Patent Description:
Examples of a humidification chamber have been described in our earlier international patent application <CIT>.

Respiratory assistance devices or systems for providing a flow of humidified and heated gases to a patient for therapeutic purposes are well known in the art. Systems for providing therapy of this type typically have a structure where gases are delivered to a humidifier chamber from a gases source, such as a blower (also known as a compressor, an assisted breathing unit, a fan unit, a flow generator or a pressure generator). As the gases pass over the hot water, or through the heated and humidified air in the humidifier chamber, they become saturated with water vapour. The heated and humidified gases are then delivered to a user or patient downstream from the humidifier chamber, via a patient interface comprising a flexible gases conduit and a user interface.

<FIG> shows a schematic view of one type of known respiratory assistance system <NUM> for delivering humidified and heated gases to a patient. The system <NUM> comprises a housing <NUM> containing a blower unit <NUM> and humidifier unit <NUM>. In operation, atmospheric air <NUM> is drawn into the blower unit <NUM>. The blower unit <NUM> generates a pressurized air or gases stream which is delivered to the inlet <NUM> of a humidification chamber <NUM>. The humidification chamber <NUM> comprises water and is heated by a heater pad <NUM>. The humidified and heated gases stream <NUM> exits the humidification chamber via an outlet <NUM> of the humidification chamber and is delivered to the patient or user <NUM> via a flexible hose or gases conduit <NUM> and user interface <NUM> as shown. The blower unit and humidification unit are typically connected via a series of connectors and/or conduits to allow gases to pass from the blower unit to the humidifier unit.

The user interface <NUM> shown in <FIG> is a nasal mask, covering the nose of the user <NUM>. However, it should be noted that in systems of these types, a mask that covers the mouth and nose, a full face mask, a nasal cannula, or any other suitable user interface could be substituted for the nasal mask shown. A mouth-only interface or oral mask could also be used. Also, the patient or user end of the conduit can be connected to a tracheostomy fitting, or an endotracheal intubation.

The humidification chamber <NUM> typically comprises a rigid plastic receptacle or container that can be filled with a volume of water. In one known form, the base of the humidification chamber comprises a circular thermally conductive metal heater plate that is fixed within a complementary aperture provide in the base of the humidification chamber via overmoulding of the plastic base about the peripheral edge of the heater plate. The overmoulding forms a seal at the interface between the perimeter edge of the heater plate and surrounding plastic base of the chamber. In use, the heater plate contacts a heating element, heater pad or heater base upon which the humidification chamber rests and heats the volume of water in the chamber via conduction.

<CIT> discloses an oxygen humidifier includes a container that defines an interior space. The oxygen humidifier also includes a top portion that is permanently coupled to the container. The top portion includes an opening for accessing the interior space of the container. The humidifier further includes a lid portion that is movably coupled to the top portion. The lid portion is configured to move between a closed configuration and an open configuration. In the closed configuration, the lid portion seals the opening, and in the open configuration, the lid portion allows access to the interior space through the opening. The oxygen humidifier additionally includes an oxygen diffuser positioned within the interior space.

<CIT> discloses a refilling device incorporated into mechanical ventilator machines as used in medical systems wherein a funnel is incorporated into the molded cover of a humidifier chamber. A lower portion of the incorporated funnel when attached to the humidifier chamber, defines a high fluid level at its narrow cylindrical dimension while the upper, wide cone-like dimension is covered by being fitted with sealing filler cap.

<CIT> discloses a breathing assistance unit for providing pressurized heated humidified air to a user is configured to increase user compliance. The breathing assistance unit comprises means for generating positive emotional and cognitive states of a user about the therapy.

<CIT> discloses a ventilator with integrated breathing air humidifier has at least two defined air pathways provided in the breathing air humidifier, wherein the breathing air humidifier is installed and fixed on a horizontal surface of the ventilator. The ventilator with integratable breathing air humidifier has a breathing air humidifier with at least a top part and a bottom part, wherein a water reservoir is provided in the bottom part, and wherein the top part cannot be removed from the bottom part when the unit is in at least one operating mode. The ventilator may have an air humidifier with at least one water reservoir, and at least one filing device for the water reservoir in the breathing air humidifier, wherein the filing device can be operated with one hand and/or opened with one hand.

<CIT> discloses an arrangement for a heatable humidifier. This document discloses a humidification chamber according to the preamble of claim <NUM>.

<CIT> discloses an evaporator for respirators, including a storage tank for a liquid, a gas intake flange and a gas outlet flange as well as an apparatus for heating the liquid, which is formed such that it can heat a small portion of the liquid and inject the formed vapor into the gas to be humidified, with the gas to be enriched with the liquid being passed through the upper part of the storage tank over the surface of the liquid, which may be located in the lower part of the storage tank, so as to provide a simple evaporator for respirators having a low consumption of energy. This document discloses a humidification chamber according to the preamble of claim <NUM>.

<CIT> discloses a humidifier system for delivering breathing gases such as air or oxygen from a respirator, anesthesia machine, oxygen source, or the like to a patient under controlled conditions of temperature and humidity is disclosed. The humidifier comprises a support housing adapted to receive a removable water tank, the housing also containing a low water sensing system, a water heating means, and a system for sensing and for regulating the temperature of the water in the tank. The tank includes an air inlet leading to a diffuser chamber, from which air flows through a diffuser plate, through the water in the humidifier, and thence to an outlet for delivery to the patient. The breathing gases are forced through the water tank under positive pressure and thereby are heated and humidified prior to delivery.

<CIT> discloses a humidifier for humidifying a flow of breathable gas to be delivered to a patient includes a chamber configured to receive the flow of breathable gas; a tub configured to contain a supply of water, the tub being configured to be inserted into the chamber; a lid provided on the chamber and being movable between an open position and a closed position; and a seal provided on the lid, the seal being configured to seal the chamber such that the flow of breathable gas pressurizes the chamber. The humidifier may be connectable to a flow generator configured to generate the flow of breathable gas. A tube for delivering the humidified flow may be connected to the humidifier. The tube may be a heated or non-heated tube. A respiratory apparatus for delivering a flow of breathable gas to a patient may include the humidifier and the flow generator and/or the tube. A method of humidifying a flow of breathable gas comprises sealing a chamber containing a supplying a water and pressurizing the chamber by directing the flow of breathable gas into the chamber.

<CIT> discloses a respiratory assistance apparatus includes a flow generator and a humidifier. The humidifier includes a humidification chamber. The humidification chamber comprises a water tub that is configured to receive a volume of water. A lid is hingedly coupled to the water tub for enclosing a volume contained within the water tub.

It is therefore an object of the disclosure to provide an improved humidification chamber which overcomes or at least ameliorates one or more disadvantages of the prior art, or alternatively to at least provide the public with a useful choice.

Further objects of the disclosure will become apparent from the following description.

According to the present invention there is provided a humidification chamber for humidifying gases according to claim <NUM>. The dependent claims define embodiments of the invention.

A humidification chamber according to the invention as claimed comprises: a water tub that is configured to receive a volume of water; a gases inlet for receiving a flow of gases into an interior volume of the humidification chamber a gases outlet through which a humidified flow of gases may exit the interior volume of the humidification chamber; one or more fill apertures in fluid communication with the water tub such that the water tub can be filled with water through the one or more fill apertures; and a sealing closure configured to be releaseably mounted on the humidification chamber, the sealing closure being configured to sealingly close each fill aperture when the sealing closure is mounted on the humidification chamber to resist gas and/or vapour escaping from the one or more fill apertures, wherein the sealing closure comprises one or more sealing formations configured to sealingly engage a region of the humidification chamber that defines, or is adjacent, the one or more fill apertures, so as to close the one or more fill apertures, and wherein each sealing formation comprises a plug depending from the sealing closure, each plug being received in a respective fill aperture (optionally engaging at least the neck surface of the respective fill aperture) and sealing closed the respective fill aperture when the sealing closure is mounted on the humidification chamber, and the humidification chamber further comprises a peripheral seal extending around the periphery of the sealing closure, the peripheral seal being configured to sealingly engage and seal around the periphery of the humidification chamber.

In some examples, the humidification chamber may comprise a plurality of fill apertures, the sealing closure comprising a corresponding plurality of sealing formations.

The sealing closure may comprise a mounting formation configured to engage the humidification chamber to mount the sealing closure to the humidification chamber such that the sealing formation is maintained in sealing engagement with the humidification chamber. The mounting formation may comprise at least one rib which projects outwardly from the sealing formatin.

At least part of the sealing closure may be resiliently deformable. Preferably at least each sealing formation of the sealing closure is resiliently deformable so as to at least partially deform into sealing engagement with the region of the humidification chamber that defines, or is adjacent, the one or more fill apertures when the sealing closure is mounted on the humidification chamber.

The peripheral seal may comprise a downwardly directed peripheral skirt depending generally downwardly from the periphery of the sealing closure. The peripheral skirt preferably comprises a radially inwardly curved portion, when the sealing closure is viewed in transverse cross section, the radially inwardly curved portion defining a channel configured to receive a margin of the humidification chamber, and/or part of a respiratory apparatus in which the humidification chamber is used, when the sealing closure is mounted on the humidification chamber. The peripheral seal may further comprise a bead projecting upwardly and/or radially outwardly from an upper surface of the sealing closure. The bead may be configured to support a lid of the respiratory apparatus with which the humidification chamber is used.

The sealing closure may comprise a hand or finger grip formation configured to be gripped to remove the sealing closure from the humidification chamber. The hand or finger grip formation may comprise a tab projecting from the sealing closure.

The sealing closure in one example is substantially planar and may comprise an upper surface and an undersurface, the undersurface being adjacent and/or in contact with the humidification chamber when the sealing closure is mounted on the humidification chamber, wherein the sealing formation projects from the undersurface. The shape and/or cross sectional profile and/or dimensions of the undersurface of the sealing closure may be configured to correspond to and mate with the shape and/or cross sectional profile and/or dimensions of the part or parts of the humidification chamber that are adjacent the undersurface when the sealing closure is mounted on the humidification chamber. The entire undersurface of the sealing closure may be configured to mate with the entire upper surface of the humidification chamber adjacent the undersurface, such that the undersurface of the sealing closure seals against the entire upper surface of the humidification chamber. The sealing closure may be further provided with at least one hinge or hinge region extending at least partially across the sealing closure and configured to enable one end region of the sealing closure to hinge relative to an opposed end region. The hinge region may comprise an elongate channel. In one example, a plurality of parallel channels are provided extending across the sealing closure from one margin to another opposed margin.

The water tub may be formed of rigid plastic and comprises a base surface and a perimeter wall that extends upwardly from the base, and wherein the base surface comprises a heater plate. The heater plate may be secured within an aperture of the base surface of the water tub by overmoulding. The heater plate may be metallic.

