Humidification chamber for respiratory assistance apparatus

Abstract

To provide an improved humidification chamber.SOLUTION: 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.SELECTED DRAWING: Figure 28A

Description

[Technical field]

[0001] The present invention relates to a humidification chamber for an exhalation assistance device that provides a stream of humidified gas to a user for therapeutic purposes. The respiratory assistance device can provide respiratory assistance to a patient or user in need of a supply of gas for respiratory therapy, such as, but not limited to, humidification and / or flow therapy, and positive airway pressure (PAP) therapy, including but not limited to CPAP therapy, Bi-PAP therapy, and OPAP therapy, commonly used to treat conditions such as obstructive sleep apnea (OSA), snoring, or chronic obstructive pulmonary disease (COPD). [Background technology]

[0002] Respiratory support devices or systems for delivering a flow of humidified warm gas to a patient for therapeutic purposes are well known in the art. Systems providing this type of therapy typically include a structure, such as a blower (also called a compressor, assisted breathing unit, fan unit, flow generator or pressure generator), that transports gas from a gas source to a humidification chamber. Within the humidification chamber, the gas passes over hot water or through warm, humidified air, where it becomes saturated with water vapor. The warm, humidified gas is then delivered from the humidification chamber downstream to a user or patient via a patient interface that includes a flexible gas conduit and a user interface.

[0003] FIG. 1 shows a schematic diagram of one known type of respiratory assistance system 1 for delivering humidified warm gas to a patient. The system 1 includes a housing 2 containing a blower unit 3 and a humidification unit 4. In operation, ambient air 5 is drawn into the blower unit 3. The blower unit 3 generates a stream of pressurized air or gas that is delivered to an inlet 7 of a humidification chamber 8. The humidification chamber 8 contains water, which is heated by a heating pad 9. A stream of humidified warm gas 10 is shown exiting the humidification chamber through a humidification chamber outlet 11 for delivery to a patient or user 12 via a flexible hose or gas conduit 13 and a user interface 14. The blower unit and humidification unit are typically connected via a series of connectors and / or conduits to allow gas to pass from the blower unit to the humidification chamber.

[0004] The user interface 14 shown in Figure 1 is a nasal mask that covers the nose of the user 12. However, it should be noted that in this type of system, a mouth and nose mask, a full face mask, a nasal cannula, or any other suitable user interface could be used in place of the nasal mask shown. A mouth-only interface, i.e., a mouth mask, could also be used. The patient or user end of the conduit could also be connected to a tracheotomy or endotracheal intubation device.

[0005] The humidification chamber 8 typically comprises a rigid plastic receptacle or container that can be filled with a body of water. In one known form, the base of the humidification chamber comprises a circular, thermally conductive metal heating plate that is secured into a complementary opening in the humidification chamber base by overmolding the plastic base along the periphery of the heating plate. The overmolding creates a seal at the interface between the periphery of the heating plate and the surrounding plastic base surface of the humidification chamber. In use, the heating plate contacts a heating pad or base on which the humidification chamber rests, and heats the body of water within the chamber by conduction. Overmolding to bond the heating plate to the plastic chamber base is a complex manufacturing process that can be difficult to control.

[0006] References in this specification to patents, other external documents, or other sources are generally for the purpose of providing content to explain features of the present invention, and unless expressly stated otherwise, the reference to such external documents shall not be construed as an admission that such documents or such sources are prior art in any jurisdiction or form part of the common general knowledge in the art. Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide an improved humidification chamber, or at least to provide the public with a useful option. [Means for solving the problem]

[0008] In a first aspect, the invention resides in a humidification chamber for humidifying a gas in a broad sense, comprising an aquarium configured to receive a body of water, a tray defining an open cavity for receiving the aquarium, a lid hinged to the tray to enclose the aquarium and define an interior space of the humidification chamber, the lid being movable between a closed position in which the aquarium is closed by the lid and an open position in which the aquarium is open, one or more operable clips for securing the lid in the closed position, a gas inlet for receiving a flow of gas into the interior space of the humidification chamber, and a gas outlet through which the flow of humidified gas exits the interior space of the humidification chamber.

[0009] In one form, the lid and tray may be formed of a rigid plastic, for example the lid and tray may be hinged together by a living hinge and integrally formed as one piece.

[0010] In one form, the water bath may be formed from a thermally conductive material, such as, but not limited to, a metal.

[0011] In one form, the water bath may be defined by a base surface and a peripheral wall extending upwardly from the base, and the tray includes a complementary base surface and an upwardly extending peripheral wall, the peripheral wall of the tray being discontinuous along a periphery of the tray to expose one or more portions of the peripheral wall of the water bath held within the tray. In such a form, the heat transfer contact surface may project from the base surface of the water bath, and the tray may be provided with a complementary, aligned opening through which the contact surface of the water bath extends such that it projects beyond the underside of the base surface of the tray.

[0012] In one form, the water reservoir may be removably received in the tray by sliding engagement.

[0013] In one embodiment, the gas inlet and gas outlet are provided on opposite sides of the lid. In such a configuration, the lid may include a vertical flow surface extending downwardly from the underside of the lid in a central region of the lid.

[0014] In one form, the gas inlet may be coupled to an inlet conduit extending between an inlet end of the gas inlet and an outlet end located at or near an upper central region of the interior space of the humidifier chamber and adjacent the first side surface of the vertical flow face, whereby the incoming gas flow enters the interior space of the humidifier chamber at the upper central region thereof. In addition, a flow directing feature in the form of an inverted curved inclined surface may be located between the outlet end of the inlet conduit and the first side surface of the vertical flow face.

[0015] In one form, the gas outlet may be coupled to an outlet conduit that is disposed at or near an upper central region of the interior space of the humidification chamber and extends between an inlet end adjacent the second side of the vertical flow surface and an outlet end of the gas outlet.

[0016] In one form, the lid may include one or more water inlet openings and at least one water inlet opening including an associated maximum water level indicator including a tab member supported from an underside of the lid and extending into the field of view of the interior space of the humidification chamber and directly visible through the water inlet opening.

[0017] In one form, the overall shape of the humidification chamber is defined by front and rear end walls with side walls extending therebetween, the walls extending between an upper surface of the lid and a base surface of the tray, the lid being hinged to the tray at the rear end of the humidification chamber, and at least one operable clip being provided at the front end of the humidification chamber.

[0018] In one form, the chamber may include at least one operable clip provided in the form of a torsion clip that is attached to either the lid or the tray and configured to engage a fastener on either the tray or the lid, respectively. For example, at least one operable clip may be provided that is hinged to either the lid or the tray and configured to engage a fastener on either the tray or the lid, respectively.

[0019] In a second aspect, the invention resides in a humidification chamber for humidifying a gas, comprising: a water basin configured to receive a body of water; a lid hinged to the water basin to enclose the water basin and define an interior space of the humidification chamber, the lid being movable between a closed position in which the water basin is closed by the lid and an open position in which the water basin is open; one or more operable clips for securing the lid in the closed position; a gas inlet for receiving a flow of gas into the interior space of the humidification chamber; and a gas outlet through which the flow of humidified gas exits the interior space of the humidification chamber.

[0020] In one embodiment, the lid may be formed from a rigid plastic. For example, the aquarium may be formed from a rigid plastic and may include a base surface and a peripheral wall extending upwardly from the base, the base surface including a heating plate. In one embodiment, the heating plate may be secured by overmolding within an opening in the base surface of the aquarium. In one configuration, a peripheral mating surface of the heating plate may be secured by overmolding within a peripheral mating portion of the base surface, around the opening of the aquarium, such that the thickness of the mating portion is greater than the thickness of the remaining base surface. For example, the mating portion may include an upper portion of the heating plate above the mating surface and a lower portion below the mating surface, the upper portion being at least as thick as the remaining base surface. For example, the heating plate may be made of metal.

[0021] In one form, the aquarium may further include a step formation along the inner periphery of the wall of the aquarium, the step formation being formed at a height above the base surface of the aquarium corresponding to the maximum water level indicator.

[0022] In one form, the base of the aquarium may be dome-shaped, whereby it curves outwardly to a central apex defined by the heating plate.

[0023] In one form, the peripheral wall of the aquarium may include one or more reinforced regions. For example, the reinforced region of the peripheral wall may include a corrugated surface having alternating ridges and grooves.

[0024] In one form, the lid and basin may be hinged by a living hinge and are integrally formed as one piece.

[0025] In one embodiment, the gas inlet and gas outlet may be located on opposite sides of the lid. In such embodiment, the lid may include a vertical flow surface extending downwardly from the lower surface of the lid in a central region of the lid. In one configuration, the vertical flow surface may further include a pair of side baffles, each extending from a respective side edge of the vertical flow surface toward the side of the lid that includes the gas inlet.

[0026] In one form, the gas inlet may be coupled to an inlet conduit extending between an inlet end of the gas inlet and an outlet end located at or near an upper central region of the interior space of the humidifier chamber and adjacent the first side surface of the vertical flow face, whereby the incoming gas flow enters the interior space of the humidifier chamber at the upper central region thereof. In addition, a flow directing feature in the form of an inverted curved inclined surface may be located between the outlet end of the inlet conduit and the first side surface of the vertical flow face.

[0027] In one form, the gas outlet may be coupled to an outlet conduit that is disposed at or near an upper central region of the interior space of the humidification chamber and extends between an inlet end adjacent the second side of the vertical flow surface and an outlet end of the gas outlet.

[0028] In one form, the gas outlet in the lid may include an engagement surface along a periphery of the gas outlet that is outwardly angled such that an upper portion of the engagement surface is offset outwardly from the lid more than a lower portion of the engagement surface.

[0029] In one form, the lid may include one or more water inlet openings and at least one water inlet opening including an associated maximum water level indicator including a tab member supported from an underside of the lid and extending into the field of view of the interior space of the humidification chamber and directly visible through the water inlet opening.

[0030] 1. In one form, the overall shape of the humidification chamber is defined by front and end walls with side walls extending therebetween, the walls extending between an upper surface of the lid and a base surface of the aquarium, the lid is hinged to the aquarium at the rear end of the humidification chamber, and at least one operable clip is provided at the front end of the humidification chamber.

[0031] In one form, the chamber may include at least one operable clip provided in the form of a torsion clip that is adapted to be attached to either the lid or the aquarium and engage a fastener provided on either the aquarium or the lid, respectively. For example, at least one operable clip may be provided that is hinged to either the lid or the aquarium and adapted to engage a fastener provided on either the aquarium or the lid, respectively.

[0032] In one form, the humidification chamber may further include a sealant along the periphery of the humidification chamber, between the lid and the water reservoir, which seals the humidification chamber when in the closed position.

[0033] In a third aspect, the present invention broadly resides in a respiratory assistance apparatus configured to provide a stream of heated and humidified gas comprising an apparatus gas inlet configured to receive a supply of gas, a blower configured to generate a stream of pressurized gas from the gas supply, a humidifier configured to warm and humidify the stream of pressurized gas, an apparatus gas outlet for the stream of heated and humidified gas, and a flow path for the stream of gas through the respiratory apparatus from the gas inlet, through the blower unit and the humidifier unit to the gas outlet, the humidifier including a sealable humidification compartment configured to receive and hold a removable humidification chamber according to either the first or second aspects of the present invention.

[0034] In one form, the humidification compartment may include a lid movable between an open position to allow removal of the humidification chamber and a closed position to seal the humidification chamber within the humidification compartment.

[0035] In one form, the humidification compartment may include a gas inlet connected to the flow path and receiving a stream of pressurized gas from the blower to create a pressurized humidification compartment, and a gas outlet connected to an apparatus gas outlet of the flow path.

[0036] In one form, the gas inlet of the humidification chamber may open within the humidification compartment and receive an incoming flow of gas from within the pressurized humidification compartment.

[0037] In one form the gas outlet of the humidification compartment may be sealingly connected to the gas outlet of the humidification chamber.

[0038] In one form, the humidification compartment may contain a heating pad, upon which the humidification chamber rests.

[0039] In one form, the devices may be housed within a single housing.

[0040] In one form, the device may be a CPAP breathing device.

[0041] The humidification chamber of the third aspect of the invention may have any one or more of the features described in relation to either the first or second aspects of the invention.

[0042] The term "comprising" as used in this specification and in the claims means "consisting at least in part of". In interpreting each statement in this specification and in the claims containing "comprising", there may be other features present in addition to the features following the term. The related terms (comprise, comprises) are to be interpreted in the same way.

[0043] Reference to a numerical range disclosed herein (e.g., 1-10) is intended to include reference to all rational numbers within that range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6.5, 7, 8, 9, 10) and all rational ranges within that range (e.g., 2-8, 1.5-5.5, 3.1-4.7), and therefore all subranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are merely examples of what is expressly intended, and all possible combinations of numerical values ​​between the minimum and maximum numerical values ​​shall be considered to be expressly set forth in this application in a similar manner.

[0044] As used in this application, the term "and / or" means "and", "or", or both.

