Patent ID: 12214135

DETAILED DESCRIPTION

In some instances it may be desirable to deliver a flow of respiratory gases to a patient via one or both nares and allow for the insertion of airway instruments or devices, for example a tube, via one of the nares. In some instances it may be desirable to allow an instrument to be inserted via a nare of a user and optionally, to block flow to that nare of the user, or to block flow to both nares or stop flow completely.

In some embodiments, a nasal cannula may comprise an asymmetric profile to reduce the size of the cannula under or near one nare of a user. For example, with reference toFIG.1A, in some configurations, a nasal cannula10comprises two nasal prongs11,12, wherein one of the nasal prongs11is shorter than the other nasal prong12. The shorter nasal prong may have a relatively minimal or substantially no extension into the nare of the patient. This arrangement provides room or space around the shorter prong for a nasal instrument to be inserted into the patient's nare. In some configurations, the cannula may comprise two prongs, wherein each prong is of a length to have relatively minimal or substantially no extension into the nares of the patient, so that an instrument may be inserted into either nare.

A cannula typically comprises a frame or manifold part. A conduit or interface tube may be attached to the frame or manifold part. The frame or manifold part supports the nasal prongs in a spaced apart relation for fitment into the patient's nares. The frame may optionally include a pair of rigid or semi rigid arms that extend across the cheeks to locate the cannula on the face. The arms may comprise an overmolded thermoplastic or other suitable material. The cannula may comprise a headgear to secure the cannula in an operational position on the user's head. In some configurations the nasal cannula may comprise a securement structure. A system for the securement of such a patient interface (e.g. nasal cannula) to the face can allow for a removable or connectable arrangement. For example, a securement structure or system may comprise a series of patches or pads, for connection to a user's face, and then one or more additional pads or patches for connection to the interface, the exposed surfaces of these pads or patches being provided with capability to connect or attach, preferably in a removable manner, to the other patches or pads. With reference toFIGS.1B to1E, in some embodiments the frame21or manifold part21of the cannula20is asymmetrical so that the frame or manifold is reduced in size on one side21acompared to the other side21b. The asymmetrical frame or manifold provides a cannula with an asymmetric profile to provide space at one nare for an instrument to enter that nare. For example, with reference toFIG.1B, in some configurations the frame or manifold21tapers in size from one side or from one nasal prong11, to the other side or other nasal prong12. In some embodiments, the frame or manifold part may be asymmetric when viewed from the front. In some embodiments, the frame or manifold part may be asymmetric when viewed in plan view. Plan view and front view are used with reference to the cannula in place on a user and with the user in a standing or upright position. As shown inFIGS.1B to1E, in some embodiments, the frame or manifold part may be asymmetric when viewed from the front of the cannula and also when viewed in plan view. The side of the cannula that is reduced in size allows for an instrument to be inserted alongside the cannula and into the nare of a user that is adjacent the reduced side of the cannula. The frame or manifold part has a thickness extending between a backside of the cannula that locates against or adjacent the user's face below the user's nose and an opposite outwards front side of the cannula, and a height extending between a top of the frame or manifold part and a bottom of the frame or manifold part. Preferably the prongs extend from the top of the frame. As shown inFIG.1D, the height of the frame or manifold part adjacent one nare of the user may be less than the height adjacent the other nare of the user. Additionally or alternatively the thickness of the frame or manifold part adjacent one nare of the user may be less than the thickness adjacent the other nare of the user.

In some embodiments the prong on the reduced in size side of the cannula may be shorter in length than the other nasal prong (for example as shown inFIG.1B), or cannula may comprise a prong-less nasal outlet on the ‘reduced in size’ side of the cannula. Alternatively, in some embodiments the prongs are of equal or similar length (FIG.1C), or the prong on the ‘reduced in size’ side of the cannula may be longer than the other prong.

In some configurations the nasal prong11at the ‘reduced in size’ side of the cannula may have an oval cross section or a shape that is flatter than a circle (for example as shown inFIG.1E) to provide a space between the prong and the user's nare for an instrument to be inserted.FIG.1Dillustrates an instrument inserted into the nare on the side of the cannula that is reduced in size. In some configurations the nasal prong11at the ‘reduced in size’ side of the cannula may be shorter than the other prong12, or the prongs may be of equal length.

An example of where a cannula comprising an asymmetric profile may be particularly useful is in suspended laryngoscopy. Equipment associated with the suspended laryngoscope is placed very close under the patient's nares and in some cases a prior art high flow cannula cannot be used as the cannula is too large to fit in place under the laryngoscope.

A gases supply tube or conduit may be connected to the cannula, or the cannula may comprise a conduit connection for connecting a supply tube or conduit. In some embodiments, the supply conduit or conduit connection may be provided to a side of the cannula opposite to the reduced side of the cannula, as shown inFIGS.1B to1E. This arrangement of the conduit away from the reduced side of the cannula further assists in maximizing space for an airway instrument or other device to be provided to the user's nare.

Unless otherwise indicated, one side of the cannula is intended to mean the portion of a cannula that is located on one side of a user's face in use (e.g. a left hand side of a user's face). An opposite side of the cannula is the portion of the cannula that is located on the other side of a user's face in use (e.g. a right hand side of a user's face). The terms “left” and “right” are intended to relate to the left hand side and right hand side of the user or patient.

In some embodiments, as illustrated inFIG.2, a cannula30does not have a nasal prong. Such a cannula comprises a manifold part or frame31that receives a flow of gases and redistributes that flow to each nare of a user via two outlets or apertures32, each outlet corresponding with (or configured to communicate with) a nare of the user.

The embodiments described above may be useful as they may not require any adjustment of the cannula on the user's face in order to insert an instrument into a nare of the user, yet a flow of gases is still delivered to both nares.

In some configurations a ‘frame’ of a cannula may comprise a strap or may be a strap for securing the cannula in place on a patient's face in use.

In some configurations a nasal cannula comprises a removable or extendable prong. For example, with reference toFIGS.3A and3B, at least one prong41is retractable into or extendable from a manifold43of the cannula40. InFIG.3Aan extendable prong41is in an extended position, and inFIG.3Bthe prong is retracted into the manifold43. For example, the prong slides into and out of the manifold of the cannula. One or both prongs41,42may be configured to be extendable, for example both prongs may slide into and out of the manifold of the cannula.

As illustrated inFIGS.4A and4B, in some configurations one or both prongs51,52of the cannula50comprises corrugations or concertina type sections53which can be extended by a user to lengthen to extend the length of the prong, as shown inFIG.4A. The corrugations may be formed at a base of the prong, or partway or fully along the length of the prong. To avoid clashing with an airway instrument the prong may be configured to a retracted position, as shown inFIG.4B.

As illustrated inFIG.5, in some configurations one or both prongs61,62may be configured to be torn from a manifold part63of the cannula60. To create space for an instrument to be inserted into a nare of the user, one prong may be torn from the cannula, to leave an opening or outlet for gases to flow to the corresponding nare of the user. Alternatively, in some configurations, for example as shown inFIG.13, one or both nasal prongs141,142may be removably attached to a manifold part143of the cannula140. To create space for an instrument to be inserted into a nare of the user, one prong141may be releasably detached from the cannula140. The prong may be releasably reattached for future use. The releasable prong may be permanently attached to the cannula assembly, for example by a lanyard or leash144.