The humidification chamber may further comprise a step formation about an inner surface perimeter of a wall of the water tub, the step formation being configured at a height above a base surface of the water tub corresponding to a maximum fill line indicator.

The base surface of the water tub is domed such that it curves outward toward a central apex defined by the heater plate.

The perimeter wall of the water tub comprises one or more reinforced regions.

The humidification chamber may further comprise a lid hingedly coupled to the water tub for enclosing the water tub to define the interior volume of the humidification chamber and which is movable between a closed position in which the water tub is closed by the lid and an open position in which the water tub is open. One or more operable clips may be provided for securing the lid in the closed position; the sealing closure being configured to be releasably mounted on the lid. The lid and water tub may be hingedly coupled by a living hinge and are integrally formed as a single item. The gases inlet and gases outlet may be provided on opposite sides of the lid. The lid may comprise a vertical flow plane that extends downwardly from the underside of the lid in a central region of the lid. The vertical flow plane may further comprise a pair of side baffles that each extend from a respective side edge of the vertical flow plane toward the side of the lid comprising the gases inlet.

The gases inlet may be coupled to an inlet conduit that extends between an inlet end at the gases inlet and an outlet end located at or toward an upper central region of the interior volume of the humidification chamber and adjacent a first side surface of the vertical flow plane such that the incoming gases flow enters the interior volume of the humidification chamber at that upper central region.

A flow director formation in the form of an inverted curved ramp surface may be located between the outlet end of the inlet conduit and the first side surface of the vertical flow plane.

The gases outlet may be coupled to an outlet conduit that extends between an inlet end located at or toward an upper central region of the interior volume of the humidification chamber and adjacent a second side of the vertical flow plane and an outlet end at the gases outlet.

The gases outlet may comprise an engagement surface about the perimeter of the gases outlet that is tilted outwardly such that an upper portion of the engagement surface is displaced further outward than a lower portion of the engagement surface.

At least one water fill aperture may comprise an associated maximum water level indicator comprising a tab member that is supported from the underside of the top of the water tub or lid such that it extends into the field of view of the interior volume of the humidification chamber visible directly through the water fill aperture.

Preferably the humidification chamber has an overall shape defined by front and end walls between which side walls extend, and the walls extending between an upper surface of a lid and base surface of the water tub, and wherein the lid is hingedly coupled to the water tub at the rear end of the humidification chamber, and at least one operable clip is provided at the front end of the humidification chamber. At least one operable clip may be provided in the form of a torsion clip that is mounted to either the lid or water tub and which is configured to engage with a catch provided on either the water tub or lid, respectively. At least one operable clip may be provided that is hingedly coupled to the lid or water tub and which is configured to engage with a catch provided on either the water tub or lid, respectively.

A seal may be provided about the perimeter of the chamber between the lid and water tub to seal the chamber when it is in a closed position.

According to another, unclaimed aspect of the disclosure there is provided a respiratory assistance device configured to provide a heated and humidified gases stream, comprising:.

The humidification compartment may comprise a lid that is movable between an open position to enable removal of the humidification chamber and a closed position to retain the humidification chamber within the humidification compartment.

The humidification compartment may comprise a gases inlet connected to the flow path to receive the pressurised gases stream from the blower to create a pressurised humidification compartment and a gases outlet connected to the device gases outlet of the flow path.

The gases inlet of the humidification chamber may be open within the humidification compartment to receive an incoming flow of gases from within the pressurised humidification compartment.

The gases outlet of the humidification compartment may be sealingly connected to the gases outlet of the humidification chamber.

The humidification compartment may comprise a heater pad upon which the humidification chamber sits.

The device may be contained within a single housing.

The device may be a CPAP respiratory device.

According to a further unclaimed aspect of the disclosure there is provided a sealing closure for a humidification chamber for humidifying gases, the humidifying chamber comprising:.

According to a yet further unclaimed aspect of the disclosure there is provided a sealing closure for sealingly closing at least one fill aperture of a humidification chamber for humidifying gases, the sealing closure:.

The disclosure consists in the foregoing and also envisages constructions of which the following gives examples only, whereas the invention is solely defined by the claims.

Further aspects of the disclosure, which should be considered in all its novel aspects, will become apparent from the following description.

Preferred embodiments of the disclosure will be described by way of example only and with reference to the drawings, in which:.

A humidification chamber according to the invention as claimed is formed, in the following detailed description, by the tub of any of the embodiments of <FIG> and <FIG>, with a sealing closure as in <FIG>.

Throughout the description like reference numerals will be used to refer to like features in different embodiments.

The disclosure relates to a humidification chamber for a respiratory assistance apparatus (respiratory device) that supplies a flow or stream of heated and humidified respiratory gases to a user or patient for respiratory therapies, such as, but not limited to, CPAP therapy.

For context, <FIG> shows an example of a typical schematic configuration of a respiratory device <NUM> within which the humidification chamber of the disclosure may be employed, although this is not intended to be limiting to the uses of the humidification chamber. The respiratory device <NUM> comprises a humidification unit or humidification compartment <NUM> that receives and retains a removable humidification chamber <NUM> in use. In this embodiment, the humidification compartment <NUM> may be formed within the housing of the respiratory device and may be an openable compartment having a lid so the humidification chamber <NUM> within the humidification compartment <NUM> may be accessed for removal for cleaning or filling. Typically the humidification compartment <NUM> is sealed and/or pressurised when the lid is closed. The humidification chamber <NUM> is filled with a volume of water as indicated at <NUM> and the chamber <NUM> rests upon a heater pad or heater base <NUM>. As is known in the art, the heater pad <NUM> is powered to heat the water <NUM> in the humidification chamber <NUM> during use via heat transfer through the base of the humidification chamber <NUM> of which at least a portion is thermally conductive.

The respiratory device <NUM> comprises a blower <NUM> which draws atmospheric air or other therapeutic gases through an inlet <NUM> and generates a pressurised gases stream <NUM> at an outlet of the blower. The outlet of the blower <NUM> is fluidly connected to an inlet <NUM> of the humidification compartment <NUM> via connecting conduits <NUM> extending to the inlet <NUM> of humidification compartment <NUM>. As the humidification compartment is sealed when closed, the gases stream <NUM> entering the inlet <NUM> pressurises the compartment and gases flow into the open gases inlet <NUM> of the humidification chamber <NUM>. It will be appreciated that in alternative embodiments, the inlets <NUM>, <NUM> of the compartment <NUM> and chamber <NUM> may be sealingly connected by a connector or other sealing configuration.

The pressurized gases stream passes through the humidification chamber <NUM> and exits via gases outlet <NUM> of the humidification chamber. In this embodiment, the gases outlet <NUM> of the chamber <NUM> is sealingly connected to or sealingly engaged with an outlet <NUM> of the humidification compartment <NUM> as shown. It will be appreciated that in alternative embodiments, the outlets <NUM>, <NUM> of the compartment <NUM> and chamber <NUM> need not be sealingly connected by a connector or otherwise sealingly engaged. In the embodiment shown, the outlet <NUM> of the humidification compartment <NUM> is fluidly connected via connectors and/or conduits to a patient interface for delivery to a patient <NUM>. The patient interface typically comprises a flexible gases conduit <NUM> coupled at one end to the main gases outlet of the respiratory device <NUM> and to a user interface <NUM> at the other end.

In the following embodiments, the humidification chamber <NUM> is typically received and retained within a complimentary enclosed and sealable humidification compartment <NUM> formed in the housing of the respiratory device <NUM>. However, it will be appreciated that the humidification chamber <NUM> could alternatively be received and retained in an open or exposed compartment or on a support platform comprising the heater pad <NUM> in alternative embodiments with the gases inlet of the chamber being connected to the blower outlet by conduits and/or connectors and the gases outlet of the chamber being connected by conduits and/or connectors directly or indirectly to the patient interface.

Referring to <FIG> a first embodiment of the humidification chamber <NUM> will be explained in further detail. As explained above, the humidification chamber <NUM> is configured to be received and retain within a complimentary humidification compartment (not shown) provided within the housing of the respiratory device. Typically the compartment comprises a heater base or heater pad upon which the humidification chamber sits. The humidification compartment is accessible via an openable lid to enable the humidification chamber <NUM> to be inserted and removed as required, for example for cleaning and/or refilling.

As shown in <FIG>, the humidification chamber or chamber assembly <NUM> comprises a cradle or lower part generally indicated at <NUM> that is shaped to receive and retain a complimentary sized and dimensioned water tub or container <NUM>. An upper part or lid <NUM> is hingedly coupled to the cradle <NUM> and is moveable between a closed position (shown in <FIG>) in which the lid securely retains the water tub <NUM> within the cradle <NUM> and an open position in which the lid is pivoted away from the cradle <NUM> to enable the water tub <NUM> to be removed from the cradle for cleaning, refilling or replacement for example. As will be explained later, the lid may comprise baffling in the form of a configuration of conduits and/or flow planes and guides to control the flow path of the gases stream through the chamber between the inlet and outlet.

In this embodiment, the cradle <NUM> and lid <NUM> are formed of a rigid plastic by injection moulding or the like. Typically, the cradle <NUM>, lid <NUM> and hinged coupling between the two components are integrally formed together as a single item, although in alternative embodiments the lid and cradle may be formed as separate parts and then hingedly coupled via one or more hinges. The lid and/or cradle may be substantially transparent or formed as opaque depending on design requirements. The water tub or chamber base <NUM> is formed of a rigid and thermally conductive material, typically pressed or shaped from sheet metal, such as aluminium, stainless steel or any other suitable material, or could be formed by die casting for example.

It will be appreciated that in alternative embodiments, the cradle <NUM>, lid <NUM> and water tub <NUM> could be formed from other materials or in other ways. For example, the cradle <NUM> and lid <NUM> could be formed by vacuum forming. The cradle and/or lid could also be formed from metal, whether pressed from sheet metal or formed from die casting for example. The water tub could alternatively be formed from a heat conductive plastic in alternative embodiments.

In this embodiment, the overall shape of the humidification <NUM> is substantially rectangular as shown in the plan view of <FIG>. The humidification chamber <NUM> is defined by first <NUM> and second <NUM> end between which first <NUM> and second <NUM> sides extend. In this explanation, the first end <NUM> is considered the rear end and the second end <NUM> is considered the front end of the humidification chamber. The first side <NUM> may be considered the inlet side of the humidification chamber as it contains the inlet through which the pressurized gases stream from the blower enters the humidification chamber. The second side <NUM> may be considered the outlet side of the humidification chamber as it contains the outlet for the humidified gases stream which exits the humidification chamber. It will be appreciated that in an alternative description of the chamber, the ends could be considered the sides and vice versa, depending on the context.

In this embodiment, the corners joining the ends <NUM>,<NUM> and sides <NUM>,<NUM> are curved or rounded as generally indicated at <NUM>, although this is not essential and the corners may be right-angle corners or any other profiled shape. In this embodiment, the corner 66a joining the front end <NUM> and inlet side <NUM> is larger than the remaining corners, although this is not essential. It will be appreciated that in alternative embodiments the humidification chamber assembly may be formed in any desired shape or profile, including circular or otherwise and that the same principals of construction and configuration will generally apply.

