WO2014097083A1

WO2014097083A1 - Diffusion device for a nasal cushion apparatus

Info

Publication number: WO2014097083A1
Application number: PCT/IB2013/060898
Authority: WO
Inventors: John Theodore GOBBLE, III
Original assignee: Koninklijke Philips N.V.
Priority date: 2012-12-18
Filing date: 2013-12-13
Publication date: 2014-06-26

Abstract

A nasal cushion apparatus (4) is structured to provide a flow of breathing gas to the airways of a patient (20). The apparatus includes a flow element (8) and a pair of diffusion devices (12). The flow element is structured to be in fluid communication with a source of breathing gas (16) and has a pair of flow outlets (28A, 28B) structured to be aligned with the patient's nostrils (24A, 24B), with each flow outlet being structured to provide to a corresponding nostril a portion of the breathing gas flow. The pair of diffusion devices each include a diffusion element (40), with the diffusion elements being aligned with the flow outlet and being structured to be situated within the portions of the breathing gas flow, and with the diffusion elements each being structured to enhance diffusion of the corresponding portions of the breathing gas flow within the corresponding nostril.

Description

DIFFUSION DEVICE FOR A NASAL CUSHION APPARATUS

CROSS-REFERENCE TO RELATED APPLICATIONS

[01] This patent application claims the priority benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 61/738,659 filed on December 18, 2012, the contents of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1 . Field of the Invention

[02] The present invention relates generally to a nasal cushion that is structured to deliver a flow of breathing gas to a patient and, more particularly, to such a nasal cushion having a device that is structured to enhance diffusion or to induce turbulence or both in a flow of breathing air delivered to the nostrils of a patient.

2. Description of the Related Art

[03] There are numerous situations where it is necessary or desirable to deliver a flow of breathable gas non-invasively to the airway of a patient, i.e., without intubating the patient or surgically inserting a tracheal tube in their esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation. It is also known to deliver continuous positive airway pressure (CPAP) or variable airway pressure, which varies with the patient's respiratory cycle, to treat a medical disorder such as sleep apnea syndrome, in particular, obstructive sleep apnea (OSA), or congestive heart failure.

[04] Non-invasive ventilation and pressure support therapies involve the

placement of a respiratory patient interface device including a patient interface that is typically secured on the face of a patient by a headgear assembly. The patient interface may be, without limitation, a nasal mask that covers the patient's nose, a nasal cushion having nasal prongs that are received within the patient's nares, a nasal/oral mask that covers the nose and mouth, or full face mask that covers the patient's face. It is known to maintain such devices on the face of a wearer by a headgear having one or more straps adapted to fit over/around the patient's head. Because such respiratory patient interface devices are typically worn for an extended period of time, it is important for the headgear to maintain the patient interface in a desired position while doing so in a manner that is comfortable to the patient.

[05] Certain patient interface devices, particularly nasal cushions and pillows- type devices that are engaged directly with the nose of the patient, provide a flow of breathing gas that can cause in the patient a sensation of jetting that is uncomfortable. Such jetting can result from the impingement of a narrow jet of breathing gas at relatively high velocity upon a limited region of the nostril, and which can result in drying at such region of the nostril. Moreover, such impingement can give the patient a sensation that the pressure of the breathing gas is higher than is actually the case, which is likewise undesirable. In some circumstances, the flow of breathing gas into each nostril can be in the form of a relatively narrow, high pressure flow of breathing gas having a steep pressure gradient and which fails to contact a desirably large portion of the interior nasal surface due to a lack of flow at the interior nasal surface. Such a flow can result in pain, a burning sensation, localized cooling, or undesired stimulation of the nasal tissue, the underlying blood vessels, the nerves, etc. It thus would be desirable to provide an improved system that overcomes these and other shortcomings.