[0045] As used in this application, an "s" after a noun refers to the plural and / or singular of that noun.

[0046] The present invention contemplates the above and other configurations which are provided by way of example only in the following description.

[0047] Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0048] [Figure 1] 1 shows a schematic diagram of a known form of respiratory assistance device in which a blower unit and a humidification unit are combined into one main housing; [Diagram 2] 1 shows a schematic diagram of the main components and configuration of a respiratory assistance device which can utilize the humidification chamber of the present invention. [Diagram 3] 1 shows a bottom perspective view of a humidification chamber according to a first embodiment of the present invention, including a lid, a discontinuous drip tray, and a water basin, in a closed state. [Figure 4] FIG. 4 shows a plan view of the humidification chamber of FIG. 3. [Diagram 5] FIG. 4 shows a bottom view of the humidification chamber of FIG. 3. [Figure 6]FIG. 4 shows a side view of the gas inlet side of the humidification chamber of FIG. 3. [Figure 7] FIG. 4 shows a side view of the gas outlet side of the humidification chamber of FIG. 3. [Figure 8] FIG. 4 shows an elevational view of the rear end of the humidification chamber of FIG. 3; [Figure 9] FIG. 4 shows an elevational view of the front end of the humidification chamber of FIG. 3; [Figure 10] FIG. 7 is a cross-sectional perspective view of the humidification chamber in a closed state taken along line AA in FIG. 6. [Figure 11A] 4 shows a top perspective view, a side view, and a bottom perspective view of the water tank of the humidification chamber of FIG. 3. [Figure 11B] 4 shows a top perspective view, a side view, and a bottom perspective view of the water tank of the humidification chamber of FIG. 3. [Figure 11C] 4 shows a top perspective view, a side view, and a bottom perspective view of the water tank of the humidification chamber of FIG. 3. [Figure 12] FIG. 4 shows a bottom view of the humidification chamber of FIG. 3 in a closed state, omitting the water reservoir. [Figure 13] FIG. 4 shows a perspective view of one of the trays and lids of the heating chamber of FIG. 3 in an open position. [Figure 14] 4 shows another perspective view of the tray and lid of the humidification chamber of FIG. 3 in the open position. [Figure 15] 4 shows a top view of the tray and lid of the humidification chamber of FIG. 3 in an open position. [Figure 16] FIG. 4 shows a side view of the tray and lid of the humidification chamber of FIG. 3 in an open position. [Figure 17] FIG. 4 is an enlarged perspective view of the upper side of the humidification chamber lid of FIG. 3. [Figure 18] FIG. 4 is an enlarged perspective view of the underside of the humidification chamber lid of FIG. [Figure 19] FIG. 4 is another enlarged perspective view of the underside of the humidification chamber lid of FIG. 3. [Figure 20] 5 shows a cross-sectional view of the humidification chamber in a closed state taken through line CC in FIG. 4. [Figure 21A] 1 shows a perspective view of a first embodiment of a humidification chamber having a first alternative form of clip mechanism, with the humidification chamber in a closed position; FIG. [Figure 21B]21B shows the humidification chamber of FIG. 21A in the open position and with the water reservoir removed. [Figure 21C] 21B shows an enlarged perspective view of the rear end of the humidification chamber tray and the catch formation of the clip mechanism of FIG. 21A. [Figure 22A] 13 shows the humidification chamber lid of the first embodiment having a second alternative type of configuration of the clip mechanism; [Figure 22B] 13 shows the tray and lid of the humidification chamber of the first embodiment having a third alternative type of configuration of the clip mechanism; [Figure 23A] A perspective view of the humidification chamber of the first embodiment having a clip mechanism of a fourth alternative type is shown in a closed position. [Figure 23B] FIG. 23B shows a side view of the humidification chamber of FIG. 23A. [Figure 24A] A cross-sectional perspective view of a first embodiment of a humidification chamber having a first alternative water level indicator that is a variation of the tab-type water level indicator is shown. [Figure 24B] 24B shows a top view of the water inlet opening of the humidification chamber lid of FIG. 24A, illustrating an alternative form of tab-type water level indicator. [Diagram 25] 2 shows a cross-sectional view of the humidification chamber of the first embodiment having a second alternative type of water level indicator in the form of a cone-shaped water level indicator; [Figure 26] 26 shows a top view of the humidification chamber lid of FIG. 25, illustrating the cone-shaped water level indicator as seen by the user. [Figure 27A] 2 shows a perspective view of a humidification chamber in a closed state according to a second embodiment of the present invention, including a lid, a continuous tray, and a water basin. [Figure 27B] The lid and continuous tray of the second embodiment of the humidification chamber are shown with the lid and continuous tray in the open position and without the water bath. [Figure 27C] A perspective view of the front end of the continuous tray of the humidification chamber of the second embodiment and the fastener of the clip mechanism is shown. [Figure 28A]A first top perspective view of a humidification chamber according to a third embodiment of the present invention, including a lid and a water bath with an overmolded heating plate, in a closed position, showing the rear end and gas inlet side of the humidification chamber. [Figure 28B] FIG. 28B is a second top perspective view of the humidification chamber of the third embodiment of FIG. 28A, showing the front end and gas outlet side of the humidification chamber. [Figure 28C] 28B shows a top view of the humidification chamber of the third embodiment of FIG. 28A. [Figure 28D] 28B shows a bottom view of the humidification chamber of the third embodiment of FIG. 28A. [Figure 28E] FIG. 28B shows a side view of the gas inlet side of the humidification chamber of the third embodiment of FIG. 28A. [Figure 28F] FIG. 28B shows a side view of the gas outlet side of the humidification chamber of the third embodiment of FIG. 28A. [Figure 28G] 28B shows an elevational view of the rear end of the humidification chamber of the third embodiment of FIG. 28A. [Fig. 28H] 28B shows an elevational view of the front end of the humidification chamber of the third embodiment of FIG. 28A. [Figure 28I] A cross-sectional view of the humidification chamber of the third embodiment taken through line EE of Figure 28C. [Figure 28J] An enlarged view of region FF of FIG. 28I is shown. [Figure 28K] 28H, but at an angle showing the angled shape of the gas outlet. FIG. 28C shows an elevational view of the front end of the humidification chamber of the third embodiment, similar to FIG. 28H, but at an angle showing the angled shape of the gas outlet. [Figure 28L] FIG. 13 shows a top perspective view of the humidification chamber of the third embodiment in the open position. [Figure 28M] FIG. 13 is an underside perspective view of the humidification chamber of the third embodiment in the open position. [Figure 28N] FIG. 2 shows another perspective view of the humidifier chamber of the third embodiment in the open position, seen from the gas inlet side of the humidifier chamber. [Figure 28O] FIG. 13 shows a first perspective top view of the lower part of a humidification compartment for receiving a humidification chamber of the third embodiment, with the gas inlet of the compartment visible. [Figure 28P]FIG. 28C shows a second perspective top view of the humidification compartment of FIG. 28O with the gas outlet of the compartment visible. [Figure 28Q] A top view of the humidification chamber of the third embodiment attached to the humidification compartment part of Figure 28O is shown. [Figure 28R] A side perspective view of a humidification chamber of a third embodiment attached to the humidification compartment part of Figure 28O is shown. [Figure 28S] A cross-sectional view of the humidification chamber of the third embodiment attached to the humidification compartment part is shown through line GG of Figure 28Q. [Figure 28T] A cross-sectional view of the humidification chamber of the third embodiment attached to the humidification compartment part is shown through line HH of Figure 28Q. [Figure 29A] 13 shows a perspective view of a fourth embodiment of a humidification chamber including a lid, a sleeve and a water reservoir. [Figure 29B] 13 shows a cross-sectional view of a humidification chamber of the fourth embodiment. [Figure 30A] 13 shows a perspective view of a humidification chamber lid according to a fifth embodiment of the present invention, including a lid that fits into a water basin. [Figure 30B] FIG. 13 shows a perspective view of a water reservoir of a humidification chamber of the fifth embodiment. [Figure 30C] A perspective view of the lid and water basin of the humidification chamber of the fifth embodiment in the assembled and closed state is shown. [Figure 31A] FIG. 13 shows a top perspective view of a humidification chamber according to a sixth embodiment of the invention, including a ducted lid that fits onto the water tub, in a closed state. [Figure 31B] A bottom perspective view of the humidification chamber of the sixth embodiment is shown. [Diagram 32] A perspective view of the water tank of the humidification chamber of the sixth embodiment is shown. [Diagram 33] FIG. 13 shows a first underside perspective view of the ducted lid of the humidification chamber of the sixth embodiment. [Diagram 34] FIG. 34 shows a side view of the ducted lid of FIG. 33. [Diagram 35] FIG. 34 shows a second bottom perspective view of the ducted lid of FIG. 33. [Diagram 36] 4 shows an enlarged cross-sectional view of the rear end of a variation of the first embodiment of the humidification chamber of FIG. 3 having a seal between the lid and the water reservoir. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] The present invention relates to a humidification chamber for a respiratory assistance device (respiratory device) that provides a flow or stream of heated humidified respiratory gas to a user or patient for respiratory therapy, for example, but not limited to, CPAP therapy.

[0050] In this regard, Figure 2 illustrates an example of a general schematic configuration of a respiratory apparatus 20 in which the humidification chamber of the present invention may be utilized, but is not intended to limit the use of the humidification chamber. The respiratory apparatus 20 includes a humidification unit or compartment 22 which receives and holds a removable humidification chamber 24 during use. In this embodiment, the humidification compartment 22 may be formed within the respiratory apparatus housing and may be an openable compartment having a lid so that the humidification chamber 24 therein may be accessed and removed for cleaning or refilling. Typically, the humidification compartment 22 is sealed and / or pressurized when the lid is closed. The humidification chamber 24 is filled with a body of water, as shown at 26, and the chamber 24 rests on a heating pad or base 28. As is known in the art, the heating pad 28 is powered during use and warms the water 26 within the humidification chamber 24 by heat transfer through the base of the humidification chamber 24, at least a portion of which is thermally conductive.

[0051] The respiratory apparatus 20 includes a blower 30 that draws in air or other therapeutic gas through an inlet 32 ​​and produces a pressurized gas stream 34 at the blower's outlet. The outlet of the blower 30 is fluidly connected to an inlet 36 of the humidification compartment 22 via a connecting conduit 38 that extends to the inlet 36 of the humidification compartment 22. When the humidification compartment is closed, it is sealed such that the gas stream 34 entering the inlet 36 pressurizes the compartment and gas flows into a gas inlet 37 of the humidification chamber 24. In an alternative embodiment, the inlets 36, 37 of the compartment 22 and chamber 24 may be sealingly connected by a connector or other sealing arrangement.

[0052] The pressurized gas stream passes through the humidification chamber 24 and exits at a gas outlet 40 of the humidification chamber. In this embodiment, the gas outlet 40 of the chamber 24 is sealingly connected to or sealingly engaged with an outlet 41 of the humidification compartment 22 as shown. Of course, in alternative embodiments, the outlets 40, 41 of the compartment 22 and chamber 24 may not be sealingly connected by a connector or otherwise sealingly engaged. In the illustrated embodiment, the outlet 41 of the humidification compartment 22 is fluidly connected via a connector and / or conduit to a patient interface for delivery to a patient 42. The patient interface generally includes a flexible gas conduit 44 coupled at one end to a main gas outlet of the respiratory apparatus 20 and at the other end to a user interface 46.

[0053] In the following embodiments, the humidification chamber 24 is generally received and held in a complementary, enclosed, sealable humidification compartment 22 formed within the housing of the respiratory apparatus 20. However, it will be appreciated that in other embodiments, the humidification chamber 24 may instead be received and held in an open or exposed compartment or on a support that includes the heating pad 28, with the gas inlet of the chamber connected by a conduit and / or connector to the blower outlet and the gas outlet of the chamber connected directly or indirectly to the patient interface by a conduit and / or connector.

[0054] First embodiment of the humidification chamber - discontinuous tray with lid The humidification chamber 50 of the first embodiment will now be described in more detail with reference to Figures 3-20. As previously mentioned, the humidification chamber 50 is configured to be received and held within a complementary humidification compartment (not shown) provided within the housing of the respiratory device. Typically, the compartment will contain a heating base or heating pad upon which the heating chamber rests. The humidification compartment is accessed via an openable lid to allow the heating chamber 50 to be inserted and removed as required, for example for cleaning and / or refilling.

[0055] As shown in Figure 3, the humidification chamber or chamber assembly 50 includes a tray or lower part, generally indicated at 52, which is shaped to receive and hold a water bath or container 54 of complementary size and dimensions. An upper part, or lid 56, is hinged to the tray 52 and is movable between a closed position (as shown in Figure 3) in which the lid holds the water bath 54 securely within the tray 52, and an open position (see, e.g., Figure 14) in which the lid is pivoted away from the tray 52 to allow the water bath 54 to be removed from the tray, e.g., for cleaning, refilling or replacement. As will be described later, the lid may include flow straighteners in the form of conduits and / or flow surfaces and guide arrangements to control the flow path of the gas stream between an inlet and an outlet within the chamber.