The cradle <NUM> is configured to receive and retain the water tub <NUM> which has a complimentary shape and slightly smaller dimensions so that it can slide down into the open cavity formed by the cradle. The tightness of the fit between the water tub <NUM> and cradle <NUM> may be varied. In some embodiments it may be snug with a friction fit and in other embodiments it may be a loose fit such that the water tub may easily slide into and out of the cradle preferably without any or minimal force or pressure applied by the user to assemble or release the parts. When the chamber is closed, the cradle acts to hold the water tub securely and accurately up against the lid. In particular, the cradle typically holds the water tub up to the lid around the full mouth of the chamber to prevent/minimise splash over of water between the lid and water tub. The cradle also has the dual function of holding the water tub in place while also hinging the lid, and keeps the lid and water tub aligned so that when the user goes to close the chamber they do not have to align the lid and water tub.

In this embodiment, the end wall formations <NUM>, <NUM> each extend about the entire corner region of the cradle and terminate along respective sides of the cradle prior to meeting each other to thereby provide open side wall formations in the cradle which expose the water tub <NUM> when retained in the cradle <NUM>. For example, <FIG> shows the inlet side of the cradle <NUM> with the front <NUM> and rear <NUM> end walls extending about the respective corners 74a,76a of the cradle and along the side of the cradle, and each terminated at a sloped curved edge 74c,76c extending downwardly from the upper edge of the cradle to the base <NUM>. It will be appreciated that the terminating edges 74c, 76c need not necessarily be declining at an angle with a curving profile but maybe abrupt vertical edges in alternative forms of the cradle if desired. Likewise, a similar configuration is provided on the opposite outlet side of the cradle shown in <FIG>. On the outlet side, the end walls <NUM> and <NUM> also extend about respective corners 74b, 76b and terminate at sloped curved edges 74d, 76d which extend from the upper edge of the cradle down to the base.

The cradle <NUM> substantially encapsulates the water tub <NUM> about at least the opposing end walls of the water tub and additionally corner portions of the water tub <NUM>. As shown in <FIG> and <FIG>, in this embodiment the perimeter wall of the cradle is discontinuous such that the walls of the cradle do not encircle or surround the entire perimeter walls of the water tub <NUM> completely or continuously, thereby leaving a portion or portions of the water tub wall exposed (not covered by the cradle). In this embodiment, the cradle walls are discontinuous on each side of the cradle such that the majority of the side walls of the water tub <NUM> are exposed (i.e. not covered by the cradle walls). For example, in this embodiment the opposed end walls <NUM> and <NUM> terminate at edges on the sides of the cradle at or towards their respective ends. It will be appreciated that displacement or distance between the terminating edges of the end walls <NUM> and <NUM> on each side may be varied to expose more or less of the water tub side wall portion as desired. For example, either or both of the end walls may terminate at or toward the centre of the wall or more toward the corner portion of the walls.

In use, the cradle provides a thermally insulated barrier or surface which the user may grasp or hold the humidification chamber by after removing the chamber from the respiratory device for refilling or cleaning for example. This enables the user to avoid direct contact with the heated thermally conductive water tub, and thereby avoid potential burns or discomfort. Additionally, the removability of the water tub from the cradle allows for both parts to be cleaned thoroughly.

Referring to <FIG>, the water tub <NUM> is shown in isolation. As previously mentioned water tub <NUM> is typically formed from sheet metal or similar and operates as a receptacle or container for holding a volume of liquid, such as water. As shown, the water tub <NUM> has a shape that is complimentary to the cradle such that the water tub <NUM> may be snugly received into the cradle <NUM>, for example via slidable engagement with a friction fit.

In this embodiment, the water tub <NUM> is substantially rectangular with a base or base surface <NUM> from which upwardly extending perimeter walls extend. In particular the water tub <NUM> comprises front <NUM> and rear <NUM> walls and first <NUM> and second <NUM> side walls extending between the end walls. The corner wall portions <NUM> joining the end and side walls are preferably curved or round with a similar curvature or radius that compliments the overall cradle plan view shape explained with reference to <FIG> previously. As shown, one of the corners 90a is larger in radius than the remaining corners to complement the larger corner 66a of the cradle. This configuration allows the water tub to be received in the cradle in a single orientation only to assist the user when assembling the parts together such that the inlets and outlets of the chamber and humidification compartment are correctly aligned with each other. It will be appreciated that the water tub, cradle and lid may have any other profiled corners, including <NUM>° right-angle corners and the profiled corners may be uniformed or non-uniformed from corner to corner.

Referring to <FIG> the upper edge of the perimeter walls is provided with a continuous outwardly extending lip, flange or rim <NUM>. In this embodiment, the lip <NUM> extends substantially horizontally or transversely outward from the vertical perimeter wall at the upper edge of the perimeter wall. The perimeter lip <NUM> is optional. When provided, it is configured to engage, abut or rest upon the upper edges 74e, 76e (see <FIG> and <FIG>) of the end walls <NUM> and <NUM> of the cradle <NUM> and which is more readily visible in the cross-sectional view of <FIG>, for example.

The water tub <NUM> is provided with a heat transfer contact surface or portion <NUM> that protrudes from the underside of the base surface <NUM>. The contact surface <NUM> is preferably integrally formed with the remainder of the water tub. For example, the contact surface <NUM> may be pressed out from the base surface <NUM>. In this embodiment, the contact surface <NUM> is circular and of a diameter substantially complimentary to the central aperture <NUM> provided in the base surface <NUM> of the cradle <NUM> (see <FIG>). In particular, the contact surface <NUM> of the water tub <NUM> is substantially aligned with the complimentary aperture <NUM> of the cradle <NUM> and is of a depth relative to remainder of the base surface <NUM> that enables it to extend through aperture <NUM> so as to protrude below the underside of base surface <NUM> of the cradle as shown in <FIG>. When the humidification chamber <NUM> is inserted into a complimentary humidification compartment in the respiratory device, the protruding contact surface <NUM> of the water tub <NUM> rests upon or abuts a heater base or pad within the compartment, which may be of a complimentary size and shape, although this is not essential. The heat from the heater base is then transferred through the thermally conductive (e.g. metal) contact surface <NUM> to the volume of water within the water tub via conduction as will be appreciated.

In alternative embodiments, the contact surface need not necessarily protrude beyond the remainder of base surface <NUM> of the water tub. For example, in one alternative embodiment, the base surface <NUM> may be planar with a flush contact surface <NUM> and the heater base or pad may be shaped in such that it protrudes through the aperture <NUM> of the cradle for engagement or contact with the base surface <NUM> of the water tub <NUM>. In a further alternative embodiment, the contact surface <NUM> may be recessed relative to the remaining underside of the base surface <NUM> of the water tub, i.e. such that it protrudes upwardly into the water tub. With such an embodiment, again the complimentary heater base or pad may be configured with a height and shape that enables it to protrude through aperture <NUM> in the cradle for engagement into the recess or cavity created by the recessed contact surface in the base of the water tub <NUM>.

In the above embodiments, the contact surface and related componentry is described for a circular contact surface and heater pad, although it will be appreciated that any other alternative shape of contact surface may be employed, including square, rectangular or any other suitable shape.

Referring to <FIG> the lid <NUM> of the humidification chamber <NUM> has a shape when viewed in plan (see <FIG>) substantially corresponds to the shape of the cradle <NUM> and water tub <NUM>. In this embodiment, the lid comprises a main body portion <NUM> which forms upper surface or top of the humidification chamber and has a substantially rectangular overall shape with rounded corners which corresponds to the outer shape of cradle <NUM> and water tub <NUM>. Extending downwardly from the main portion <NUM> are perimeter walls. For example, front <NUM> and rear <NUM> end walls are provided at each end of the main portion as can be seen most clearly in <FIG>. Additionally, first <NUM> and second <NUM> side walls extend along the sides of the main body portion <NUM> between the front and rear end walls <NUM>, <NUM>. The first side wall <NUM> is on the inlet side of the humidification chamber and the second side wall <NUM> is on the outlet side of the humidification chamber. Rounded corner wall portions <NUM><NUM> are also provided which join the side and end walls to form an overall perimeter wall extending vertically downwardly from the substantially horizontally extending main body portion <NUM>.

In this embodiment, a perimeter ledge or flange <NUM> (see <FIG> and <FIG>) is provided about the entire perimeter of the lid. The ledge <NUM> extends outwardly from perimeter walls and in a substantially horizontal direction in this embodiment, although an angled ledge may be used as an alternative. The ledge is provided towards but displaced from the lower edge <NUM> of the perimeter vertical walls of the lid <NUM>. In use, the lower surface of the ledge <NUM> of the lid is configured to abut or engage with the upper surface of the rim <NUM> of the water tub <NUM>. In this embodiment, the outer surface of the lower perimeter wall portion <NUM> of the lid <NUM> below the ledge <NUM> has some clearance (i.e. is displaced by a small amount) from the adjacent inner surface of the upper perimeter wall portion <NUM> of the water tub below the rim <NUM> as shown in <FIG>. This allows the lid to engage and disengage with the water tub without the user being required to apply significant force. In this embodiment, the lower perimeter wall portion <NUM> of the lid acts as a water guard or shield in that it deflects water from splashing out between the lid and water tub, and additionally assists in aligning the lid into engagement with the water tub when a user is closing the chamber. It will be appreciated that other embodiments may be configured for a tighter friction fit such that the lower perimeter wall portion <NUM> of the lid abuts or contacts the upper perimeter wall portion <NUM> of the water tub.

Referring to <FIG>, the lid <NUM> is provided with one or more water fill apertures or holes through which water may be poured to fill or refill the water tub <NUM> of the humidification chamber. In this embodiment, two identical water fill holes generally indicated at <NUM> are provided, one at or toward front end of the lid and the other at or toward the rear end of the lid, although the location of the water fill holes may be varied from this configuration. In this embodiment, each water fill hole is provided by a funnel-like formation which extends into the humidification chamber from the main body portion <NUM> of the lid. For example, each water fill hole <NUM> is provided with a frusto -conical formation <NUM> having a first end flush with the main body portion <NUM> of the lid and extending down into the humidification chamber with a progressively reducing diameter to terminate at a second end corresponding to the water fill aperture edge <NUM>, which in this case is circular. It will be appreciated that the funnel-like formation of the water fill holes is optional, but helps reduce splashing or spillage during filling of the chamber. In an alternative embodiment, the water fill holes may simply be apertures formed in the main body portion, circular or otherwise, without any such guiding funnel-like formation.

