`Document made available under
`Patent Cooperation Treaty (PCT)
`Patent Cooperation Treaty (PCT)
`
`the
`the
`
`International application number: PCT/NZ05/000023
`International application number: PCT/NZ05/000023
`
`International filing date:
`International filing date:
`
`18 February 2005 (18.02.2005)
`18 February 2005 (18.02.2005)
`
`Document type:
`Document type:
`
`Certified copy of priority document
`Certified copy of priority document
`
`Document details:
`Document details:
`
`Country/Office: NZ
`Country/Office: NZ
`Number:
`534606
`534606
`Number:
`Filing date:
`06 August 2004 (06.08.2004)
`Filing date:
`06 August 2004 (06.08.2004)
`
`Date of receipt at the International Bureau:
`19 April 2005 (19.04.2005)
`Date of receipt at the International Bureau: 19 April 2005 (19.04.2005)
`
`Remark:
`Remark:
`
`Priority document submitted or transmitted to the International Bureau in
`Priority document submitted or transmitted to the International Bureau in
`compliance with Rule 1 7. 1 (a) or (b)
`compliance with Rule 17.1(a) or (b)
`
`World Intellectual Property Organization (WIPO) - Geneva, Switzerland
`World Intellectual Property Organization (WIPO) - Geneva, Switzerland
`Organisation Mondiale de la Propriete Intellectuelle (OMPI) - Geneve, Suisse
`Organisation Mondiale de la Propriete Intellectuelle (OMPI) - Geneve, Suisse
`
`1
`
`RMD
`EXHIBIT 1008 - PAGE 1
`
`
`
`of Economic
`Development
`Manati2 Ohanga
`Intellectual Property Office
`of New Zealand
`
`PCT/NZ2005/000023
`
`CERTIFICATE
`
`This certificate is issued in support of an application for Patent registration in a country
`outside New Zealand pursuant to the Patents Act 1953 and the Regulations thereunder.
`
`I hereby certify that annexed is a true copy of the Provisional Specification as filed on
`6 August 2004 with an application for Letters Patent number 534606 made by FISHER &
`PAYKEL HEALTHCARE LIMITED.
`
`Dated 24 March 2005.
`
`Neville Harris
`Commissioner of Patents, Trade Marks and Designs
`
`330 High Street, Lower Hutt
`PO Box 30687, Lower Hutt. New Zealand or DX SX 11129, Wellington
`Fi'eephonc: 0508 4 IPONZ (0508 447 669), International callers dial; +64 3 962 2607, Fax: +64 4 560 1691, www.iponz.govt.nz
`
`
`
`•
`
`53460 6
`
`Intellectual Property
`Office of N.Z.
`-. 6 AUG 2004
`ECE1VED
`PATENTS ACT, 1953
`
`NEW ZEAL
`
`PROVISIONAL SPECIFICATION
`
`"Breathing Assistance Apparatus"
`
`We, FISHER & PAYKEL HEALTHCARE LIMI I ED, a company duly incorporated
`
`under the laws of New Zealand of 15 Maurice Paykel Place, East Tamaki, Auckland, New
`
`Zealand do hereby declare this invention to be described in the following statement:
`
`
`
`• FIELD OF INVENTION
`
`FIELD OF INVENTION
`The present invention relates to apparatus for treating sleep apnoea. More specifically,
`The present invention relates to apparatus for treating sleep apnoea. More specifically,
`
`the present invention provides a nasal positive airway pressure device.
`the present invention provides a nasal positive airway pressure device.
`SUMMARY OF THE PRIOR ART
`SUMMARY OF THE PRIOR ART
`Obstructive Sleep Apnoea (OSA) is a sleep disorder that affects up to at least 5% of
`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
`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
`collapse, sealing the airway. The sleep pattern of an OSA sufferer is characterised by
`repeated sequences of snoring, breathing difficulty, lack of breathing, waking with a start and
`repeated sequences of snoring, breathing difficulty, lack of breathing, waking with a start and
`
`then returning to sleep. Often the sufferer is unaware of this pattern occurring. Sufferers of
`then returning to sleep. Often the sufferer is unaware of this pattern occurring. Sufferers of
`
`OSA usually experience daytime drowsiness and irritability due to a lack of good continuous
`OSA usually experience daytime drowsiness and irritability due to a lack of good continuous
`
`(
`
`sleep.