As illustrated inFIG.6, in some configurations one or both prongs71,72may be slidable or rotatable relative to the other prong or to a manifold part73of the cannula, to displace the prong from a user's nare in use to provide access for an instrument to be inserted into the nare left vacant by sliding the prong. For example, as illustrated inFIG.6, in some configurations a nasal cannula may comprise a gas supply rail or conduit (manifold part)73, and one prong71may be slidable on the rail or supply conduit73. The slidable prong may comprise a prong portion71ato be inserted into a nare of the user, and a base portion71badapted to receive the manifold part to slide thereon. Where the prong is slid out of alignment with a user's nare, an orifice or aperture74in a wall of the rail or conduit is exposed and may provide some gas flow from the rail or conduit to the exposed nare of the user. With the prong slid out of alignment with the user's nare, space is created to allow an instrument to be inserted into the exposed nare. In some embodiments both prongs71,72may be slidable on a rail or supply conduit or manifold of the cannula.

The embodiments described with reference toFIGS.3A to6andFIG.13maintain delivery of respiratory gas flow to both nares, while providing a cannula that is flexible in terms of treatment options, for example:

Change may be temporary and respiratory support can be restored when instrument/device is not in use.

Change can be achieved easily and without removing interface.

As flow through both nares is maintained some flow may be able to enter the nare around instrument/device. This may help to keep the nare/airway patent and also allow minimal change in respiratory support.

Flow through one nare may be maintained by one prong as flow and delivered pressure to that nare does not change. This may avoid higher velocity jets that may damage nasal tissue, as is the case where all flow is redirected to one nare.

Allowing the flow to continue to flow through both orifices may prevent large pressure changes in the system. If the gas supply is sensitive to pressure changes (e.g. a blower) this may also help to reduce potential fluctuations in flow and/or humidity, or a reduction in flow if the supply is not able to overcome the increase in pressure.

As illustrated inFIG.7, in some configurations flow to one nare may be optional, while flow to the other nare may be permanently provided. In the embodiment ofFIG.7, the cannula80comprises one nasal prong81to provide a flow of gas to a nare of a user, and an opening or aperture82in a manifold83of the nasal cannula that may be capped or plugged by a cap84. Flow to one nare is provided optionally by capping or uncapping the opening. In an alternative embodiment the nasal cannula may comprise a pair of outlets, wherein the outlets are prong-less.

As shown inFIGS.8A and8B, in some embodiments a cannula90may comprise a rotatable cuff91to block or unblock an opening or aperture92on a manifold94of the cannula to optionally provide a flow of gas to one nare of the user. The rotatable cuff has an aperture93to align with the manifold aperture92to allow flow from the manifold aperture92to the user's nare. The nasal prong95maintains flow permanently to the other nare.FIG.8Ashows the cuff91rotated to block the opening92and prevent flow to one nare, andFIG.8Bshows the cuff91rotated to unblock the opening92by aligning the cuff aperture93with the manifold aperture92and allow flow to the nare. The blocking of one outlet may assist a clinician to insert a nasal instrument into the nare that corresponds with the occluded outlet.

The embodiments described with reference toFIGS.7and8A/8B maintain delivery of respiratory gas flow to at least one nare, while providing a cannula that is flexible in terms of treatment options, for example:The user can optionally block the flow to one of the nares.The change may be temporary.The change can be achieved easily and without removing the interface.A prong is absent from one nare allowing instruments to be inserted at all times without having to alter the interface.The choice of providing flow to the nare causes minimal interference with the nare; even if flow is provided through the opening, there is reduced or no physical obstruction to an instrument inserted into the nare.Where flow is permitted through the opening (i.e. flow is delivered to both nares), some flow may be able to enter the nare around the instrument/device. This may help to keep the nare/airway patent and also allow minimal change in respiratory support.If the opening is blocked, flow may be redirected to the main prong, maintaining total flow delivered to the patient and pressure delivered to the lower airway.The ability to block the opening/gas flow means lightweight or sensitive instruments can be used without gas flow interfering with alignment.

With reference toFIGS.9to16B, in some configurations flow to one nare may be optionally provided via a nasal prong. Flow to the other nare may be permanently provided via a nasal prong. As shown inFIG.9, in some configurations a nasal cannula100comprises a rotatable prong101. One or both prongs may be rotatable. The prong may be rotatable on a gas supply rail or conduit or manifold104part of the cannula (herein called a manifold part). In an open configuration the prong103is rotated to be aligned with a user's nare in use, and be in fluid communication with the manifold part of the cannula via an aperture102in the manifold part. In a closed configuration the prong103is rotated, for example rotated forward from the user's face, so that the prong is not in fluid communication with the manifold part as the prong is rotated out of alignment from the aperture of the manifold. In the closed position the prong is moved out of alignment with the user's nare to provide access into the nare for an instrument to be inserted. In the closed configuration, 100% of the flow is directed via the single prong into one nare of the user. In some embodiments both prongs103,105may be rotatable on a rail or supply conduit or manifold of the cannula, so that a user may choose which prong to rotate and which nare to insert an instrument.

As shown inFIG.10, in some configurations a nasal cannula110comprises a slidable prong111. The prong111is slidable on a gas supply rail or conduit or manifold part113of the cannula (herein called a manifold part). In an open configuration the prong is moved along the manifold part to be aligned with a user's nare in use, and be in fluid communication with the manifold part of the cannula via an aperture114in the manifold part. In a closed configuration the prong is moved along the manifold so that the prong is not in fluid communication with the manifold part as the prong is moved out of alignment from the aperture of the manifold, as shown inFIG.10. In the closed position the prong is moved out of alignment with the user's nare to provide access into the nare for an instrument to be inserted. In the closed configuration, 100% of the flow is directed via the single prong into one nare of the user. Movement of the prong in one direction along the manifold part may be limited by a stop115, to prevent the aperture114in the manifold becoming uncovered. Movement of the prong in an opposite direction along the manifold part may be limited by a stop or by the other prong112, to set the alignment of the sliding prong with the aperture. The slidable prong111may comprise a prong portion111a, to be inserted into a nare of the user, and a base portion111badapted to receive the manifold part to slide thereon. The embodiment ofFIG.10is similar to the embodiment ofFIG.6, however inFIG.10the base portion111bof the sliding prong111extends laterally from the prong portion111ato cover the aperture114so that the aperture is blocked by the base portion when the prong portion is not aligned with the aperture. In some embodiments both prongs are slidable prongs, each slidable on a manifold part of the cannula.

In some configurations, a cannula has a first prong attached to and in fluid communication with a first conduit part, and a second prong attached to and in fluid communication with a second conduit part, wherein the second conduit part is slidable relative to and in fluid communication with the first conduit part to displace the second prong from the first prong. In some embodiments, as illustrated, the second conduit part comprises an aperture in a side wall to align with the first prong when the second prong is positioned for alignment with a nare of the user, so that the first prong is in fluid communication with a flow of gases provided via an inlet of the cannula.

As shown inFIGS.11A and11B, in some configurations a cannula120may comprise a collapsible or crushable or squashable prong or portion including a prong. The collapsible or crushable or squashable prong121is squashed, collapsed or crushed to block flow from that prong. When the prong is squashed, collapsed or crushed it is clear of the user's nare to allow access for an instrument to be inserted. In some configurations both prongs may be collapsible or crushable or squashable.