In this embodiment, each water fill hole <NUM> is provided with one or more concentric circular raised sealing ribs <NUM> or protrusions extending about the perimeter of the water fill hole. These sealing ribs <NUM> may be integrally formed with the lid or attached to the lid. The sealing ribs <NUM> may be formed of a rigid or hard plastic such that a soft seals may sealingly engage with the ribs to close the water fill holes. By way of example, the soft seals may be provided on the lid of the humidification compartment within which the chamber is located in use. In an alternative embodiment, the ribs <NUM> may be a soft overmoulded plastic or rubber or silicone for sealingly engaging with a hard surface or formations provided on the lid of the humidification compartment to close the water fill holes when in use within the respiratory device.

Referring to <FIG>, the humidification chamber <NUM> may comprise at least one water level indicator which is configured to provide the user with at least an indication as to when the water level is approaching a maximum water level. In this embodiment, a water level indicator <NUM> is provided for each water fill aperture <NUM> and is in the form of a tab water level indicator <NUM> comprising a tab or member that is supported from the lid and which extends down into the interior volume of the humidification chamber, and in particular into the region defined by the water tub <NUM>.

The lid <NUM> of the humidification chamber <NUM> is provided with a gases inlet through which a pressurized gases stream generated by the blower of the respiratory device may flow through into the interior of the humidification chamber <NUM>. Referring to <FIG>, the gases inlet <NUM> is provided on the inlet side <NUM> of the humidification chamber <NUM>. As shown in <FIG> the gases inlet <NUM> is provided in a form of an aperture, in this case rectangular but could be any other shape such as circular or otherwise, provided through the inlet side perimeter wall <NUM> of the lid <NUM>. In this embodiment, the gases inlet <NUM> is centrally located along the perimeter wall <NUM>, although this position may be varied. Referring to <FIG>, in this embodiment the inlet aperture <NUM> is provided with an associated inlet channel or conduit <NUM> that channels or directs the inlet gases flow stream into a central zone or region of the lid before exiting the conduit <NUM> into the interior of the humidification chamber. In this embodiment, the inlet conduit <NUM> extends between a first end 142a located at the inlet aperture of the wall <NUM> and terminates at a second end 142b located toward a central zone of the lid. The hollow inlet conduit <NUM> has a cross-sectional shape that corresponds to the shape of the inlet aperture <NUM> and extends inwardly in a substantially horizontal direction from the vertical perimeter wall <NUM> of the lid <NUM>. The inlet conduit <NUM> extends into a central zone of the lid to assist in minimizing or reducing water backflow into the blower and device if the respiratory device is accidently tilted or tipped over from its normal upright operating orientation.

In this embodiment, the gases inlet <NUM> and inlet conduit <NUM> is located at or toward the top of the lid. However, in alternative embodiments, the lid may be deeper with taller perimeter walls, and the inlet <NUM> and conduit <NUM> may be displaced away from the top of the lid, for example located at or toward the bottom of the lid. Such a configuration provides a volume of space above the inlet in the lid for water to collect during tilting of the chamber, and may reduce the likelihood of water backflow through the inlet.

At the exit of the inlet conduit <NUM>, a flow directing formation <NUM> is provided for directing the gases stream exiting the inlet conduit. In this embodiment, the flow direction formation <NUM> is in the form of a curved inverted ramp surface that begins at or towards the main body portion <NUM> of the lid at the exit end 142b of the inlet conduit <NUM> and terminates at a first side 146b of a vertical flow panel <NUM> which extends downwardly from the main body portion <NUM> of the lid. This configuration causes some of the incoming gases stream to turn back upon itself back toward the inlet walls of the humidification chamber where it is humidified before circulating back around past the side edges 146e of the flow panel <NUM> toward the outlet of the humidification chamber. The configuration also assists in directing the air flow directly into the surface of the water to increase the absorption of moisture from the water into the incoming gases. The vertical flow plane <NUM> is displaced from the exit end 142b of the inlet conduit <NUM>.

<FIG> shows the first side 146b of the vertical flow panel <NUM>. In this embodiment, the width (W) of the vertical flow panel <NUM> or baffle is shorter than the overall length of the humidification chamber from the front end <NUM> to the rear end <NUM> but preferably wider than the width (WI) of the inlet conduit <NUM>. In this embodiment, the height (H) of the vertical flow panel is such that it's lower edge 146a at least extends below the lower edge 142a of the inlet conduit <NUM>- and typically extends further at least below the horizontal maximum water level line, indicated by the indicator formations <NUM> of the tab water level indicators. In this embodiment, the lower edge 146a of the vertical flow plane 146a is situated between the maximum water level indicator formation <NUM> and the lower base surface <NUM> of the water tub <NUM>, but may in an alternative embodiment extend substantially to the bottom surface <NUM> of the water tub <NUM>. Preferably, the height of the vertical flow panel <NUM> is such that its lower edge 146a extends into or through the surface of the volume of water in the water tub <NUM>, for at least water volumes that reach the maximum water level line, and more preferably the lower edge 146a is configured to extend into the surface of the water for at least a portion of water volumes below the maximum water level line, and even more preferably all water volumes (i.e. where the lower edge 146a extends substantially to the base surface of the water tub). Typically, the height of the flow panel is configured such that it protrudes or penetrates sufficiently deeply into the surface of the water to prevent gases exiting the inlet conduit <NUM> from passing underneath the lower edge 146a and directly to the outlet conduit <NUM>, such that the gases are forced to flow around the flow panel and increasing the path the gases take around the chamber while exposed to the water vapour before exiting the chamber. If the height of the flow panel is too short such that gases can travel under the flow panel directly to the outlet, then this results in a shortened flow path and reduced humidification, and can also result in the gases stream blowing or splashing water into the outlet conduit <NUM> as the gases stream travels back up from underneath the flow panel.

Referring to <FIG> and <FIG>, a gases outlet <NUM> is provided on the opposite side of the humidification chamber to the gases inlet <NUM>. In this embodiment, the gases outlet <NUM> is provided on the outlet side perimeter wall <NUM> of the lid <NUM> of the humidification chamber and like the gases inlet <NUM> is centrally located relative to the front and rear ends of the humidification chamber, although this is not essential. The gases outlet <NUM> comprises an aperture extending through the perimeter wall <NUM> that is substantially rectangular, although other shaped apertures such as circular or otherwise could alternatively be utilized. Once the gases are heated and humidified in the humidification chamber, the gases stream exits the humidification chamber via gases outlet <NUM>.

Referring to <FIG> and <FIG>, in this embodiment the gases outlet <NUM> comprises an outlet conduit <NUM> that extends into a central zone or region of the lid of the humidification chamber from gases outlet aperture in a horizontal or perpendicular direction relative to the perimeter wall <NUM>. In particular, the outlet conduit <NUM> extends from a first end 152a located at the aperture of the gas outlet <NUM> in the wall <NUM> and extends into the interior of the lid <NUM> and terminates at second end 152b. In this embodiment, the second end 152b of the outlet conduit <NUM> abuts or engages with the second side 146c of the vertical flow panel <NUM>. At or toward the second end 152b of the outlet conduit <NUM> are provided one or more inlet apertures through which gases in the humidification chamber may enter the conduit <NUM> and may exit the humidification chamber via the gases outlet <NUM>. In this embodiment, the outlet conduit <NUM> is substantially rectangular having lower 152c and upper 152d walls and left 152e and right 152f side walls which extend along its length. In this embodiment, two main inlet apertures 154a and 154b are provided at or towards the second end 152b of the inlet conduit in each of the side walls 152e and 152f such that inlets open toward either the front or rear ends of the lid. In this embodiment, the inlet apertures 154a, 154b are substantially rectangular, but may be circular or otherwise. As shown in <FIG> and <FIG> vertical wall formations 155a, 155b extend up from the lower wall 152c of the conduit in the region of each respective inlet aperture 154a, 154b. The wall formations 155a, 155b act as water splash barriers and are configured to force the gases stream to move up around the wall before entering the apertures 154a, 154b rather than moving directly into the apertures from the surface of the water directly underneath the apertures. This configuration reduces the likelihood of water being picked up or carried by the gases stream (particularly at high flow rates) and entering into the outlet conduit <NUM>. It will be appreciated that the inlet conduit <NUM> need not necessarily extend all the way into contact with the vertical flow panel <NUM>, and may alternatively terminate at a position between the vertical flow panel <NUM> and side wall <NUM> of the lid.

As described above, the gases inlet <NUM> and the gases outlet <NUM> have associated conduits <NUM> and <NUM> for creating the desired gas flow path within the humidification chamber to maximize humidification, although it will be appreciated that these conduits are not essential. In an alternative embodiment the gases inlet <NUM> and gases outlet <NUM> may simply be apertures in the side walls without conduits extending into the interior of the humidification chamber.

When inlet and outlet conduits <NUM>, <NUM> are provided, it will be appreciated that these need not necessarily enter the chamber lid centrally from opposite sides at a perpendicular angle to the respective perimeter walls. The conduits may be located at corners of the lid and may enter the chamber at any desired angle. Additionally, the conduits need not necessarily be straight conduits, but could be non-straight, and include one or more bends or turns.

As will be appreciated, the gases inlet <NUM> and gases outlet <NUM> of the humidification chamber may be connected into the gas flow path of the respiratory device in various ways. It will be appreciated that the gases inlet <NUM> may be coupled or fluidly connected into the gases flow path by one or more conduits, connectors, and/or gaskets that are coupled to the gases flow path exiting the blower, in a sealed or non-sealed configuration. Likewise, gases outlet <NUM> may be coupled in any suitable manner, including connectors, conduits and/or gaskets in a sealed or non-sealed configuration to the gas flow path leading to the gases outlet of the respiratory device, which is in turn connected to a patient interface, such as a flexible gases delivery conduit and user interface, as previously discussed.

In this embodiment, as described with reference to <FIG> previously, the chamber is retained within a sealable humidification compartment comprising a gases inlet that is fluidly connected to the blower outlet and a gases outlet that is fluidly connected to the main gases outlet of the respiratory device, which is typically coupled or connectable to a patient interface. In this embodiment, the gases inlet <NUM> of the chamber is not sealingly connected to the inlet of the compartment but rather open to the pressurized gases entering the sealed compartment. Alternatively, a sealed connection between the inlet of the chamber and compartment may be employed. In this embodiment the gases outlet <NUM> of the chamber is preferably sealingly connected or coupled via a gasket or other sealed connection configuration to the gases outlet of the humidification compartment or at least closely aligned to each other to minimize gas bypassing the chamber directly to the compartment outlet.

As previously mentioned, the lid <NUM> is hingedly coupled or connected to the cradle <NUM> such they are moveable between an open position in which lid is pivoted away from the cradle to enable the water tub <NUM> to be removed from the cradle (or to allow the tub to be filled with water or cleaned with the lid open) and a closed position in which the lid pivots into engagement with the cradle to encapsulate and secure the water tub between the lid and cradle. In this embodiment, the lid <NUM> is pivotal about a hinge located at the rear end of the chamber between the closed position or configuration as shown in <FIG> and the open position or configuration as shown.