`sleep.
`
`In an effort to treat OSA sufferers, a technique known as Continuous Positive Airway
`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
`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
`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
`pressurised air supplied to the patient effectively assists the muscles to keep the patient's
`
`airway open, eliminating the typical OSA sleep pattern ..
`airway open, eliminating the typical OSA sleep pattern.
`
`The procedure for administering CP AP treahnent has been well documented in both
`The procedure for administering CPAP treatment has been well documented in both
`
`the technical and patent literature. Briefly stated, CP AP treatment acts as a pneumatic splint
`the technical and patent literature. Briefly stated, CPAP treatment acts as a pneumatic splint
`
`of the airway by the provision of a positive pressure, usually in the range 4 to 20 cm H 20.
`of the airway by the provision of a positive pressure, usually in the range 4 to 20 cm H2O.
`The air is supplied to the airway by a motor driven blower whose outlet pass'es via an air
`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
`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 is provided in the delivery tube
`means of a harness or other headgear. An exhaust port is provided in the delivery tube
`
`proximate to the mask. More sophisticated forms of positive airway pressure devices, such as
`proximate to the mask. More sophisticated forms of positive airway pressure devices, such as
`
`bi-level devices and auto-titrating devices, are described in US Patent No. 5,148,802 of
`bi-level 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.
`Respironics, Inc. and US Patent No. 5,245,995 ofRescare Limited, respectively.
`US Patent No. 5,477,852 of Airways Ltd, Inc. discloses a nasal positive airway
`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
`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
`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
`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
`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 the sidewall of
`communicating with the lumen of the cannula through at least one aperture in the sidewall of
`the cannula. The nasal members are connected to one or more flexible hoses that, in turn, are
`the cannula. The nasal members are connected to one or more flexible hoses that, in tum, are
`connected to a source of positive air pressure. In use, positive air pressure is supplied to each
`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
`cannula tip through the air hoses and nasal members. The positive air pressure inflates the
`
`-2-
`—2—
`
`4
`
`RMD
`EXHIBIT 1008 - PAGE 4
`
`
`
`• 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, also 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 a narrow 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
`
`cannula. The NASALAIRETM creates a physical seal between the flares 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.
`
`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:
`
`—3—
`
`
`
`• nasal cannula, shaped to fit within a user's nares,
`
`a pressurised source of gases,
`transportation means adapted to, in use, be 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 creates positive airway pressure in said patient's airway, the at least one prong
`
`having an end that is flared outwardly, such that in use, said flared end seals within said user's
`
`nares.
`
`Preferably said nasal cannula has two nasal prongs.
`
`Preferably said prongs are oval and shaped to follow the contours of human nares.
`
`Preferably said prongs are angled toward one another to prevent dislodgement from
`
`said user's nares and assist in flow of gases into the user's nasal passages.
`
`Preferably said prongs each have a step formed in them such that in use the sides of
`
`said prong abut the user's nasal septum so as to prevent said prongs from dislodging from said
`
`user's nares.
`
`Preferably each of said prongs include a protrusion foiiiied opposite said step that
`
`assists in correct orientation of said prongs within said user's nares
`
`Preferably said nasal cannula includes a body that has a plurality of apertures that act
`
`as a bias flow outlet vent for gases exhaled by said user.
`
`Preferably said nasal cannula is connected to said transportation means by way of a
`
`ball and socket joint.
`
`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,
`
`humidification means adapted to, in use, be in fluid communication with said source
`
`of gases and adapted to in use humidify said gases,
`humidified gases transport means adapted to, in use, he in fluid communication with
`said humidification means and adapted to in use convey said humidified gases to said cannula,
`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 creates positive airway pressure in said patient's airway, the at least one prong
`
`—4—
`
`
`
`• having an end that is flared outwardly, such that in use, said flared end seals within said user's
`
`nares.
