(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`(19) World Intellectual Property
`Organization
`International Bureau
`
`
`
`(43) International Publication Date
`1 September 2005 (01.09.2005)
`
`(10) International Publication Number
`
`WO 2005/079726 A1
`
`(51) International Patent Classification7:
`A62B 7/00, 18/00, A61M 16/00
`
`A61H 31/00,
`
`Auckland, 1005 (NZ). GLEESON, Oliver [NZ/NZ]; 19A
`Ropata Avenue Point England, 1006 Auckland (NZ).
`
`(21) International Application Number:
`PCT/NZ2005/000023
`
`(22) International Filing Date: 18 February 2005 (18.02.2005)
`
`(25) Filing Language:
`
`(26) Publication Language:
`
`English
`
`English
`
`(30) Priority Data:
`53 1332
`534606
`
`23 February 2004 (23.02.2004)
`6 August 2004 (06.08.2004)
`
`NZ
`NZ
`
`(74)
`
`(31)
`
`(71) Applicants (for all designated States except US): FISHER
`& PAYKEL HEALTHCARE LIMITED [NZ/NZ]; 15
`Maurice Paykel, East Tamaki, Auckland, 1706 (NZ).
`PRENTICE, Craig, Robert
`[NZ/NZ]; 95 Kiwi Es-
`planade, Mangere Bridge, Auckland, 1701 (NZ).
`
`(34)
`
`(72) Inventors; and
`(75) Inventors/Applicants (for US only): MCAULEY, Alas-
`tair, Edwin [NZ/NZ]; 58A Ngapuhi Road, Remuera,
`
`Agents: ADAMS, Matthew, D et al.; A J Park, 6th Floor
`Huddart Parker Building, PO Box 949, Wellington, 6015
`(NZ).
`
`Designated States (unless otherwise indicated, for every
`kind of national protection available): AE, AG, AL, AM,
`AT, AU, AZ, BA, BB, BG, BR, BW, BY, BZ, CA, CH, CN,
`CO, CR, CU, CZ, DE, DK, DM, DZ, EC, EE, EG, ES, FI,
`GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE,
`KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD,
`MG, MK, MN, MW, MX, MZ, NA, NI, NO, NZ, OM, PG,
`PH, PL, PT, RO, RU, SC, SD, SE, SG, SK, SL, SY, TJ, TM,
`TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, YU, ZA, ZM,
`ZW.
`
`Designated States (unless otherwise indicated, for every
`kind of regional protection available): ARIPO (BW, GH,
`GM, KE, LS, MW, MZ, NA, SD, SL, SZ, TZ, UG, ZM,
`ZW), Eurasian (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM),
`European (AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI,
`FR, GB, GR, HU, IE, IS, IT, LT, LU, MC, NL, PL, PT, RO,
`
`[Continued on next page]
`
`(54) Title: BREATHING ASSISTANCE APPARATUS
`
`
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`05/079726A1|||||||||||||||||||||||||||||||||||||||||I|||||||||||||||||||||||||||||||||||||||||||||||||||||
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`airway. The prongs have angled ends (31, 32), such that in use, gases flowing through the prongs are directed to the user’s nasal
`passages. The nasal cannula body is partially swivelling and preferably has a ball joint connector (37, 39). In another embodiment
`the nasal cannula may have at least one flared end prong (31, 32) that preferably seals within a patient’s nare.
`
`RMD 1034
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`RMD 1034
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`||||||||||||||ll|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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`SE, SI, SK, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN,
`GQ, GW, ML, MR, NE, SN, TD, TG).
`
`For two—letter codes and other abbreviations, refer to the "Guid-
`ance Notes on Codes andAbbreviations” appearing at the begin-
`
`Published:
`— with international search report
`
`ning of each regular issue of the PCT Gazette.
`
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`PCT/NZ2005/000023
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`_ 1 _
`
`“BREATHING ASSISTANCE APPARATUS”
`
`FIELD OF INVENTION
`
`The present
`
`invention relates to apparatus for treating sleep apnoea. More
`
`specifically, the present invention provides a nasal positive airway pressure device.
