EP4665436A1

EP4665436A1 - A humifidication chamber and system incorporating a humidification chamber

Info

Publication number: EP4665436A1
Application number: EP24756409.9A
Authority: EP
Inventors: Joshua Thomas WORKMAN; Frank SEOC; David-Reyner Cailun HOW; Zane Robert HAMILTON; Craig Karl White; Graeme Matthew SMITH; Taylor James EDWARDS
Original assignee: Fisher and Paykel Healthcare Ltd
Current assignee: Fisher and Paykel Healthcare Ltd
Priority date: 2023-02-17
Filing date: 2024-02-07
Publication date: 2025-12-24
Also published as: TW202448541A; WO2024171002A1; CN222399879U; AU2024222547A1

Abstract

Embodiments of the application are directed to a humidification chamber. The humidification chamber comprises a fluid compartment for containing a fluid. The humidification chamber further includes an inlet portion defining an inlet of the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment, an outlet portion defining an outlet of the fluid compartment for allowing an outgoing flow of gases to exit the fluid compartment, and a deflector configured to direct the incoming flow of gases from the inlet portion towards the outlet portion.

Description

A HUMIDIFICATION CHAMBER AND SYSTEM INCORPORATING A HUMIDIFICATION CHAMBER

Technical Field

[0001] The disclosure generally relates to humidification chambers for humidification systems. More specifically, the disclosure relates to humidification chambers for medical use such as in, for example, but not limited to, respiratory and/or surgical humidification systems. There is also provided a system incorporating a humidification chamber, for example as described herein.

Background of Invention

[0002] Patients with reduced respiratory support or having a risk of reduced respiratory support can benefit from humidified high flows. A medical procedure involving administration of anaesthetic agents is one such situation where the patient may experience or be at risk of diminished respiratory function. A patient may require respiratory support during medical procedures, particularly when they become apneic before intubation. Other situations may include respiratory disorders in Intensive Care Units (ICU), or at home.

[0003] Humidification systems can deliver humidified gases to a patient, or other person(s) in need of such gases, and operate under controlled operating parameters. For example, in respiratory systems, it may be desirable to deliver gases to the patient at a particular temperature, pressure, humidity, and flow rate.

[0004] Some existing humidification chambers use floats to mechanically detect/control a level of water within the chamber. An external water source (e.g. a waterbag) is typically used in combination with such humidification chambers to continuously refill water in the humidification chamber to ensure that the water level does not go below a desired level. However, such humidification chambers can be costly to manufacture and may require additional components/time to setup. For example, such humidification chambers may require the use of an external water source (e.g. waterbag) for optimal operation. As such, additional componentry may be required to adequately support the waterbag above the humidification chamber. These setup and cost considerations can become important in use cases where the duration of use of such humidification chambers may be short. For example, when used for patients undergoing procedures in which they are under the effect of anaesthesia, the procedure may be a few hours, less than an hour, or 30 minutes or less in some instances.

[0005] Some existing systems such as anaesthesia delivery systems (also known as anaesthesia workstations) typically include anaesthesia machines having various components and/or medical instrumentation coupled and mountable to the machines, for example via specific mounting structures, rails and the like. These components and/or medical instrumentation may include monitors, infusion pumps, suction equipment, some of which may also include associated connecting fluid conduits and electrical cords. In some instances, the mounting of numerous components and instruments can present challenges during medical procedures. For example, the overabundance of mounted parts can create clutter and congestion at the anaesthesia workstation, and the operating room, potentially obstructing the clinician’s access to instrument controls on or around the anaesthesia workstation, which may impede the flow of a medical procedure.

[0006] It would be desirable to provide a cost-effective humidification chamber that is easy to setup for providing humidified gases to a patient, and/or a system for providing respiratory support which overcomes or ameliorates one or more of the disadvantages or problems described above, or which at least provides the consumer with a useful choice.