As shown inFIGS.12A and12B, in some configurations a cannula130comprises a foldable prong131and a retaining member133such as a clip to retain the foldable prong in a folded position. In the folded position the prong is blocked or pinched off to prevent flow through the folded prong, and is clear of the user's nare to allow access for an instrument to be inserted. In some configurations both prongs may be foldable. The cannula130may comprise two retaining members, each member corresponding with one folding prong.

As shown inFIGS.14A and14B, in some configurations, a cannula150comprises a tearable manifold part153. The manifold part is tearable at a section154located in between the left and right nasal prongs. The torn section may be self-sealing so that 100% of the flow is directed via the single prong into one nare of the user when one half is torn from the cannula.

As shown inFIG.15, in some configurations, a cannula160may comprise a first side161comprising a first prong162and an inlet163for receiving a flow of gas, and a second side164comprising a second prong165, wherein the first and second sides are separable. The first prong is in fluid communication with the inlet. When the first and second sides are connected together, the second prong is in fluid communication with the inlet. The first side also may comprise a valve166or aperture166that seals on itself, so that when the second side is separated from the first side the flow from the inlet passes through the first prong, without flow through the aperture or valve. Attachment of the second side to the first side forces or holds the valve166open so that the inlet communicates with the second prong.

As shown inFIGS.16A and16B, in some configurations, a cannula170comprises a sealable aperture173(for example an aperture and a valve) for inserting an instrument through the cannula. The aperture173seals around an instrument when inserted into the aperture, and closes in a sealed configuration when the instrument is removed from the aperture. Such an aperture173may be provided to any one of the nasal cannulas described herein. The aperture may be provided in a manifold part of the cannula in alignment with a nasal prong so that an instrument may be inserted through the aperture and along the prong into a user's nasal passage. The aperture may also be provided in the manifold without being in alignment with a prong, such that the instrument may be inserted into the manifold without extending into or along the prong.

In some embodiments, the cannula comprises a valve174. The valve may be actuated from open to closed by inserting an instrument through the cannula. The valve may be located within the manifold part of the cannula and between the prongs or outlets of the cannula. The valve is closed by the instrument extending through a second prong of the cannula so that gas flow from an inlet of the cannula is directed to a first prong of the cannula. When the instrument is inserted through the aperture the instrument actuates a valve element (e.g. a flap) against a valve seat to fluidly isolate one nasal prong or outlet from the other nasal prong or outlet and stop or reduce flow to the prong that receives the instrument. In some configurations, the cannula may comprise two sealable apertures, each aperture aligned with a corresponding prong. The cannula may comprise two valves, each valve corresponding with a prong. In such an embodiment, an instrument may be inserted simultaneously via both nares of the user. In some embodiments, the cannula may comprise a pressure relieve valve in the event that flow from both nasal prongs or nasal outlets is blocked.

In some configurations, one or both prongs may be configured to be torn from a manifold part of the cannula. However, unlike the configuration described with reference toFIG.5, in some embodiments the action of tearing a prong from the cannula could act to seal or close off the flow conduit provided by the cannula so that there is no opening or outlet from where the prong is torn.

The nasal cannula configurations described with reference toFIGS.9to16Ballow for easier interfacing with a nasal instrument. Specifically the nasal instrument can be interfaced with the nasal cannula at the region of the prong that is modified or manipulated, for example by moving a prong out of the way of the user's nare as described. The cannulae therefore may be manipulated or modified so they interface with nasal instruments inserted into at least one nare while still being able to maintain high flow therapy delivery via the other nare. The embodiments described with reference toFIGS.9to16Bmaintain delivery of respiratory gas flow to at least one nare, for example high flow delivery of respiratory gas, while providing a cannula that is flexible in terms of treatment options, for example:the user can optionally block the flow to one of the nares,change may be temporary,change can be achieved easily and without removing interface,can be configured so that flow or prong does not interfere with an instrument,when prong is oriented to be clear of the nare, flow is directed to the other prong, maintaining total flow and pressure delivered to the user.

Furthermore, in all embodiments, the arrangement described for modifying or manipulating one nasal prong may be applied for modifying or manipulating both nasal prongs, for example if access to both nares is desired. Where both nasal prongs or outlets can be blocked, a pressure relief valve may be provided to limit a maximum pressure that the system may be exposed to.

With reference toFIGS.17A and17B, in some configurations flow to the cannula180may be provided by two respiratory gas conduits183,184, one conduit per side of the cannula, or in other words each nasal prong181,182has a dedicated gas supply. The left and right sides of the cannula may not be in fluid communication when coupled together as shown inFIG.17A. In such embodiments, a left side and a right side of the cannula may be releasably connectable. Where insertion of an instrument is not required, the left and right sides of the cannula may be clipped or connected together and respiratory gas provided from the left and right nasal prongs to both nares of the user. Where an instrument is to be inserted, the left and right sides may be disconnected, and one of the sides used to provide the flow of gas via a nare of the user.

In some embodiments, the left and right sides of the cannula may be in fluid communication when coupled together as shown inFIG.17A. Where an instrument is to be inserted, the left and right sides may be disconnected. The side of the cannula not in use may be placed away from the user's face, and may be folded to pinch the flow of gas to close off the flow of gas to the side of the cannula not being used. The side of the cannula not in use may be held in a folded position by a retaining member185or clip. Or the removed side may remain open and flow still allowed to flow, for example where a reduced flow to the patient is acceptable or if the instrument is to be inserted into the patient's nare for a short time period. Alternatively, the cannula may comprise a valve in each side of the cannula that is configured between an open state and a closed state by connecting and disconnecting the sides of the cannula. The valve may close when the sides of the cannula are disconnected. When an instrument is removed from the user's nare the two sides may be reconnected and gas supply via both nares may resume.

With reference toFIGS.18A and18B, in some configurations a cannula190comprises an extendable region or expandable region193positioned between a left prong192and a right prong191of the cannula. The expandable region may comprise corrugations or concertina type sections which can be extended by a user to lengthen or to extend the length of the prong, as shown inFIG.18B. In use, where an instrument is to be inserted in a nare of the user, the expandable region may be expanded to an expanded or extended position as shown inFIG.18Bto vacate the user's nare. Where no instrument is required, the expandable region may be in the retracted or non-extended position as shown inFIG.18Ato provide a flow of gases to both nares of the user.

A cannula may be secured in place on a user's face by a dermal patch. A dermal patch may be adhered to a user's face, for example by a dermatologically sensitive adhesive. A second patch (interface patch) may be attached to a face side of a cannula. The dermal patch and the interface patch each have one half of a two-part releasable connection, for example one patch may have the hooks of a hook and loop connection and the other patch may have the loops of a hook and loop connection (for example the connection may be Velcro®). Thus the patches retain the cannula in position on the user's face. In some configurations, where a dermal patch is used to secure the cannula in place on the users face, the cannula190may be held in the extended position (FIG.18B) or in the retracted position (FIG.18A) by the dermal patch. Alternatively, the expandable region may be rigid enough to allow the extended side of the cannula to be disconnected from its dermal patch and be self-supported in the expanded position, or folded away from the patient's face.