`
`SUMMARY OF THE PRIOR ART
`
`Obstructive Sleep Apnoea (OSA) is a sleep disorder that affects up to at least 5% of
`
`the population in which muscles that normally hold the airway open relax and ultimately
`
`collapse, sealing the airway. The sleep pattern of an OSA sufferer is characterised by
`
`repeated sequences of snoring, breathing difficulty, lack of breathing, wakin g with a start
`
`and then returning to sleep. Often the sufferer is unaware of this pattern occuning.
`
`Sufferers of OSA usually experience daytime drowsiness and irritability due to a lack of
`
`good continuous sleep.
`
`In an effort to treat OSA sufferers, a technique known as Continuous Positive
`
`Airway Pressure (CPAP) was devised. A CPAP device consists of a gases supply (or
`
`blower) with a conduit connected to supply pressurised gases to a patient, usually through
`
`a nasal mask. The pressurised air supplied to the patient effectively assists the muscles to
`
`keep the patient’s airway open, eliminating the typical OSA sleep pattern.
`
`The procedure for administering CPAP treatment has been well documented in
`
`both the technical and patent literature. Briefly stated, CPAP treatment acts as a pneumatic
`
`splint of the airwayby the provision of a positive pressure, usually in the range 4 to 20 cm
`
`H20. The air is supplied to the airway by a motor driven blower whose outlet passes via
`
`an air delivery hose to a nose (or nose and/or mouth) mask sealingly engaged to a patient’s
`
`face by means of a harness or other headgear. An exhaust port isprovided in the delivery
`
`tube proximate to the mask. More sophisticated forms of positive airway pressure devices,
`
`such as bi-lcvcl devices and auto-titrating devices, are described in US Patent No.
`
`5,148,802 of Respironics,
`
`inc. and US Patent No. 5,245,995 of Rescare Limited,
`
`respectively.
`
`US Patent No. 5,477,852 of Airways Ltd, Inc. discloses a nasal positive airway
`
`pressure device that has a pair of nasal members each having a cannula tip to be inserted
`
`into the nares of the patient. Each cannula is tapered from a substantially circular
`
`cross—section outside the patient’s nostril to a substantially oval cross—section at the tip
`
`inserted into the nostril. An inflatable cuff surrounds each cannula with the interior space
`
`of the cuff communicating with the lumen of the cannula through at least one aperture in
`
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`the sidewall of the cannula. The nasal members are connected to one or more flexible
`
`hoses that, in turn, are connected to a source of positive air pressure.
`
`In use, positive air
`
`pressure is supplied to each cannula tip through the air hoses and nasal members. The
`
`positive air pressure inflates the cuffs to hold the nasal members in place and to effect
`
`treatment. The nasal device of US Patent No. 5,477,852 is attached to headgear that is
`
`located about a patient’s head; this headgear could be considered by many patients as
`
`cumbersome and uncomfortable.
`
`Conventional nasal masks used for administrating CPAP treatment are also
`
`considered uncomfortable and cumbersome, and prior art nasal masks and the like are
`
`noisy (due to air leaks). These disadvantages in many cases are a formidable obstacle to
`
`patient acceptance of such treatment. Therefore, a substantial number of patients either
`cannot tolerate treatment or choose to forego treatment.
`It is believed a substantial number
`
`of such patients could benefit from a nasal positive airway pressure apparatus that is more
`
`convenient to use and comfortable to wear,
`
`thereby resulting in increased treatment
`
`compliance.
`
`As oxygen is supplied as a dry gas it is Well known in the art to either heat and/or
`
`humidify gases before delivering them for breathing by a patient.