SUMMARY OF THE INVENTION

[06] In certain embodiments, the general nature of the invention can be stated as including an improved nasal cushion apparatus that is structured to provide a flow of breathing gas to the airways of a patient. The nasal cushion apparatus can be generally stated as including a flow element and a pair of diffusion devices. The flow element is structured to be in fluid communication with a source of breathing gas. The flow element has a pair of flow outlets that are structured to be aligned with the nostrils of the patient. Each flow outlet is further structured to provide to a corresponding nostril a portion of the flow of breathing gas. The diffusion devices each include a diffusion element. The diffusion elements are aligned with the flow outlets. The diffusion elements are structured to be situated within the portions of the flow of breathing gas and to enhance diffusion of the portions of the flow of breathing gas that flow into the nostrils. [07] In other embodiments, the general nature of the invention can be stated as including an improved diffusion device that is structured to be installed on a nasal cushion apparatus which is structured to provide a flow of breathing gas to the airways of a patient. The nasal cushion apparatus has a flow element which includes a pair of flow outlets that are each structured to provide to a corresponding nostril of the patient a portion of the flow of breathing gas. The diffusion device can be generally stated as including a support and a diffusion element. The support includes a base portion that is structured to be engaged with the flow element. The diffusion element is disposed on the support and is structured to be aligned with a flow outlet of the pair of flow outlets. The diffusion element is further structured to be situated within the portion of the flow of breathing gas and to enhance diffusion of the portion of the flow of breathing gas within at least a portion of the corresponding nostril.

These and other objects, features, and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[09] FIG. 1 is a perspective view of an improved nasal cushion apparatus in accordance with a first embodiment of the present invention that employs a flow element and includes a pair of improved diffusion devices in accordance with the present invention;

[10] FIG. 2 is a partially cut away view of the nasal cushion apparatus of FIG. 1 engaged with a nose of a patient;

[11] FIG. 3 is a perspective view of the pair of improved diffusion devices of

FIG. 1 ; [12] FIG. 4 is another perspective view of the pair of improved diffusion devices of FIG. 1 ;

[13] FIG. 5 is a perspective view of an improved nasal cushion apparatus in accordance with a second embodiment of the present invention that employs the same flow element as is depicted in FIG. 1, and that includes a pair of alternative diffusion devices in accordance with the present invention;

[14] FIG. 6 is a perspective view of the pair of alternative diffusion devices of

FIG. 5;

[15] FIG. 7 is another perspective view of the pair of alternative diffusion

devices of FIG. 5;

[16] FIG. 8 is a perspective view of a nasal cushion apparatus in accordance with a third embodiment of the present invention that includes a pair of the diffusion devices of FIGS. 3 and 4 but that employs a different flow element; and

[17] FIG. 9 is a perspective view of a nasal cushion in accordance with a fourth embodiment of the present invention that includes a pair of the alternative diffusion devices of FIGS. 6 and 7 and that employs the different flow element of FIG. 8.

[18] Similar numerals refer to similar parts throughout the specification.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[19] As used herein, the singular form of "a", "an", and "the" include plural references unless the context clearly dictates otherwise. As used herein, the statement that two or more parts or components are "coupled" shall mean that the parts are joined or operate together either directly or indirectly, i.e., through one or more intermediate parts or components, so long as a link occurs. As used herein, "directly coupled" means that two elements are directly in contact with each other. As used herein, "fixedly coupled" or "fixed" means that two components are coupled so as to move as one while maintaining a constant orientation relative to each other.

[20] As used herein, the word "unitary" means a component is created as a single piece or unit. That is, a component that includes pieces that are created separately and then coupled together as a unit is not a "unitary" component or body. As employed herein, the statement that two or more parts or components "engage" one another shall mean that the parts exert a force against one another either directly or through one or more intermediate parts or components.

[21] Directional phrases used herein, such as, for example and without

limitation, top, bottom, left, right, upper, lower, front, back, and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein.

[22] An improved nasal cushion apparatus 4 is depicted in FIGS. 1 and 2. Nasal cushion apparatus 4 can be generally stated as including a flow element 8 and as further including a pair of diffusion devices 12 that are best shown in FIGS. 3 and 4.

[23] As can be understood from FIG. 2, nasal cushion apparatus 4 is configured to be connected with a source of breathing gas 16 and is further configured to be engaged with a nose of a patient 20 having a pair of nostrils 24A and 24B. Nasal cushion apparatus 4 is configured to provide a flow of breathing gas to patient 20. In particular, flow element 8 includes a pair of flow outlets 28A and 28B that are in fluid

communication with nostrils 24AB and that each provide a portion 26A and 26B of the flow of breathing gas to nostrils 24 AB. The portions 26A and 26B of the flow of breathing gas together form the flow of breathing gas that is provided to patient 20. In the depicted exemplary embodiment, flow element 8 includes a pair of protuberant nozzles 32A and 32B that include flow outlets 28A and 28B. Also in the depicted exemplary embodiment (FIG. 2), nozzles 32A and 32B are engaged with nostrils 24A and 24B and potentially may be at least partially received in nostrils 24A and 24B.