In some configurations, the expandable region193of the cannula may be formed from an elastic material to stretch between an extended position and a non-extended position. In use, where no instrument is required, the expandable region may be in a non-stretched state so that both prongs interface with the nares of the user. Where an instrument is to be inserted, the expandable region formed from elastic material may be stretched to an extended position and held in the extended or stretched position by a dermal patch that is attached to the user's face. The cannula may be held in the stretched state by a dermal patch as described above. Alternatively, the cannula may comprise a frame that defines an extended position and a retracted position. For example, in the expanded condition (FIG.18B) the cannula may be clipped to a frame to retain it in the expanded position.

The embodiments described with reference toFIGS.17A to18Bmaintain flow to one nare of the user, and is configurable to displace a prong away from the other nare of the user. Where a prong is displaced from the user's nare, gas flow to the cannula may not be directed to the other single prong, which may be advantageous in some circumstances as this arrangement may avoid a higher velocity jet of gas into the user's nare due to directing all flow to a single prong, like in embodiments ofFIGS.9to16B. The various embodiments allow for easier interfacing with a nasal instrument via the nare corresponding to the prong that is manipulated (e.g., moved or removed from the user's nare).

In some embodiments, a patient interface such as a cannula or face mask may be adapted to interface with an airway instrument, for example a scope or diagnostics instrument, or an airway tube or conduit. To interface with an airway instrument a cannula may comprise a guiding channel to receive and guide the instrument. For example, as illustrated inFIG.19A, in some configurations, a cannula200may comprise a guiding channel203along the length of one or both nasal prongs201,202, and/or on a manifold of the cannula. As illustrated inFIG.19B, in some embodiments a prong202may have a guiding channel203extending laterally across the prong. As shown inFIGS.19A and19B, in some embodiments the guiding channel is formed in an outer surface of the nasal prong. In some configurations, the guiding channel may be formed in an inner surface of a nasal prong. For example, a nasal prong may be a multi-lumen nasal prong, wherein a lumen provides for a gas flow and another lumen provides a port or conduit for insertion of an instrument. With multiple lumens the insertion of a device or instrument may not cause a large increase in back pressure as one lumen is dedicated to the passage of the device or instrument while another lumen provides a flowpath to the user's airway.

FIG.20illustrates a face mask210which includes guiding channels211,212for guiding instruments into the airway of a patient provided at an inside of the mask. The guiding channels may be open channels (like212), or fully closed channels (like211). That is, in some configurations the guiding channel may be a tubing conduit along which the instrument may be threaded. In the embodiment ofFIG.20, the guiding channels are curved to guide flexible instruments into the patient's airway. A channel may be provided to guide an instrument into the user's mouth, and another channel to guide an instrument into the user's nose. An inside of the mask may be coated with material designed to allow condensate to drain down the surface. This would help a user see inside the mask to guide instruments. Alternatively the mask may have micro-channels in an internal surface of the mask to help condensate drain down.

A face mask (e.g. nasal mask or full face mask) includes a seal to seal against the face of a user. In some configurations, a face mask may have thinned portions in the seal on one side or on all sides. The thinned portions in the seal allow for a tube or other airway instrument to be inserted, and may allow for a seal to be created over the tube or instrument. The thinned portion of the seal may be more malleable and pliable and hence may conform to the shape of the tube while still maintaining a seal. The tube may be a nasogastric tube (NG or NT tube, e.g., a tube inserted through the nostrils).

Patient interfaces may have entry ports for instruments to be inserted through the interface and into a patient's airway. For example, as shown inFIG.21, a nasal prong or other respiratory gas conduit220may comprise instrument ports or conduits221formed in a wall222of the prong or gas conduit, the instrument conduits extending longitudinally along the prong or gas conduit. The conduits221provide a lumen along which an instrument may be threaded to be guided into the patient's airway. A face mask may comprise two instrument ports, one for inserting an instrument to a patient's mouth, and a second port for inserting an instrument into the patient's nose. The ports may be closed by a valve, for example a duck billed valve, if necessary to prevent leaking of breathing gases via the port.

In some embodiments, as illustrated inFIG.22, a cannula240may be provided with a ‘bite-block’241. The bite block is an item that is inserted into a patient's mouth and on which the patient may bite down but which holds the patient's mouth open. The block includes an opening through which instruments may be provided into the patient's mouth, and prevents a patient from biting an instrument.

The various embodiments described above may be particularly suitable for use with a range of instruments or airway instruments, including airway tubes or conduits, oral or nasal catheters, drug (medicament) delivery devices (eg: spray bottle, atomiser device, syringe), surgical instruments including spatulas, introducers/bougies, stylets, guides, tube exchangers, oral/nasal endotracheal tubes, nasopharyngeal airways (nasal trumpets), and scopes or diagnostics instruments such as laryngoscopes (direct or video) endoscopes, rigid or flexible bronchoscopes, esophagoscopes and fibreoptic scopes.

A patient interface230, such as a nasal cannula, may comprise of a port232for delivery of a medicament into a flow F of a fluid (such as a gas) being delivered to a user and/or for interfacing with a medicament delivery device or an instrument. When a delivery device (dispenser) interfaces with a patient interface (e.g. nasal cannula) the dispenser may be used to dispense medicament into a flow path (e.g. a patient's airways) with or without a flow of fluid applied to the patient's airways via the cannula.

The medicament may optionally include one or more excipients, such as pharmaceutically acceptable excipients. Such a medicament may be those suitable for being administered to the airway of a user, whether as an atomised, nebulised or dispersed or other form suitable to be introduced into a flow of gas for administration and/or delivery to a user.

In some configurations, the port232may allow an instrument1000(e.g. a tube) or a medicament dispenser234(e.g. a spray bottle, atomiser device or syringe) to be insert thereto for dispensing of said medicament. For example, the port232may be located upon a manifold part236of the interface230such that dispensing of the medicament provides for dispersal into a relatively high flow rate of gas provided to the user, and which can carry the medicament into an airway of the user. For example, seeFIG.23A. Delivery of the medicament simultaneously with the delivery of high flow may help to deposit the medicament far down into the patient's airway (for example to the patient's vocal cords), reducing the chance of the medicament being deposited prematurely within the patient's airway (for example depositing in the patient's nasal cavity).

Other instruments that the port232may be adapted to interface with include airway tubes or conduits, introducers/bougies, stylets, guides, tube exchangers, and scopes or diagnostics instruments such as endoscopes, rigid or flexible bronchoscopes, esophagoscopes and fibreoptic scopes.

Alternatively, in still further embodiments, the port232may be provided upon one prong or as a feature of or integrated as a part of a pair of nasal prongs233. For example, seeFIG.24A. For example, the port may be provided on a prong near a base of the prong.

In some configurations, the patient interface230may comprise of a shaped or otherwise moulded region237suitable for accepting or receiving or locating or seating of a medicament dispenser234or instrument1000to the interface230. For example, in this manner a dispenser234, such as a syringe, may be seated for greater or more accurate placement or control of its placement relative to the interface230which is located upon the user. A depression237in a manifold part236may be provided for such a seating or location of an instrument1000and/or a dispenser234. For example, seeFIGS.23B and23C. A depression237may act as a keyway to receive a corresponding key of the instrument or dispenser to correctly orientate the instrument or dispenser to the cannula. Alternatively, the interface may comprise a protrusion that provides a key to be received in a corresponding keyway of the instrument or dispenser.