`
`In particular when
`
`delivering oxygen, or oxygen or air mixture, it has proven beneficial to humidify the gases
`
`first. In W001/41854 of Vapotherm, Inc. a system is disclosed that allows the delivery of
`humidified oxygen through a nasal cannula. This system uses anarrow bore conduit and
`
`nasal cannula with a high resistance to gas flows, thereby requiring the oxygen be of a high
`
`pressure. Air, as Well as oxygen can also be passed down the conduit and nasal cannula
`
`and it too must be of a high pressure. This system allows the delivery of high flows of
`
`oxygen enriched air to the patient, but is limited in the flows achievable due to the narrow
`
`bore of the cannula resulting in high resistance gas flow and excessive velocity and noise
`
`upon exiting the cannula. Furthermore, the narrowness of the nasal cannula in this system
`
`allows easy expiration of gases between the prongs and nares and therefore does not create
`
`any positive airway pressure.
`
`Innomed Technologies,
`
`Inc. manufactures a nasal cannula device called the
`
`NASALAIRETM.
`
`In this device air or oxygen travels down a wide bore conduit to nasal
`
`carmula. The NASALAIRETM creates a physical seal between the nares and itself, and
`
`relies on the absence of leaks around itself and the nares to deliver pressure supplied by a
`
`continuous positive airway pressure (CPAP) blower to the airway of the wearer.
`
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`SUMMARY OF THE INVENTION
`
`It is an object of the present invention to provide a breathing assistance apparatus
`
`which goes someway to overcoming the above mentioned disadvantages or which will at
`
`least provide the public a useful choice.
`
`Accordingly in a first aspect the present invention consists in a breathing assistance
`
`apparatus comprising:
`
`nasal cannula, shaped to fit within a user’s nares, and adapted to deliver said
`
`humidified gases to said user,
`
`a pressurised source of gases,
`
`transportation means adapted to, in use, he in fluid communication with said source
`
`of gases andpsaid nasal cannula and adapted to in use convey said gases to said user,
`
`wherein said nasal cannula including at least one prong allowing high flow delivery
`
`of said humidified gases and creating a positive airway pressure in said patient’s airway,
`
`said at least one prong having an angled end, such that in use, gases flowing through said
`
`prong are directed to said user’s nasal passages.
`
`In a second aspect the present invention consists in a breathing assistance apparatus
`
`comprising:
`
`nasal cannula, shaped to fit within a user’s nares,
`
`a pressurised source of gases,
`
`transportation means adapted to, in use, he in fluid communication with said source .
`
`of gases and said nasal cannula and adapted to in use convey said gases to said user,
`
`wherein said nasal cannula are adapted to deliver said humidified gases to said user,
`
`said nasal cannula including at
`
`least one prong allowing high flow delivery of said
`
`humidified gases and creating positive airway pressure in said patient’s airway, said at
`
`least one prong having an end that is flared outwardly.
`
`To those skilled in the art to which the invention relates, many changes in
`
`construction and widely differing embodiments and applications of the invention will
`
`suggest themselves without departing from the scope of the invention as defined in the
`
`appended claims. The disclosures and the descriptions herein are purely illustrative and
`
`are not intended to be in any sense limiting.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Preferred fomis of the present invention will now be described with reference to the
`
`accompanying drawings.
`
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`Figure 1 is a block diagram of a system providing humidified continuous positive
`
`airway pressure to a user as might be used in conjunction with a nasal cannula of the
`
`present invention.
`
`Figure 2 is a perspective view of a first embodiment of the nasal cannula of the
`
`present invention.
`
`Figure 3 is a side View of the nasal cannula of Figure 2.
`
`Figure 4 is a plan view of the nasal cannula of Figure 2.
`
`Figure 5 is a prong end View of the nasal cannula of Figure 2
`
`Figure 6 is an exploded View of the nasal cannula of Figure 2.
`
`Figure 7 is a side View of a second embodiment of a nasal cannula" of the present
`
`invention.
`
`Figure 8 is a side View of a third embodiment of a nasal carmula of the present
`
`invention.
`
`Figure 9 is a perspective view of a fourth embodiment of a nasal cannula of the
`
`present invention.