In this embodiment, one or more hinges are located at the rear end of the humidification chamber which are configured to hingedly couple the lid <NUM> to the cradle <NUM>. Referring to <FIG> in this embodiment, a single elongate living hinge <NUM> extends along a portion of the rear end of the humidification chamber between the lid <NUM> and cradle <NUM>. In particular, the living hinge <NUM> is a thin flexible plastic hinge that is integrally formed and coupled between a portion of the upper edge 76e of the rear wall <NUM> of the cradle and a portion of the ledge <NUM> at the rear end of the lid <NUM>. However, it will be appreciated that two or more hinges may be provided along the rear end of the humidification chamber between the lid and cradle and the hinges need not necessarily be integrally formed living hinges but may be hinges or hinging mechanisms that are formed separately and attached or fixed to the lid and cradle.

To secure the humidification chamber in the closed configuration one or more operable clips or clipping mechanisms are provided and are operable between a latched or locked position for securing the humidification chamber in a closed position, or an unlatched or unlocked position to enable lid <NUM> to be pivoted away from the cradle into the open position or configuration.

Referring to <FIG> and <FIG>, in this embodiment, a single operable clip <NUM> is provided or fixed to the lid <NUM> and which is resiliently moveable between an engaged position and disengaged position with a complimentary catch <NUM> provided on the cradle <NUM>. In particular, the clip <NUM> is provided in a central location on the front wall <NUM> of the lid <NUM>. Referring to <FIG>, in this embodiment the operable clip <NUM> is in the form of a torsion clip that is moveable between an engaged and disengaged position relative to the complimentary catch <NUM> provided on the cradle <NUM>. The clip <NUM> comprises a user contact portion <NUM> that may be pressed by a user to move or pivot the clip into a disengaged position and an engagement tab portion <NUM> which comprises an engagement aperture 176a. In use, the catch <NUM> is a protrusion or engagement formation that protrudes from the front wall <NUM> of the cradle and is aligned with the clip such that it engages into engagement aperture 176a of clip <NUM> when the clip is in a latched or locked position to thereby secure the lid <NUM> to the cradle <NUM>.

As shown, the clip <NUM> is mounted to the lid <NUM> via torsion members 178a, 178b which extend from each side of the clip at an intermediate position between the end of engagement tab portion <NUM> and user contact portion <NUM>. The torsion members 178a, 178b are longitudinally aligned and define a pivot axis DD about which the clip <NUM> may pivot or rotate relative to the lid <NUM> between a rest (engaged, latched) position shown and an unlatched or disengaged position to enable release of the lid from the cradle. As shown, the user contact portion <NUM> is located adjacent front wall <NUM> of the lid while the engagement tab portion <NUM> extends downwardly below the ledge <NUM> and lower edge of the lid <NUM>. The torsion members 178a, 178b each extend between a respective support strut 180a, 180b provide on the front wall <NUM> and a side of the clip <NUM>. In this embodiment, the torsion members 178a, 178b are substantially cylindrical (although could have a different cross-sectional shape along their length like square, rectangular or otherwise) and are configured to provide a small degree of twist or flex about their longitudinal axis to thereby enable the clip to pivot or rotate about the pivot axis DD. As shown, the clip <NUM> is biased into or toward its rest position by the torsion members 178a, 178b.

In use, when the lid <NUM> is moved from the open position to the closed position the tip of the engagement tab <NUM> engages a camming surface 172a on the catch <NUM> which causes the clip to pivot outwardly away from the Ud front wall <NUM> in direction F as shown in <FIG>. Once the lid <NUM> is brought into full engagement with the cradle <NUM>, the catch <NUM> snaps into full engagement with the engagement aperture 176a of the engagement tab portion <NUM> to thereby allow the clip to return and spring-back into its rest position thereby latching the lid securely to the cradle without the user needing to operate the clip in order to engage it with the aperture. To release the clip mechanism to enable the humidification chamber to be opened, a user simply presses upon the user contacting portion <NUM> to move it toward the front wall <NUM> of the lid in direction E as shown. This causes the engagement tab to again rotate in direction F away from the front wall about the pivot axis DD to thereby disengage the engagement aperture 176a from the complimentary catch <NUM>, thereby enabling the lid <NUM> to be fully pivoted away from the cradle <NUM> into the open configuration. Once the user releases the pressure on the user contacting portion <NUM>, the clip reverts back to its rest position ready for latching again when the humidification chamber is closed.

As shown in <FIG>, the front wall <NUM> of the lid is provided with two limit protrusions <NUM> on the front wall of the chamber behind the user contacting portion <NUM>, which act to stop the user from over-rotating or twisting the clip to prevent breakage of the clip mechanism. Guide formations <NUM> are optionally provided on either side of the catch <NUM> which protrude from the front wall <NUM> of the cradle <NUM>. In use, the guide formations <NUM> are displaced a sufficient distance apart such that the engagement tab portion <NUM> of the clip may fit between the guide formations <NUM> when in the engaged position.

The clip <NUM> is mounted to the lid and the catch <NUM> to the cradle in the embodiment shown, but it will be appreciated this may be reversed if desired such that the clip may be fixed to the cradle and the catch to the lid.

It will be appreciated that various other alternative clip arrangements or mechanisms may be employed for securing the lid <NUM> to the cradle <NUM> of the humidification chamber. Two or more operable clips or latches may be provided around the periphery of the humidification chamber on one or multiple walls as required. Other examples of various clipping mechanisms will be explained with reference to alternative embodiments of the humidification chamber below and it will be appreciated that such clipping mechanisms be employed in this first embodiment of the humidification chamber also.

Referring to <FIG>, in this embodiment there is no flexible seal (e.g. silicone or rubber, or otherwise) provided about the perimeter of the humidification chamber between the lid <NUM> and water tub <NUM>. The pressure created by the clipping mechanism when the humidification chamber is closed is considered sufficient to reduce or minimize leakage of gases and/or water at the interface between the lid <NUM> and water tub <NUM>. Also, additional downward pressure may be applied upon the lid <NUM> when located within the humidification compartment of the respiratory device. For example, the lid of the humidification compartment may be configured to press down or engage with the lid <NUM> of the humidification chamber to thereby exert downward force on the lid <NUM> into a more tightly closed configuration. As the chamber is located in a pressurised humidification compartment, the pressure difference between the outside and inside of the chamber is negligible or near zero. This substantially neutral pressure differential results in minimal tendency for a flow of air out of or into the chamber via the interface or perimeter boundary between the lid and water tub, and therefore sealing is typically not required.

However, it will be appreciated in alternative embodiments one or more flexible seals may be provided about the perimeter of the humidification chamber between the lid <NUM> and water tub <NUM> to further minimize any possible gas and/or water leakage from the humidification chamber at the interface between the water tub and lid. For example, referring to a perimeter flexible seal may even be mounted to either or both of the rim <NUM> of the water tub <NUM> or to the lower edge <NUM> or ledge <NUM> of the lid <NUM>. Referring to <FIG>, one possible sealed chamber configuration is shown in which a perimeter recess or groove is provided on the underside of the ledge <NUM> of the lid about the entire chamber perimeter and a seal, for example a silicone or rubber o-ring or the like, is mounted or located within the groove for sealingly engaging with the rim <NUM> of the water tub when the chamber is closed.

Referring to <FIG>, a further possible sealed configuration is possible with a flexible closure (e.g. silicone or rubber, or otherwise) <NUM> provided which may be mounted upon the lid <NUM> of the humidification chamber (see <FIG>) and releasably sealed about either or both of the lid <NUM> and the cradle <NUM> of the humidification compartment (see <FIG>). The flexible closure <NUM> may be configured to engage with the shape of the lid <NUM> of the humidification chamber for a more tightly closed sealing configuration and thereby reducing any residual moisture or gases which may otherwise accumulate about the lid <NUM> when in use.

As mentioned, various alternative clipping mechanisms may be utilized for securing the lid <NUM> to the cradle <NUM> of the humidification chamber <NUM>. These may be as described in international patent application <CIT>.

It will be appreciated that various other water level indicators to assist the user in identifying when they have filled the water tub to the maximum water level line could be used, some non-limiting examples of which may be as described in international patent application <CIT>.

Referring to <FIG>, a second embodiment of the humidification chamber <NUM> will be explained. The humidification chamber <NUM> is substantially similar to the first embodiment. As shown, the lid <NUM> is substantially similar to the first embodiment although it comprises a different clip mechanism <NUM> on the front wall. In this embodiment, the clip <NUM> is a U-shaped member mounted to the front wall and which has a degree of flex about the axis indicated at II on <FIG>. As shown on <FIG>, the clip <NUM> engages securely with a catch formation <NUM>. Referring to <FIG>, the catch formation comprises an elongate formation having a substantially triangular cross-section. In particular, an angled front camming surface <NUM> extends downwardly and outwardly from the front wall and a substantially horizontal engagement surface <NUM> returns back to the front wall from the lower edge of the front camming surface <NUM>. The U-shape clip <NUM> comprises two vertical legs <NUM> which extend downwardly from the lid and are joined by a cross-member <NUM>. In use the cross-member <NUM> engages with the camming surface <NUM> of the catch formation <NUM> as the lid is brought into engagement with the cradle <NUM> until snapping or locking into full engagement with engagement surface <NUM>.

As to other aspects, the second embodiment humidification chamber <NUM> is substantially similar to the first embodiment, and comprises a plastic lid <NUM> that is hingedly coupled with a plastic cradle <NUM> which receives a metal water tub of the type previously described. The primary difference of the second embodiment humidification chamber <NUM> is that the cradle is substantially continuous about the peripheral wall of the water tub such that it substantially encapsulates and surrounds the entire water tub peripheral wall surface.

Referring to <FIG>, a third embodiment humidification chamber <NUM> will be described in further detail. The humidification chamber <NUM> is similar in overall shape to the previous embodiments, and where applicable similar features are represented by similar drawing reference numerals. It will be appreciated that the description of the previous embodiments in relation to similar features, including variants or alternatives, also applies to this embodiment and will not be repeated. The following description focuses on the differences of the third embodiment relative to the previous embodiments.

The primary difference with the third embodiment humidification chamber <NUM> is that it is a two-part chamber assembly, rather than a three-part chamber assembly like the previous embodiments. The phrases "two-part" and "three-part" assemblies are intended to refer to the number of main components of the assembly, regardless of whether they are integrally formed or otherwise connected, coupled or assemble together. In particular, the previous embodiments relate to three-part chamber assemblies comprising: an upper part (lid - part one) which is hingedly coupled to open and close relative to a lower part (cradle - part two) which releasably receives and retains a separate water tub (part three). In contrast, this third embodiment humidification chamber <NUM> is a two-part assembly comprising the upper part in the form of a lid <NUM> (part one) that is hingedly coupled at one side to a lower part that is the form of a water tub <NUM> (part two) comprising a thermally conductive metallic heater plate in its base surface.