In some configurations, the port comprises a closable opening235(e.g. shown inFIG.23C), such as, but not limited to, a screw-cap or a push-fit cap. Alternatively, the port232may be a luer-type connection or may comprise of a valve that seals over an opening of the port232when the dispenser234is not connected or inserted. For example, a duck-bill type valve may be utilised to improve sealing or closure of the port232and to reduce likelihood of gas leaks from such a port232.

In some configurations, the port232may further comprise of a director or guide238. The director or guide238may be used to direct an instrument more accurately, for example towards or up through a nasal prong233, for example as shown inFIG.23E. In some configurations, the director or guide may be a flow director or medicament director or guide. Such a director238may be used for directing dispensed medicament or a nozzle or outlet of a dispenser234more accurately, for example toward or up through one or more nasal prongs233, to minimise the amount of medicament dispensed onto the interior side walls of the interface230or wall parts more associated with the port232, which otherwise may not reach the user. Such a director or guide238may be a geometry of the port232or other protrusion shaped to direct the dispenser4or an outlet therefrom to a desired angle or position when in-situ with the port2. For example, seeFIG.23F. With reference toFIG.23F, the guide or director238(instrument or device director, or medicament director) may comprise a wall238extending from the port232. The guide or director238may extend from the port232within a lumen or flowpath of the cannula230. The guide or director238may extend from the port towards a nasal prong233within the flowpath of the cannula. The wall238may be an annular wall extending from the port through which the medicament or device or instrument passes into the flowpath of the cannula230. For example, the guide may form a tubular structure extending from the port within the cannula. The guide238may be configured to provide a clearance between the guide238and the medicament delivery device234or the instrument1000to prevent or reduce friction between the guide and the medicament delivery device or the instrument as the medicament delivery device or the instrument is inserted into the cannula via the port232. Further, in some configurations the port is configured to provide a clearance between the port and the medicament delivery device234or the instrument1000. Therefore in some configurations the guide and the port do not rigidly hold the instrument or dispenser in a fixed position relative to the patient interface. The device may slide freely into the cannula (and possibly into the patient's airway) via the port and the guide. The guide or director238may be formed of a relatively rigid material to additionally form a relatively rigid component239(compared with other parts of the patient interface) to support an device or a dispenser, as described below.

In some configurations, the port232may provide for an opening which provides for a relatively rigid component239(compared with other parts of the patient interface) to support an device1000or a dispenser234(e.g. such as a syringe tip) upon insertion or entrance to the port232(such as a port provided upon a manifold). Such a relatively more rigid component239can allow for a user to apply a force against the port232while inserting an instrument or undertaking a dispensing of medicament (or at least configuring such a dispenser relative to the interface and/or user for subsequent dispensing a medicament). Provision of a relatively more rigid component239may assist in a positive and/or more defined or more secure location or a more positive seating of an instrument or a dispenser234to the interface230and port232. A nasal cannula may comprise a resilient material for contacting the user, beneath the user's nose and/or the user's nares. For example nasal prongs are preferably formed of a resilient material to be inserted into the user's nares. In some embodiments, the relatively more rigid component is more rigid than the resilient material of the cannula. In some embodiments the rigid component239may be integrated into the cannula by overmoulding of the resilient material of the cannula.

In some configurations, the port comprising a relatively more rigid component provides for a pre-determined angle of insertion by the instrument or the dispenser to the port. In this manner, such a relatively rigid component requires a device (e.g. instrument or dispenser) to be successfully inserted to the port at a particular angle, such an angle may be that which may more accurately allow insertion of the instrument or dispenser or delivery of the medicament.

In some alternative configurations, the port232may comprise of a relatively softer or more flexible or compressible component that seals over the port232when not in use. Such a component can optionally provide for a seal about an instrument or a dispenser234or parts of the dispenser234(e.g. such as the tip of a syringe) when the instrument/dispenser234is inserted into the port232. A seal may help minimise or reduce leaks between the device and the port232when they are operationally engaged, optionally particularly so during a medicament dispensing operation.

In some embodiments, the port232may be covered by a relatively elastic or elasticated cover material that stretches when the instrument/dispenser is inserted and allows extension. Such a cover may provide for a seal. A small cut or opening in the end of the elastic or elasticated cover is normally in a closed configuration and can seal the port232when relaxed, preventing leak; and when an instrument/dispenser is inserted into the port232and pushed through the elastic or elasticated cover, the cut or opening may be stretched over the end of the instrument/dispenser, thereby being opened sufficiently to allow for the instrument or dispenser to be inserted and/or medicament to be dispensed/deposited through it.

In still further alternative configurations, the port232may be formed of a relatively more rigid component or a material covered by, or surrounded by at least one layer of a relatively compressible material. In this manner, when the instrument or dispenser is inserted into the port232, the relatively softer or compressible materials could be compressed or be conformable to the shape of the immediate surfaces of the instrument or dispenser, thereby assisting to promote a sealing around the instrument or dispenser. This can allow for the instrument or dispenser to remain substantially supported by the relatively more rigid component239or the structure underneath, yet provided with a sealing capability about a perimeter or other portion of the port232which becomes engaged or operatively in contact with the instrument or dispenser.

In some embodiments, the port234is adapted or configured to allow for a relatively long, thin instrument or medicament dispenser, such as a conduit or tube, to be inserted or to be ingressed into the port232. Such a dispenser can then be extended to project along at least a length of or through the flowpath of the patient interface230or a component such as a gas supply conduit associated with the interface230. Optionally, such a medicament dispenser may terminate at the outlet from one or more of said nasal prongs233, alternatively such a medicament dispenser may terminate within the nasal cannula (i.e. upstream of the outlet from one or more nasal prongs) or may terminate at a position beyond the outlet of the one or more nasal prongs233(i.e. downstream of the outlet from the one or more nasal prongs). In some configurations outlet of the dispenser may terminate at a small distance beyond the outlet of a nasal prong downstream of the nasal cannula. For example, a small distance may be a distance that is less than an internal diameter of the outlet of the nasal prong, or less than twice the internal diameter of the outlet of the nasal prong, or a distance less than half the length of the nasal prong.

In some embodiments the nasal cannula may comprise a medicament supply tube that extends from the port so that medicament may be delivered further downstream from the port232, for example, as illustrated inFIGS.23G and23H. The supply tube243may extend from the port232located at the manifold236of the nasal cannula to an outlet end233aof the nasal prong233, so that the medicament is dispensed from the cannula at or adjacent to an outlet of the prong into a patient's airway. As shown inFIG.23G, in some embodiments the supply tube243may be formed within a wall of a nasal prong. For example, a supply tube may be over-moulded into the wall of a prong. The supply tube may be formed in a curved or otherwise shaped configuration prior to integration into the wall of the prong. InFIG.23Gthe tube243is illustrated positioned along an upper side of the prong. In some embodiment the tube may be positioned in the wall of the prong to locate at least an outlet end of the tube towards an inward side of the prong, so that the outlet end of the tube is near or adjacent to the patient's septum in use. An inward side of a prong is a side of the prong that faces towards or bears against a patient's septum in use (or faces towards the other prong of the cannula). In some embodiments the tube243may be located along an inside wall surface of the prong, for example along an inside wall surface on an inward side of the prong.

