] In some forms, the inhalation nasal element 155a can become an exhalation nasal element, and vice versa. In particular, gas flow can be selectively directed to either the first nasal element 155a or the second nasal element 155b, with the selected nasal element becoming a dedicated inhalation element and the other nasal element becoming a dedicated exhalation element.

[0208] In the configuration of FIG. 4D, the patient interface 100 is configured to provide unidirectional flow, where only one nasal element 155a provides the nasal element inhalation lumen 120, and only the other nasal element 155b provides the nasal element exhalation lumen 130.

[0209] As with the embodiment of FIG. 2, the inhalation conduit 170 and the exhalation conduit 173 are on a single limb and are coaxial.

[0210] As in FIG. 4A, the exhalation conduit 173 is coupled to a filter component that includes a filter 140 .

[0211] As shown by the arrows NL and ML in Fig. 4D, in any of the configurations described herein, some amount of nasal leakage NL and / or mouth leakage ML may be tolerated without adversely affecting the function of the technology. That is, the nasal elements 155a, 155b do not need to completely seal the patient's nares, and the patient may be able to exhale a portion of the exhaled gases through the mouth. However, it is envisioned that the majority of the exhaled gases from the patient will be directed through the filter 140 before exiting to the ambient air.

[0212] For example, more than 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or substantially 100% of the exhaled gas from the patient may be directed to pass through filter 140 before exiting to the ambient air.

[0213] In the configuration of FIG. 4E, the patient interface 100 is configured to provide unidirectional flow, where only one nasal element 155a provides the nasal element inhalation lumen 120, and only the other nasal element 155b provides the nasal element exhalation lumen 130.

[0214] As in the embodiment of FIG. 2, the inhalation conduit 170 and the exhalation conduit 173 are on a single limb and are coaxial.

[0215] In this configuration, as in the configuration of Figure 2, the wall of the expiratory conduit 173 includes a filter 140. The wall of the expiratory conduit upstream of the filter may be substantially impermeable.

[0216] In the configuration of FIG. 4F, the patient interface 100 is configured to provide unidirectional flow, where only one nasal element 155a provides the nasal element inhalation lumen 120, and only the other nasal element 155b provides the nasal element exhalation lumen 130.

[0217] In this configuration, as in the configuration of Figure 4C, the wall of the exhalation conduit 173 includes the filter 140. The wall of the exhalation conduit upstream of the filter may be substantially non-permeable. In an alternative configuration, as in the configuration of Figure 4B, the exhalation conduit 173 is coupled to a filter component that includes the filter 140.

[0218] In the configuration of Figure 4F, nasal elements 155a, 155b comprise separate, unconnected nasal elements. The nasal elements may be sealing or non-sealing.

[0219] As discussed above with respect to the configurations of Figures 4B and 4C, in the configuration of Figure 4F the patient interface 100 includes a first nasal element 155a provided for fluid communication with a first nostril of the patient and an associated first conduit 170 provided for separate and / or dedicated fluid connection with the first nasal element 155a. The patient interface 100 includes a second nasal element 155b provided for fluid communication with a second nasal element of the patient and an associated second conduit 173 provided for separate and / or dedicated fluid connection with the second nasal element 155b. Either the first nasal element 155a with said associated first conduit 170 or the second nasal element 155b with said associated second conduit 173 is configured as the only inhalation line or conduit for delivering gas from a gas source to one or the first patient's nostril. The other of the first nasal element 155a with the associated first conduit 170, or the second nasal element 155b with the associated second conduit 173, is configured as the only exhalation line or conduit for receiving gases from the other or second patient nostril. The patient interface 100 includes a partition or other physical separator between the first nasal element 155a and the second nasal element 155b. The partition or other physical separator provides a mechanical fluidic decoupling between the fluid flow paths of the first nasal element 155a and the second nasal element 155b.

[0220] In the configuration of FIG. 4F, the physical separation between the fluid flow paths of the first nasal element 155a and the second nasal element 155b is due to the physical independence or blocking of the nasal elements 155a, 155b and / or associated conduits 170, 173.

[0221] In some configurations, the inhalation nasal element can become the exhalation nasal element, and vice versa. In particular, gas flow can be selectively directed to either the first nasal element 155a or the second nasal element 155b, with the selected nasal element becoming a dedicated inhalation element and the other nasal element becoming a dedicated exhalation element.

[0222] With physically separate nasal delivery elements, when filter 140 needs to be replaced, the expiratory nasal element may be replaced without the need to replace the inhalation nasal element.

[0223] The patient interface 100 may be held in place on the patient's face by any suitable arrangement, such as, for example, headgear, straps, and / or one or more skin patches.

[0224] In the configuration of Figure 4G, the patient interface 100 is configured to provide unidirectional flow, where only one nasal element 155a provides the nasal element inhalation lumen 120, and only the other nasal element 155b provides the nasal element exhalation lumen 130. The configuration is similar to that of Figure 4C.

[0225] The patient interface 100 includes a gas port 132 for drawing exhaled gases from the patient's nose and / or the patient's mouth that are not directed into the exhalation nose element. The gas port 132 may be configured to be positioned proximal to the patient's mouth during use of the patient interface.