In this embodiment, the lid <NUM> and water tub <NUM> (except the metallic heater plate) are formed of a rigid plastic by injection moulding, vacuum forming, or some other suitable production process, in a similar manner to the formation of the lid and cradle of the previous embodiments. Typically, the lid <NUM>, water tub <NUM>, and hinged coupling <NUM> between the lid and water tub are integrally formed together as a single item, although in alternative embodiments the lid and water tub may be formed as separate parts and then hingedly coupled via one or more separate hinging components or assemblies. The water tub and/or lid may be substantially transparent or formed as opaque depending on design requirements.

Like the previous embodiments, the humidification chamber <NUM> is operable or moveable between a closed position in which the lid <NUM> is secured to the water tub <NUM> to create an enclosed chamber (as shown in <FIG> for example) and an open position or configuration as shown in <FIG> in which the lid <NUM> is displaced or rotated about the hinge <NUM> away from the water tub to open the chamber for access. One or more operable clips <NUM> or latches are provided at the front end of the humidification chamber for securing or locking the humidification chamber into the closed position ready for insertion and operation within a respiratory device as previously discussed.

Referring to <FIG>, <FIG>, and <FIG>, the water tub <NUM> comprises a base surface <NUM> from which upright sidewalls extend about the periphery of the base surface. As shown, the water tub comprises front <NUM> and rear <NUM> walls at the front and rear ends of the humidification chamber respectively, and first <NUM> and second <NUM> sidewalls extending along the gases inlet and gases outlet sides of the humidification chamber respectively.

Referring to <FIG>, <FIG>, one or more of the walls or portions of the walls may be provided with a reinforcing profile that is configured to resist bending or deformation of the wall surfaces. In this embodiment, each of the sidewalls <NUM>, <NUM> are provided with reinforced portions or regions <NUM>, <NUM> respectively comprising a corrugated or undulating surface profile of alternate furrows and ridges. In this embodiment, the furrows and ridges have a vertical orientation, but it will be appreciated that a horizontal orientation may be used in the alternative if desired. In this embodiment, the thickness of the sidewalls in the reinforced or corrugated regions is substantially uniform such that the ridges and furrows and the transition zones between the ridges and furrows are of a substantially similar wall thickness as can be seen in <FIG>. In alternative embodiments, the thickness of the sidewalls in the reinforced regions may be non-uniform. In this embodiment, the height of each corrugated region extends on the sidewalls from the base surface to an intermediate point below the edge or rim of the water tub as shown in <FIG>, but it will be appreciated that the corrugated region may start at a point above the base surface or alternatively the corrugated region may extend the entire height of the sidewalls if desired. In alternative reinforcing profiles, spaced-apart reinforcing ridges or ribs, whether vertically or horizontally oriented, or may be provided on one or more portions of the side walls, on either the inner or outer surfaces, or both. In such embodiments, the ridges or ribs increase the thickness of the wall in the region of the ridge or rib. In other alternative embodiments, the sidewalls of the water tub <NUM> may be stiffened or reinforced to prevent or minimise bending and/or deformation with a perimeter ledge, lip, or rim extending or protruding outwardly from or at the top perimeter edge of the water tub sidewalls. The rim may be of the type or form shown at <NUM> or 52a in <FIG> for example, i.e. integrally formed about the upper perimeter edge of the sidewalls. The reinforcing rim may be provided in combination with the reinforced regions of the sidewalls or as an alternative instead of the reinforcing regions.

Referring to the side elevation in <FIG>, in this embodiment the humidification chamber <NUM> comprises a convex or domed base surface <NUM> that is curved or rounded outward toward an apex defined by a central heater plate, discussed further next. In alternative embodiments, the base surface <NUM> may be substantially flat.

Referring to <FIG>, <FIG>, and <FIG>, the base surface <NUM> of the water tub <NUM> is provided with a centrally located metallic or thermally conductive heater plate <NUM>. In this embodiment, the heater plate <NUM> is circular and joined or fixed into a complementary circular aperture provided in the centre of the base surface <NUM> of the plastic water tub <NUM> by overmoulding. The heater plate may be formed of a rigid and thermally conductive material, and is typically pressed or shaped from sheet metal, such as aluminium, stainless steel or any other suitable material, or could be formed by die casting for example. In this embodiment, the heater plate <NUM> and complementary aperture in the base surface <NUM> of the water tub are circular, although it will be appreciated that this shape may be varied to provide an integrated heater plate surface of any other alternative shape, including square, rectangular, or any arbitrary shape. In this embodiment, the heater plate <NUM> is substantially flat prior to the overmoulding process but may have a slightly outwardly domed or convex profile caused by compression force from the surrounding domed base surface after the overmoulding process. The compression force or bias which causes the slightly outwardly convex engagement surface of the heater plate reduces or resists the likelihood of the heater plate being deformed inwardly overtime and usage as a deformed inwardly concaved engagement surface would reduce the contact surface area of the heater plate with the heater pad it sits on in the humidification compartment, which would reduce the heat transfer efficiency of the configuration.

In this embodiment, the heater plate <NUM> is provided with a main circular contact surface <NUM> that is configured to protrude or extend beyond the surrounding plastic base surface <NUM> of the water tub <NUM>, to encourage full engagement and heat transfer when the chamber sits on a complementary shaped heater pad in the bottom of the humidification compartment. In this embodiment, the heater plate further comprises an upright or substantially vertical wall portion <NUM> that extends around the periphery of the main contact surface portion <NUM> and an outer substantially horizontal peripheral coupling surface or ledge portion <NUM> that extends outwardly from the top of the wall portion <NUM> around the perimeter of the heater plate. As shown, the main contact surface portion <NUM> and outer coupling ledge <NUM> extend in substantially parallel planes but are displaced vertically from each other by the height of the vertical wall portion <NUM>. As shown, it is the coupling ledge <NUM> of the heater plate <NUM> that is coupled or fixed to the surrounding plastic about the periphery of the central aperture of the base surface <NUM> by overmoulding. In particular, an engagement portion <NUM> of the base surface material about the periphery of the central aperture of the base surface <NUM> is moulded over at least a portion of the coupling ledge <NUM> of the heater plate <NUM>, about its entire periphery.

Referring to <FIG>, in this embodiment the overmoulding process is configured to vary the thickness of the engagement portion <NUM> of the base surface relative to the remainder of the base surface. In this embodiment, the overall thickness <NUM> of the engagement portion <NUM> that is moulded over at least a portion of the coupling ledge <NUM> of the heater plate <NUM> is larger than the thickness <NUM> of the remaining base surface <NUM> of the water tub. This configuration assists in reducing lifting of the plastic of the base surface <NUM> away from the coupling ledge <NUM> of the heater plate after moulding, which in turn reduces the amount of hard water deposit ingress at the transitional interface region between the metal heater plate and plastic base surface. In one arrangement, the thickness <NUM> of an upper portion of the engagement portion <NUM> above the coupling ledge <NUM> of the heater plate <NUM> is similar to or at least as thick as the thickness <NUM> of the remaining base surface, to reduce or minimise lifting of the upper portion away from the coupling ledge <NUM>. As shown, in this embodiment, the thickness <NUM> of a lower portion of the engagement portion <NUM> below the coupling ledge <NUM> may be of smaller thickness than the thickness <NUM> of the upper portion of the engagement portion <NUM> of the base surface <NUM>. In alternative embodiments, the thickness <NUM> of the lower portion of the engagement surface may also be similar to or at least as thick as the thickness <NUM> of the remaining base surface to reduce or minimise lifting of lower portion from the coupling ledge.

It will be appreciated that in alternative embodiments, the heater plate may be a substantially flat circular plate which is secured within the central aperture of the base surface by overmoulding such that it is substantially flush with the remainder of the base surface rather than protruding as described above.

Referring to <FIG>, in this embodiment, the water tub <NUM> is also provided with a continuous horizontal step formation <NUM> extending about the perimeter of the inner sidewall surface. The step formation is displaced a uniform height from the base surface of the water tub about the inner perimeter. The step formation is integrally formed into the sidewalls and may be in the form of an angled step as shown in <FIG>. In this configuration, the step formation <NUM> is located at a height from the base surface that corresponds to a maximum fill line. When the lid of the chamber is in the open position, the user may fill the water tub with water up to the level of the step formation, as an alternative option to using the water fill holes.

The lid <NUM> of the third embodiment humidification chamber <NUM> is substantially similar to the lid <NUM> of the previous embodiments, although there are some main differences, which will be explained in the following. It will also be appreciated that the third embodiment humidification chamber could also use the same lid <NUM> as previously described.

Referring to <FIG>, <FIG> and <FIG>, in this embodiment the lid <NUM> is provided with tab water level indicators <NUM> of the type explained previously with reference to <FIG> and <FIG>. In particular, the tab water level indicators <NUM> comprise an angle tab <NUM> which is suspended below each water fill aperture <NUM> by upright support members <NUM>, <NUM> at each end. In this embodiment, the indicia "MAX" for maximum is printed backwards on the underside surface of the tab portions <NUM> as shown in <FIG>. At least the tab portions <NUM> are formed of transparent plastic such that the indicia "MAX" is presented to the user through in the correct readable format when viewed through the water fill holes <NUM>.

Referring to <FIG> and <FIG>, the inlet side perimeter wall <NUM> of the lid <NUM> is provided with a projection or projections <NUM>, such as bumps or ridges or formations, that extend from the surface of the perimeter wall. In this embodiment, a protrusion <NUM> is provided on each side of the central inlet aperture <NUM> of the lid for engaging with aligned rails provided on the inner inlet gases side wall of the humidification compartment, which will now be explained. Referring to <FIG> shows a lower part of a humidification compartment <NUM> that is shaped and dimensioned with a complementary cavity <NUM> that receives and retains the humidification chamber <NUM>. The lower part of the humidification compartment may be part of the housing or body of a respiratory device of the type previously described. As previously described with reference to <FIG>, the humidification compartment may further comprise an openable lid for sealing or enclosing the compartment once the humidification chamber <NUM> is installed in the cavity. As shown, two vertical rails <NUM> protrude from the inner wall surface of the humidification compartment on each side of the gases inlet <NUM>, which receives a flow of gases from the blower of the respiratory device as explained previously with reference to <FIG>. In this embodiment, each rail <NUM> extends from a first upper end at or toward the height of the gases inlet <NUM> and a second lower end at or toward the floor surface of the compartment. In this embodiment, referring to <FIG> and <FIG>) each rail comprises a first short start ramp portion 806a that tapers or slopes outwardly from the wall surface, and then extends into a second longer return ramp portion 806b that tapers or slopes back toward the inner wall surface. In operation, the protrusions <NUM> on the gases inlet side of the humidification chamber <NUM> are aligned with engagement rails <NUM> on the inlet side of the humidification compartment. As the humidification chamber <NUM> is lowered or inserted down into the humidification compartment, the protrusions <NUM> abut or engage with their respective rail <NUM>, and the rails urge the chamber <NUM> toward the opposite outlet sidewall of the compartment comprising the gases outlet <NUM>, which is shown in <FIG>. This configuration assists in urging and holding the gases outlet <NUM> of the chamber into sealing engagement or connection with the gases outlet <NUM> of the compartment once the chamber is foil inserted or installed. In this configuration, the gases outlet <NUM> of the compartment is provided with a seal <NUM> that extends about the perimeter of the gases outlet <NUM>. The seal may be an elastomer or rubber component or insert for example. As will be explained next, in this embodiment, the gases outlet <NUM> of the chamber is provided with an engagement surface <NUM> that sealingly engages with the seal <NUM> about the perimeter of the gases outlet <NUM> to thereby create a sealed connection between the outlets. In alternative embodiments, it will be appreciated that the seal may be provided on the gases outlet <NUM> of the chamber, or both the outlets of the chamber and compartment may have complementary seals.