In an alternative embodiment as shown inFIG.23H, the supply tube243may be located or positioned within a lumen of the nasal prong, for example centrally within the prong so as to typically not press against a user's nare during use. The tube may be curved or otherwise shaped to follow or corresponding with a shape of the lumen of the prong. The port232may provide a recess244for receiving an outlet or nozzle of a dispenser to dispense medicament into the supply tube for delivery to the patient's airway. Alternatively, the port232may comprise a protrusion or male connector to be received within a nozzle or outlet of a dispenser. In some embodiments the port may be formed by an inlet end of the supply tube243to receive a nozzle or outlet of a dispenser. In some embodiments the port may be provided by an inlet end of the supply tube243that is to be received in a nozzle or outlet of a dispenser, such as an aerosol canister. The supply tube may extend from the manifold a distance so that the dispenser may be connected to the supply tube remotely from the manifold.

As shown inFIGS.23G to23I, in a preferred embodiment the port232is provided on a wall of the cannula that faces away from the face of a patient in use. For example, inFIGS.23G to23I, the port232is provided on a front wall236aof the manifold236of the cannula. The front wall is opposite to a rear wall that is in contact with or adjacent the upper lip or philtrum of the patient in use. With the port in a front wall of cannula the port is presented facing away from the patient's face is use, to provide unobstructed access to the port by a medical professional, for applying a dispenser to the port.

Preferably the supply tube243comprises a small diameter outlet243a, such that the outlet operates as a nozzle or spray nozzle to assist with dispersing the medicament into a flowpath of the cannula or the patient's airway, either with or without a flow of gases provided by the cannula. For example, the supply tube may have an outlet with an internal diameter of less than 2 mm, or less than 1 mm. The diameter of the supply tube outlet is preferably substantially smaller than the internal diameter of a nasal prong. For example, the nasal prong may have an internal diameter of 4 mm or 5 mm or greater than 5 mm. The internal cross sectional area of the spray tube outlet may be less than 20% or 10% of the internal cross sectional area of the outlet of a nasal prong of the nasal cannula. In a preferred embodiment the tube243has a small diameter relative to the internal diameter of the nasal prong. In some embodiments the tube243has a constant cross section along its length. Preferably the spray tube is formed of a relatively rigid material to retain its shape during use, for example a curved shape to correspond with a curvature of the nasal prong233.

Alternatively, in some further embodiments, connection or insertion of a dispenser to the port232may promote a protrusion (e.g. such as a lumen provided) to extend along and through one or more nasal prongs233. In such a manner, there can be allowed for a deposition of a medicament further downstream from the port232, or alternatively closer to the airway of a user. For example, if a long dispenser is instead used rather than a syringe tip (i.e. as was used inFIG.23F).

In some embodiments, insertion of the dispenser may promote a protrusion2310to extend from the port232(e.g. at least as an extension through the nasal prong233). See for exampleFIG.23J, such a protrusion2310may be attached to the inside of the patient interface (e.g. the port232or an inner part of the interface, such as a manifold, or as a part of a nasal prong233). Such a protrusion2310may comprise of corrugations or other concertina-type arrangements that can unfold and extend to allow an extension and the protrusion2310to extend beyond or past the end of one or a pair of nasal prongs233, or other structures associated with a patient interface230so that the medicament may be deposited further into the user's airway, or at another preferred position along the flowpath of the cannula or user's airway. Such a protrusion can be an extendible lumen, optionally such a protrusion may be curved or shaped to fit comfortably into the nasal anatomy.

In some embodiments, when in an extended position, the protrusion2310allows for maintenance of the flowpath through the cannula or of a flow of gases to one or a pair of nasal prongs233of the cannula230. In yet other embodiments, when in an extended position, the protrusion2310may engage with one or a pair of nasal prongs233or the flowpath to one or each said nasal prong233so as to block a flow of gases to one both nasal prongs of a pair of nasal prongs.

Alternatively the insertion of the dispenser234may promote a protrusion2310to extend into a nasal prong233or a flowpath associated with a nasal prong, blocking the flow of gases to the user via that flowpath. See for exampleFIG.23K.FIG.23K-ashows a first configuration in which a protrusion2310is relatively unextended, whileFIG.23K-bshows a further configuration in which the protrusion2310is in a relatively more extended position. Such a configuration in which there is a reduced flow or a block entirely of a flowpath may be advantageous in situations where the delivered flow of gases (e.g. litres per minute) exceeds the user's inspiratory demand. In this case, excess gas flow escapes the nares during inspiration and medicament carried on this gas flow may be less effectively communicated to the user or may be wasted entirely and not directed to the user's airway. In some instances, medicament may be undesirably expelled into the room, such as a surgical theatre or pre-operative room. In this embodiment the flow of gases to the nasal prongs233can be blocked in the prong itself and thereby the prong stops delivering the gas—in this way, preferentially, only medicament will be directed to enter the user's nare (i.e. no gas flow). Blocking the flow may also allow the user to accurately control the deposition of the medicament into the patient's airway without interference from the flow of fluid. The gas flow from the blocked prong will exit through the other prong, or such gas flow may be relieved via a pressure relief valve or other arrangement or such device. Alternatively, the cannula may comprise a valve to block flow to the cannula when the dispenser is inserted. For example the cannula may comprise a valve with a valve element such as a flap that is moved to a closed position against a valve seat when the dispenser is inserted.

There may be a relatively high force required to cause the protrusion2310to extend. If the user wishes to allow high flow to continue during medicament delivery the user may insert the dispenser along the protrusion2310but not push so hard as to cause the protrusion to extend and block the flowpath through the cannula. The protrusion may be formed to tighten onto the dispenser when the dispenser is inserted into or through the protrusion. In this way, when the dispenser is retracted back through the protrusion to remove the dispenser from the nasal cannula the protrusion is pulled back to its original, unblocked position. For example, the protrusion may be formed from a soft/and or compressible or resilient material that tightens around the dispenser when inserted.

In some embodiments, a scavenging mechanism or system may be utilised in conjunction with the patient interface230as described herein. Such a system may be utilised to collect exhaled gases from a user, including exhaled medicament which has not been absorbed or taken-up by the user. Such a system may comprise a recirculation system including filtration, for re-delivery of the collected gases and medicament to the user. Such a mechanism attached to the patient interface could cover the user's mouth and/or nose to prevent medicament being exhaled back into a room. In particular, such a mechanism or system:could use a one way valve attached to additional conduit that delivers that exhaled flow back to the systemcould allow the system to ‘scrub’ the excess medicament from the gas flow, thereby assisting in minimising wastagecould be embodied in a face mask that is placed over a nasal cannula—such a face mask may be placed on the user during medicament delivery times.

In some embodiments, a nasal cannula may be designed to have one or both prongs233relatively long, such that they extend relatively deep into the user's nasal cavity. Optionally, one or both nasal prongs may be curved to conform to nasal geometry, for example this may allow for improved capabilities of successfully delivering administered medicament into the user's airway.

In various alternative configurations, one or both of a pair of nasal prongs may be extendable or comprises portions which are extendible in length, such as a protrusion2310. For example, a nasal prong may comprise of an inner secondary prong portion, such as a protrusion2310which may comprise of corrugations or concertina-type sections which can be extended to lengthen and allow such a secondary prong to project further than a main nasal prong into a user's airway. Such an extended secondary prong may be utilised as a protrusion for improved for extending of the flowpath for delivery of medicament to a user's airway. In various instances, seeFIG.23Jas an example, the prongs may utilise such a secondary prong that can be extended when the user wants to deliver a medicament, or when the user is asleep and can tolerate greater discomfort. Longer prongs may also have the additional benefit of creating greater flushing of the airway and potentially further reducing CO2 from a user's airways.