[0056] In this embodiment, the tray 52 and lid 56 may be formed from a rigid plastic by injection molding or otherwise. Typically, the tray 52, lid 56, and the hinge means between these two components are integrally formed with one another as one piece, although in other embodiments the lid and tray may be formed as separate pieces and then hinged together by one or more hinges. The lid and / or tray may be formed to be substantially transparent or opaque depending on design requirements. The aquarium or chamber base 54 is formed from a rigid thermally conductive material and may typically be stamped or molded from sheet metal such as, for example, aluminum, stainless steel, or other suitable material, or may be formed by, for example, die casting.

[0057] Of course, in alternative embodiments, the tray 52, lid 56, and water bath 54 can be formed from other materials or in other ways. For example, the tray 52 and lid 56 can be formed by vacuum forming. The tray and / or lid can also be formed from metal, such as stamped from sheet metal, or by die casting. In alternative embodiments, the water bath can instead be formed from a thermally conductive plastic.

[0058] Humidification chamber shape In this embodiment, the overall shape of the humidification chamber 50 is substantially rectangular, as shown in plan view in FIG. 4. The humidification chamber 50 is defined by a first end 58 and a second end 60 with a first side 62 and a second side 64 extending therebetween. For purposes of this description, the first end 58 will be considered the rear end of the humidification chamber and the second end 60 will be considered the front end. The first side 62 may be considered the inlet side of the humidification chamber because it includes an inlet through which the pressurized gas stream from the blower enters the humidification chamber. The second side 64 may be considered the outlet side of the humidification chamber because it includes an outlet for the humidified gas stream to exit the humidification chamber. Of course, other descriptions of the chamber may consider ends as sides and vice versa, depending on the context.

[0059] In this embodiment, the corners joining the ends 58, 60 and sides 62, 64 are curved or rounded as generally indicated at 66, although this is not critical and the corners may be right angled corners or any other contoured shape. In this embodiment, the corner 66a joining the front end 60 and the inlet side 62 is larger than the remaining corners, although this is not critical. Of course, in other embodiments, the humidification chamber assembly may be formed in any desired shape or contour, including circular or otherwise, and the same construction and configuration principles generally apply.

[0060] Saucer The tray 52 is configured to receive and hold the water bath 54, which has a complementary shape and slightly smaller dimensions so that it can slide into the open cavity formed by the tray. The tightness of the fit between the water bath 54 and the tray 52 may vary. In some embodiments, it may be a tight friction fit, while in other embodiments, it may be a loose fit so that the water bath can easily slide in and out of the tray, preferably with no or minimal force or pressure applied by the user to assemble or disassemble the parts. When the chamber is closed, the tray functions to hold the water bath firmly and precisely against the lid. In particular, the tray generally holds the water bath against the lid around the entire opening of the chamber, preventing / minimizing water splashing between the lid and the water bath. The tray also has the dual function of holding the water bath in place while hinged to the lid, keeping the lid and the water bath aligned, so that the user does not have to align the lid and the water bath when closing the chamber.

[0061] 13, in this embodiment, the tray 52 includes a base or bottom surface 70 upon which the base or bottom surface of the aquarium 54 rests. The base 70 of the tray 52 also includes a central opening 72 through which a heating base or heating pad of a respiratory device may contact a portion of the base of the aquarium 54 for heat transfer to heat the body of water within the aquarium 54, as will be described in more detail below. The tray 52 has a discontinuous peripheral wall, which in this embodiment is in the form of at least one pair of opposing walls extending upwardly from the periphery of the base 70 to form a tray-like formation having an open receiving cavity. In this embodiment, the tray 52 includes a front wall 74 and a rear wall 76 that extend upwardly from the base 70. End wall formations 74, 76 extend along each of the respective front and rear ends of the tray and extend along at least a portion of the periphery of a corner of tray 52, and each end wall formation includes a central planar portion which extends at each respective end of the central planar portion to curved corners shown as 74a, 74b and 76a, 76b.

[0062] In this embodiment, the end wall formations 74, 76 each extend along the entire corner area of ​​the tray and terminate along a respective side of the tray before joining one another, thereby providing an open side wall formation for the tray to expose the water reservoir 54 held within the tray 52. ​​For example, FIG. 6 shows the inlet side of the tray 52 with the front end wall 74 and the rear end wall 76 extending along respective corners 74a, 76a of the tray and along the sides of the tray, each terminating in a sloped curved edge 74c, 76c that extends downwardly from the upper edge of the tray to the base 70. Of course, the terminating edges 74c, 76c need not necessarily slope downwardly in a curved profile, but could be steep vertical edges in alternative configurations of the tray, if desired. Similarly, a similar arrangement is provided on the opposite outlet side of the tray shown in FIG. 7. On the outlet side, end walls 74 and 76 also extend along respective corners 74b, 76b and terminate in angled curved edges 74d, 76d which extend downwardly from the upper edge of the tray to the base.

[0063] The tray 52 encompasses the basin 54 at least along the opposing end walls of the basin and further along the corners of the basin 54. As shown in Figures 6 and 7, in this embodiment, the perimeter of the tray is discontinuous such that the tray walls do not completely or continuously surround or encircle the entire perimeter of the basin 54, thereby leaving a portion or portions of the basin walls exposed (i.e., not covered by the tray). In this embodiment, the tray walls are discontinuous on each side of the tray, thereby leaving a majority of the side walls of the basin 54 exposed (i.e., not covered by the tray walls). For example, in this embodiment, the opposing end walls 74, 76 terminate at edges at or near the respective ends of the sides of the tray. Of course, the offset or distance between the edges at which the end walls 74, 76 on each side terminate may be varied to expose more or less of the side walls of the basin as desired. For example, either or both of the end walls may terminate at or near the center of the wall, or closer to a corner portion of the wall.

[0064] During use, the tray provides an insulating barrier or surface by which a user may grasp or hold the heating chamber after removing the chamber from the respirator, for example for refilling or cleaning. This prevents the user from directly contacting the heated, thermally conductive water bath, thereby avoiding burns and discomfort. Additionally, the ability to remove the water bath from the tray allows for thorough cleaning of both components.

[0065] Aquarium 11A-11C, the water basin 54 is shown by itself. As previously mentioned, the water basin 54 is generally formed from sheet metal or the like and serves as a receptacle or container for holding a liquid, such as a body of water. As shown, the water basin 54 has a shape complementary to the tray 52 such that the water basin 54 may be snugly received within the tray 52, such as by sliding engagement via a friction fit.

[0066] In this embodiment, the water basin 54 is substantially rectangular and has a base or bottom surface 80 from which extends an upwardly extending peripheral wall. In particular, the water basin 54 includes a front end wall 82 and a rear end wall 84, and a first side wall 86 and a second side wall 88 extending between the end walls. Corner wall portions 90 joining the end walls and the side walls are preferably curved or rounded with a similar curvature or radius that is complementary to the general plan view shape of the basin described above with respect to FIG. 4. As shown, one of the corners 90a has a larger radius than the remaining corners and is complementary to the larger corner 66a of the basin. This configuration allows the water basin to be received in the basin in only one orientation and aids the user in assembling the parts so that the inlets and outlets of the chamber and humidification compartment are properly aligned with one another. Of course, the basin, tray and lid may have corners of any other contour, including 90 degree right angle corners, and the corner contours may be uniform or non-uniform from corner to corner.

[0067] 11B, the upper edge of the peripheral wall is provided with a continuous, outwardly extending lip, flange or rim 92. In this embodiment, the lip 92 extends substantially horizontally or laterally outwardly from the vertical peripheral wall at the upper edge of the peripheral wall. The peripheral lip 92 is optional. If provided, it is configured to engage, abut or rest on the upper edges 74e, 76e of the end walls 74, 76 of the pan 52 (see FIGS. 13 and 14), which is more easily seen in the cross-sectional view of, for example, FIG.

[0068] The water bath 54 is provided with a heat-conducting contact surface or portion 94, which protrudes from the underside of the base surface 80. The contact surface 94 is preferably integrally formed with the remainder of the water bath. For example, the contact surface 94 may be extruded from the base surface 80. In this embodiment, the contact surface 94 is circular and has a diameter that is substantially complementary to the central opening 72 (see FIG. 13) provided in the defining surface 70 of the tray 52. ​​In particular, the contact surface 94 of the water bath 54 is substantially aligned with the complementary opening 72 of the tray 52 and is of a depth, relative to the remainder of the base surface 80, such that it exits the opening 72 and protrudes below the underside of the defining surface 70 of the tray 52, as shown in FIG. 6. When the humidification chamber 50 is inserted into a complementary humidification compartment of the respiratory device, the protruding contact surface 94 of the water bath 54 rests on or abuts a heating base or pad within the compartment, the heating base or pad being of complementary size and shape, although this is not critical. Heat from the warming base is then transferred by conduction through the thermally conductive (eg, metallic) contact surface 94 to the body of water in the aquarium.

[0069] In alternative embodiments, the contact surface need not necessarily protrude beyond the remainder of the aquarium base surface 80. For example, in one alternative embodiment, the base surface 80 may be flat and flush with the contact surface 94, and the warming base or pad may be shaped such that it protrudes through the basin opening 72 to engage or contact the aquarium base surface 80. In another alternative embodiment, the contact surface 94 may be recessed relative to the remaining underside of the aquarium base surface 80, i.e., it protrudes upwardly, into the aquarium. In such an embodiment, again, a complementary warming base or pad may be configured with a height and shape such that it can protrude through the basin opening 72 and engage a recess or cavity created by the recessed contact surface in the base of the aquarium 54.

[0070] In the above embodiments, the contact surface and associated components are described in terms of a circular contact surface and heating pad, however, it will be appreciated that any other alternative shape of contact surface may be used, including a square, rectangular or any other suitable shape.

[0071] lid 3 and 4, the lid 56 of the humidification chamber 50, when viewed in plan (see FIG. 4), substantially corresponds to the shape of the drip tray 52 and water basin 54. In this embodiment, the lid includes a main body portion 100, which forms the top surface or upper portion of the humidification chamber and is substantially rectangular in overall shape with rounded corners that correspond to the contours of the drip tray 52 and water basin 54. Extending downwardly from the main portion 100 is a peripheral wall. For example, as best seen in FIG. 18, the main portion includes a front end wall 102 and a rear end wall 104 at each end. In addition, a first side wall 106 and a second side wall 108 extend along the side of the main body portion 100 between the front and rear end walls 102, 104. The first side wall 106 is at the inlet side of the humidification chamber and the second side wall 108 is at the outlet side of the humidification chamber. Radiused corner wall portions 110 are also provided which join the side and end walls to form a total peripheral wall which extends vertically downwardly from the substantially horizontally extending main body portion 100 .

[0072] In this embodiment, a peripheral ledge or flange 105 (see Figures 10 and 18) is provided along the entire perimeter of the lid. The ledge 105 extends substantially horizontally outwardly from the peripheral wall in this embodiment, although an angled ledge may alternatively be used. The ledge is provided toward but offset from a lower edge 107 of the peripheral vertical wall of the lid 56. In use, the underside of the ledge 105 of the lid is configured to abut or engage with an upper surface of the rim 92 of the aquarium 54. In this embodiment, the outer surface of the lower peripheral wall portion 91 of the lid 56 below the ledge 105 has some clearance (i.e., is offset by a small amount) from the adjacent inner surface of the upper peripheral wall portion 93 of the aquarium below the rim 92, as shown in Figure 10. This allows the lid to engage and disengage from the aquarium without the application of significant force by the user. In this embodiment, the lower peripheral wall portion 91 of the lid acts as a water guard or shield in that it prevents water from splashing between the lid and the aquarium, plus aids in aligning the lid and the aquarium when the user closes the chamber. Of course, other embodiments may be configured for a tighter friction fit whereby the lower peripheral wall portion 91 of the lid abuts or contacts the upper peripheral wall portion 93 of the aquarium.

[0073] water supply hole 3 and 4, the lid 56 is provided with one or more water inlets or holes through which water may be poured to fill or replenish the water reservoir 54 of the humidification chamber. In this embodiment, two identical water inlet holes, generally designated 120, are provided, one at or near the front end of the lid and the other at or near the rear end of the lid, although the location of the water inlet holes may vary from this configuration. In this embodiment, each water inlet hole is provided with a funnel-shaped formation that extends from the main body portion 100 of the lid into the interior of the humidification chamber. For example, each water inlet hole 120 is provided with a frusto-conical formation 122 that has a first end that is flush with the main body portion 100 of the lid and extends downwardly into the humidification chamber with a gradually decreasing diameter, terminating at a second end that corresponds to the edge 124 of the water inlet, which in this case is circular. Of course, the funnel-shaped formation of the water inlet hole is optional, but helps to reduce splashing and spilling during filling of the chamber. In alternative embodiments, the water inlet hole may simply be a circular or other opening formed in the main body portion, without any such guide funnel formation.