`
`Figure 10 is a side view of the nasal cannula of Figure 9.
`
`Figure 11 is an exploded perspective View of the nasal cannula of Figure 9.
`
`Figure 12 is a front View of the prongs of the nasal cannula of Figure 9.
`
`Figure 13 is an exploded side View of the nasal cannula of Figure 9.
`
`Figure 14 is a side cross-sectional View of a fifth embodiment of thenasal carmula
`
`of the present invention including a shield that protects an outlet vent from inlet gases.
`
`Figure 15 is a cross-section through AA" of the nasal cannula of Figure 14.
`
`Figure 16 is a side cross-sectional View of a sixth embodiment of the nasal cannula
`
`of the present invention where the connection between a body part and connector of the
`
`carmula includes a plurality of channels.
`
`Figure 17 is a cross-section through BB of the nasal cannula of Figure 16.
`
`DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
`
`Whether used in a hospital environment or in a home environment,
`
`the nasal
`
`cannula of the present invention will generally have associated three main pieces of
`
`apparatus. Firstly, an active humidifier, which that controls the temperature of a heater
`
`plate heating a body of water to achieve a desired temperature and humidity of the gases
`
`being humidified. Secondly, a transport conduit from the humidifier to the patient is also
`
`required, which is preferably heated to reduce condensation, or “rain out”. Thirdly, a
`
`cannula designed to fit into the nasal cavity and deliver humidified, pressurized gases.
`
`In
`
`6
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`_ 5 -
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`particular, in one embodiment the nasal cannula of the present invention has two flared end
`
`prongs that seal within a patient’s nares, although in some embodiments the cannula may
`
`have a single prong. The cannula prongs are Shaped such that a step is created between
`
`them so that the prongs abut the user’s nasal septum in use. Furthermore, the gripping
`
`action of the sides of the prongs to the user’s septum in use prevents the prongs fiom
`
`dislodging from the user’s nares.
`
`In another embodiment the prongs of the nasal cannula
`
`are angled toward one another as well as having an angled profile at the outlet of gases,
`
`such that gases flow from the prongs flows back into the nasal passage and is not forced up
`
`into the rest of the nasal cavity.
`
`With reference to Figure l a humidified Continuous Positive Airway Pressure
`
`(CPAP) system is shown in which a patient 1 is receiving humidified and pressurised gases
`
`through the nasal cannula 2 of the present invention. The cannula 2 is connected to a
`
`humidified gases transportation pathway or inspiratory conduit 3.
`
`It should be understood
`
`that delivery systems could also be VPAP (Variable Positive Airway Pressure) and BiPAP
`
`(Bi-level Positive Airway Pressure) or numerous other forms of respiratory therapy.
`
`Inspiratory conduit 3 is connected to the outlet 4 of a humidification chamber 5 that
`
`contains a volume of water 6. The inspiratory conduit 3 may contain heating means or
`
`heater wires (not shown) which heat the walls of the conduit to reduce condensation of
`
`humidified gases within the conduit. The humidification chamber 6 is preferably formed
`
`fiom a plastics material and may have a highly heat conductive base (for example an .
`
`aluminium base) which is in direct contact with a heater plate 7 of humidifier 8. The
`
`humidifier 8 is provided with control means or electronic controller 9 that may comprise a
`
`microprocessor based controller executing computer software commands stored in
`
`associated memory.
`
`The controller 9 receives input from sources such as user input means or dial 10
`
`through which a user of the device may, for example, set a predetermined required value
`
`(preset value) of humidity or temperature of the gases supplied to patient 1. The controller
`
`may also receive input from other sources; for example, temperature and/or flow velocity
`
`sensors 11 and 12 through connector 13 and heater plate temperature sensor 14.