In some embodiments, the port232may be a guiding channel or other shaped accommodation region for allowing improved access to the nares by a dispenser234without affecting the delivery of respiratory support. For example, the port may be a channel203in an outer surface of the prong as described above with reference toFIG.19B, one or both nasal prongs233shaped to accommodate the shape of a dispenser234or at least the dispensing tip of a dispenser. For example seeFIG.24B. Alternatively, a nasal prong233may comprise a port232or accommodation region233through which a dispenser234may be inserted for delivery of medicament to the gas flow F and/or into a user's airway—see for exampleFIG.24A.

In some configurations there is a pre-formed medicament dispenser pre-loaded with medicament for use with the patient interface as described above.

In some embodiments, the dispenser234may be pre-formulated with a pre-determined quantity of medicament in a ready-to-dispense configuration. For example, lignocaine may be provided in a dispenser234in a pre-determined quantity for administration to a user.

In some embodiments, the dispenser may be provided with the cannula to ensure correct fit with the port(s). Or an attachment/adaptor may be provided to fit to existing dispensers, for example to attach to the end of a syringe.

In some embodiments, the patient interface230may comprise of a reservoir2312for receiving and/or storing of a medicament. In other embodiments, the reservoir2312may be actuated manually or by other forms (e.g. such as by an electronic dosing or administration arrangement which allows for release of the medicament from the reservoir into the flowpath for delivery to the user). The reservoir may be permanently attached and refillable by the user, or be detachable and attached when desired.

Where the dispensing of medicament may be manually actuated by a user, this may for example be by way of a button on the interface or by depressing a syringe plunger. Such actuation can allow for the release of the medicament from the reservoir2312.

In one example, actuation may result in the medicament being forced or encouraged to release out of reservoir and into the flowpath of the interface or a flowpath associated with the interface (e.g. that of a gas supply conduit). For example inFIG.25Athe reservoir enables medicament to be delivered into the flow F of gases being directed to a user's airway; whileFIG.25Bshows the medicament having been released into the flow and being directed toward the interface230. The reservoir may be made of a non-rigid material that may be squeezed to force the medicament to open a valve and release the medicament into the flow path of the conduit. The valve may be biased to a normally closed position so that the valve closes when the reservoir is not squeezed to force the valve open.

As high gas delivery flow rates may be used, the medicament may be carried in the gas stream to the user's airway.

For example, according to those various embodiments and configurations described herein, a flow rate of gases supplied or provided to an interface or via a system, such as through a flowpath, may comprise, but is not limited to, flows of at least about 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150 L/min, or more, and useful ranges may be selected between any of these values (for example, about 40 to about 80, about 50 to about 80, about 60 to about 80, about 70 to about 100 L/min, about 70 to 80 L/min).

Such relatively high flowrates of gases may assist in providing the supplied gases into a user's airway, or to different parts of a user's airway, for example such flowrates may allow for a delivery of such gases to the upper, middle or lower airway regions.

Such relatively high flowrates can assist to, in combination with a medicament delivered to the flowpath or the flow of gases being delivered to the user, provide assisted delivery of medicament to a user's airway, or different parts of a user's airway. For example, such relatively high flowrates may effectively help drive or push medicament further into a user's airways than under normal respiratory conditions by the user.

FIG.28shows a typical airway of a person, and includes arrows to indicate the path of how a relatively high flowrate of gases supplied to a user may be utilised to effectively push or drive the supplied gases further or deeper into a user's airway than when the person is under normal or typical self-driven respiratory conditions.

If liquid medicament is used, the gas flow may help to partially nebulise the medicament into smaller particles that can carry further down the airway. A valve may be provisioned to sit between the reservoir and a main gas supply conduit, such that the valve is normally closed. However, actuation of the reservoir may be used to put the valve under pressure (e.g. by squeezing or button actuation (not shown)) with the valve consequently opening and allowing the medicament to be made available for release into the gas stream (seeFIG.25B)

In alternative configurations, the medicament in the reservoir2312may be released or made available to the flowpath by actuation of a negative pressure in the flowpath, thereby opening a valve or other member which may be sealing the reservoir from the flowpath. For example, if the patient were asked to inhale deeply a valve or seal can be opened and medicament released. The valve or seal may be designed such that normal tidal breathing does not create enough negative pressure to open it. In this way medicament delivery can also be timed with inspiration, avoiding wastage and encouraging the medicament to travel further down the airway particularly when the patient inhales deeply.

In still further embodiments, where a valve or seal is used to close off the reservoir, the aperture of the valve may be designed to be small and create nebulised particles of a certain size that enable medicament delivery to a specific location.

In other configurations, details of the above embodiments could be applied here as well however the medicament may be delivered via another channel, not necessarily through the nasal prongs. Such a channel may be sized differently to the prongs e.g. may have a smaller internal diameter to create high gas/medicament velocities and effectively jet medicament further down the user's airway than the prongs might otherwise be able to achieve. The channel could use gas delivered via a sidestream or other source of gas from the main gas flow, a separate gas flow or from another pressurized source, for example an aerosol canister, or may not deliver gas and only be used as a medicament delivery port. In this manner:there could be multiple channels for delivery of medicament (e.g. different medicament through each separate channel).a different medicament could be delivered through each channel, or prong, at the same time.flow through each channel/prong could be independently controlled to manage each medicament concentration or administration separately.

In other configurations, the port232that dispenses the medicament (e.g. whether the port is located on the patient interface or as a port on a conduit associated with the gas flow) could be designed so that when liquid medicament is dispensed through it, the medicament is atomised. For example, inside one or each nasal prong233there could be serrations/ribs or walls/partitions242as shown inFIGS.26A and26C, and/or the opening or outlet of the nasal prong could be made of many small apertures instead of a single one large outlet, as shown inFIGS.26A and26B. Forcing or directing liquid through such features may assist in breaking the liquid up into small droplets with a lower weight than a large liquid bolus. Alternatively, such structures as shown inFIG.26A to26Cmay cover only a portion of the cross-sectional area of the prong or prong outlet.

According to the configuration above, reducing particle size of the medicament being dispensed to a user can aid the medicament to be carried in the gas flow and delivered to the user. For example, the force of a depressed syringe containing liquid medicament or an automated piston, depressing the medicament through the features could be used to create the atomization or nebulisation (i.e. turning the medicament into particles or reducing medicament particle size). As such, nebulised or reduced particle sizes could be sized to target deposition at the larynx, or other desired locations depending on the target for the medicament.

In some configurations, the port232on the interface230could comprise a single aperture but sized so as to cause nebulisation or atomization of liquid medicament when it is administered into and dispensed therefrom (i.e., the port may have a relatively small exit aperture through which dispensed medicament must pass, e.g. less than 1 mm diameter). For example, as shown inFIG.23I, the port may comprise a small diameter outlet232aso that as medicament is dispensed from a medicament delivery device into the port232the medicament is atomized or sprayed into the flow path of the nasal cannula, for example into the manifold of the cannula. In the case of a nasal cannula, one of the prongs3may have a relatively small inner diameter or include serration/ribs or the opening or outlet of the nasal prong could be made of many small apertures instead of a single one large outlet so as to effect such an in-line atomisation or nebulisation of medicament, as described above with reference toFIGS.26A to26C.