[0074] In this embodiment, each water inlet hole 120 is provided with one or more concentric circular raised sealing ribs 121 or protrusions extending around the periphery of the water inlet hole. These sealing ribs 121 may be integrally formed with the lid or attached to the lid. The sealing ribs 121 may be formed of a rigid or hard plastic whereby a soft sealant can sealingly engage with the ribs to close the water inlet hole. For example, the soft sealant may be provided on the lid of the humidification compartment in which the chamber is placed during use. In an alternative embodiment, the ribs 121 may be a soft overmolded plastic or rubber or silicone that sealingly engages with a hard surface or formation on the lid of the humidification compartment to close the water inlet hole when used in the breathing apparatus.

[0075] water level indicator 18, the humidification chamber 50 includes at least one water level indicator that is configured to provide a user with an indication that the water level is approaching a maximum water level. In this embodiment, a water level indicator 130 is provided for each water inlet 120 and is in the form of a tab-type water level indicator 130 that is supported from the lid and includes a tab or member that extends downwardly into the interior space of the humidification chamber, particularly into the area defined by the water basin 54. In this embodiment, each water level indicator 130 includes a substantially vertically extending support member 132 that extends downwardly from the underside of the edge 124 of the water inlet opening and terminates in an inwardly extending tab portion or member 134 that extends into a substantially vertical water inlet path area or field of view associated with that water inlet opening. In particular, the tab portion 134 is substantially visible when a user looks directly at the center of the water inlet opening from above, i.e., is located within the field of view of the chamber interior as viewed from the water inlet opening. In this embodiment, the angle between the vertical support member 132 and the tab portion 134 is an obtuse angle, with the tab portion 134 extending at a downward slope from the vertically extending support member 132. As shown in Figures 4 and 18, each tab portion 130 is provided with a maximum water level indicator formation 138. In this embodiment, the maximum water level indicator formation 138 is provided as a triangular formation extending outwardly from either side of the tab portion 134, although it will be appreciated that any other form of indicator could be utilized, including a printed indicator, mark or indicia, such as a printed line or otherwise. The tab portion 134 has a downward slope or incline with respect to the horizontal, providing a warning to the user that the maximum water level is approaching when filling the aquarium and when the water level begins to rise upon contact with the tab portion 134. However, it will be appreciated that in alternative embodiments, the tub portion 134 may be substantially horizontal, thereby providing a 90° or right angle between the tub portion 134 and the vertical support member 132, and in such embodiments, the user will be alerted to filling the aquarium to its maximum level immediately after the water comes into contact with the tub.Of course, the greater the downward slope or incline of the tab portion 134, the more warning is provided to the user that the maximum water level supply is approaching as the water level on the tab gradually approaches the maximum water level indicator formation 138.

[0076] Alternatively, the viewing area associated with the water inlet opening 120 is the visible area of ​​the chamber interior that is visible when a user is directly above the center of the water inlet opening. For example, with reference to Fig. 20, the viewing area can be thought of as an imaginary cylindrical zone that extends downward from the edge 124 of the water inlet opening 120, as shown between the arrows BB in Fig. 20's cross-sectional view of the humidification chamber. As shown, the tab portion 134, including the maximum water level indicator formation 138, is configured to extend into the viewing area of ​​the water inlet opening 120. This means that the water level indicator is directly visible through the water inlet opening and is visible to the user at the same time while filling the water through the same hole.

[0077] Lid entrance The lid 56 is provided with a gas inlet through which a pressurized gas stream generated by a breathing apparatus blower flows into the interior of the humidification chamber 50. With reference to Figures 3-6, the gas inlet 140 is provided on the inlet side 62 of the humidification chamber 50. As shown in Figure 6, the gas inlet 140 is provided in the inlet side peripheral wall 106 of the lid 56 in the form of an opening, which in this case is rectangular but may be circular or any other shape. In this embodiment, the gas inlet 140 is centrally provided along the peripheral wall 106, although this location may vary. With reference to Figure 18, in this embodiment, the inlet opening 140 is provided with an associated inlet passage or conduit 142 which directs or directs the inlet gas flow stream towards a central area or region of the lid before exiting the conduit 142 and exiting into the interior of the humidification chamber. In this embodiment, the inlet conduit 142 extends between a first end 142a at the inlet opening in the wall 106 and a second end 142b near the central area of ​​the lid. A hollow inlet conduit 142 has a cross-sectional shape corresponding to the shape of the inlet opening 140 and extends substantially horizontally inwardly from the vertical peripheral wall 106 of the lid 52. The inlet conduit 142 extends into a central region of the lid to help minimize or reduce the backflow of water into the blower or apparatus in the event that the breathing apparatus is accidentally tilted or tipped from its normal upright operating orientation.

[0078] In this embodiment, the gas inlet 140 and inlet conduit 142 are located at or near the top of the lid. However, in alternative embodiments, the lid may have a higher perimeter and be deeper, and the inlet 140 and conduit 142 may be offset away from the top of the lid, for example, at or near the bottom of the lid. This configuration may provide space above the lid inlet for water to pool when the chamber is tilted, reducing the chance of water backing up through the inlet.

[0079] At the outlet of the inlet conduit 142, a flow directing feature 144 is provided to direct the gas stream exiting the inlet conduit. In this embodiment, the flow directing feature 144 is in the form of a curved downwardly sloping surface that begins at or near the lid main body portion 100 at the outlet end 142b of the inlet conduit 142 and terminates at a first face 146b of a vertical flow panel 146 that extends downwardly from the lid main body portion 100. This configuration causes a portion of the incoming gas stream to return toward the inlet wall of the humidification chamber where it is humidified before circulating again through the side end 146e of the flow panel 146 toward the outlet of the humidification chamber. This configuration also helps direct the air flow directly onto the surface of the water to increase absorption of moisture from the water into the incoming gas. The vertical flow surface 146 is offset from the outlet end 142b of the inlet conduit 142.

[0080] 20 shows a first surface 146b of the vertical flow panel 146. In this embodiment, the width (W) of the vertical flow panel 146, or flow straightener, is less than the overall length of the humidification chamber from the front end 60 to the rear end 58, but is preferably greater than the width (W1) of the inlet conduit 142. In this embodiment, the height (H) of the vertical flow panel is such that its lower end 146a extends at least below the lower end 142a of the inlet conduit 142, and generally extends at least further below the horizontal maximum water line indicated by the indicator formation 138 of the tab-type water level indicator. In this embodiment, the lower end 146a of the vertical flow surface 146 is positioned between the maximum water level indicator formation 138 and the lower base surface 80 of the water basin 54, although in alternative embodiments it may extend substantially to the base surface 80 of the water basin 54. Preferably, the height of the vertical flow panel 146 is such that its lower end 146a extends into or through the surface of the water in the basin 54 for at least the amount of water that has reached the high-water mark, and more preferably, the lower end 146a is configured to extend into the surface of the water (i.e., the lower end 146a extends substantially to the base of the basin) for at least the amount of water that has not reached the high-water mark, and even more preferably, for all amounts of water. In general, the height of the flow panel is configured such that it protrudes or penetrates into the surface of the water a sufficient depth to prevent gases exiting the inlet conduit 142 from passing under the lower end 146a and directly into the outlet conduit 142, thereby forcing the gases to flow around the flow panel and increasing the path the gases have to travel within the chamber and through which they are exposed to water vapor before exiting the chamber. If the flow panel height were too low to allow the gas to flow directly from underneath the flow panel to the outlet, it would result in a shortened flow path, reduced humidification, and could also cause the gas stream to spray or splash water into the outlet conduit 152 as it returns from underneath the flow panel.

[0081] Lid outlet 4 and 7, a gas outlet 150 is provided on the opposite side of the humidification chamber from the gas inlet 140. In this embodiment, the gas outlet 150 is provided on the outlet side peripheral wall 108 of the humidification chamber lid 56 and, like the gas inlet 140, is centrally located with respect to the front and rear ends of the humidification chamber, although this is not critical. The gas outlet 150 comprises a substantially rectangular opening extending through the peripheral wall 108, although circular or other shaped openings could alternatively be utilized. Once the gas has been warmed and humidified within the humidification chamber, the gas stream exits the humidification chamber through the gas outlet 150.

[0082] 12 and 19, in this embodiment, the gas outlet 150 includes an outlet conduit 152 that extends horizontally or vertically with respect to the peripheral wall 108 to a central area or region of the humidification chamber lid. In particular, the outlet conduit 152 extends from a first end 152a at the opening of the gas outlet 150 in the wall 108, extends into the interior of the lid 56, and terminates at a second end 152b. In this embodiment, the second end 152b of the outlet conduit 152 abuts or engages the second face 146c of the vertical flow panel 146. One or more inlet openings are provided at or near the second end 152b of the outlet conduit 152 through which gas within the humidification chamber may enter the conduit 152 and may exit the humidification chamber through the gas outlet 150. In this embodiment, the outlet conduit 152 is substantially rectangular, with a lower wall 152c, an upper wall 152d and a left side wall 152e and a right side wall 152f extending along its length. In this embodiment, two main inlet openings 154a and 154b are provided in each of the side walls 152e and 152f at or near the second end 152b of the inlet conduit, whereby the inlets open towards either the front or rear end of the lid. In this embodiment, the inlet openings 154a, 154b are substantially rectangular, but may be circular or otherwise. As shown in Figures 7, 12 and 19, vertical wall formations 155a, 155b extend upwardly from the lower wall 152c of the conduit within the region of each of the respective inlet openings 154a, 154b. The wall formations 155a, 155b are configured to act as a water splash barrier and cause the gas stream to rise around the walls before entering the openings 154a, 154b, rather than moving from the surface of the water just below the openings directly into the openings. This configuration reduces the likelihood that water will be entrapped or carried away by the gas stream (especially at high flow velocities) and enter the outlet conduit 152. Of course, the inlet conduit 152 need not necessarily extend all the way to contact the vertical flow panel 146, but instead may terminate at some location between the vertical flow panel 146 and the lid sidewall 108.

[0083] Lid inlet and outlet connections As previously mentioned, the gas inlet 140 and gas outlet 150 have associated conduits 142 and 152 for establishing the desired gas flow paths within the humidification chamber to maximize humidification, although it will be appreciated that these conduits are not critical. In alternative embodiments, the gas inlet 140 and gas outlet 150 may simply be openings in the side walls with no conduits extending into the interior of the humidification chamber.

[0084] If inlet and outlet conduits 142, 152 are provided, it will be appreciated that they do not necessarily need to enter the chamber lid from opposite sides, centrally, and perpendicular to their respective peripheral walls. The conduits may be located at corners of the lid and may enter the chamber at any desired angle. In addition, the conduits do not necessarily need to be straight conduits, but may be other than straight and include one or more bends or bends.

[0085] It will be appreciated that the gas inlet 140 and gas outlet 150 of the humidification chamber may be connected to the gas flow path of the respiratory apparatus in a variety of ways. It will be appreciated that the gas inlet 140 may be coupled or fluidly connected to the gas flow path by one or more conduits, connectors, and / or gaskets coupled to the gas flow path exiting the blower in a sealed or unsealed configuration. Similarly, the gas outlet 150 may be coupled in any suitable manner, including, for example, connectors, conduits, and / or gaskets, in any suitable manner, including, for example, in a sealed or unsealed configuration, to a gas flow path leading to a gas outlet of the respiratory apparatus, which in turn is connected to a patient interface, such as a flexible gas delivery conduit and a user interface, as previously described.

[0086] In this embodiment, the chamber is held within a sealable humidification compartment that includes a gas inlet fluidly connected to the blower outlet and a gas outlet fluidly connected to a main gas outlet of a respiratory device, typically coupled or connectable to a patient interface, as described above with respect to FIG. 2. In this embodiment, the gas inlet 140 of the chamber is not sealingly connected to the inlet of the compartment, but is open to pressurized gas entering the sealed compartment. Alternatively, a sealed connection may be utilized between the inlet of the chamber and the compartment. In this embodiment, the gas outlet 150 of the chamber is preferably sealingly connected or coupled to the gas outlet of the humidification compartment via a gasket or other sealed connection arrangement, or at least closely aligned with each other, to minimize gas bypassing the chamber directly to the outlet of the compartment.

[0087] Hinges and clips As previously mentioned, the lid 56 is hinged or connected to the tray 52 and is movable between an open position in which the lid pivots away from the tray to remove the aquarium 54 from the tray (or the lid can be opened to fill or clean the aquarium) and a closed position in which the lid pivots into engagement with the tray such that the aquarium is enclosed and secured between the lid and the tray. In this embodiment, the lid 56 pivots about a hinge at the rear end of the chamber between a closed position, i.e., as shown in Figure 3, and an open position, i.e., as shown in Figures 13-16, for example.