Referring to <FIG>, <FIG>, and <FIG>, in the third embodiment humidification chamber <NUM> the gases outlet <NUM> on the outlet side perimeter wall <NUM> of the lid <NUM> comprises an engagement surface or formation <NUM> about the perimeter of the aperture <NUM>. The engagement surface <NUM> is configured to sealingly engage with the seal <NUM> gases outlet <NUM> of the humidification compartment <NUM> when the humidification chamber <NUM> is installed within the compartment. In this embodiment, the gases outlet <NUM> is substantially rectangular and therefore the engagement surface <NUM> is also substantially rectangular and comprises upper <NUM> and lower <NUM> horizontal portions extending along the upper and lower perimeters of the gases outlet <NUM> and side vertical portions <NUM>, <NUM> along the side perimeter portions of the gases outlet <NUM>. In this embodiment, the engagement surface <NUM> is substantially planar about the perimeter or periphery of the gases outlet <NUM> such that it may sealingly engage with a complementary seal <NUM> or outlet surface associated with the gases outlet <NUM> of the humidification compartment <NUM>. In the arrangement shown, the engagement surface <NUM> is preferably angled or tilted outward relative to the vertical outlet side perimeter wall <NUM>. In particular, as shown more clearly in <FIG>, the engagement surface <NUM> is angled such that the upper portion <NUM> is displaced outward from the outlet side perimeter wall <NUM> further than the lower portion <NUM>. In this arrangement the engagement surface <NUM> can be considered as being tilted or pivoted outward about a horizontal axis extending across its surface such that the upper portion of the engagement surface protrudes or is displaced further from the outlet side perimeter wall <NUM> of the lid <NUM> than the lower portion or region <NUM> of the engagement surface. It will be appreciated that the same principles may be applied should the gases outlet and engagement surface be circular or otherwise shaped. The angled engagement surface <NUM> assists in enabling the humidification chamber to be easily received or inserted into the complementary humidification compartment <NUM> and assists in creating a sealed engagement or connection between the gases outlet <NUM> of the chamber and the gases outlet <NUM> of the humidification compartment <NUM>.

Referring to <FIG>, the vertical flow panel <NUM> of the lid <NUM> is modified relative to the previous embodiments. In this embodiment, the vertical panel or plane <NUM> additionally comprises a pair of baffle portions or vanes <NUM> which extend along the side edges <NUM> of the flow panel <NUM> along the full height (H) of the flow panel, and which act as flow deflectors or guides. The side baffles <NUM> protrude or extend away from the first side surface 146b of the flow panel <NUM> along each of its side edges. In particular, the side baffles <NUM> extend substantially perpendicular to the flow plane <NUM> such that they extend towards the inlet side of the lid. In this arrangement, the side baffles <NUM> of the vertical flow panel <NUM> have a width W2 (extending in a direction perpendicular to the surface of the flow panel) that is substantially smaller than the overall width W of the vertical flow panel. In use, the side baffle portions or surfaces <NUM> are configured to minimise or prevent air flow exiting the inlet conduit <NUM> from flowing directly around the side edges 146e of the vertical flow panel toward the gases outlet conduit <NUM>, which a flow path that results in reduced humidification. The side baffles <NUM> force or encourage the air to circulate back toward the inlet side of the humidification chamber and lengthen the general air flow circulation path in the chamber before the gases exit the chamber to enhance the moisture absorption. As previously described, the height (H) of the flow panel <NUM> is typically configured such that it protrudes or penetrates sufficiently deeply into the surface of the water to prevent gases exiting the inlet conduit <NUM> from shortcutting underneath the lower edge 146a and directly to the outlet conduit <NUM>.

As previously mentioned, the upper part or lid <NUM> is hingedly coupled or connected to the lower part or water tub <NUM> such that they are moveable between an open position in which the lid is pivoted away from the water tub (to allow the tub to be filled with water or cleaned with the lid open) and a closed position in which the lid pivots into engagement with the water tub to close the chamber. In this embodiment, lid <NUM> is hingedly coupled to the water tub <NUM> in a similar manner to the hinging coupling between the lid and cradle of the previous embodiments. In particular, the lid <NUM> is pivotable about a hinge located at the rear of the chamber between the closed position or configuration shown in <FIG> and an open position or configuration as shown in <FIG>, for example. As shown in <FIG>, <FIG> and <FIG>, in this embodiment the hinge is a single elongate living hinge <NUM> that extends along a portion of the rear end of the humidification chamber between the lid <NUM> and water tub <NUM>, and is of a form as previously described in the previous embodiments.

To secure the humidification chamber in the closed configuration, one or more operable clips or clipping mechanisms are provided and are operable between a latched or locked position for securing the chamber in the closed position, or in an unlatched or unlocked position to enable the lid <NUM> to be pivoted away from the water tub into the open position or configuration. Referring to <FIG>, <FIG>, <FIG>, in this embodiment the humidification chamber comprises a single operable clip <NUM> and complementary catch formation <NUM> of the type described with reference to Figures 217A and <FIG>. In particular, the clip <NUM> is pivotably mounted to the lid and is moveable into engagement with the catch <NUM> to securely close the chamber or may be disengaged or released from the catch <NUM> to enable the chamber to be opened. As shown in <FIG>, a recessed portion <NUM> is provided on the front wall of the water tub <NUM> in the vicinity of the clip <NUM> to enable a user to grip and pull the tab to disengage the clip from the catch formation <NUM> when desired.

As with the previous embodiments, the third embodiment chamber <NUM> need not necessarily be sealed between the lid <NUM> and water tub <NUM>. However, it may be sealed if desired as shown in this embodiment. Referring to <FIG>, the ledge <NUM> of the lid <NUM> is provided with or forms a perimeter groove or recess and a seal <NUM> is mounted in the groove about the perimeter of the lid in a similar configuration to that described with reference to the embodiment of <FIG>. As shown, the seal <NUM> engages with the upper surface or rim <NUM> of the perimeter wall of the water tub <NUM> when the chamber is closed to seal the chamber. The other seal configurations discussed with reference to <FIG> may also be employed in alternative configurations.

Referring to <FIG>, the fourth embodiment humidification chamber <NUM> is a variant of the second embodiment humidification chamber <NUM>. In this embodiment, the lid <NUM> is not hingedly coupled at one end to a full cradle but rather to a sleeve <NUM> in the form of a continuous perimeter wall that encircles or extends about the entire peripheral wall of the water tub <NUM> as shown. In particular, the sleeve <NUM> leaves the entire base surface <NUM> in the water tub exposed. The sleeve <NUM> is preferably formed of the same material as the lid, for example injection moulded from plastic or similar. The height of the sleeve as indicated at <NUM> may be varied as desired. In this embodiment, the sleeve extends substantially from the upper edge of the rim of the water tub to the base surface of the water tub, but may be thinner and extend only part way down the peripheral wall from the upper edge in alternative embodiments. As shown in <FIG>, the sleeve is prevented from lifting or sliding off the water tub <NUM> by virtue of the lip or rim <NUM> extending outwardly from the upper edge of the water tub <NUM>. Otherwise, the humidification chamber is substantially similar to the previous embodiment and is provided with a living hinge coupling the lid to the sleeve <NUM> along the rear end (not shown) and a clipping mechanism <NUM> at the front, which in this embodiment is of a form described with respect to Figures 16A-16C.

Referring to <FIG>, the fifth embodiment humidification chamber <NUM> (see <FIG>) comprises a plastic lid <NUM> which is releasably coupled to a metal water tub <NUM> (see Figure 30B) via internal clips. The plastic lid <NUM> is substantially similar to the lids of the previous embodiments although comprising a slightly different water level indicator configuration. In particular, there is a water fill hole <NUM> centrally located toward one end of the lid and a conical water level indicator <NUM> located toward one corner of the opposite end of the lid. Additionally, a finger gripping recess <NUM> is provided centrally on the water level indicator end of the lid. The internal structure of the lid <NUM> is otherwise similar, including the gases inlet, gases outlet and vertical flow plane configuration.

The water tub <NUM> is entirely formed from metal such as stainless steel, aluminium or similar. Optionally, a sleeve or cradle of insulating material such as plastic or other thermally insulating material may be provided on the outer peripheral walls and/or underside surfaces of the metal tub to prevent user from burning their hands if picking up the metal tub, although the user may pick up the metal tub via the lid by gripping of the water fill aperture <NUM> and the figure grip recess <NUM> with a finger and thumb for example.

The lid <NUM> is not hingedly coupled to the water tub <NUM> but rather is completely detachably removable from the water tub. Each end of the lid is provided with clips or engagement protrusions <NUM> (only one end visible) which are configured to engage into the complimentary recesses <NUM> provided at each end of the water tub <NUM> at or toward the upper edge of the water tub. Assembling the lid <NUM> with the water tub <NUM> requires the user to press the lid until the clip formations <NUM> engage in the complimentary recesses <NUM>. To release the lid, the user pulls the lid in a vertical direction from the water tub with sufficient force to disengage the clip formations <NUM> from the recesses <NUM>.

Referring to <FIG>, the sixth embodiment humidification chamber <NUM> will be described. This embodiment comprises a plastic lid <NUM> which clips into a complimentary shaped metal water tub <NUM> by a similar manner described above with reference to the fifth embodiment humidification chamber <NUM>. <FIG> shows the inlet aperture <NUM> of the humidification chamber and <FIG> shows the gases outlet <NUM> of the humidification chamber.

Referring to <FIG>, a sealing closure <NUM> is configured for mounting upon a humidification chamber <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> and optionally a humidification compartment <NUM> of a respiratory device <NUM> in which a humidification chamber is positioned as described in previous embodiments with reference to <FIG>.