In some configurations, the reservoir2312may be provided as a part of the patient interface, or may be associated with a gas supply conduit (e.g. that conduit supplying gas to the patient interface) or may be provided as a reservoir at a source device for providing a gas flow to the patient interface. It will be appreciated the medicament may be delivered via main gas path or could be provided via a separate conduit up to interface.

Dispensation of medicament can be controlled via mechanically actuated valve or by software. (e.g. mechanical actuation or may be electronically controlled).

In various configurations, the delivery or dispensing of medicament can be timed to coincide with a user's inspiration, or a part of the inspiratory phase, to avoid wastage during exhalation phase of breath. As such, delivery of medicament may be timed to occur at the peak of inspiration to ensure the most flow possible is travelling down the user's airway and to encourage deep deposition. For example, if medicament delivery was desired during inspiration a population average of inspiratory pressures could be determined and a valve associated with the reservoir designed to open at pressures below this value. Medicament could be actuated by a pressure in a main gas conduit, or if a separate line was run next to the main gas conduit and terminated in the user's nares, then this could also be triggered in a similar way.

Alternatively, the inspiration phase could be detected by measuring the interface pressure or pressure at some place in the system and the medicament delivery could be activated (e.g. by opening a valve, controlled by software) when the pressure falls below a pre-determined value, such as the (rolling) average. A pressure below the average pressure would indicate the user is causing a reduction in the pressure in the system and is therefore inspiring. The average could be calculated over a set number of breaths (e.g. 5 breaths) or time (e.g. 1 minute).

In other configurations, if the medicament delivery conduit does not have gas flow through it the release of medicament could be activated via an additional electrically activated piston or other release system. Alternatively, delivery could be timed to activate with a certain inspiratory flow rate that matches a flow most likely to carry the medicament down the airway to deposit at the vocal cords (or other desired location). More specifically, if the medicament were delivered as part of the main gas flow, the gas flow could also be controlled to meet inspiratory demand to avoid wastage of medicament with high flow rates in excess of the inspiratory demand and to ensure delivery of the correct amount of medicament.

In yet other configurations:

High flow rates may be used to deliver dry powder medicaments. This may be desirable for depositing medicament in the nasal airway where blood flow is high and medicament may be quickly absorbed into the blood stream via the thin epithelium layer.

An anti-coagulant may be added to powders. This may prevent the powder from caking and potentially blocking the medicament delivery port. This may be particularly important when the powder is delivered via a humidified gas conduit.

Alternatively the powder may be delivered via a separate conduit that may use the same gas source as the main gas supply, or a side-stream supply of it, but is not humidified.

Delivery via other airway equipment may be utilised, for example an attachment could be fitted to end of a laryngoscope to allow for delivery of medicament into a user's airway without requiring an additional medicament delivery device (e.g. atomiser or nebulisers etc.).

Still further, in other configurations it may be possible to:

Coat the medicament in a chemical that has a half life that degrades after set time (e.g. if it is known that at 70 litre per minute it takes 0.5 seconds for flow to reach the larynx, use a coating that will degrade sufficiently after 0.5 s).

Coat the medicament in a chemical that degrades on contact with preferential tissue or materials, such as vocal cord tissue. For example, the vocal cords epithelium is stratified squamous epithelium. This type of epithelium is also present in the oral cavity and the nasal vestibule; however the rest of the conducting portion is lined by respiratory epithelium. If medicament is delivered via a nasal cannula, this avoids the oral cavity. If the delivered medicament is delivered at sufficient velocity and in a manner directed past the nasal vestibule, the majority of it should get past the nasal vestibule. Hence it may pass down to the vocal cords before coming in contact with any other stratified squamous epithelium, and deposit at this location.

Nasal prong length could be extendable or adjustable for delivery of medicament further into airway. For example, with corrugations at the base of a nasal prong, similar toFIG.23J. Again a dispenser (e.g. a syringe r other forms of a dispenser) could be inserted into the prong, and in doing so, could activate the prong length extension.

The flow rate could be adjusted for a short time (e.g. one breath, or part of a breath) during medicament deposition, to encourage deposition on the larynx. For example, the flow rate could be increased for a short time to increase flow velocity and jet medicament further down the airway. This could be timed with inspiration to help medicament flow down the airway. Or, it may be found that the current flow rate (e.g. 70 lpm) may cause the medicament to be deposited too far down the airway, so the flow may need to be reduced when medicament deposition is desired/activated. Flow rate may be adjusted manually by a user as medicament is dispensed.

The medicament polarity could be determined, or the medicament could be electrically polarised to be attracted to magnets. A magnet could be placed behind the user's neck while supine at the position of the desired medicament deposition location to attract the medicament to deposit there as it travels down the airway.

Another embodiment is explained inFIG.27. In this case the delivered gas flow may help to force the liquid medicament onto the back of the laryngeal wall as it travels down.FIG.27shows an arrangement where a relatively long tube or conduit2313may be utilised to separately dispense or direct a medicament delivered from a dispenser or a reservoir (not shown) into the airway of a user, when a nasal prong233of a patient interface230is simultaneously also in in-situ with a nare or nares.

In further configurations:

Medicament could be delivered as (gas-filled) bubbles. Bubbled delivered through prongs or additional medicament delivery channel. Prong diameter, or medicament channel diameter could be sized to control the diameter of the bubbles and encourage deposition at the larynx, or other location.

Medicament bubbles could be delivered orally. The airway has a decreasing cross-section diameter as it extends towards the vocal cords from the mouth if the patient's mouth is open wide. Thus if the patient is asked to keep their mouth open and the bubble diameter is the same size as the trachea at the position of the vocal cords, the bubbles may travel down the airway and burst only at the vocal cords as they come into contact with an area the same size as them, depositing the medicament there.

The medicament could be delivered via a coaxial conduit. The liquid medicament is pushed along the outer layer and flow is passed through the centre. The liquid medicament may form a film over the end of the conduit (e.g. prongs) when no flow is passed through it. When flow is re-started this may allow a bubble to form at the end and be pushed along with the gas stream. As an example, if two conduits are used (e.g. separate gas supply to a pair of nasal prongs) the flow may be delivered alternately through each conduit and a film may be able to form over the other conduit when flow is not delivered. Bubbles can thus be delivered alternately from each conduit/prong.

Bubbles may be filled with a composition of gases that target deposition in a certain location. For example helium, nitrogen, and/or oxygen may be used to create a stokes number that targets deposition on the vocal cords taking account of the flow rate, medicament composition and particle drag, and oral/nasal anatomy.

In further configurations:

Once a user is reclined the medicament may delivered via a liquid bolus (rather than aerosolized).

If the bolus is delivered while the patient is supine the effect of gravity may allow the medicament to flow down the back of the throat to the vocal cords.

The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scope of the invention.

The term “comprising” as used in this specification and claims means “consisting at least in part of”. When interpreting each statement in this specification and claims that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner.

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.

The invention consists in the foregoing and also envisages constructions of which the following gives examples only.