[24] As can be further understood from FIG. 2, exemplary nozzles 32A and 32B each include a ledge 36 that extends generally transverse to a flow direction of the portions 26AB of the flow of breathing gas through nozzles 32AB. Such flow direction of the portions 26 AB of the flow of breathing gas through nozzles 32AB is also generally along an axis 56, which is an axis of elongation of diffusion element 12, as will be described in greater detail below. Ledge 36 is structured to carry diffusion device 12 as will also be described in greater detail below. [25] As can be seen in FIGS. 3 and 4, diffusion device 12 can be said to include a diffusion element 40 and a support 44 that are connected together. Support 44 can be said to include a base portion 48 having a set of openings 50 formed therein to permit the portions 26AB of the flow of breathing gas to flow past base portion 48. More particularly, base portion 48 includes an arcuate engagement element 52 and a plurality of struts 54, with openings 50 being situated between adjacent pairs of struts 54. Struts 54 extend in a radial direction from diffusion element 40 to engagement element 52. As can be understood from FIG. 4, base portion 48 and diffusion element 40 each have an elongated, roughly elliptical shape in a direction transverse to the flow direction of the portions 26AB of the flow of breathing gas.

[26] As mentioned elsewhere, and as can be understood from FIG. 3, diffusion element 40 is elongated along axis of elongation 56 and can be said to include an upstream portion 60 and a terminal portion 64. Upstream portion 60 has a cross-sectional profile, i.e., a profile that is generally transverse to axis of elongation 56, which is generally elliptical in shape. As mentioned above, axis of elongation 56 also corresponds with a flow direction of the portions 26AB of the flow of breathing gas that flow through nozzles 32A and B and that flow out of flow outlets 28A and 28B and into nostrils 24A and 24B.

[27] The cross-sectional profile of upstream portion 60 can be said to increase in size when moving along the flow direction of the portions 26AB of the flow of breathing gas along axis of elongation 56 and generally away from base portion 48. The increase in such cross-sectional profile is, in the depicted exemplary embodiment of FIG. 3, an exponential increase in size.

[28] Terminal portion 64 is situated opposite base portion 48 and is of a

generally elliptical disk configuration. In this regard, terminal portion 64 has a terminal surface 66 that is generally planar in shape but could be of other shapes without departing from the present concept.

[29] It can be understood that by receiving diffusion devices 12 against ledges

36 in nozzles 32A and 32B, diffusion elements 40 will be aligned with flow outlets 28A and 28B and will be situated within the portions 26AB of the flow of breathing gas flowing through nozzles 32A and 32B. By situating diffusion elements 40 within the portions 26AB of the flow of breathing gas, diffusion element 40 will enhance diffusion of the portions of the flow of breathing gas, both in the immediate vicinity of diffusion element 40 as well as downstream thereof, which would be at regions within nostrils 24A and 24B. That is, the portions 26AB of the flow of breathing gas in the absence of diffusion devices 12 would be relatively narrow jets of breathing gas having velocity and pressure gradients, but the presence of diffusion devices 12 within the portions 26AB of the flow of breathing gas disturbs the velocity and pressure gradients. Such disruption of the velocity and pressure gradients causes the relatively narrow jet of high velocity and high pressure breathing gas to become a diffused and relatively wider stream of relatively lower velocity and relatively lower pressure breathing gas. The diffused flow typically will have more turbulence or more vortices or both when compared with the narrow jet.

[30] Such diffusion is highly desirable within nostrils 24A and 24B since such diffusion reduces the otherwise jet-like character of the portions 26AB of the flow of breathing gas that would flow from flow outlets 28A and 28B in the absence of diffusion devices 12. The diffused and relatively more turbulent flows having more vortices within nostrils 24A and 24B advantageously contacts a relatively greater proportion of the tissues within the interiors of nostrils 24A and 24B, which advantageously reduces the sensation of jetting and high pressure that would be felt by patient 20 in the absence of diffusion device 12. Moreover, such contact with a relatively greater proportion of the tissues of nostrils 24A and 24B has the advantageous effect of reducing drying within nostrils 24A and 24B because the diffused and more turbulent flow of breathing gas absorbs a relatively smaller amount of moisture from a relatively greater surface area of nasal tissues.