[0226] Gas port 132 is open to atmosphere / ambient.

[0227] The gas port 132 is in fluid communication with or opens into the expiratory conduit 173 and / or the expiratory lumen 135 .

[0228] The flow of exhalation gas along the exhalation conduit 135 creates a negative pressure at the gas port 132, which may act to draw in gas from the patient's mouth and / or the patient's nose that is not directed into the expiratory prong 155b.

[0229] The gas port 132 is positioned and oriented so as to draw in at least a portion of the exhaled gases from the patient's mouth and / or the patient's nose that are not directed into the exhalation lumen 135 via the exhalation nose element 155b.

[0230] Gas port 132 is positioned and oriented such that the flow of exhaled gas from the patient's mouth and / or the patient's nose is directed from gas port 132, into exhalation lumen 135 and to filter 140.

[0231] The effect of inhalation can be enhanced by increasing the flow rate of gas delivered into the patient interface 100 through the inhalation conduit 170, thereby increasing the flow rate of gas passing along the exhalation conduit 173 to inhale more gas.

[0232] Active suction may be applied at a point along the expiratory conduit 173, such as at the distal end of the expiratory conduit 173, to increase the gases that are inhaled. Active suction may be applied, for example, by a side flow generator or by a vacuum, such as those available from wall outlets in most hospitals.

[0233] In the configuration of Figure 4H, as in the configuration of Figure 4B, exhalation conduit 173 is coupled to a filter component including filter 140. The features and functions of the configuration of Figure 4H are otherwise as described in Figure 4G.

[0234] As mentioned above, the cannula manifold may be reconfigurable relative to the cannula body. Figures 5A-5O show alternative configurations of the patient interface 1100 that allow the cannula manifold 1150 to be reconfigured relative to the cannula body 1110 to select which nasal elements provide the inhalation component and which nasal elements provide the exhalation component, and Figures 6A and 6B show two configurations diagrammatically.

[0235] The patient interface 1100 may have any one or more of the features, functions and options outlined in the embodiments described above, and like reference numerals indicate like parts with the addition of 1000.

[0236] The frame portion 1102 of the interface 1100 includes a first side arm 1106 and a second side arm 1108. The side arms 1106, 1108 may include a headgear retention mechanism adapted to retain headgear. The retention mechanism may include a buckle, connector, or any other suitable feature for engaging with the headgear.

[0237] The patient interface 1100 includes a manifold inlet lumen 1125 in fluid communication with a manifold inlet 1125a, and a manifold outlet lumen 1135 in fluid communication with a manifold outlet 1135a.

[0238] Frame portion 1102 includes a cannula body 1110 .

[0239] The cannula body 1110 has a first nasal element 1155a and a second nasal element 1155b, which may include, for example, nasal prongs of the type described above. The nasal elements 1155 may be integrally formed with the cannula body 1110, or alternatively may be formed as part of an elastomeric component. The elastomeric component may be an overmolded component overmolded onto the cannula body, with a lower portion of the cannula body including the cavity 1111 being more rigid. The body may include a polymeric material, such as, for example, polypropylene, and the elastomeric component may include, for example, a thermoplastic elastomer.

[0240] 5C-5O, cannula manifold 1150 includes flow directing member 1152. Cannula manifold 1150 is reconfigurable relative to the cannula body such that in a first configuration, flow directing member 1152 is positioned to direct gas flow from manifold inlet lumen 1125 to first nasal element 1155a and from second nasal element 1155b to exhalation lumen 1135 (e.g., as shown in FIG. 6A), and in a second configuration, flow directing member 1152 is positioned to direct gas flow from manifold inlet lumen 1125 to second nasal element 1155b and from first nasal element 1155a to manifold exhalation lumen 1135 (e.g., as shown in FIG. 6B).

[0241] Cannula manifold 1150 is configured to be inserted into cavity 1111 of cannula body 1110. In particular, cannula manifold 1150 is configured to be inserted into cavity 1111 of cannula body 1110 in a first configuration and a second configuration.

[0242] Cannula body 1110 has a cavity 1111 for receiving cannula manifold 1150. Cannula body 1110 has a first open end 1111a for inserting cannula manifold 1150 in a first configuration and a second open end 1111b for inserting cannula manifold 1150 in a second configuration.

[0243] Cavity 1111 extends across cannula body 1110 from a first open end 1111 a on one side of cannula body 1110 to a second open end 1111 b on the other side of cannula body 1110 .

[0244] Cavity 1111 serves as a gas chamber for cannula body 1110. Cavity 1111 is in fluid communication with nasal element inspiratory lumen 1120 and nasal element expiratory lumen 1130, for example as shown in Figures 5J and 5L.

[0245] The cannula manifold 1150 may be received in the cavity 1111 in two configurations - either via the first open end 1111a or the second open end 1111b. If a user wishes the tube 174 to extend to the right from the patient interface 1100, the cannula manifold 1150 may be inserted into the cavity 1111 via the first open end 1111a. Alternatively, if a user wishes the tube 174 to extend to the left from the patient interface 1111b, the cannula manifold 1150 may be inserted into the cavity 1111 via the second open end 1111b.