Mounting the sealing closure <NUM> directly on the humidification chamber may provide one or more advantages over prior art arrangements. For example, the sealing closure is not permanently attached to any component and can be relatively easily removed for cleaning or replacement. The sealing closure <NUM>, as will be described in more detail below, is relatively simply, quickly and easily mounted on the humidification chamber simply by pushing the sealing closure <NUM> onto the chamber. In some examples, the sealing closure <NUM> is mounted on the chamber simply by pushing parts of the sealing closure into the fill apertures of the chamber. Additionally, the sealing closure <NUM> may provide some thermally insulating function which reduces heat loss from the humidification chamber, by virtue of the material of the sealing closure <NUM>, and/or any air pocket(s) that are present between the underside of the sealing closure <NUM> and the humidification chamber.

The sealing closure <NUM> is configured to be releaseably mounted on the humidification chamber, adjacent the water tub, the sealing closure <NUM> being configured to sealingly close the or each fill aperture <NUM> when the sealing closure <NUM> is mounted on and sealingly engaged with the humidification chamber. This sealing of the fill apertures <NUM> is effected by the sealing closure <NUM> sealing over the top of, and around the periphery of, the water tub and/or humidification chamber, and by the sealing closure <NUM> sealingly engaging the region defining and/or adjacent the fill apertures <NUM> directly. The sealing closure provides a double or multiple seal.

The sealing closure <NUM> in this example is configured such that the shape, cross sectional profile, dimensions and features of an undersurface <NUM> of the sealing closure <NUM> are complimentary to the shape, cross sectional profile, dimensions and features of the uppermost surfaces of the humidification chamber upon which the sealing closure <NUM> is mounted.

In the example of <FIG>, the sealing closure <NUM> comprises a pair of sealing formations each configured to sealing engage one of the fill apertures <NUM>, the sealing engagement sealing closed each fill aperture <NUM>.

Each sealing formation comprises a plug <NUM> which projects downwardly from the undersurface <NUM> of the sealing closure <NUM> and at least partially fits inside the fill apertures <NUM>. Each plug <NUM> has a diameter, cross sectional profile, and shape, when viewed from the top and side, which compliment and match the diameter, cross sectional profile, and shape, when viewed from the top and side, of each fill aperture <NUM>. The exterior of each plug <NUM> therefore engages at least the neck surface of the respective fill aperture <NUM>, when the sealing closure <NUM> is mounted on the humidification chamber, and seals closed that fill aperture <NUM> such that vapour and/or liquid in the water tub cannot escape via the fill apertures <NUM>.

The plugs <NUM> may be further provided with inner and or outer mounting formations which in this example comprise gripping protrusions or ribs <NUM> which frictionally engage surfaces of the fill apertures <NUM> to maintain retention of the sealing plugs <NUM> in the fill apertures <NUM>.

The plugs <NUM>, in the illustrated embodiment, may each be further provided with a pair of opposed elongate slots <NUM> formed in the exterior surface of each plug <NUM>, the exterior surface being that surface which sealingly engages with the surfaces of the fill apertures <NUM>. Each slot <NUM> is recessed from the reminder of the sealing surface of the respective plug <NUM>. The slots <NUM> are present to facilitate manufacture, and in particular, moulding, of the sealing closure <NUM>. When under moulding pressure during manufacture, the silicone or rubber material may otherwise not fill the entire plug section. The slots <NUM> create a path of relatively high flow resistance, which encourages the silicone/rubber to flow along a path of lower resistance, namely, through the bottom of the plugs <NUM>. Depending on the manufacturing process involved, slots <NUM> may not be useful and may be omitted.

A central region <NUM> of the sealing closure <NUM>, midway between the opposed ends of the sealing closure <NUM>, between the plugs <NUM>, is shaped, dimensioned and profiled to match the shape, dimensions and profile of a region of a central region of the upper surface of the humidification chamber <NUM>, above inlet and outlet ducts <NUM>, <NUM> of the humidification chamber <NUM>. The region of chamber <NUM> above the ducts <NUM>, <NUM> has a relatively complex shape and profile as a result of the manufacturing process used to manufacture the ducts <NUM>, <NUM>. At least some of this region of the chamber <NUM> is recessed from the remainder of the upper surface of the chamber <NUM>, when viewed from the side and/or end, and various cavities and protrusions are defined. The undersurface of the sealing closure <NUM> is arranged to match and mate with this region of the chamber <NUM>, including in the region above the ducts <NUM>, <NUM> so that the undersurface of the sealing closure <NUM> contacts and sealingly engages as much as possible of that region of the chamber <NUM>. This helps to ensure that moist vapour is not trapped between the sealing closure <NUM> and the chamber <NUM>, and helps to prevent condensation forming between the sealing closure <NUM> and the chamber <NUM>. This part of the sealing closure <NUM> is further provided with a plurality of parallel channels <NUM> extending across the sealing closure from one margin to another. These channels <NUM> may help to allow one half of the sealing closure to pivot relative to the other, about the channels <NUM>, which functions as regions of relative weakness. This enables only one plug <NUM> from one fill aperture <NUM>, whilst the other plug <NUM> remains in the other fill aperture <NUM>.

The sealing closure <NUM> further comprises a peripheral seal <NUM> which extends around the periphery of the sealing closure <NUM>. The peripheral seal <NUM> sealingly engages with the periphery of the humidification chamber <NUM>, and may also sealingly engage with the periphery and/or sidewalls of the humidification compartment <NUM> of the respiratory device <NUM> in which the humidification chamber is received in use. By sealing around the periphery of the humidification chamber <NUM>, the peripheral seal <NUM> may therefore function as a further or secondary or backup seal of the fill apertures <NUM>. By sealing around the periphery of the humidification compartment <NUM> of the respiratory device <NUM>, the peripheral seal <NUM> may function as a seal between the humidification compartment <NUM> and the humidification chamber <NUM>, preventing any gases or vapour in the humidification compartment <NUM> from escaping.

Further reference is made to the enlarged views of <FIG>. The peripheral seal <NUM> comprises a raised bead <NUM> which projects upwardly and radially outwardly from the upper surface of the sealing closure <NUM>. This bead <NUM> may engage and provide a seal against a lid or closure that may be provided to close the humidification compartment <NUM>, when the humidification chamber <NUM> is mounted therein.

Adjacent the raised bead <NUM> is a recessed gully <NUM> which extends around the periphery of the sealing closure <NUM> adjacent the bead <NUM>.

The peripheral seal <NUM> further comprises a downwardly directed skirt <NUM> which depends downwardly from the bead <NUM>. The downwardly directed skirt <NUM> is arcuate in transverse cross sectional profile so that the lower part of the skirt <NUM> is curved downwardly and radially inwardly. The curve of the skirt <NUM> defines a channel <NUM> which extends around the periphery of the sealing closure, and which receives the rim and/or sidewalls of the humidification compartment <NUM> of the respiratory device <NUM>.

The sealing closure <NUM> further comprises downwardly directed wall <NUM>, spaced radially inwardly from the periphery of the sealing closure <NUM>, and extending around the sealing closure <NUM>. The wall <NUM> is provided with corresponding cut-outs <NUM> at the central region of the sealing closure so that the wall <NUM> avoids obstruction with the inlet and outlet ducts <NUM>, <NUM>, when the sealing closure <NUM> is mounted on the humidification chamber <NUM>. The wall <NUM> contacts and sealingly engages with the upper part of the humidification chamber <NUM> to provide an additional sealing function, and also a locating and retaining function in guiding the sealing closure <NUM> onto the humidification chamber <NUM> during assembly.

A hand or finger gripping tab <NUM> may be provided to aid in the user releasing the sealing closure <NUM> from the humidification chamber <NUM> by pulling the tab <NUM> in a vertical direction from the humidification chamber <NUM>. The tab <NUM> may be provided with an aperture <NUM> for hanging or otherwise storing the sealing closure <NUM>.

The sealing closure <NUM>, in this example, is oblong with rounded corners when viewed in plan. One corner has a significantly larger radius than the other three corners, and the gripping tab <NUM> extends from that larger radius corner. The sealing closure <NUM> may be any other shape as required to correspond to the shape of the humidification chamber <NUM> and/or the shape of the humidification compartment <NUM>.

The sealing closure <NUM> is of unitary construction of planar sheet material, being a single component with the features described above formed in the sheet. The sealing closure <NUM> is resiliently deformable and flexible and may be manufactured from any suitable material, such as a rubber and/or silicone material for example. The material, and dimensions of the sealing features, may be selected such the sealing closure <NUM> engages the humidification chamber and deforms sufficiently to form a sealing engagement with the humidification chamber and/or the humidification compartment <NUM>, where required. For example, the plugs <NUM> may resilient deform as they are pushed into the fill apertures <NUM> to sealingly engage therewith.

A sealing closure in accordance with one or more aspects of the above disclosure, may provide one or more advantages over prior art arrangements. For example, the sealing closure may assist in reducing or preventing spillage from the humidification chamber during filling and/or carrying of the humidification chamber. For example, use of a hinged sealing closure may help to reduce condensation dripping from the closure into the chamber at the end of therapy.

Unless the context clearly requires otherwise, throughout the description, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

Although this disclosure has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the scope of the disclosure, whereas the invention is solely defined by the appended claims.

Claim 1:
A humidification chamber (<NUM>) for humidifying gases, comprising:
a water tub (<NUM>) that is configured to receive a volume of water;
a gases inlet (<NUM>) for receiving a flow of gases into an interior volume of the humidification chamber (<NUM>);
a gases outlet (<NUM>) through which a humidified flow of gases may exit the interior volume of the humidification chamber (<NUM>);
one or more fill apertures (<NUM>) in fluid communication with the water tub (<NUM>) such that the water tub (<NUM>) can be filled with water through the one or more fill apertures (<NUM>); and
a sealing closure (<NUM>) configured to be releaseably mounted on the humidification chamber (<NUM>), the sealing closure (<NUM>) being configured to sealingly close each fill aperture (<NUM>) when the sealing closure (<NUM>) is mounted on the humidification chamber (<NUM>) to resist gas and/or vapour escaping from the one or more fill apertures (<NUM>),
wherein the sealing closure (<NUM>) comprises one or more sealing formations configured to sealingly engage a region of the humidification chamber (<NUM>) that defines, or is adjacent, the one or more fill apertures (<NUM>), so as to close the one or more fill apertures (<NUM>), and
wherein each sealing formation comprises a plug (<NUM>) depending from the sealing closure, each plug (<NUM>) being received in a respective fill aperture (<NUM>) and sealing closed the respective fill aperture (<NUM>) when the sealing closure (<NUM>) is mounted on the humidification chamber (<NUM>), and
characterised in that
the humidification chamber (<NUM>) further comprises a peripheral seal (<NUM>) extending around the periphery of the sealing closure (<NUM>), the peripheral seal (<NUM>) being configured to sealingly engage and seal around
the periphery of the humidification chamber (<NUM>).