[31] This improves temperature and humidity conditioning of the diffused flow of breathing gas into the air passages of patient 20. This is in contrast to a narrow and relatively less turbulent jet of breathing gas that would be provided in the absence of diffusion device 12 and which could result in concentrated drying of a relatively small portion of nasal tissues where the non- turbulent jet impinges the tissues within nostrils 24A and 24B. All of this has the advantageous result in improving comfort for patient 20. That is, the diffused flow of breathing gas can results in a desirable reduction or elimination in patient 20 of any one or more of a variety of symptoms such as pain, burning sensations, localized cooling, and undesired stimulation of tissue, underlying blood vessels, or nerves, by way of example.

[32] Such diffusion can be said to occur via any of a variety of mechanisms.

One such mechanism can be characterized as "drag" between diffusion devices 12 and the portions 26AB of the flow of breathing gas. Such drag can include skin drag, form drag, and the like. Another such mechanism can be characterized as "disruption", which is similar to the wake turbulence created downstream of an object that is moving through a fluid. Such disruption can be said to disrupt the otherwise high velocity and pressure gradients in an otherwise undisturbed flow of breathing gas. These and other mechanisms serve to diffuse the flow of breathing gas by altering the velocity and pressure gradients in the flow of breathing gas and by inducing turbulence and vortices therein. Other mechanisms not expressly described herein can be usable to diffuse the flow of breathing gas without departing from the present concept.

[33] In the depicted exemplary embodiment of FIGS. 1 and 2, diffusion element

40 is situated generally centrally within flow outlets 28A and 28B. It can be seen, however, that a portion of diffusion element 40 is situated external to flow outlets 28A and 28B. That is, while diffusion elements 40 are aligned with flow outlets 28A and 28B and are situated in the portions 26AB of the flow of breathing gas, at least a portion of the diffusion enhancement operation that is provided by diffusion elements 40 occurs external to flow element 8, albeit within nostrils 24A and 24B. Such a configuration may be desirable depending upon particular aspects of the nasal passages of the nose of patient 20.

[34] It is expressly noted that diffusion device 12 is installable on flow element 8 and is removable therefrom. Such removability enables cleaning of diffusion devices 12, which is advantageous. Moreover, it is expressly noted that diffusion device 12 can be retrofitted to an existing flow element 8 to provide the advantages described herein. It is understood that in other embodiments, diffusion device 12 can be of different

configurations without departing from the present concept. [35] By way of example, an improved nasal cushion apparatus 104 in accordance with a second embodiment of the present invention is depicted generally in FIG. 5. Nasal cushion apparatus 104 includes the same flow element 8 as is depicted in FIGS. 1 and 2 in connection with nasal cushion apparatus 4, but nasal cushion apparatus

104 includes a diffusion device 112 that is different than diffusion device 12.

[36] More particularly, and as is best shown in FIGS. 6 and 7, diffusion device

112 includes a diffusion element 140 situated on a support 144, with support 144 including a base portion 148 and a set of openings 150 to permit the portions 26AB of the flow of breathing gas to flow therepast. Base portion 148 includes an arcuate engagement element 152 and a plurality of radially-oriented struts 154, with openings 150 being situated between adjacent pairs of struts 154.

[37] However, diffusion element 140 includes an upstream portion 160 that is in the exemplary form of an elliptical shank that extends from base portion 148. Upstream portion 160 is of substantially fixed dimensions throughout at least a portion of its longitudinal extent. Moreover, diffusion element 140 includes an elliptical terminal portion 164 situated on the end of upstream portion 160 opposite base portion 148.

Terminal portion 164 protrudes sharply and radially outwardly from upstream portion 160 and has a rounded terminal surface 166. Terminal portion 164 further has a impingement surface 168 opposite terminal surface 166 and facing generally toward base portion 148. The different configuration of diffusion element 140 compared with diffusion element 40 provides different diffusion effects than diffusion element 40, as will be understood by one of ordinary skill in the relevant art.

[38] It can further be seen from FIG. 5 that when diffusion device 112 is

installed on flow element 8, terminal portion 164 is situated external to flow element 8. Diffusion element 140 is still configured to be aligned with flow outlets 28 A and 28B and to be disposed in the portions 26AB of the flow of breathing gas that flows out of flow elements 28A and 28B, but at least a portion of the diffusion that is provided by terminal portion 164 can be said to be initiated (i.e., formed or generated) at a location situated downstream of and external to flow element 8, i.e., within the nostrils of patient 20. Again, the particular diffusion characteristics of diffusion device 112 may have characteristics that are desirable for particular geometries of the noses of various patients. Diffusion device 112 provides the same types of benefits of enhancing diffusion in a flow of breathing gas as diffusion device 12, i.e., reducing the jetting effect that would tend to occur in the absence of diffusion device 112, resisting the concentrated drying of nasal tissues at a location where a high pressure jet of breathing gas would impinge on the nasal passages in the absence of diffusion device 112, etc., as set forth above in connection with diffusion device 12. Moreover, diffusion device 112 is removable from flow element 8 and can be used to retrofit an existing flow element 8 to provide the benefits mentioned above.