[0088] In this embodiment, one or more hinges are located at the rear end of the humidification chamber and are configured to hingeably couple the lid 56 to the tray 52. ​​Referring to Figures 8, 15 and 16, in this embodiment, one long living hinge 160 extends along a portion of the rear end of the humidification chamber between the lid 56 and the tray 54. In particular, the living hinge 160 is a thin flexible plastic hinge that is integrally formed with and connected to a portion of the upper edge 76e of the rear wall 76 of the tray and a portion of the ledge 105 at the rear end of the lid 56. 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 the tray, and that the hinges need not necessarily be integrally formed living hinges, but may be hinges or hinge mechanisms that are separately formed and secured to the lid and tray.

[0089] To secure the humidification chamber in a closed state, one or more operable clips or clip mechanisms are provided and are operable between a latched or locked position to secure the humidification chamber in a closed position and an unlatched or unlocked position in which the lid can be pivoted away from the tray and into an open position or configuration.

[0090] 9 and 17, in this embodiment, an operable clip 170 is provided or secured to the lid 56, which is resiliently movable between an engaged position and a disengaged position with a complementary catch 172 provided on the tray 52. ​​In particular, the clip 170 is provided at a central location on the front wall 102 of the lid 56. Referring to FIG. 17, in this embodiment, the operable clip 170 is in the form of a torsion clip, which is movable between engaged and disengaged positions with respect to a complementary catch 172 provided on the tray 52. ​​The clip 170 includes a user contact portion 174 which can be pressed when a user moves or pivots the clip to a disengaged position, and an engagement tab portion 176 which includes an engagement opening 176a. In use, the catch 172 is a protrusion or engagement formation which projects from the front wall 74 of the tray and is aligned with the clip to engage the engagement opening 176a of the clip 170 when the clip is in the latched or locked position, thereby securing the lid 56 to the tray 52.

[0091] As shown, clip 170 is attached to lid 56 via torsion members 178a, 178b that extend from each side of the clip between an end of engagement tab portion 176 and user contact portion 174. Torsion members 178a, 178b are longitudinally aligned and define a pivot axis DD about which clip 170 can pivot or rotate with respect to lid 56 between a rest (engaged, latched) position as shown and an unlatched or disengaged position in which the lid can be released from the tray. As shown, user contact portion 174 is disposed adjacent front wall 102 of the lid while engagement tab portion 176 extends downwardly below ledge 105 and the bottom end of lid 56. Each of torsion members 178a, 178b extends between a respective support post 180a, 180b on front wall 102 and a side of clip 170. In this embodiment, torsion members 178a, 178b are substantially cylindrical (although the cross-sectional shape along their length may vary, such as square, rectangular or otherwise) and twist or bend at a small angle about their longitudinal axis, thereby allowing the clip to pivot or rotate about pivot axis DD. As shown, clip 170 is biased to or toward its rest position by torsion members 178a, 178b.

[0092] In use, as the lid 56 is moved from the open to the closed position, the tip of the engagement tab 176 engages the cam surface 172a of the catch 172 (see FIG. 14), causing the clip to pivot outwardly from the lid's front wall 102 in the direction F shown in FIG. 17. When the lid 56 is fully engaged with the tray 52, the catch 172 fully snap-engages with the engagement opening 176a of the engagement tab portion 176, causing the clip to return to its rest position, springing back and securely hooking the lid to the tray without the user having to manipulate the clip to engage it with the opening. To release the clip mechanism so that the heating chamber can be opened, the user simply presses the user contact portion 174 and moves it in the direction E, as shown, toward the lid's front wall 102. This again causes the engagement tabs to rotate in direction F about pivot axis DD away from the front wall, disengaging the engagement openings 176a from the complementary catches 172, thereby pivoting the lid 56 fully open from the tray 52. ​​When the user releases pressure on the user-contacting portion 174, the clip returns to its rest position where it can again be latched when the humidification chamber is closed.

[0093] As shown in Figure 17, the front wall 102 of the lid is provided with two limit projections 182 behind the user-contacting portion 174 of the front wall of the chamber which serve to prevent the user from over-turning or twisting the clip which could damage the clip mechanism. Referring to Figure 14, guide formations 184 are optionally provided on each side of the catch 172 which protrude from the front wall 74 of the tray 52. ​​In use, the guide formations 184 are spaced apart a sufficient distance to allow the engagement tab portion 176 of the clip to fit between the guide formations 184 when in the engaged position.

[0094] In the illustrated embodiment, clip 170 is attached to the lid and catch 172 to the tray, although it will be appreciated that this could be reversed, with the clip secured to the tray and the catch secured to the lid, if desired.

[0095] It will be appreciated that a variety of other alternative clip configurations or mechanisms may be utilized to secure the humidification chamber lid 56 to the drip tray 52. ​​Two or more operable clips or latches may be provided on one or more walls along the perimeter of the heating chamber, as desired. Other examples of various clip mechanisms are described below with respect to alternative embodiments of the heating chamber, but it will be appreciated that such clip mechanisms may also be utilized with this first embodiment of the humidification chamber.

[0096] Sealing Referring to FIG. 10, in this embodiment, no flexible seal (e.g., silicone or rubber, or otherwise) is provided between the perimeter lid 56 of the humidification chamber and the water reservoir 54. It is believed that the pressure generated by the clip mechanism when the humidification chamber is closed is sufficient to reduce or minimize gas and / or water leakage at the interface between the lid 56 and the water reservoir 54. Also, additional downward pressure may be applied to the lid 54 when placed in the humidification compartment of the respiratory device. For example, the humidification compartment lid may be configured to press down on or engage the humidification chamber lid 56, thereby exerting a downward force on the lid 56 to more tightly close it. Because the chamber is placed in a pressurized humidification compartment, there is negligible or close to zero pressure difference between the outside and inside of the chamber. Such a substantially neutral pressure difference reduces the tendency for airflow to enter or exit the chamber through the interface or peripheral boundary between the lid and the water reservoir, and therefore generally eliminates the need for a seal.

[0097] However, it will be appreciated that in alternative embodiments, one or more flexible seals may be provided between the lid 56 and the water basin 54 along the humidification chamber perimeter to further minimize the possibility of gas and / or water leaking from the humidification chamber at the interface between the water basin and the lid. For example, a peripheral flexible seal may be attached to either the rim 92 of the water basin 54 or the bottom edge 107 or ledge 105 of the lid 56, or both. Referring to FIG. 36, one possible sealed chamber configuration is shown in which a peripheral recess or groove is provided in the underside of the lid ledge 105 along the entire chamber perimeter, and a seal, such as a silicone or rubber O-ring or the like, is mounted or positioned in the groove to sealingly engage the water basin rim 92 when the chamber is closed.

[0098] Alternative Clip Mechanism As previously mentioned, a variety of alternative clip mechanisms may be used to secure the lid 56 of the humidification chamber 50 to the drip tray 52. ​​Several alternative types of clip mechanisms are described herein merely by way of example, and it should be understood that these examples are not intended to be limiting.

[0099] First Alternative Clip Mechanism 21A-21C, a first alternative clip mechanism includes a clip 190 rotatably coupled to the front end wall of the lid 56 via a living hinge, indicated at 191. As shown, the clip 190 is hinged to the ledge 105 of the lid 56. In this embodiment, the clip 190 includes a main flat tab portion 190a including a central engagement opening 190b configured to engage a complementary shaped catch or protruding formation 192 on the front wall of the tray 52. ​​The clip 190 further includes a downwardly extending tab or grip portion 190c. In this embodiment, the finger tab 190c is in the form of a thin plastic flexible U-shaped member that extends from the bottom end of the main tab portion 190a. In particular, the tab includes first and second legs 193 extending downwardly from opposite sides of the bottom end of the main tab portion 190a, which are joined by a cross member 194 to provide a gripping opening 198. Finger grip portion 190c may be integrally formed as one piece with main tab portion 190a of the clip, or may be formed separately and attached or secured to the clip.

[0100] As shown, the finger tab portion is preferably thinner, more flexible, or more flexible than its corresponding main tab portion 190a. In this embodiment, the finger tab portion 190c extends substantially toward or to the bottom surface of the tray 52, making it easier for the user to hook or grasp the finger. This configuration also allows the user to insert more of their finger and / or fingers into the gripping opening 198, allowing them to use the strength of their arm to pull the clip, rather than using their fingertips to exert most of the load through the first joint. Additionally, as shown in FIG. 21C, the front wall of the tray 52 may be provided with a recess 195 that aligns with the tab 190c, thereby allowing the user's fingers to reach and grasp the tab 190c. In this embodiment, the catch formation 192 includes an elongated formation having a triangular cross section. In particular, a forward, downwardly angled, front cam surface 192a extends from the pan front wall 74 and a substantially horizontal engagement surface 192b is provided on the underside of the formation. The forward end of engagement surface 192b is also provided with a ridge or protruding lip which extends downwardly to assist in retaining the clip in engagement with the fastener formation 192.

[0101] In use, the user pushes or pivots clip 190 about its living hinge to engage catch formation 192 into the latched position shown in Figure 21 A. To release the clip mechanism, the user uses one or more fingers to apply force to tab portion 190c of the clip (or to main tab portion 190a itself, depending on the user's preference) in a direction away from the front wall of the tray, disengaging the clip from engagement formation 192, thereby removing the clip, and thereby lid 56, from tray 52.

[0102] Second Alternative Clip Mechanism 22A, a second alternative clip 200 is shown. Clip 200 includes a main tab portion 201 which, similar to first alternative clip 190, is integrally connected to ledge 105 on front wall 102 of lid 56 via a living hinge 202. As previously described, living hinge 202 is formed from a reduced thickness section of plastic and is flexible, thereby allowing clip 200 to pivot relative to lid 56. Unlike engagement opening 190b of first alternative clip 190, second alternative clip 200 is provided with a protruding engagement formation 203 which is configured to engage a complementary catch formation or opening (not shown) in the front wall of the tray.

[0103] Third Alternative Clip Mechanism 22B, a third alternative type of clip mechanism is shown. The third alternative type of clip 210 is similar to the first alternative clip 190 and includes a hinged tab 211 having an engagement opening configured to engage a catch formation 212 on the front wall of the tray. In this embodiment, the tab 211 includes an extension tab. There is no provision.

[0104] Fourth Alternative Clip Mechanism 23A and 23B, a fourth alternative type of clip mechanism is shown. The fourth alternative type clip 290 is similar to the first alternative clip 190, and like reference numerals indicate like features. The clip 290 includes a hinged tab that does not have an extension tab. Rather, the tab has a vertical first upper portion 291 that is hinged to the lid and a larger lower angled portion 292 that extends diagonally away from the upper portion. The upper portion 291 provides an engagement opening for engaging the catch formation 192 in the front wall of the tray, as previously described. In the illustrated engaged position, the lower angled portion 292 of the tab is angled outwardly, i.e., away from the wall of the tray 52, thereby forming a gripping recess or access cavity between the lower angled portion 292 and the recess 195 in the front wall, allowing a user to grasp and pull the tab to release the clip as desired.

[0105] Alternative Water Level Indicators Of course, various other water level indicators can be used to assist the user in identifying when the aquarium has been filled to the maximum water level mark, some non-limiting examples of which are described herein by way of example.

[0106] First alternative water level indicator 24A and 24B, a first alternative water level indicator 220 is shown which is a variation of the previously described tab type water level indicator 130. Like reference numbers indicate similar components and features. In this variation, an additional vertical post or member 221 extends downwardly from the underside of the lid 56 and mates with the end of the tab 134 to stiffen the water level indicator and maintain the angle of the tab.

[0107] Second Alternative Water Level Indicator 25 and 26, a second alternative water level indicator 230 is shown. The water level indicator 230 is a cone-shaped water level indicator and includes a hollow cylindrical formation 231 that extends downwardly from the upper main portion of the lid and terminates in a cone end 232 that includes an indicating means or marking indicating at least the maximum water level, generally indicated at 233. The water level indicator is formed from a transparent material, such as clear plastic. The steepness of the cone portion 232 may be varied to vary the amount of warning the user gets as they approach the maximum water level. A steeper angle provides less warning, a shallower cone provides more warning. In this embodiment, the lid 56 is provided with one water inlet opening, generally indicated at 234.

[0108] Third alternative water level indicator Additionally or alternatively, in other embodiments, the water level indicator(s) may be provided on the inner surface of the perimeter wall of the aquarium, for example by printing a line on the surface or by otherwise stamping or forming a line into the inner wall of the aquarium. Such water level indicator may be visible when the lid is open, thereby allowing water to be poured directly into the aquarium up to the aquarium's maximum water level line. In such embodiments, a separate water inlet hole in the lid may be omitted.

[0109] Various other humidification chamber embodiments will now be described, with like reference numbers indicating the same or equivalent components or features. It will be appreciated that features and components of the various embodiments may be substituted and / or combined to create alternative, varying embodiments.