`
`Preferably said nasal cannula has two nasal prongs.
`
`Preferably said prongs are oval and shaped to follow the contours of human nares.
`
`Preferably said prongs each have a step faulted in them such that in use the sides of
`
`said prong abut the user's nasal septum so as to prevent said prongs from dislodging from said
`
`user's nares.
`
`Preferably each of said prongs include a protrusion formed opposite said step that
`
`assists in correct orientation of said prongs within said user's nares
`
`Preferably said nasal cannula includes a body that has a plurality of apertures that act
`
`as a bias flow outlet vent for gases exhaled by said user.
`
`Preferably said nasal cannula is connected to said transportation means by way of a
`
`ball and socket joint.
`
`In a third 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, be 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 creates 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.
`
`Preferably said nasal cannula includes arms or loop to attach a head strap to said
`
`cannula.
`Preferably said head strap is a small flexible tube.
`
`Preferably said at least one prong includes a flange near or about it's end.
`
`Preferably said at least one prong is two prongs that are angled toward one another and
`are oval in shape such that they substantially follow the shape and contour of human nares.
`
`Preferably said flange causes the sealing of said at least one prong in the nares of said
`
`user in use.
`
`Preferably said flange is a thin flexible extension that extends substantially completely
`
`around the circumference of said at least one prong.
`
`—5—
`
`
`
`• Preferably said flange is elliptical in shape with one side of said flange extending out
`
`from said at least one prong further than the other side.
`
`Preferably said at least one prong includes a flange, recessed area and shaped end.
`
`The recessed area is disposed between the flange and shaped end and in use the flange
`
`extends into and seals within a user's nares.
`
`Preferably said shaped end is progressively thinner in cross-section towards it's tip.
`
`This invention may also be said broadly to consist in the parts, elements and features
`
`referred to or indicated in the specification of the application, individually or collectively, and
`any or all combinations of any two or more of said parts, elements or features, and where
`
`specific integers are mentioned herein which have known equivalents in the art to which this
`
`invention relates, such known equivalents are deemed to be incorporated herein as if
`
`individually set forth.
`
`The invention consists in the forgoing and also envisages constructions of which the
`
`following gives examples.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`One preferred form of the present invention will now be described with reference to
`
`the accompanying drawings.
`
`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 cannula 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.
`
`—6—
`
`
`
`• 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 the nasal cannula 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 cannula
`
`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 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 particular, in one embodiment the nasal
`
`cannula of the present invention has two flared end prongs that seal within a patient's flares.
`
`The cannula prongs are shaped such that a step is created between them such 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 from 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 1 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, that are 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.
`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.
`Humidification chamber 6 is preferably formed from a plastics material and may have a
`
`—7—
`
`
`
`• highly heat conductive base (for example an aluminium base) which is in direct contact with a
`
`heater plate 7 of humidifier 8. 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.
`
`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 of the chamber above the water's
`
`surface and is passed out of the humidification chamber 5 through outlet 4. Exhaled gases
`
`from the patient's mouth are passed directly to ambient surroundings in Figure 1.
`
`Blower 15 is provided with variable pressure regulating means or variable speed fan
`
`20 which draws air or other gases through blower inlet 17. The speed of variable speed fan 20
`
`is controlled by electronic controller 18 (or alternatively the function of controller 18 could
`
`carried out by controller 9) in response to inputs from controller 9 and a user set
`
`predetermined required value (preset value) of pressure or fan speed via dial 19.
`
`Flared Prong Nasal Can_nula
`
`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 thetmoplastic
`elastomers such as KratonTM. The prongs 24, 25 are substantially oval tubular members that
`allow for a passage of gases. In particular, 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
`
`—8—
`
`
`
`• 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 to
`
`flare outwardly more and seal against the inside of the user's nares.
`The prongs 24, 25 each include a step 33, 34 foinied 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 (opposite to the nasal
`
`septum). The protrusions 35, 36 assist 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 (half sphere) socket end 39. The body part 22 also has
`
`a number of apertures 38 formed in it, which acts as a bias flow outlet vent. Therefore, any
`
`gases exhaled by the user through their nose will exit through the apertures.