[0246] This means that the same cannula manifold 1150 can be used regardless of which side of the patient interface 1100 the tubes 174 extend to, thereby reducing the number of separate components required.

[0247] The first configuration corresponds to the cannula manifold 1150 being inserted into the cavity 1111 of the cannula body from a first side of the cannula body 1110, and the second configuration corresponds to the cannula manifold 1150 being inserted into the cavity 1111 of the cannula body from a second side of the cannula body 1110.

[0248] Figures 5B, 5C, 5L-5O, and 6A show a first configuration, in which the cannula manifold 1150 is inserted into the right side (relative to the patient) of the cannula body 1110 via the first open end 1111a, so that the inhalation lumen 1125 and the exhalation lumen 1135 are accessible from the right side of the patient interface. Figure 6B shows a second configuration, in which the cannula manifold 1150 is inserted into the left side (relative to the patient) of the cannula body 1110 via the second open end 1111b, so that the inhalation lumen 1125 and the exhalation lumen 1135 are accessible from the left side of the patient interface.

[0249] Referring to Figure 5L, one end of the cannula manifold 1150 includes a manifold inlet 1125a for interfacing with or attaching to the inhalation conduit 170 of the tube 174. Referring to Figure 5D, that end of the cannula manifold 1150 further includes a manifold outlet 1135a for interfacing with or attaching to the exhalation conduit 173 of the tube 174. The manifold inlet 1125a and the manifold outlet 1135a may be substantially parallel to one another. Alternatively, the manifold inlet 1125a and the manifold outlet 1135a may both extend at a non-parallel angle from one side of the patient interface.

[0250] The opposite end 1151 of the cannula manifold 1150 is closed to form a plug or cap that, depending on the orientation of insertion of the cannula manifold 1152, closes the first and second open ends 1111a, 1111b of the cannula body.

[0251] Cannula manifold 1150 has sealing surfaces 1151a, 1151b at or towards each end for sealing against first and second open ends 1111a, 1111b of body 1110 such that when cannula manifold 1150 is inserted into cavity 1111, cannula manifold 1150 forms a seal with both first and second open ends 1111a, 1111b.

[0252] Cannula manifold 1150 includes an intake gas delivery opening 1125 b that communicates with one of the nasal elements and with the gas chamber within cavity 1111 when cannula manifold 1150 is inserted into cavity 1111 .

[0253] The cannula manifold 1150 includes an expiratory gas receiving opening 1135b that is substantially pneumatically isolated from the inhalation gas delivery opening 1125b. The expiratory gas receiving opening 1135b communicates with the other nasal element when the cannula manifold 1150 is inserted into the cavity 1111.

[0254] When the cannula manifold 1150 is inserted into the cavity 1111, the manifold inlet 1125a is in fluid communication with a section of the cavity 1111 via the inhalation gas delivery opening 1125b. When the cannula manifold 1150 is inserted into the cavity 1111, the manifold outlet 1135a is in fluid communication with another section of the cavity 1111 via the exhalation gas receiving opening 1135b.

[0255] In some embodiments, the body 1110 or the cannula manifold 1111 may include a resilient material to form a seal between a portion of the cannula manifold 1111 and the body 1110, substantially preventing gas flow through the first and second open ends 1111a, 1111b between the body and the cannula manifold.

[0256] For example, the body 1110 may include a resilient material within the cavity 1111 and contact the sealing surfaces 1151a, 1151b of the cannula manifold. In some embodiments, the resilient material may be integrally formed with the surface-contacting portions of 1110.

[0257] In some embodiments, the intake gas delivery opening 1125b may be formed toward the rear, and in some embodiments, may extend a substantial length of the manifold. If the intake gas delivery opening 1125b is formed toward the rear, the resilient surface contact portion of the frame may not be supported by the manifold assembly at the upper lip (between the upper lip and the nose), so the surface contact portion in the area of ​​the intake gas delivery opening 1125b provides a cushion for resting against the user's upper lip. The surface contact portion at the manifold assembly outlet may act as an air-filled cushion to contact the upper lip area of ​​the user.

[0258] Manifold inlet 1125a and inhalation gas delivery opening 1125b form a manifold inhalation lumen 1125 of cannula manifold 1150. Manifold outlet 1135b and exhalation gas receiving opening 1135b form a manifold exhalation lumen 1135 of cannula manifold 1150.

[0259] The flow directing members 1152 are positioned such that the first and second nasal elements distal to the manifold inlet 1125a and manifold outlet 1135a are inhalation nasal elements for directing gas flow to the patient, and the first and second nasal elements proximal to the manifold inlet 1125a and manifold outlet 1135a inhalation lumens are exhalation nasal elements for directing exhalation gas flow away from the patient. When the cannula manifold 1150 is in a first configuration relative to the cannula body 1110, the first nasal element 1155a is an inhalation nasal element, and the second nasal element 1155b is an exhalation nasal element. When the cannula manifold 1150 is in a second configuration relative to the cannula body 1110, the second nasal element 1155b is an inhalation nasal element, and the first nasal element 1155a is an exhalation nasal element.