[0110] Second embodiment of the humidification chamber - using a continuous tray A second embodiment of the humidification chamber 300 will now be described with reference to Figures 27A-27C. The humidification chamber 300 is substantially similar to the first embodiment. As shown, the lid 56 is substantially similar to the first embodiment, but includes a different clip mechanism 310 on the front wall. In this embodiment, the clip 310 is a U-shaped member that is attached to the front wall and bends to some degree about an axis indicated at II in Figure 27B. As shown in Figure 27A, the clip 310 securely engages with a catch formation 312. With reference to Figure 27C, the catch formation includes an elongated formation having a substantially triangular cross section. In particular, an inclined front cam surface 314 extends downwardly and outwardly from the front wall, and a substantially horizontal engagement surface 316 returns from the lower end of the front cam surface 314 to the front wall. The U-shaped clip 310 includes two vertical legs 318 that extend downwardly from the lid and are joined by a cross member 320. In use, the cross bar 320 engages the cam surface 314 of the catch formation 312 as the lid is engaged with the tray 352 and eventually snaps or locks into full engagement with the engagement surface 316 .

[0111] In other respects, the second embodiment humidification chamber 300 is substantially similar to the first embodiment and includes a plastic tray 352 for receiving a metal water bath of the type previously described, and a hinged plastic lid 56. The primary difference with the second embodiment humidification chamber 300 is that the tray is substantially continuous around the perimeter of the water bath such that it encompasses and surrounds substantially the entirety of the water bath perimeter surface.

[0112] Humidification chamber of the third embodiment - using a heating plate overmolded overview The third embodiment of the humidification chamber 400 will now be described in more detail with reference to Figures 28A-28T. The humidification chamber 400 is similar in general shape to the previous embodiment, and like features, where applicable, are represented by like drawing reference numerals. It will be appreciated that the description of the previous embodiment with respect to like features, including variations and alternatives, also applies to this embodiment and will not be repeated. The following description will focus on the differences of the third embodiment from the previous embodiment.

[0113] The main difference between the third embodiment of the humidification chamber 400 is that it is a two-part chamber assembly and not a three-part chamber assembly as in the previous embodiment. The terms "two-part" and "three-part" assembly refer to the number of major components of the assembly, whether they are integrally formed or otherwise connected, coupled or assembled to each other. In particular, the previous embodiment relates to a three-part chamber assembly, which includes an upper part (lid-part 1) that is hinged to open and close with respect to a lower part (basin-part 2), which releasably receives and holds a separate water reservoir (part 3). In contrast, the humidification chamber 400 of this third embodiment is a two-part assembly, which includes an upper part in the form of a lid 456 (part 1) that is hinged on one side to a lower part in the form of a water reservoir 452 (part 2) that includes a thermally conductive metal heating plate on its base surface.

[0114] In this embodiment, the lid 456 and water bath 452 (excluding the metal heating plate) are formed by injection molding, vacuum forming, or other suitable production process from a rigid plastic in a manner similar to the formation of the lid and basin of the previous embodiment. Typically, the lid 456, water bath 452, and the hinge joint 160 between the lid and water bath are integrally formed with one another as one piece, although in alternative embodiments, the lid and water bath may be formed as separate pieces and then hinged together via one or more separate hinged components or assemblies. The water bath and / or lid may be formed to be substantially transparent or opaque depending on design requirements.

[0115] As with the previous embodiments, the humidification chamber 400 is operable or movable between a closed position (e.g., as shown in Figures 28A and 28B) in which the lid 456 is secured to the water reservoir 452 to create a closed chamber, and an open position or condition as shown in Figures 28L to 28N in which the lid 456 is moved or rotated about the hinge 160 away from the water reservoir to open the chamber for access. One or more operable clips 290 or latches are provided on the front end of the humidification chamber to secure or lock the humidification chamber in the closed position for insertion and operation within the respiratory apparatus, as previously described.

[0116] Aquarium 28A, 28B, 28L and 28M, the water reservoir 452 includes a base surface 470 having upstanding side walls extending therefrom around the periphery of the base surface. As shown, the water reservoir includes a front wall 474 and a rear wall 476 at the front and rear ends, respectively, of the humidification chamber, and a first side wall 475 and a second side wall 477 extending along the gas inlet and gas outlet sides, respectively, of the humidification chamber.

[0117] 28D, 28E, 28F, one or more of the walls or portions of the walls may be provided with a reinforcing feature configured to resist bending or deformation of the wall surface. In this embodiment, each of the side walls 475, 477 is provided with a reinforcing portion or region 478, 479, respectively, which includes a corrugated or undulating surface profile with alternating grooves and ridges. In this embodiment, the grooves and ridges have a vertical orientation, although of course, in the alternative, a horizontal orientation can be utilized as desired. In this embodiment, the thickness of the side walls of the reinforcing, i.e., corrugated portion, is substantially uniform, and the ridges and grooves and the transitional sections between the ridges and grooves are of substantially similar wall thickness, as can be seen in FIG. 28D. In an alternative embodiment, the thickness of the side walls of the reinforcing region may be non-uniform. In this embodiment, the height of each of the corrugated regions extends from the base surface to a midpoint on the sidewall below the edge or rim of the aquarium as shown in Figures 28E and 28F, although it will be appreciated that the corrugated regions may begin at a point above the base surface, or may extend the entire height of the sidewall, as desired. In an alternative reinforcing configuration, one or more portions of the sidewall may have spaced apart reinforcing ridges or ribs, either vertically or horizontally oriented, on the inner or outer surface, or both. In such an embodiment, the ridges or ribs increase the thickness of the wall in the region of the ridges or ribs. In another alternative embodiment, the sidewall of the aquarium 452 may be stiffened or reinforced by a peripheral ledge, lip, or rim extending or projecting outwardly from or at the upper periphery of the aquarium sidewall to prevent or minimize bending and / or deformation. The rim may be of the type or shape shown, for example, at 92 or 52a in Figure 36, i.e., integrally formed along the upper periphery of the sidewall. The reinforcing rim may be provided in combination with or as an alternative to the reinforcing region in the sidewall.

[0118] 28E-28H, in this embodiment, the humidification chamber 400 includes a convex or dome-shaped base surface 470 that curves or rounds outwardly to an apex defined by a central heating plate, which will be described in more detail below. In an alternative embodiment, the base surface 470 may be substantially flat.

[0119] 28D, 28L, and 28M, the base surface 470 of the water bath 452 is provided with a centrally located metallic or thermally conductive heating plate 494. In this embodiment, the heating plate 494 is circular and is bonded or secured by overmolding to a complementary circular opening in the center of the base surface 470 of the plastic water bath 452. The heating plate may be formed of a rigid, thermally conductive material and is typically pressed or formed from sheet metal, e.g., aluminum, stainless steel, or other suitable material, e.g., by die casting. In this embodiment, the heating plate 494 and the complementary opening in the base surface 470 of the water bath are circular, but it should be appreciated that the shapes may vary to provide an integral heating plate surface of any other alternative shape, including square, rectangular, or any other arbitrary shape. In this embodiment, the heating plate 494 may be substantially flat prior to the overmolding process, but may have a slightly outwardly domed or convex shape after the overmolding process due to compression forces from the surrounding domed base surface. The compression or biasing force that causes the mating surface of the heating plate to be slightly outwardly convex reduces or resists the likelihood of the heating plate deforming inwardly over time, but using a deformed inwardly concave mating surface would reduce the surface area of ​​contact between the heating plate and the heating pad it rests on in the humidification compartment, thereby reducing the thermal conductivity of this configuration.

[0120] In this embodiment, the heating plate 494 is provided with a circular primary contact surface 495 that projects from and extends beyond the surrounding plastic base surface 470 of the water bath 452 and is configured to facilitate sufficient engagement and heat transfer when the chamber rests on a complementarily shaped heating pad at the bottom of the humidification compartment. In this embodiment, the heating plate further includes an upstanding or substantially vertical wall portion 496 that extends along the periphery of the primary contact surface portion 495 and a substantially horizontal outer peripheral interlocking surface or ledge portion 497 that extends outwardly from the top of the wall portion 496 along the periphery of the heating plate. As shown, the primary contact surface portion 495 and the outer interlocking ledge 497 extend in substantially parallel planes but are vertically offset from one another by the height of the vertical wall portion 496. As shown, it is the interlocking ledge 497 of the heating plate 494 that is overmolded or secured to the surrounding plastic along the periphery of the central opening of the base surface 470. In particular, an engaging portion 471 of the base material along the periphery of the central opening of the base 470 is overmolded onto at least a portion of an interlocking ledge 497 of the heating plate 494 along its entire periphery.

[0121] 28J, in this embodiment, the overmolding process is configured such that the engaging portion 471 of the base surface varies in thickness relative to the remainder of the base surface. In this embodiment, the overall thickness 401 of the engaging portion 471 that is overmolded onto at least a portion of the connecting ledge 497 of the warming plate 494 is thicker than the thickness 402 of the remaining base surface 470 of the aquarium. This configuration helps reduce the amount of lift of the plastic of the base surface 470 away from the connecting ledge 497 of the warming plate after molding, which in turn reduces the amount of ingress of hard water deposits at the transition interface area between the metal warming plate and the plastic base surface. In one configuration, the thickness 403 of the upper portion of the engaging portion 471 above the connecting ledge 497 of the warming plate 494 is comparable or at least the same as the thickness 402 of the remaining base surface, reducing or minimizing the lift of the connecting ledge 497 of the upper portion. As shown, in this embodiment, the thickness 404 of the lower portion of the engagement portion 471 below the interlocking ledge 497 may be less than the thickness 403 of the upper portion of the engagement portion 471 at the base surface 470. In an alternative embodiment, the thickness 404 of the lower portion of the engagement surface is also comparable to or at least the same thickness as the thickness 402 of the remaining base surface, reducing or minimizing lift-up of the lower portion of the interlocking ledge.

[0122] Of course, in an alternative embodiment, the heating plate may be a substantially flat circular plate that is overmolded into a central opening in the base surface so that it is substantially flush with the remainder of the base surface rather than protruding as previously described.

[0123] Referring to FIG. 28L, in this embodiment, the aquarium 452 is also provided with a continuous horizontal step formation 472 that extends around the periphery of the inner sidewall surface. The step formation is offset from the base of the aquarium by a uniform height along the inner periphery. The step formation may be integral with the sidewall and may be in the form of a sloped step, as shown in FIG. 28I. In this configuration, the step formation 472 is located at a height above the base corresponding to the maximum water level. When the chamber lid is in the open position, a user may fill the aquarium with water up to the level of the step formation as an alternative option to using the water fill hole.

[0124] lid The lid 456 of the third embodiment humidification chamber 400 is substantially similar to the lid 56 of the previous embodiment, with some key differences, which are described below. It will be appreciated that the third embodiment humidification chamber can also use the same lid 56 as previously described.

[0125] 28C, 28I, and 28L, in this embodiment, the lid 456 is provided with a tab-type water level indicator 220 of the type previously described with respect to FIGS. 24A and 24B. In particular, the tab-type water level indicator 220 includes an inclined tab 134 that is suspended below the water inlet opening 120 by upstanding support members 132, 221 at each end. In this embodiment, the indicia "MAX", meaning maximum, is printed reverse-side down on the underside of the tab portion 134 as shown in FIG. 28L. At least the tab portion 134 is formed of clear plastic so that the indicia "MAX" is visible in a properly readable format for a user when looking through the water inlet hole 120.

[0126] 28E and 28C, the inlet side peripheral wall 106 of the lid 456 is provided with one or more projections 407, e.g., ridges, ridges or formations extending from the surface of the peripheral wall. In this embodiment, the projections 407 are provided on each side of the central inlet opening 140 of the lid and engage with matching rails on the inner inlet gas side wall of the humidification compartment, which will now be described. Referring to FIG. 28O, a lower portion of a humidification compartment 800 is shown that is shaped and dimensioned to have a complementary cavity 802 that receives and holds the humidification chamber 400. The lower portion 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 respect to FIG. 2, the humidification compartment may further include an openable lid that seals or encloses the compartment when the humidification chamber 400 is installed within the cavity. As shown, two vertical rails 406 protrude from the interior wall of the humidification compartment on either side of a gas inlet 804 that receives gas flow from the respiratory apparatus blower as described above with respect to FIG. 2. In this embodiment, each rail 806 extends from a first upper end at or near the level of the gas inlet 804 and a second lower end at or near the floor of the compartment. In this embodiment, referring to FIGS. 28O and 28T, each rail includes a first short starting sloped portion 806a that tapers or slopes outwardly from the wall and then extends to a second, longer return sloped portion 806b that again tapers or slopes toward the interior wall. In operation, the protrusion 407 on the gas inlet side of the humidification chamber 400 aligns with a mating rail 806 on the inlet side of the humidification compartment. When the heating chamber 400 is lowered or inserted into the humidification compartment, the projections 407 abut or engage their respective rails 806, which urge the chamber 400 toward the opposite outlet sidewall of the compartment, which contains the gas outlet 808 shown in Figure 28P. This configuration helps to urge and hold the chamber's gas outlet into sealing engagement or connection with the compartment's gas outlet 808 when the chamber is fully inserted or installed.In this configuration, the compartment gas outlet 808 is provided with a seal 810 that extends around the periphery of the gas outlet 808. The seal may be, for example, an elastomeric or rubber component or insert. As will now be described, in this embodiment, the chamber gas outlet 150 is provided with an engagement surface 430 that sealingly engages the seal 810 around the periphery of the gas outlet 808, thereby providing a sealing connection between the outlets. It will be appreciated that in alternative embodiments, a seal may be provided at the chamber gas outlet 150, or both the chamber and compartment outlets may have complementary seals.