[0007] A reference herein to a patent document or any other matter identified as prior art, is not to be taken as an admission that the document or other matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

Summary of Invention

[0008] According to one aspect of the invention, there is provided a humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet of the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; an outlet portion defining an outlet of the fluid compartment for allowing an outgoing flow of gases to exit the fluid compartment; and a deflector configured to direct the incoming flow of gases from the inlet portion towards the outlet portion.

[0009] Advantageously, the deflector reduces the residence time of the incoming flow of gases in the fluid compartment to thereby reduce the rate of liquid (e.g., water) usage in the fluid compartment, whilst maintaining a desired level of humidity in the outgoing flow of gases for delivery to a patient. In this manner, a time interval between refilling of the fluid compartment can be maximised in use.

[0010] The deflector may be located proximate the inlet portion. The deflector may be configured to direct a bulk flow of gases from the inlet towards the outlet and away from a side wall portion of the fluid compartment proximal to the inlet.

[0011] In some embodiments, the fluid compartment may include a base, and a peripheral side wall extending around a perimeter of the base. The peripheral side wall may include an inlet adjacent wall portion. The inlet adjacent wall portion may be a portion of the peripheral side wall that has a minimum spatial separation from the inlet. The deflector may be configured to direct a bulk flow of gases from the inlet away from the inlet adjacent wall portion.

[0012] The peripheral side wall may further include a front wall portion. The front wall portion may be a forward-facing portion of the peripheral side wall when the humidification chamber is in use. The deflector may be configured to direct a bulk flow of gases from the inlet towards the front wall portion.

[0013] The deflector may be configured to direct a bulk flow of gases from the inlet in a direction generally parallel to a tangential plane of the inlet adjacent wall portion towards the front wall portion. The inlet may be spaced from the inlet adjacent wall portion.

[0014] The humidification chamber may further define a channel for providing a low resistance gas flow pathway between the inlet and the outlet. The deflector may be configured to direct a bulk flow of gases from the inlet to the outlet across at least a portion of the channel. [0015] In some embodiments, the channel may be spaced from the inlet adjacent wall portion. The channel may be generally C-shaped or U-shaped.

[0016] Optionally, the humidification chamber may further include a fluid directing member proximate the outlet for directing gases towards the outlet.

[0017] In some embodiments, the deflector may be configured to direct a bulk flow of gases from the inlet portion substantially along a direct path between the inlet and the outlet.

[0018] Typically, wherein the deflector extends inwardly of the fluid compartment from an inner surface of the humidification chamber.

[0019] An angle between the deflector and a wall of the fluid compartment for a given flow rate of the incoming flow of gases and/or the outgoing flow of gases may be based on at least a humidity of the outgoing flow of gasses.

[0020] In particular, the angle between the deflector and a top wall of the fluid compartment may be between about 20° and 70°. Moreover, the deflector may extend at an angle of about 30° with respect to a top wall of the fluid compartment. The top wall of the fluid compartment may refer to a generally flat portion of an upper wall of the fluid compartment located between the inlet and outlet. In some embodiments, the angle between the deflector and the top wall of the fluid compartment may be between about 0 and 90°. In some embodiment, the angle between the deflector and a top wall of the fluid compartment may be between about 20° and 50°, or between about 20° and 40°. In one embodiment, the angle between the deflector and a top wall of the fluid compartment may be 0. In this embodiment, the deflector may be partially enclosed and be generally shaped like a scoop, for example as shown in Figures 34 and 35.

[0021 ] The deflector may be sized to substantially correspond with a cross- sectional area of the inlet such that a bulk flow of gases is directed by the deflector towards the outlet portion. More specifically, an area of the deflector may be between about 50% to 150% of the cross-sectional area of the inlet.

[0022] In various embodiments, the bulk flow of gases may be directed by the deflector towards the outlet portion at an angle consistent with or equal to the angle of the deflector. For example, the bulk flow of gases may be directed by the deflector towards the outlet portion at an angle between about 0 and 90°, between about 20° and 70°, between about 20° and 50°, or between about 20° and 40°.