[0260] Proximal portion 1152a of flow directing member 1152 extends substantially longitudinally of body portion 1154 of cannula manifold 1150. Distal portion 1152b of the flow directing member extends transversely from the distal end of proximal portion 1152a into contact with body portion 1154 of the cannula manifold.

[0261] The distal portion 1152b may extend from the distal end of the proximal portion 1152a at a substantially right angle or may extend from the distal end of the proximal portion 1152a at an obtuse angle.

[0262] A cavity defined between proximal portion 1152a, distal portion 1152b, and body portion 1154 forms exhaled gas receiving opening 1135b. The cavity forming exhaled gas receiving opening 1135b is in fluid communication with a proximal one of the nasal elements when cannula manifold 1150 is in place within cavity 1111 of cannula body 1110 such that nasal element exhaled lumen 1130 is in fluid communication with cannula manifold exhaled lumen 1135.

[0263] An intake gas delivery opening 1125b is provided on an opposite side of the flow directing member distal portion 2152b from the cavity.

[0264] A channel 1125c is provided opposite and along the length of the flow directing member proximal portion 1152a and is in fluid communication with the manifold inlet 1125a and the intake gas delivery opening 1125b which is in fluid communication with a distal one of the nasal elements when the cannula manifold 1150 is in place within the cavity 1111 of the cannula body 1110 such that the nasal element intake lumen 1210 is in fluid communication with the cannula manifold intake lumen 1125.

[0265] In the illustrated form, the cannula manifold 1150 includes an assembly of components.

[0266] In some embodiments, the cannula manifold 1150 includes a first component 1150a and a second component 1150b that is engageable with the first component 1150a. The cannula manifold may include a third component 1150c that acts as a fastening component that holds the first and second components 1150a, 1150b together. The cannula manifold 1150 may be formed from a series of modular components, which allows for the use of relatively simple tooling designs to create a smooth transition between the manifold inlet 1125a and the intake gas delivery opening 1125b of the cannula manifold. In particular, the use of a modular design allows for a combination of relatively simple components to be assembled to form more complex shapes. Alternatively, the cannula manifold may have fewer components.

[0267] An inner end of the second component 1150b is received in a recess in the first component 1150a. The third component 1150c may include an annular sleeve configured to receive and hold together the outer ends of the first component 1150a and the second component 1150b. The first component 1150a, the second component 1150b, and the third component 1150c may have suitable engagement features, such as clips, fasteners, or any other suitable features, that keep the components engaged with one another.

[0268] The cannula manifold 1152 may comprise a rigid polymeric component, for example, polycarbonate.

[0269] It will be appreciated that the configuration of the cannula manifold 1152 , including the flow directing members 1152 , may vary depending on the cannula used in conjunction with the cannula manifold 1152 .

[0270] The patient interface 1100 may be provided in combination with or formed integrally with any of the tube 174 configurations described above.

[0271] For example, the patient interface 1110 may include or be coupled to an inhalation conduit 170 that defines or is in fluid communication with an inhalation lumen 1125, and may include or be coupled to an exhalation conduit 173 that defines or is in fluid communication with an exhalation lumen 1135.

[0272] An inhalation conduit 170 may be coupled to the manifold inlet 1125a. An exhalation conduit 173 may be coupled to the manifold outlet 1135a.

[0273] The inhalation conduit 170 and the exhalation conduit 173 may be coaxial, substantially parallel, or non-parallel.

[0274] The inhalation conduit 170 and the exhalation conduit 173 may be on a single limb such that both the inhalation and exhalation elements extend in one direction from the cannula body 1110 during use.

[0275] 7A-7E show an alternative configuration of cannula manifold 2150, and FIGS. 6C and 6D show schematic diagrams of the flow paths through cannula manifold 2150. Unless otherwise stated below, features, functions, and options are the same as for cannula manifold 1150, and like reference numerals indicate like parts with the addition of 1000.

[0276] In this configuration of the cannula manifold 2150, the flow directing members 2152 are positioned such that the first and second nasal elements proximal to the manifold inlet 2125a and manifold outlet 2135a are inhalation nasal elements for directing gas flow toward the patient, and the first and second nasal elements distal to the manifold inlet 2125a and manifold outlet 2135a are exhalation nasal elements for directing the flow of exhalation gas away from the patient.

[0277] In a first configuration of the cannula manifold 2150 relative to the cannula body 1110, shown in Figure 6C, the right nasal element 1155b (relative to the patient) is the inhalation nasal element and the left nasal element 1155a is the exhalation nasal element. In a second configuration of the cannula manifold 2150 relative to the cannula body 1110, shown in Figure 6D, the left nasal element 1155a is the inhalation nasal element and the right nasal element 1155b is the exhalation nasal element.