[0127] 28F, 28K, 28P-28S, in a third embodiment of a humidification chamber 400, the gas outlet 150 in the outlet side peripheral wall 108 of the lid 456 includes an engagement surface or formation 430 along the periphery of the opening 150. The engagement surface 430 is configured to sealingly engage a seal 810 of the gas outlet 808 of the humidification compartment 800 when the humidification chamber 400 is installed within the compartment. In this embodiment, the gas outlet 150 is substantially rectangular and therefore the engagement surface 430 is also substantially rectangular and includes upper and lower horizontal portions 431, 432 that extend along the upper and lower peripheries of the gas outlet 150 and lateral vertical portions 433, 434 along the lateral peripheries of the gas outlet 150. In this embodiment, the engagement surface 430 may be substantially flat along the perimeter or periphery of the gas outlet 150, thereby sealingly engaging a complementary seal or outlet surface associated with the gas outlet 808 of the humidification compartment 800. In the illustrated configuration, the engagement surface 430 is preferably inclined or tilted outwardly with respect to the vertical outlet periphery 108. In particular, as more clearly shown in FIG. 28K, the engagement surface 430 is inclined such that an upper portion 431 is offset further outwardly from the outlet periphery 108 than a lower portion 432. In this configuration, the engagement surface 430 may be considered to be inclined or pivoted outwardly about a horizontal axis extending across its surface, such that an upper portion of the engagement surface projects or is offset further outwardly from the outlet periphery 108 of the lid 456 than a lower portion or region 432 of the engagement surface. Of course, the same principles apply whether the gas outlet and engagement surface are circular or otherwise shaped. The inclined engagement surface 430 assists in allowing the humidification chamber to be easily received or inserted into the complementary humidification compartment 800 and aids in providing a sealing engagement or connection between the gas outlet 150 of the chamber and the gas outlet 808 of the humidification compartment 800.

[0128] Referring to FIG. 28L, the vertical flow panel 146 of the lid 456 is improved with respect to the previous embodiment. In this embodiment, the vertical panel or face 146 further includes a pair of baffle portions or wings 435 that extend along the side edges 146 of the flow panel 146 across the entire height (H) of the flow panel and act as flow deflectors or guides. The side baffles 435 protrude or extend along each of the side edges 146b of the flow panel 146 away from the first side 146b thereof. In particular, the side baffles 435 extend substantially perpendicular to the flow face 146, such that they extend toward the inlet side of the lid. In this configuration, the width W2 (extending perpendicular to the surface of the flow panel) of the side baffles 435 of the vertical flow panel 146 is substantially less than the overall width W of the vertical flow panel. In use, the side baffle portion or face 435 is configured to minimize or prevent flow exiting the inlet conduit 142 from following a path that reduces humidification, around the side end 146e of the vertical flow panel directly towards the gas outlet conduit 152. The side baffle 435 forces or encourages air to circulate back towards the inlet side of the humidification chamber, lengthening the general air flow circulation path of the chamber before the gases exit the chamber, increasing moisture absorption. As previously mentioned, the height (H) of the flow panel 146 is generally configured such that it protrudes or penetrates into the surface of the water to a depth sufficient to prevent gases exiting the inlet conduit 142 from taking a shortcut directly under the lower end 146a to the outlet conduit 152.

[0129] Hinges and clips As previously described, the upper part, lid 456, is hinged or connected to the lower part, basin 452, such that they can move between an open position in which the lid pivots away from the basin (so that the lid can be opened to fill or clean the basin) and a closed position in which the lid pivots into engagement with the basin to close the chamber. In this embodiment, the lid 456 is hinged to the basin 452 in a manner similar to the hinge between the lid and the tray in the previous embodiment. In particular, the lid 456 can pivot about a hinge at the rear of the chamber between a closed position or state as shown in Figures 28A and 28B, for example, and an open position or state as shown in Figures 28L-28N. As shown in Figures 28A, 28G, and 28M, in this embodiment the hinge is a single long living hinge 160 that extends between the lid 456 and the basin 452 along a portion of the rear end of the humidification chamber, in the manner described above in the previous embodiment.

[0130] To secure the humidification chamber in a closed condition, one or more operable clips or clip mechanisms are provided and are operable between a latched or locked position which secures the chamber in a closed position and an unlatched or unlocked position which allows the lid 456 to be pivoted away from the water bath to an open position or condition. Referring to Figures 28B, 28H, 28M and 28N, in this embodiment the heating chamber includes a catch formation 192 complementary to one of the operable clips 290 of the type described with respect to Figures 23A and 23B. In particular, the clip 290 may be pivotally mounted to the lid and movable into engagement with the catch 192 to securely close the chamber or disengage or release the catch 192 to allow the chamber to be opened. As shown in Figure 28H, a recess 195 is provided in the front wall of the water bath 452 adjacent the clip 290 to allow a user to grasp and pull a tab to disengage the clip from the catch formation 192 as desired.

[0131] Sealing As with the previous embodiment, the chamber 400 of the third embodiment does not necessarily need to be sealed between the lid 456 and the water basin 452. However, it may be sealed as shown in this embodiment if desired. Referring to FIG. 28I, the ledge 105 of the lid 456 is provided with or forms a peripheral groove or recess, and a sealant 99 is mounted in the groove along the periphery of the lid, similar to the configuration described for the embodiment of FIG. 36. As shown, the sealant 99 engages with the top surface or rim 461 of the peripheral wall of the water basin 452 when the chamber is closed to seal the chamber. In other configurations, the other sealing configurations described with respect to FIG. 36 may be used.

[0132] Using the fourth embodiment of the humidification chamber sleeve 29A and 29B, a fourth embodiment of the humidification chamber 500 is a variation of the second embodiment of the humidification chamber 300. In this embodiment, the lid 56 is not hinged at one end to a continuous tray, but is hinged at one end to a sleeve 552 in the form of a continuous perimeter that surrounds or extends around the entire perimeter of the aquarium 54 as shown. In particular, the sleeve 552 leaves the entire base surface 54 of the aquarium exposed. The sleeve 552 is preferably formed from the same material as the lid 56, preferably injection molded from plastic or the like. The height of the sleeve, indicated at 554, may vary as desired. In this embodiment, the sleeve extends substantially from the upper edge of the aquarium rim to the base surface of the aquarium, although in alternative embodiments it may be thinner and extend only part way up the perimeter from the upper edge. As shown in Figure 29B, the sleeve is prevented from lifting or sliding off the water basin 54 by a lip or rim 92 extending outwardly from the upper edge of the water basin 54. The humidification chamber is otherwise substantially similar to the previous embodiment, with a living hinge connecting the lid to the sleeve 552 along its rear end (not shown) and a forward clip mechanism 560, which in this embodiment is as described with respect to Figures 21A-21C.

[0133] Fifth embodiment of the humidification chamber - with internal clip 30A-30C, a fifth embodiment of a humidification chamber 600 (see FIG. 30C) includes a plastic lid 602 that is releasably coupled to a metal water basin 604 (see FIG. 30B) via an internal clip. The plastic lid 602 is substantially similar to the lids of the previous embodiments, but includes a slightly different water level indicator configuration. In particular, there is a water inlet hole 606 centrally located near one end of the lid, and a conical water level indicator 608 located near one corner of the opposite end of the lid. In addition, a finger recess 610 is provided in the center of the water level indicator end of the lid. The internal structure of the lid 602 is otherwise similar to that of the previous embodiments, with a gas inlet, gas outlet, vertical flow surface 606, and a water level indicator 608. The structure is the same.

[0134] Water bath 604 is formed entirely from metal, such as stainless steel, aluminum, or the like. Optionally, a sleeve or tray of insulating material, such as plastic or other insulating material, may be provided on the outer perimeter and / or underside of the metal water bath to prevent burns to the user's hands when holding the metal tab, but the user may pick up the metal water bath through the lid by grasping the water inlet opening 606 and finger recess 610, for example, with one finger and thumb.

[0135] The lid 602 is not hinged to the aquarium 604 and is completely removable from the aquarium. Each end of the lid is provided with a clip or engagement projection 612 (only one end is visible) that is configured to engage with a complementary recess 614 provided at or near the top edge of the aquarium 604 at each end. To assemble the lid 602 and aquarium 604, a user must push the lid to engage the clip formations 612 with the complementary recesses 614. To remove the lid, a user must pull the lid vertically away from the aquarium with enough force to disengage the clip formations 612 from the recesses 614.

[0136] Humidification chamber of the sixth embodiment - using ducted lid A sixth embodiment of a humidification chamber 700 will now be described with reference to Figures 31A-35. This embodiment includes a plastic lid 702 that fastens to a complementarily shaped metal water basin 704 in a similar manner as described above for the fifth embodiment of the humidification chamber 600. Figure 31A shows the inlet opening 706 of the humidification chamber, and Figure 31B shows the gas outlet 708 of the humidification chamber.

[0137] Referring to Figure 32, in this embodiment the water bath is formed of metal or other heat conductive material that is adapted to directly contact or rest on the warming base. Engagement openings 710 are provided at each end of the water bath to receive complementary elastic clips 730 on the lid 702 to secure the lid to the water bath. The gas inlet 706 is an opening in the peripheral wall on one side of the water bath near a corner of the top edge of the water bath, but may be centrally or otherwise located. The opposite side of the water bath is provided with a notch or recess 712 into which the gas outlet 708 of the lid may reside when the lid is engaged with the water bath in a closed or assembled condition.

[0138] 33-35, the lid 702 includes an upper frame member 714 that is connected to a lower frame member 716 via an interior vertical wall 718. The interior walls are recessed or offset inwardly from the edges of the frame members 714, 716 along the periphery of the lid such that a circumferential gas flow passage is formed along a substantial portion of the interior circumference of the lid when engaged with the water bath 704. As gas enters the circumferential passageway at the inlet 706, it flows along the passageway and enters the interior space of the humidification chamber through a series of one or more interior inlet openings 720 that are formed through the interior wall 718 of the lid. In this embodiment, the majority of the inlet openings 720 are provided in the inlet wall, however, one or more openings may extend along the entire peripheral surface of the interior wall, including the end wall and the opposing wall disposed adjacent the outlet, as shown at 720 in FIG. 35, although not visible. Additionally or alternatively, the inlet openings may be provided in the lower frame member 716 along at least a portion of the periphery of the lid.

[0139] 35, the inside surface or underside of the interior peripheral wall 718 of the lid is provided with a configuration of vertical flow surfaces 722 associated with each interior inlet opening 720 which force the incoming gas stream into the humidification chamber volume and facilitate the humidification process. The gas outlet 708 includes an outlet conduit 724 which extends horizontally from the opening 708 into the interior volume of the lid and terminates at an inlet opening 726 whereby humidified gas enters the outlet conduit 724 and exits the gas outlet 708. 33, the lid 702 is provided at the center of each end with a resilient spring clip 730 that includes a clip forming portion 732 configured to engage a complementary mating opening 710 in the aquarium to secure the lid to the aquarium. EXAMPLES