[39] An improved nasal cushion apparatus 204 in accordance with a third

embodiment of the present invention is depicted generally in FIG. 8. Nasal cushion apparatus 204 includes diffusion device 12 that was depicted in FIGS. 1 and 2 in association with nasal cushion apparatus 4 and by itself in FIGS 3 and 4. However, nasal cushion apparatus 204 includes a different flow element 208 having a pair of protuberant nozzles 232A and 232B that are relatively longer than nozzles 32A and 32B of flow element 8. In particular, nozzles 232A and 232B are configured such that when diffusion devices 12 are received therein, a relatively greater portion of each diffusion element 40 is situated within nozzles 232A and 232B. In the depicted exemplary embodiment, diffusion elements 40 are situated in their entireties within nozzles 232A and 232B such that terminal portions 64 are situated within an interior region of flow element 238.

[40] That is, flow element 208 includes a pair of flow outlets 228A and 228B, and diffusion elements 40 are aligned with flow elements 228A and 228B and are situated in the portions 26 AB of the flow of breathing gas flowing therethrough. However, diffusion elements 40 are situated generally in their entireties upstream from or adjacent flow outlets 228A and 228B. As such, the portions 26AB of the flow of breathing gas that flow past terminal portions 64 can generally be said to interact both with terminal portions 64 as well as with nozzles 232A and 232B and to initiate diffusion in the portions 26 AB of the flow of breathing gas prior to flowing out of flow outlets 228 A and 228B. For instance, the portions 26AB of the flow of breathing gas flow through the annular space that is situated between nozzles 232AB and terminal portions 64.

[41] This is not to say that all diffusion is created within the interior of flow element 208 since it is understood that additional diffusion will typically occur from the formation of turbulence vortices that are formed in the voids that are immediately downstream of diffusion element 40 and that are created by the flow of the portions 26 AB of the flow of breathing gas past diffusion element 40. However, diffusion element 40 in the depicted exemplary embodiment of FIG. 8 is situated entirely within flow element 208. Again, the aerodynamic effects of situating diffusion device 12 in nozzles 232A and 232B will have diffusion effects that may be desired for particular nasal geometries of particular patients.

[42] An improved nasal cushion apparatus 304 in accordance with a fourth embodiment of the disclosed and claimed concept is depicted generally in FIG. 9. Nasal cushion apparatus 304 includes diffusion device 112 that was depicted in FIGS. 5-7 in conjunction with nasal cushion apparatus 104, and further includes flow element 208 that was depicted in FIG. 8 and described in conjunction with nasal cushion apparatus 204. Diffusion device 112 in the depicted exemplary device of FIG. 9 is depicted as being situated substantially in its entirety within flow element 208, which provides unique diffusion effects that may be desirable depending upon the particular nasal geometries of specific patients.

[43] As can be understood from the foregoing, diffusion devices 12 and 112 can be installed on either of flow elements 8 and 208 and are also removable therefrom for purposes of cleaning and the like. Moreover, diffusion devices 12 and 112 can be retrofitted to preexisting flow elements 8 and 208 in order to provide the enhanced diffusion benefits that are described herein. The various combinations of these structures provide unique diffusion and flow characteristics that can be selected based upon the nasal geometry of any given patient.

[44] It thus can be seen that the various embodiments provided herein enhance the diffusion of the portions 26AB of the flow of breathing gas, which is desirable from a therapeutic standpoint. That is, such enhanced diffusion increases comfort to patient 20 by reducing localized dryness and a reduced sense of high pressure within nostrils 24A and 24B, which is desirable. Other benefits will be apparent to one of ordinary skill in the art.

[45] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" or "including" does not exclude the presence of elements or steps other than those listed in a claim. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. In any device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain elements are recited in mutually different dependent claims does not indicate that these elements cannot be used in combination.

[46] Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.