[0278] A proximal portion 2152a of the flow directing member 2152 extends substantially longitudinally of the body portion 2154 of the cannula manifold 2150. A distal portion 2152b of the flow directing member extends transversely from the distal end of the proximal portion 2152a into contact with the body portion 2154 of the cannula manifold.

[0279] The distal portion 1152b may extend from the distal end of the proximal portion 1152a at a substantially right angle or may extend from the distal end of the proximal portion 1152a at an obtuse angle.

[0280] A cavity defined between the proximal portion 2152a, the distal portion 2152b, and the body portion 2154 forms an intake gas delivery opening 2125b in fluid communication with the manifold inlet 2125a. The cavity forming the intake gas delivery opening 2125b is in fluid communication with a proximal one of the nasal elements such that the nasal element intake lumen 1120 is in fluid communication with the cannula manifold intake lumen 2125 when the cannula manifold 1150 is in place within the cavity 1111 of the cannula body 1110.

[0281] An exhaled gas receiving opening 2135b is provided on an opposite side of the flow directing member distal portion 2152b from the cavity.

[0282] A channel 2152c is provided opposite the flow directing member proximal portion 2152a and is in fluid communication with the manifold outlet 2135a and the exhalation gas receiving opening 2135b which is in fluid communication with a distal one of the nasal elements when the cannula manifold 2150 is in place within the cavity 1111 of the cannula body 1110 such that the nasal element exhalation lumen 1130 is in fluid communication with the cannula manifold exhalation lumen 2125.

[0283] The inner tubular component 2126 providing the manifold inlet 2125a and the outer tubular component providing the manifold outlet 2135a are coaxial. The patient interface 1100 with this alternative cannula manifold 2150 may be provided in combination with or integrally formed with any of the configurations of the coaxial tube 174 described above. The coaxial configuration used with the coaxial tube 174 reduces the number of separate conduits proximal to the patient.

[0284] The components may be configured with any suitable dimensions depending on the desired application and properties. For example, the inhalation rim inner tubular component 2126 may have an inner hydraulic diameter range of about 3 mm to about 13 mm, and the exhalation rim outer tubular component 2128 may have an outer hydraulic diameter of about 10 mm to about 30 mm, and in some forms up to about 23 mm. The geometric shapes may be selected to provide the desired resistance to flow. For example, the components may be circular / cylindrical or any suitable non-circular shape.

[0285] Cannula manifold 2150 may include second and third components similar to second and third components 1125b, 1125c of cannula manifold 1150.

[0286] The cannula manifolds 1150, 2150 described herein may be provided with a pressure monitoring port. Figures 8A-8G and 9A-9F show two alternative cannula manifolds 3150, 4150 with a pressure monitoring port. Unless otherwise described below, features, functions, and options are the same as for cannula manifold 2150, and like reference numerals are used to designate like parts with the addition of 1000 and 2000, respectively.

[0287] 8A-8G, the cannula manifold 3150 includes a manifold inlet lumen 3125 for the inhalation gas flow, and a manifold outlet lumen 3135 for the exhalation gas flow.

[0288] The cannula manifold 3150 includes a pressure monitoring port 3180. The pressure monitoring port 3180 is in fluid communication with the manifold inspiratory lumen 3125 and the manifold expiratory lumen 3135.

[0289] The pressure monitoring port 3180 is configured to provide a gas flow for pressure monitoring through the pressure monitoring port, the gas flow comprising an average of the inhalation and exhalation gas flows. The average of the inhalation and exhalation gas flows can be applied to a unidirectional flow system.

[0290] In the illustrated embodiment, the pressure monitoring port 3180 is provided in a tubular member 3182 that projects outwardly from the body 3140 of the cannula manifold 3150 .

[0291] A lumen 3184 extends from the base of the tubular member 3182 and terminates in a pressure monitoring port 3180 at the outer end of the tubular member 3182 .

[0292] The tubular member 3182 is provided in a section of the cannula manifold that corresponds to the coaxial members 3126, 3128 which provide the manifold inlet 3125a and the manifold outlet 3135a.

[0293] The base of the tubular member 3184 includes an inlet gas port 3186a in fluid communication with the manifold inlet lumen 3125, and an outlet gas port 3186b in fluid communication with the manifold outlet lumen 3135. The lumen 3184 in the tubular member provides fluid communication between the inlet gas port 3186a, the outlet gas port 3186b, and the pressure monitoring port 3180.

[0294] As gas passes through the manifold inlet lumen 3125 and the manifold outlet lumen 3135 , a portion of the inhaled and exhaled gas can pass through ports 3186 a , 3186 b and pressure monitoring port 3180 .

[0295] The pressure monitoring port 3180 is fluidly connected to both nasal elements via the manifold inhalation lumen 3125 and the manifold exhalation lumen 3135. The pressure monitoring port 3180 may have a sufficiently high resistance to flow to minimize gas flow escaping through the pressure monitoring port 3180. However, the dimensions may be selected to minimize gas flow not only into the pressure monitoring port 3180 but also between the manifold inhalation lumen 3125 and the manifold exhalation lumen 3135, which may otherwise reduce the effects induced by the unidirectional flow design as described herein. The pressure measurements of the manifold inhalation lumen 3125 and the manifold exhalation lumen 3135, which are effectively the average of the inhalation and exhalation pressures, are useful as a good estimate of the patient's internal nasopharyngeal pressure. Only traditional pressure measurement tubes fluidly connected to the inhalation or exhalation circuit components can measure the inhalation or exhalation pressures, respectively, which is not necessarily a good estimate of the nasopharyngeal pressure.