[0140] Embodiment 1. A humidification chamber for humidifying a gas, comprising: a water basin configured to receive a body of water; a tray defining an open cavity for receiving the water basin; a lid hinged to the tray to enclose the water basin and define an interior space of the humidification chamber, the lid being movable between a closed position in which the water basin is closed by the lid and an open position in which the water basin is open; one or more operable clips for securing the lid in the closed position; a gas inlet for receiving a flow of gas into the interior space of the humidification chamber; and a gas outlet through which a flow of humidified gas exits the interior space of the humidification chamber. 2. The humidification chamber of paragraph 1, wherein the lid and the tray are formed of rigid plastic. 3. A humidification chamber as claimed in claim 1 or 2, wherein the lid and the tray are hinged together by a living hinge and integrally formed as one piece. 4. A humidification chamber according to any one of claims 1 to 3, wherein the water tank is made of a thermally conductive material. 5. The humidification chamber of claim 4, wherein the water tank is formed of metal. 6. A humidification chamber as described in any one of claims 1 to 5, wherein the water tank is defined by a base surface and a peripheral wall extending upwardly from the base, and the tray includes a complementary base surface and an upwardly extending peripheral wall, and the peripheral wall of the tray is discontinuous along a periphery of the tray such that one or more portions of the peripheral wall of the water tank held within the tray are exposed. 7. A humidification chamber as described in paragraph 6, wherein the heat transfer contact surface protrudes from a base surface of the water reservoir and the tray is provided with a complementary, aligned opening through which the contact surface of the water reservoir extends so as to protrude beyond the underside of the base surface of the tray. 8. A humidification chamber as described in any one of claims 1 to 7, wherein the water tank is removably received in the tray by sliding engagement. 9. A humidification chamber according to any one of claims 1 to 8, wherein the gas inlet and the gas outlet are provided on opposite sides of the lid. 10. The humidification chamber of paragraph 9, wherein the lid includes a vertical flow surface extending downwardly from the underside of the lid in a central region of the lid. 11. The humidification chamber of claim 10, wherein the gas inlet is connected to an inlet conduit extending between an inlet end of the gas inlet and an outlet end located at or near an upper central region of the interior space of the humidification chamber and adjacent the first side surface of the vertical flow face, whereby the incoming gas flow enters the interior space of the humidification chamber at its upper central region. 12. A humidification chamber as described in paragraph 11, wherein a flow directing feature in the form of an inverted curved inclined surface is disposed between the outlet end of the inlet conduit and the first side surface of the vertical flow surface. 13. A humidification chamber as described in any one of paragraphs 11 or 12, wherein the gas outlet is connected to an outlet conduit that is located at or near an upper central region of the interior space of the humidification chamber and extends between an inlet end adjacent the second side of the vertical flow surface and an outlet end of the gas outlet. 14. A humidification chamber as described in any one of claims 1 to 13, wherein the lid includes one or more water inlet openings and at least one water inlet opening including an associated maximum water level indicator including a tab member supported from an underside of the lid and extending into the field of view of the interior space of the humidification chamber and directly visible through the water inlet opening. 15. A humidification chamber as described in any one of paragraphs 1 to 14, wherein the overall shape of the humidification chamber is defined by front and end walls with side walls extending therebetween, the walls extending between an upper surface of the lid and a base surface of the tray, the lid being hinged to the tray at the rear end of the humidification chamber, and at least one operable clip being provided at the front end of the humidification chamber. 16. A humidification chamber as described in any one of claims 1 to 15, wherein at least one operable clip is provided in the form of a torsion clip attached to either the lid or the tray and configured to engage with a fastener provided on either the tray or the lid, respectively. 17. A humidification chamber as described in any one of claims 1 to 15, comprising at least one operable clip that is hinged to either the lid or the tray and configured to engage with a fastener on either the tray or the lid, respectively. 18. A humidification chamber for humidifying a gas, comprising: a water basin configured to receive a body of water; a lid hinged to the water basin to enclose the water basin and define an interior space of the humidification chamber, the lid being movable between a closed position in which the water basin is closed by the lid and an open position in which the water basin is open; one or more operable clips for securing the lid in the closed position; a gas inlet for receiving a flow of gas into the interior space of the humidification chamber; and a gas outlet through which the flow of humidified gas exits the interior space of the humidification chamber. 19. The humidification chamber of paragraph 18, wherein the lid is formed from a rigid plastic. 20. A humidification chamber as described in paragraph 18 or 19, wherein the water reservoir is formed of a rigid plastic and includes a base and a peripheral wall extending upwardly from the base, the base including a heating plate. 21. The humidification chamber of claim 20, wherein the heating plate is fixed to the inside of the opening in the base surface of the aquarium by overmolding. 22. A humidification chamber as described in paragraph 21, wherein the peripheral connecting surface of the heating plate is secured by overmolding into the peripheral engaging portion of the base surface, around the opening of the water tank, whereby the thickness of the engaging portion is greater than the thickness of the remaining base surface. 23. The humidification chamber of claim 22, wherein the engagement portion includes an upper portion above the connecting surface of the heating plate and a lower portion below the connecting surface, the upper portion being at least as thick as the remaining base surface. 24. A humidification chamber as described in any one of items 20 to 23, wherein the heating plate is made of metal. 25. A humidification chamber as described in any one of claims 20 to 24, further comprising a step formation along the inner periphery of the wall of the aquarium, the step formation being formed at a height above the base surface of the aquarium corresponding to a maximum water level indicator. 26. A humidification chamber as described in any one of paragraphs 20 to 25, wherein the base surface of the water tank is dome-shaped, whereby it curves outwardly toward a central apex defined by the heating plate. 27. A humidification chamber as described in any one of paragraphs 20 to 26, wherein the peripheral wall of the water tank includes one or more reinforced regions. 28. A humidification chamber as described in paragraph 27, wherein the reinforced region of the peripheral wall includes a corrugated surface having alternating ridges and grooves. 29. A humidification chamber as described in any one of paragraphs 18 to 28, wherein the lid and the water basin are hinged together by a living hinge and integrally formed as one piece. 30. A humidification chamber as described in any one of paragraphs 18 to 29, wherein the gas inlet and the gas outlet are provided on opposite sides of the lid. 31. The humidification chamber of claim 30, wherein the lid includes a vertical flow surface extending downwardly from the underside of the lid at a central region of the lid. 32. A humidification chamber as described in paragraph 31, wherein the vertical flow surface further includes a pair of side baffles, each of which extends from a respective side edge of the vertical flow surface toward the side of the lid including the gas inlet. 33. A humidification chamber as described in paragraph 31 or 32, wherein the gas inlet is connected to an inlet conduit extending between an inlet end of the gas inlet and an outlet end located at or near an upper central region of the interior space of the humidification chamber and adjacent the first side surface of the vertical flow face, whereby the incoming gas flow enters the interior space of the humidification chamber at an upper central region thereof. 34. A humidification chamber as described in paragraph 33, wherein a flow directing feature in the form of an inverted curved inclined surface is disposed between the outlet end of the inlet conduit and a surface on the first side of the vertical flow surface. 35. A humidification chamber as described in paragraph 33 or 34, wherein the gas outlet is located at or near an upper central region of the interior space of the humidification chamber and is connected to an outlet conduit extending between an inlet end adjacent the second side of the vertical flow surface and an outlet end of the gas outlet. 36. A humidification chamber as described in any one of paragraphs 18 to 35, wherein the gas outlet of the lid includes an engagement surface along the periphery of the gas outlet that is inclined outwardly such that an upper portion of the engagement surface is offset outwardly from the lid more than a lower portion of the engagement surface. 37. A humidification chamber as described in any one of paragraphs 18 to 36, wherein the lid includes one or more water inlet openings and at least one water inlet opening including an associated maximum water level indicator including a tab member supported from an underside of the lid and extending into the field of view of the interior space of the humidification chamber and directly visible through the water inlet opening. 38. A humidification chamber as described in any one of paragraphs 18 to 37, wherein the overall shape of the humidification chamber is defined by front and rear end walls with side walls extending between them, the walls extending between an upper surface of the lid and a base surface of the aquarium, the lid is hinged to the aquarium at the rear end of the humidification chamber, and at least one operable clip is provided at the front end of the humidification chamber. 39. A humidification chamber as described in any one of paragraphs 18 to 38, wherein at least one operable clip is provided in the form of a torsion clip attached to either the lid or the aquarium and configured to engage a fastener provided on either the aquarium or the lid, respectively. 40. A humidification chamber as described in any one of paragraphs 18 to 39, comprising at least one operable clip hinged to either the lid or the water basin and configured to engage with a fastener provided on either the water basin or the lid, respectively. 41. A humidification chamber as described in any one of paragraphs 18 to 40, further comprising a sealant along the periphery of the humidification chamber, between the lid and the water reservoir, to seal the chamber when in the closed position. 42. A respiratory assistance apparatus configured to provide a stream of heated and humidified gas, comprising: an apparatus gas inlet configured to receive a supply of gas; a blower configured to generate a stream of pressurized gas from the gas supply; a humidifier configured to warm and humidify the stream of pressurized gas; an apparatus gas outlet for the stream of heated and humidified gas; and a flow path for the stream of gas through the respiratory apparatus from the gas inlet, through the blower unit and the humidifier unit to the gas outlet, wherein the humidifier includes a sealable humidification compartment configured to receive and hold a removable humidification chamber described in any one of clauses 1 to 41. 43. A respiratory assistance device as described in paragraph 42, wherein the humidification compartment includes a lid movable between an open position to allow removal of the humidification chamber and a closed position to seal the humidification chamber within the humidification compartment. 44. A respiratory assistance device as described in paragraph 42 or 43, wherein the humidification compartment includes a gas inlet connected to the flow path and receiving a stream of pressurized gas from the blower to create a pressurized humidification compartment, and a gas outlet connected to the device gas outlet of the flow path. 45. A respiratory assistance apparatus as described in paragraph 44, wherein the gas inlet of the humidification chamber opens within the humidification compartment and receives an incoming flow of gas from within the pressurized humidification compartment. 46. ​​A respiratory assistance device as described in paragraph 44 or 45, wherein the gas outlet of the humidification compartment is sealedly connected to the gas outlet of the humidification chamber. 47. A respiratory assistance device as described in any one of paragraphs 42 to 46, wherein the humidification compartment includes a heating pad on which the humidification chamber rests. 48. A respiratory assistance device as described in any one of claims 42 to 47, wherein the device is contained within a single housing. 49. A respiratory assistance device as described in any one of paragraphs 42 to 48, wherein the device is a CPAP respiratory device.

[0141] The above description of the invention includes preferred forms thereof, and modifications may be made thereto without departing from the scope of the invention as defined by the claims appended hereto.

Claims

1. 1. A humidification chamber for humidifying a gas, comprising: a water reservoir configured to receive a predetermined amount of water; a lid that covers the water reservoir to define an interior volume of the humidification chamber, the lid being movable between a closed position in which the water reservoir is closed by the lid and an open position in which the water reservoir is open; one or more operable clips for securing the lid in a closed position; a gas inlet for receiving a flow of gas into the interior volume of the humidification chamber; a gas outlet through which a flow of humidified gas is discharged from the interior volume of the humidification chamber; the lid is formed from a rigid plastic; The water tank is made of rigid plastic and includes a base and a peripheral wall extending upward from the base, the base includes a heating plate; The heating plate is fixed to the inside of the opening in the base of the water tank by overmolding; the base includes a peripheral engagement portion surrounding a periphery of the opening in the base and an enclosing portion surrounding the peripheral engagement portion; the heating plate has a peripheral connection surface, the peripheral connection surface is overmolded into the peripheral connection portion of the base around the opening of the aquarium, and the thickness of the peripheral connection portion is greater than the thickness of the surrounding portion of the base; the heating plate has a major contact surface configured to protrude from or extend beyond the surrounding portion of the base of the aquarium; the heating plate includes an upstanding wall portion extending around the periphery of the major contact surface, the peripheral connecting surface extending outwardly from the top of the upstanding wall portion along the periphery of the heating plate; A humidification chamber, wherein the peripheral engaging portion of the base around the central opening of the base is overmolded around at least a portion of the peripheral connecting surface of the heating plate.

2. 2. The humidification chamber of claim 1, wherein the major contact surface and the peripheral coupling surface extend in planes that are substantially parallel to one another.

3. 3. The humidification chamber of claim 2, wherein the major contact surface and the peripheral connecting surface are longitudinally offset from one another by the height of the upstanding wall portions.

4. The humidification chamber of claim 1 , wherein the peripheral engagement portion includes an upper portion above the outer peripheral mating surface of the heating plate and a lower portion below the outer peripheral mating surface.

5. 5. The humidification chamber of claim 4, wherein the upper portion of the peripheral engagement portion has a thickness at least as thick as the surrounding portion of the base.

6. 4. A humidification chamber according to claim 2 or 3, wherein the lower part of the peripheral engagement portion has a thickness at least as thick as the surrounding part of the base.

7. The humidification chamber of claim 1 , wherein the heating plate is circular.

8. 8. The humidification chamber of claim 1, wherein the opening in the base is circular and has a shape complementary to that of the heating plate.

9. A humidification chamber according to any one of claims 1 to 8, wherein the major contact surface is circular.

10. The humidification chamber according to any one of claims 1 to 9, wherein the heating plate is made of metal.

11. A humidification chamber according to any one of claims 1 to 10, wherein the major contact surface is flat.

12. 12. The humidification chamber of claim 1, wherein the surface of the base of the water tank is dome-shaped, whereby the surface of the base curves outward toward a central apex defined by the heating plate.

13. 13. A humidification chamber according to any one of claims 1 to 12, wherein the lid is hinged to the water reservoir.

14. 14. A humidification chamber according to any one of claims 1 to 13, wherein the gas inlet and the gas outlet are provided in the lid.

15. 1. A respiratory assistance device configured to provide a heated and humidified gas stream, comprising: an apparatus gas inlet configured to receive a supply gas; a blower configured to generate a pressurized gas stream from the supply gas; a humidifier configured to warm and humidify the pressurized gas stream; an apparatus gas outlet for said warmed and humidified gas stream; a flow path for the gas stream passing through the respiratory aid apparatus from the apparatus gas inlet, through the blower and the humidifier, to the apparatus gas outlet; Including, 15. A respiratory assistance device, wherein the humidifier comprises a sealable humidification compartment configured to removably receive and hold a humidification chamber according to any one of claims 1 to 14.

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