`
`The connector 23 is preferably connected to the inspiratory conduit 3 (see Figure 1)
`
`that supplies gases flow to the cannula 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 foinied
`
`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 cannula 2 of the present invention the body part 22
`
`and connector 23 are preferably made from a hard or rigid plastics material, such as
`polypropylene, polycarbonate or acetyl. Tn other fauns the body part 22 and connector 23
`may be of different plastics materials to allow for increased slidability between these parts.
`
`—9—
`
`
`
`• 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.
`
`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
`
`alternative 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 weights
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`less as it is only comprised of a prong body 45 and prongs 43, 44, where the body 45 is
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`connected to a small tube that is folined with corrugations or bellows 48 that connect to an
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`inspiratory tube or conduit 47 (similar to the inspiratory conduit 3 described above) that
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`receives a supply of gases.
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`The corrugations of bellows 48 will bend or move when a weight or force is placed on
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`the cannula, thereby preventing dislodgement of the cannula 42 foiui a user's face in use. In
`particular, the corrugations or bellows 48 prevent in use transferral of the torque onto the
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`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
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`for gases exhaled by the users to be expelled into the ambient air.
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`The prong body and prongs of this embodiment of the cannula of the present invention
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`are preferably formed a flexible plastics material or rubber, such as silicone, other theinioset
`elastomers or thermoplastic elastomers such as KratonTM
`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 baffled sections on the prongs. The
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`nasal cannula 49 of this embodiment is similar to that of Figure 2 but the prongs 50, 51 have a
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`— 10 —
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`• series of corrugations 52, 53 formed in them. The corrugations 52, 53 allow for movement of
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`each of the prongs 50, 51 for a better user fit, and allow for movement of the cannula 49
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`without causing dislodgement of the prongs from the user's nares.
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`Angled Prong Nasal Cannula
`A fourth embodiment of the nasal cannula of the present invention is shown in Figures
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`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
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`63.
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`The prong part 61 has two nasal prongs 64, 65, each of which are substantially shaped
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`to follow the contours of the human nares and in use are placed inside a user's nares. The
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`prongs 64, 65 extend out from a hollow tubular body 66 that in use fits to the body part 62,
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`preferably about an extension 67 (as shown in the exploded view of the nasal cannula of
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`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 thermoset elastomers or
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`theiinoplastic elastomers, such as KratonTM. The prongs 64, 65 are substantially oval tubular
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`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 shaped
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`of human nares) and angled in the same manner as a human's nares. The prongs 64, 65 are
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`angled toward one another (or toward the horizontal axis X) such that angles a are foinied
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`between the midlines m, n through each respective prong 64, 65. The angled profile of the
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`prongs 64, 65 means that they are more ergonomically correct with a human's nares and may
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`assist in directing the gases flow from the prongs to the user's nasal cavities. The prongs 64,
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`65 are constructed such that their cross-sectional width narrows closer to the tip of each
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`prong.
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`In the preferred form the prongs 64, 65 have an angled profiled end 76 (see Figure 10).
`The angled ends 76 assist in directing gases flow to the user's nasal passages.
`Each of the prongs 64, 65 has a flange 73, 74 disposed about its circumference. The
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`flanges 73, 74 are at a position on the prongs 64, 65 such that the each of the flanges rests
`against the outside of each of the patient's nares. The flanges 73, 74 do not extend inside the
`flares, but rest at the entranceway of the user's nares, and preferably seal the nares. In other
`users the flanges 73, 74 may extend within the user's flares and provide sealing of the nares.
`The flanges 73, 74 are thin flexible extensions that extend substantially completely around the
`circumference of the prongs 64, 65. The flanges 73, 74 are substantially elliptical in shape
`with one side (for example side 89, which in use will abut the nasal septum of a user) of said
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`— 11 —
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`• flange extending out from said at least one prong further than the other side. There is a
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`recessed area 88 on each of the prongs between the flange and