[0296] Advantageously, the pressure monitoring port 3180 provides the ability to measure or determine a patient's pressure without having to position or place a sensor within the patient's airway.

[0297] If the patient interface and cannula manifold 3150 are symmetrical or substantially symmetrical, the measured pressure will provide a useful approximation of the patient's pressure.

[0298] Alternatively, if the patient interface and cannula manifold 3150 have a predictable, known, or predetermined asymmetry, then the measured pressure plus or minus an offset accounting for the asymmetry provides another useful approximation of the patient pressure. The particular amount of offset may depend, for example, on the geometry of the patient interface, and can be calculated by one of ordinary skill in the art using known methodologies.

[0299] 9A-9F, an alternative cannula manifold 4150 includes a manifold inlet lumen 4125 for inhalation gas flow, and a manifold outlet lumen 4135 for exhalation gas flow.

[0300] The cannula manifold 4150 includes a pressure monitoring port 4180. The pressure monitoring port 4180 is in fluid communication with the manifold inspiratory lumen 4125 and the manifold expiratory lumen 4135.

[0301] The pressure monitoring port 4180 is configured to provide a gas flow for pressure monitoring through the pressure monitoring port, the gas flow comprising an average of the inhaled and exhaled gas flows.

[0302] In the illustrated form, the pressure monitoring port 4180 is provided in a tubular member 4182 that projects axially between the inhalation rim inner tubular component 4126 and the exhalation rim outer tubular component 4128 .

[0303] Referring to FIG. 9F, a lumen 4184 extends from the base of the tubular member 4182 and terminates in a pressure monitoring port 4180 at the outer end of the tubular member 4180 .

[0304] The base of the tubular member 4184 includes an inlet gas port 4186a in fluid communication with the manifold inlet lumen 4125, and an outlet gas port 4186b in fluid communication with the manifold outlet lumen 4135. The lumen 4184 in the tubular member provides fluid communication between the inlet gas port 4186a, the outlet gas port 4186b, and the pressure monitoring port 4180.

[0305] As gas passes through the manifold inlet lumen 4125 and the manifold outlet lumen 4135 , a portion of the inhaled and exhaled gases can pass through ports 4186 a , 4186 b and pressure monitoring port 4180 .

[0306] The pressure monitoring ports 3180, 4180 of the cannula manifold 3150, 4150 may be in fluid communication with any suitable pressure monitoring device, such as a pressure sensor. An extension tube 4186 may be coupled to the pressure monitoring port 3180, 4180 to couple it to the pressure monitoring device.

[0307] Although the pressure monitoring ports 3180, 4180 are described with reference to cannula manifolds 3150, 4150 with coaxial manifold inlets 3125a, 4125a and manifold outlets 3135a, 4135a, pressure monitoring ports may be provided in cannula manifolds having non-coaxial arrangements of manifold inlets and outlets. Additionally or alternatively, pressure monitoring ports may be provided in cannula manifolds that deliver gas to the distal nasal elements and receive exhaled gas from the proximal nasal elements rather than in the opposite configuration as shown.

[0308] Any of the patient interface 1100 and / or cannula manifold 1150, 2150, 3150, 4150 may include a filter 140 in fluid communication with the patient interface or manifold exhalation lumen 1135, 2135, 3135, 4135 (e.g., via the manifold outlet 1135a, 2135a, 3135a, 4135a), and the filter 140 is configured to filter the flow of gas from the patient interface before the flow of exhaled gases enters the ambient air from the patient interface.

[0309] The filter 140 and / or the tubing 174 for coupling the filter to the patient interface 1100 or the cannula manifold 1150, 2150, 3150, 4150 may have any of the features described or illustrated herein.

[0310] 10A-10E show an external flow director on the cannula body of the patient interface for capturing and redirecting at least a portion of the exhaled air flow to redirect and / or slow the exhaled gas flow. The external flow director may be provided as part of or used in combination with any of the patient interfaces 1100 disclosed herein.

[0311] Aerosols directed forward at high velocity from an infected patient are believed to be more likely to be contacted by others, such as hospital staff and visitors. Flows directed below, above, to the side, or behind the patient are believed to be less likely to infect others. Similarly, flows with lower velocities cannot carry infectious aerosols as far, thus reducing the risk of infection as well. Therefore, the following concepts are designed to modify the direction and / or velocity of exhaled airflow from a patient undergoing treatment, such as with a high-flow nasal cannula or other patient interface.