`
`In
`
`response to the user set humidity or temperature value input via dial 10 and the other
`
`inputs, controller 9 determines when (or to what level) to energise heater plate 7 to heat the
`
`water 6 within humidification chamber 5. A flow of gases (for example air) is provided to
`
`the chamber through inlet 16 from a gases supply means or blower 15. As the volume of
`
`water 6 within humidification chamber 5 is heated, water vapour begins to fill the volume
`
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`of the chamber above the water’s surface and is passed out of the humidification chamber
`
`5 through outlet 4. Exhaled gases fi"om the patient’s mouth are passed directly to ambient
`
`surroundings in Figure 1.
`
`The blower 15 is provided with variable pressure regulating means or a variable
`
`speed fan 20 which draws air or other gases through the blower inlet 17. The speed of the
`
`variable speed fan 20 is controlled by the electronic controller 18 (or alternatively the
`
`function of the controller 18 could carried out by the controller 9) in response to inputs
`
`fiom the controller 9 and a user set predetermined required value (preset value) of pressure
`
`or fan speed via the dial 19.
`
`Flared Prong Nasal Cannula
`
`A first embodiment of a nasal cannula of the present invention is shown in detail in
`Figures 2 to 6. Referring to Figures 2 and 6, the nasal cannula 2 comprises three main
`
`components; the prong part 21, body part 22 and ball connector 23.
`
`The prong part 21 has two nasal prongs 24, 25, each of which are substantially
`
`shaped to follow the contours of the human nares and in use are placed inside a user’s
`
`nares. The prongs 24, 25 extend out from a hollow tubular body 26 that in use fits to the
`
`body part 22. Each of the prongs 24, 25 are integrally moulded with the tubular body 26 in
`
`a flexible plastics material or rubber, such as silicone, other thermoset elastomers or
`thermoplastic elastomers such as KratonTM. The prongs 24, 25 are substantially oval
`
`tubular members that allow for a passage of gases. In particu1ar,.as shown in Figure 5, the
`
`prongs are oval in shape and angled in the same manner as a human’s nares. The prongs
`
`24, 25 are angled toward one another (or toward the vertical axis Y) at the top 27, 28 of the
`
`prongs and away from one another at the bottom 29, 30 of the prongs. Furthermore, the
`
`ends 31, 32 of the prongs flare outwardly and preferably are formed such that the ends of
`
`the prongs are thinner in cross-section than the rest of the prongs. The flared thinner
`
`section ends 31, 32 of the prongs assist with the sealing of the prongs 24, 25 in use within
`
`the user’s nares. When in use and with gases flowing through the prongs the force of the
`
`gas pressure will force the prong ends 31,32 to flare outwardly and seal against the inside
`
`of the user’s nares.
`
`The prongs 24, 25 each include a step 33, 34 formed along their lengths. Each of
`
`the steps 33, 34 are formed on the prongs 24, 25 in an opposing manner such that in use,
`
`when the prongs are within a user’s nares the steps 33, 34 abut the user’s nasal septum and
`
`form a ledge that prevents dislodgement of the prongs. The prongs 24, 25 also have
`
`protrusions 35, 36 formed on their outer edges that abut the sides of the user’s nares
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`«
`
`(opposite to the nasal septum).
`
`The protrusions 35, 36 assist
`
`in preventing the
`
`dislodgement of the prongs, especially if the user moves his or her head. The protrusions
`
`35, 36 also maintain the prongs within the user’s nares in a correct orientation such that in
`
`use gases flow through the prongs and directly up the user’s nasal passages.
`
`The body part 22 is a tubular passageway in which the prong part 21 is connected at
`
`one end and a ball joint 37 at the other end. The ball joint 37 extends from the connector
`
`23 and slots into a complementary shaped (partial sphere) socket end 39. The body part 22
`
`also has a number of apertures 38 formed in it, which act as a bias flow outlet vent.
`
`Therefore, any gases exhaled by the user through their nose will exit through the apertures
`
`38.
`
`The connector 23 is preferably connected to the inspiratory conduit 3 (see Figure 1)
`
`that supplies gases flow to the carmula 2. The inspiratory conduit 3 may be moulded
`
`directly to the connector 23 or other connection mechanisms may be used, such as a
`
`friction fit formed between the connector and conduit.