Claims

What is Claimed is:

1. A nasal cushion apparatus (4) structured to provide a flow of breathing gas to the airways of a patient, the nasal cushion apparatus comprising:

a flow element (8) structured to be in fluid communication with a source of breathing gas, the flow element having a pair of flow outlets (28AB) structured to be aligned with the nostrils (24AB) of the patient, each flow outlet being further structured to provide to a corresponding nostril a portion of the flow of breathing gas; and

a pair of diffusion devices (12) each comprising a diffusion element (40), the diffusion elements being aligned with the flow outlets, the diffusion elements being structured to be situated within the portions of the flow of breathing gas and to enhance diffusion of the portions of the flow of breathing gas that flow into the nostrils.

2. The nasal cushion apparatus of claim 1 , wherein at least a portion of each diffusion element is elongated in a direction substantially parallel with the portion of the flow of breathing gas.

3. The nasal cushion apparatus of claim 2, wherein the at least portion has a cross-sectional profile that is transverse to a flow direction of the portion of the flow of breathing gas and that varies along its longitudinal extent.

4. The nasal cushion apparatus of claim 3, wherein the cross-sectional profile increases in size along the flow direction of the portion of the flow of breathing gas.

5. The nasal cushion apparatus of claim 4, wherein the cross-sectional profile increases exponentially in size along the flow direction of the portion of the flow of breathing gas.

6. The nasal cushion apparatus of claim 1 , wherein each diffusion device includes a support upon which the diffusion element is disposed, the support being structured to support the diffusion element in the corresponding portion of the flow of breathing gas.

7. The nasal cushion apparatus of claim 6, wherein the flow element comprises a pair of protuberant nozzles that are structured to be at least partially received in the nostrils of the patient, wherein the nozzles each have a ledge oriented generally transverse to a flow direction of the nozzle, and wherein the support comprises a base portion that is engaged with the ledge.

8. The nasal cushion apparatus of claim 7, wherein the support further comprises a shank that extends from the base portion, the diffusion element being disposed on the shank.

9. The nasal cushion apparatus of claim 7, wherein the diffusion devices are removably situated in the nozzles.

10. The nasal cushion apparatus of claim 1, wherein at least a portion of each diffusion element is situated external to the flow element.

11. The nasal cushion apparatus of claim 10, wherein the flow element comprises a pair of protuberant nozzles that are structured to be at least partially received in the nostrils of the patient, and wherein at least a portion of each diffusion element is situated external to the nozzles.

12. The nasal cushion apparatus of claim 1, wherein the diffusion elements are situated within an interior region of the flow element.

13. The nasal cushion apparatus of claim 12, wherein the flow element comprises a pair of protuberant nozzles that are structured to be at least partially received in the nostrils of the patient, and wherein the diffusion elements are situated within the nozzles.

14. A diffusion device (12) that is structured to be installed on a nasal cushion apparatus (4) which is structured to provide a flow of breathing gas to the airways (24AB) of a patient, the nasal cushion apparatus having a flow element (8) which comprises a pair of flow outlets (28AB) that are each structured to provide to a corresponding nostril of the patient a portion of the flow of breathing gas, the diffusion device comprising:

a support (44) comprising a base portion (48) that is structured to be engaged with the flow element; and

a diffusion element (40) disposed on the support, the diffusion element being structured to be aligned with a flow outlet of the pair of flow outlets and being structured to be situated within the portion of the flow of breathing gas and to enhance diffusion of the portion of the flow of breathing gas within at least a portion of the corresponding nostril.

15. The diffusion device of claim 14, wherein at least a portion of the diffusion element is elongated in a direction that is structured to be along a flow direction of the portion of the flow of breathing gas and has a transverse cross-sectional profile that varies along its longitudinal extent.

16. The diffusion device of claim 15, wherein the cross-sectional profile increases in size in a direction that is structured to be generally in the flow direction of the portion of the flow of breathing gas.

17. The diffusion device of claim 16, wherein the cross-sectional profile increases exponentially in size.

18. The diffusion device of claim 14, wherein the support further comprises a shank that that extends from the base portion, the diffusion element being disposed on the shank.

19. The diffusion device of claim 14, wherein the base portion comprises an engagement element and at least a first strut, the engagement element being structured to be engaged with the flow element, the at least first strut extending between the engagement element and the diffusion element and being structured to extend in a direction generally transverse to a flow direction of the portion of the flow of breathing gas.

20. The diffusion device of claim 14, wherein the base portion comprises a plurality of struts, the plurality of struts extending in a radial arrangement from the diffusion element and being structured to extend in a direction generally transverse to a flow direction of the portion of the flow of breathing gas, the base portion further having a plurality of openings situated between adjacent pairs of the struts, the openings being structured to permit flow therethrough of the portion of the flow of breathing gas.