[0312] In some forms, the patient interface 1100 includes an external fluid guide 5000 for redirecting and / or slowing the exhaled gas flow. The external fluid guide 5000 may include one or more structures or modifications to the cannula body (i.e., may be integrally formed with the cannula body) or may include one or more fittings that may be optionally used with the patient interface if and when needed. That is, the external fluid guide 5000 may include one or more cannula body features or one or more fittings.

[0313] The external fluid guide 5000 may encourage exhaled gas to travel outwardly, away from the patient, in a more desirable direction, i.e., in one or more directions, which may help reduce the risk of transmission of disease or undesirable substances from the patient's exhaled gases.

[0314] As well as providing an arrangement for redirecting the exhaled gas flow in a more desirable direction, the external fluid guide 5000 may alternatively or additionally direct the captured exhaled gas flow into a filter, such as a filter tube of the type described above.

[0315] Figure 10A shows an exemplary patient interface 1100 in use on a patient. The patient interface 1100 includes a cannula body with an external fluid conducting body 5000. Figures 10B and 10C show the external fluid conducting body 5000 in more detail.

[0316] The external flow guide 5000 is configured to capture and redirect the exhaled air flow.

[0317] The external fluid guide 5000 includes an elongated, tubular, rigid body 5001. The body 5001 may rest on or be supported by the cannula body. The nasal elements 155 extend through the external fluid guide 5000 and into the patient's nostrils.

[0318] Both nasal elements 155 may deliver flow. Both nasal elements 155 may be non-sealing.

[0319] Exhaled gases exiting the nares can enter the external fluid guide 5000 through apertures 5003 in the external fluid guide around each nasal element 155. The size of these apertures 5003 is larger than the size of the portion of the nasal element 155 that extends through the apertures 5003. The size of these apertures 5003 may be approximately the same size as the patient's nares or may be larger than the nares for a larger collection area.

[0320] The upper surface of the external fluid guide 5000, including the aperture 5003, is displaced from the nostril by a short distance during use. In other words, the aperture 5003 is non-sealing. In another embodiment, the upper surface of the external fluid guide 5000 may be configured to seal against the nostril.

[0321] A mesh or filter covers the aperture 5003 to diffuse and / or filter the flow as it enters the interior chamber 5005 of the cannula body feature or fitting 5000 .

[0322] The external fluid guide 5000 includes two further lower apertures 5007 at the bottom of the external fluid guide 5000 through which the nasal elements are inserted when the cannula body features or fittings 5000 are attached to the cannula. These apertures 5007 substantially seal the cannula so that exhaled gases cannot escape the fitting through the lower apertures 5007. Alternatively, the cannula body features or fittings 5000 may be integrally formed with the cannula body 174 and not removable.

[0323] The external flow guide 5000 is configured such that gas flow entering the external flow guide 5000 is redirected along its length. In one form, one or both of the ends 5008 of the external flow guide 5000 distal from the nasal elements 155 may include one or more small apertures 5009 that direct flow upward, backward, downward, sideways, or some combination thereof.

[0324] In an alternative configuration shown in FIG. 10D, one or both ends 5008 of the external fluid guide 5000 may be open to direct gas flow laterally away from the patient.

[0325] The body 5001 of the external fluid guide 5000 may have a cross-sectional area that expands towards one or more ends 5008, which has the effect of slowing down the velocity of the gas flow exiting the open end.

[0326] In an alternative configuration, shown in FIG. 10E, the external fluid guide 5000 may extend laterally from the nasal elements 155 in only a single direction.

[0327] The distal end 5008 of the external fluid guide 5000 may include a filter and / or diffuser 140 configured to capture aerosols and / or slow down the velocity of gas flow exiting the distal end 5008 of the external fluid guide 5000.

[0328] The filter and / or diffuser 140 may be provided on one or more walls of the body 5001 or may be provided by a separate filter component that provides the filter.

[0329] Embodiments of the present disclosure have provided examples of various patient interfaces that use gas permeable bodies and / or physical structures to process exhaled gases before they exit the breathing circuit. These may include part or all of the novel patient interfaces of the present disclosure, or may be provided as part of an attachment for attachment to or application to existing patient interfaces, such as nasal cannulas, masks, ETTs, tracheostomy tubes, etc.

[0330]

[0004] Embodiments of the present disclosure relate to, but are not limited to, improvements to patient interfaces for administering respiratory therapy to patients that may be aimed at reducing the risk of infection to staff and others during treatment of infected patients who exhale airborne pathogens. For example, in the case of SARS-CoV-2, respiratory droplets are known to pose a risk of transmission. However, the risk of transmission via airborne droplets is less understood. The present disclosure provides prophylactic improvements to patient interfaces that may be used in administering NHF and other respiratory therapies (including positive pressure therapy) that may cause aerosolization of particles in exhaled gases, particularly to patients known to have infectious or transmissible respiratory disease.

[0331] The patient interface, cannula manifold, and / or tubing and conduits may have any one or more of the features described in PCT / IB2015 / 054585 (published as WO 2015 / 193833) and U.S. Pat. No. 10,806,887, the entire contents of which are incorporated herein by reference.

[0332] It will be appreciated that various modifications, additions and / or alterations may be made to the foregoing without departing from the scope of the invention as defined in the appended claims.