`
`Although a ball and socket joint, as described above, between the body part 22 and
`
`connector 23 is preferred other connections may be utilised, such as a flexible piece of
`
`silicone, or other appropriate connection. The connection between the cannula body and
`
`connector must be able to be flexed or rotated to allow for the inspiratory conduit 3 to be
`
`moved without causing the dislodgement of the nasal cannula 2 from the user’s nares.
`
`In the preferred form of the nasal carmula 2 of the present invention the body part
`
`22 and connector 23 are preferably made fiom a hard or rigid plastics material, such as
`
`polypropylene, polycarbonate or acetyl. In other forms the body part 22 and connector 23
`
`may be of different plastics materials to allow for increased slidability between these parts.
`
`The prong part 21 may be supplied in various different sizes such that different
`
`sized user’s may remove an existing prong part and simply attach a different sized flexible
`
`plastics prong part over the body part 22.
`
`To provide additional comfort for the user or ensure the nasal cannula of the
`
`present invention do not fall from a user’s nares, the nasal cannula may be used in
`
`combination with a headgear strap. For example, Figure 1 shows a headgear strap 40
`
`extending from the nasal cannula 2. The ends of the headgear strap that attach to the
`
`cannula may attach to extensions (or loops) 40, 41 on the body part 22 of the cannula
`
`shown in Figure 2, or may attach about other appropriate areas of the cannula, for example,
`
`about the connector 23.
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`9
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`_ 3 _
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`The abovementioned embodiment of the nasal cannula 2 of the present invention is
`
`preferably a wide bore pronged cannula used for high flow conditions.
`
`A second embodiment of the present invention is shown in Figure 7.
`
`In this
`
`embodiment of the nasal cannula 42 the prongs 43, 44 are preferably small bore prongs for
`
`use with lower flow conditions. The prongs 43, 44 are similarly shaped to the prongs 24,
`
`25 detailed above, but may not seal in the same manner as the abovementioned prongs due
`
`to the smaller size of the prongs.
`
`In fact these prongs may not seal at all in use within the
`
`user’s nares.
`
`Furthermore, in this second embodiment the nasal cannula 42 is smaller and weighs
`
`less as it is only comprised of a prong body 45 and prongs 43, 44, where the body 45 is
`
`connected to a small tube that is fonned with corrugations or bellows 48 that connect to an
`
`inspiratory tube or conduit 47 (similar to the inspiratory conduit 3 described above) that
`
`receives a supply of gases.
`
`The corrugations of bellows 48 will bend or move when a weight or force is placed
`
`on the cannula, thereby preventing dislodgement of the carmula 42 from a user’s face in
`
`use. In particular, the corrugations or bellows 48 prevent transferral of the torque onto the
`
`cannula 42 when a user moves his or her head.
`
`The body 45 of the cannula 42 is provided with a number of apertures 48 that
`
`allows for gases exhaled by the users to be expelled into the ambient air.
`
`The prong body and prongs of this embodiment of the cannula of the present
`
`invention are preferably formed a flexible plastics material or rubber, such as silicone,
`
`other thermoset elastomers or thermoplastic elastomers such as Kratonm.
`
`A third embodiment of the nasal cannula of the present invention is shown in
`
`Figure 8 where the cannula may be provided with corrugated or baflled sections on the
`
`prongs. The nasal cannula 49 of this embodiment is similar to that of Figure 2 but the
`
`_ prongs 50, 51 have a series of corrugations 52, 53 formed in them. The corrugations 52,
`
`53 allow for movement of each of the prongs 50, 51 for a better user fit, and allow for
`
`movement of the cannula 49 without causing dislodgement of the prongs from the user’s
`nares.
`
`Angled Prong Nasal Cannula
`
`A fourth embodiment of the nasal cannula of the present invention is shown in
`
`Figures 9 to 13. The nasal cannula 60 has a similar construction to the nasal cannula of
`
`Figure 2 and comprises three main components; a prong part 61, body part 62 and ball
`
`jointed connector 63.