[0333] Future patent applications may be filed in the United States or abroad based on or claiming priority to this application. It is understood that the following claims are provided by way of example only and are not intended to limit the scope of what may be claimed in any such future applications. Features may be added to or omitted from the claims at a later date in order to further define or redefine the invention.

Claims

1. 1. A patient interface for respiratory therapy comprising: a cannula body including a first nasal element and a second nasal element; and a cannula manifold including a manifold inhalation lumen, a manifold exhalation lumen, and a flow directing member, the cannula manifold being reconfigurable with respect to the cannula body such that in a first configuration, the flow directing member is positioned to direct gas flow from the manifold inhalation lumen to the first nasal element and to direct gas flow from the second nasal element to the manifold exhalation lumen, and in a second configuration, the flow directing member is positioned to direct gas flow from the manifold inhalation lumen to the second nasal element and to direct gas flow from the first nasal element to the manifold exhalation lumen. a patient interface including

2. The patient interface of claim 1 , wherein the cannula manifold is configured to be inserted into the cannula body.

3. 3. A patient interface as claimed in claim 1 or 2 for use with an inhalation conduit in fluid communication with the inhalation lumen and with an exhalation conduit in fluid communication with the exhalation lumen.

4. 4. A patient interface according to claim 3, wherein the inhalation conduit and the exhalation conduit are coaxial or substantially parallel.

5. The patient interface of claim 4 , wherein the inhalation conduit and the exhalation conduit are on a single limb such that both the inhalation element and the exhalation element extend in one direction from the cannula body.

6. 6. A patient interface according to claim 1, wherein the flow directing members are positioned such that one of the first and second nasal elements distal to the manifold inlet and manifold outlet is an inhalation nasal element for directing gas flow towards a patient, and the other of the first and second nasal elements proximal to the manifold inlet and manifold outlet is an exhalation nasal element for directing exhalation gas flow away from the patient.

7. 6. A patient interface according to claim 1, wherein the flow directing members are positioned such that one of the first and second nasal elements proximal to the manifold inlet and manifold outlet is an inhalation nasal element for directing gas flow towards the patient, and the other of the first and second nasal elements distal to the manifold inlet and manifold outlet is an exhalation nasal element for directing exhalation gas flow away from the patient.

8. 8. A patient interface according to claim 6 or 7, comprising a gas port for drawing exhaled gases from the patient which is not directed into the exhalation nose element.

9. 9. A patient interface according to any one of claims 1 to 8, wherein the cannula manifold includes a body portion and the flow directing member includes a proximal portion extending substantially longitudinally of the body portion and a distal portion extending transversely from a distal end of the proximal portion to contact the body portion.

10. 10. A patient interface as described in claim 9, wherein a cavity defined between the proximal portion, the distal portion, and the body portion defines a cavity for forming one of an exhalation gas receiving opening and an inhalation gas delivery opening.

11. The patient interface of claim 10 , wherein the other of the inhalation gas delivery opening and the exhalation gas receiving opening is provided on an opposite side of the distal portion of the flow directing member from the cavity.

12. A patient interface according to any preceding claim, wherein the cannula manifold is configured for insertion into the cannula body in the first configuration and in the second configuration.

13. 13. The patient interface of claim 12, wherein the first configuration corresponds to the cannula manifold being inserted into the cannula body from a first side of the cannula body, and the second configuration corresponds to the cannula manifold being inserted into the cannula body from a second side of the cannula body.

14. A patient interface according to any preceding claim, wherein the cannula manifold includes a pressure monitoring port, the pressure monitoring port in fluid communication with the manifold inspiratory lumen and the manifold expiratory lumen.

15. 15. A patient interface according to any one of claims 1 to 14, comprising a filter in fluid communication with the manifold exhalation lumen, the filter configured to filter the flow of exhaled gas from the patient interface before the flow of gas enters the ambient air from the patient interface.

16. 1. A patient interface for respiratory therapy comprising: a cannula body including a first nasal element configured to direct gases into one nostril of the patient and a second nasal element configured to direct gases from another nostril of the patient; and a manifold for receiving a gas from said first nasal element and a manifold outlet for receiving said gas from said second nasal element; a manifold inlet for receiving a gas from said first nasal element; a manifold outlet for receiving said gas from said first nasal element; a manifold outlet for receiving said gas from said first nasal element; a patient interface including

17. 1. A patient interface for respiratory therapy comprising: a cannula body including a first nasal element and a second nasal element; and a cannula manifold including a manifold inhalation lumen, a manifold exhalation lumen, and a flow directing member positioned to direct gas flow from the manifold inhalation lumen to the first nasal element and to direct gas flow from the second nasal element to the manifold exhalation lumen. a patient interface including

18. 20. The patient interface of claim 17, wherein the cannula manifold comprises a pressure monitoring port.

19. 20. The patient interface of claim 18, wherein the pressure monitoring port is configured to provide a gas flow for pressure monitoring therethrough, the gas flow comprising an average of the inhaled and exhaled gas flows.

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