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`The prong part 61 preferably has two nasal prongs 64, 65, each of which are
`
`substantially shaped to follow the contours of the human nares and in use are placed inside
`
`a user’s nares. In some forms a cannula with only one prong may be provided. The prongs
`
`64, 65 extend out fiom a hollow tubular body 66 that in use fits to the body part 62,
`
`preferably about an extension 67 (as shown in the exploded View of the nasal cannula of
`
`Figure 11). Each of the prongs 64, 65 are integrally moulded with the tubular body 66 in a
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`flexible plastics material or rubber, such as silicone, other therrnoset elastomers or
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`thermoplastic elastomers, such as KratonTM. The prongs 64, 65 are substantially oval
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`tubular members that allow for a passage of gases.
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`In particular, as shown in Figure 12, the prongs are oval in shape (to reflect the
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`shape of human nares) and angled in the same manner as a human’s nares. The prongs 64,
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`65 are angled toward one another (or toward the horizontal axis X) such that angles on are
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`fonned between the midlines m, 11 through each respective prong 64, 65. The angled
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`profile of the prongs 64, 65 means that they are more ergonomically correct with a
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`human’s nares and may assist in directing the gases flow from the prongs to the user’s
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`nasal cavities. The prongs 64, 65 are constructed such that their cross-sectional width
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`narrows closer to the tip of each prong.
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`In the preferred form the prongs 64, 65 have an angled and profiled end 76 (see
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`Figure 10). The angled ends 76 assist in directing gases flow to the user’s nasal passages.
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`Each of the prongs 64, 65 has a flange 73, 74 disposed about its circumference.
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`The flanges 73, 74 are at a position on the prongs 64, 65 such that the each of the flanges
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`rests against the outside of each of the patient’s nares. The flanges 73, 74 do not extend
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`inside the nares, but rest at the entranceway of the user’s nares, and preferably seal the
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`nares.
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`In some users the flanges 73, 74 may extend within the user’s nares and provide
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`sealing of the nares. The flanges 73, 74 are preferably thin flexible extensions that extend
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`substantially completely around the circumference of the prongs 64, 65 . The flanges 73,
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`74 are preferably substantially elliptical in shape with one side (for example, side 89,
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`which in use will abut the nasal septum of a user) of the flange extending out from each
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`prong further than the other side of each prong. There is a recessed area 88 on each of the
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`prongs between the flange and the shaped ends of the prongs in which preferably in use the
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`ends of a user’s nares rest.
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`The body part 62 is a tubular passageway in which the prong part 61 is connected at
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`one end and a ball joint 69 at the other end. The ball joint 69 extends from the connector
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`63 and slots into a complementary shaped (partial sphere) socket end 70 on the body part
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`62. The body part 62 may also have a plurality of apertures 71 formed in it, which acts as
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`a bias flow outlet vent. Therefore, any gases exhaled by the user through their nose will
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`exit through the apertures 71.
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`A shield 75 (illustrated by the dashed line in Figure 10) may extend over the bias
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`vent 71 inside the body part 70 to prevent gases from the blower (gases supply 15) from
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`interacting with the bias vent 71 and vent holes, causing noise in use.
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`In a sixth embodiment as shown in Figures 16 and 17 a nasal cannula without a
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`prong part is shown, but that includes a shield similar to that described above.
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`In this
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`embodiment a body part 90 and a ball jointed connector 91 fit together as described above.
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`The body part 90 includes an expiratory vent shield 92 that extends down from the top wall
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`94 of the body part 90 and shields the outlet vent 93.
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`Referring back to Figures 10 to 13, preferably the ball joint connector 63 is angled
`and extends into a swivelable connector 68‘. The swivel connector 68 is capable in use of
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`being connected to the inspiratory conduit 3 (see Figure 1) that supplies gases flow to the
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`cannula 60. The inspiratory conduit 3 may be moulded directly to the connector 68 or
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`other connection mechanisms may be used, such as a friction fit formed between the
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`connector 68 and the conduit 3.
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`In other forms of the present invention the ball joint connector 63 or the ball joint
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`69 may have formed in it a plurality of channels. One example of this is the embodiment
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`of Figures 14 and 15. Such channels allow there to be a leak when gases flow through the
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`connector to the cannula and prongs. The channels are therefore capable of acting as a bias
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`flow and a separate bias flow out outlet (such as that outlet 71 described above) may not be
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`required.
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`In Figures 14 and 15 only a body part 82 and ball jointed connector 83 are shown.
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`The body part 82 and ball jointed connector 83 join in a manner as described above, where
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`the substantially half sphere shaped end 84 of the body part 82 receives the substantially
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`A, half sphere shaped end 85 of the connector 83. The ends 84, 85 enable a rotation between
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`the body part 82 and connector 83.
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`In this embodiment two channels 85, 87 are formed in
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`the connector end 85. Two channels are shown in this embodiment but there may be only
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`one or any number of channels. Similarly, channels may be formed in the body part end
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`84.
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`It is preferred that there is a ball and socket joint, as described above, between the
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`body part 62 and connector 63, although other connections may be utilised, such as a
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`flexible piece of silicone, or other appropriate connection. The connection between the
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`cannula body and connector must be able to be flexed or rotated to allow for the inspiratory
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`conduit 3 to be moved without causing the dislodgement of the nasal cannula 60 from the
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`user’s nares.
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`In the preferred form of the nasal cannula 60 of the present invention the body part
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`62, connector 63, ball joint 69 and swivel connector 68 are preferably made from a hard or
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`rigid plastics material, such as polypropylene, polycarbonate or acetyl.
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`In other forms
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`these may be of different plastics materials to allow for increased slidability between these
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`parts.
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`The prong part 61 may be supplied in various different sizes such that different
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`sized user’s may remove an existing prong part and simply attach a different sized flexible
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`plastics prong part over the body part 62.
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`To provide additional comfort for the user or ensure the nasal cannula of the
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`present invention does not fall from a user’s nares, the nasal carmula 60 is preferably used
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`in combination with a headgear strap. The strap may be similar to that shown in Figure l
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`with relation to the first form of the nasal cannula 2.
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`In this fourth form of the nasal
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`cannula 60 the body part 62 has headgear extensions 72, 73 that extend out flom the body
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`part 70. The extensions 72, 73 each have a channel 77, 78 fonned in them that is capable
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`of receiving an end 80, 81 of the headgear strap 79. The strap ends 80, 8] in use are
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`threaded through apertures (preferably two) and extend into and are held in the channels
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`77, 78.
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`In this form the headgear strap 79 is made from a small diameter silicon, rubber or
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`similar type material. Therefore, when the strap ends 80, 81 are threaded through the
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`apertures friction is created that maintains the straps within the apertures and prevents the
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`straps from slipping from the cannula.
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`In other forms the ends of the headgear strap that attach to the cannula may attach
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`to extensions (or loops) 40, 41 on the body part 22 of the carmula shown in Figure 6, or
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`may attach about otheryappropriate areas of the cannula, for example, about the connector
`23.
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`PCT/NZ2005/000023
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`WE CLAIM:
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`1.
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`A breathing assistance apparatus comprising:
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`nasal cannula, shaped to fit within a user’s nares, and adapted to deliver said
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`humidified gases to said user,
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`a pressurised source of gases,
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`transportation means adapted to, in use, be in fluid communication with said source
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`of gases and said nasal cannula and adapted to in use convey said gases to said user,
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`wherein said nasal carmula includes at least one prong that is capable of high flow
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`delivery of said humidified gases and creates a positive airway pressure in said patient’s
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`airway, said at least one prong having an angled end, such that in use, gases flowing
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`through said prong are directed to said user’s nasal passages.
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`2.
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`A breathing assistance apparatus according to claim 1 wherein said nasal cannula
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`includes