[0023] The deflector may have a thickness of about 1 ,4mm.

[0024] The inlet portion may include a generally straight connector for connection with an incoming gas flow conduit delivering the incoming flow of gases into the fluid compartment.

[0025] The generally straight connector may direct the incoming flow of gases downwardly into the fluid compartment.

[0026] The outlet portion may include a bent connector for connection with an outgoing gas flow conduit for delivering the outgoing flow of gases away from the fluid compartment. The bent connector may be configured to direct the outgoing flow of gases through a bend in the bent connector. The bend in the bent connector may be a substantially 90° bend. The bent connector may direct the outgoing flow of gases upwardly out of the fluid compartment and redirect the outgoing flow of gases through the bend.

[0027] The inlet portion and the outlet portion may be positioned above the fluid compartment. The inlet portion may be spaced from the outlet portion. The inlet portion and the outlet portion may be located adjacent opposite ends of the humidification chamber above the fluid compartment. The inlet portion may be spaced from the outlet portion at a distance of about 30 to 100 mm.

[0028] The outgoing flow of gases may have an absolute humidity of about 10mg/L to 45 mg/L. The outgoing flow of gases may have a relative humidity of about 10% to 100%, or about 80% to 100%, or about 100%. The incoming flow of gases and the outgoing flow of gases may have a flow rate of about 5L/min to 90L/min, or 10L/min to 70L/min. The incoming flow of gases may have a flow rate of about 70L/min. The outgoing flow of gases may have a humidity of about 20mg/L to 35 mg/L. The incoming flow of gases may have a flow rate of about 70L/min. The outgoing flow of gases may have a humidity of about 30mg/L.

[0029] In some embodiments, the predetermined flow rate of the flow of gases provided by the flow source may be 70 L/min, the outgoing flow of gases may have an absolute humidity of about 20mg/L to 35mg/L and a relative humidity of about 80% to 100%.

[0030] The fluid compartment may have a fluid capacity of about 350mL. The fluid compartment may have a fluid capacity of about 320mL.

[0031 ] The fluid compartment may have a substantially circular base.

[0032] The humidification chamber may further comprise at least one light guide for detecting a fluid level in the fluid compartment. The at least one light guide may extend downwardly into the fluid compartment from a top wall of the fluid compartment. The at least one light guide may include a proximal end adjoining the top wall of the fluid compartment, and a distal end opposite the proximal end.

[0033] The at least one light guide may include: an input side for receiving an input beam of light from an external light source and propagating the input beam of light through the input side of the light guide; and an output side for propagating an output beam of light through the output side of the light guide, the output beam of light being reflected from the input beam of light.

[0034] The at least one light guide may include at least one angled portion disposed at the distal end of the at least one light guide. The at least one angled portion may be configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

[0035] The output side of the at least one light guide may be parallel and adjacent to the input side of the at least one light guide.

[0036] In some embodiments, the at least one light guide may include a pair of opposed angled portions. The pair of angled portions may be disposed opposite one another at the distal end of the at least one light guide. Each angled portion may be disposed at about 45° to a base of the fluid compartment. [0037] The pair of angled portions may be configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

[0038] The light intensity of the output beam of light may be above a threshold when the at least one light guide is solely in contact with gases.

[0039] The distal end of the at least one light guide may include a jagged portion. The jagged portion may include a plurality of angled surfaces for scattering light. The jagged portion may be disposed between the pair of angled portions.

[0040] The pair of angled portions may be configured such that the input beam of light is refracted when the at least one light guide is in contact with a liquid such that an output beam of light having light intensity below the threshold or no output beam of light is present for propagation through the output side of the at least one light guide. The threshold may be about 40% of light intensity of the input beam of light.

[0041 ] The input beam of light and the output beam of light may be any suitable light. In one embodiment, the input beam of light and the output beam of light is infrared light.

[0042] The at least one light guide may have any suitable length to detect a desired liquid level in the fluid compartment. In one embodiment, the at least one light guide may have a length of between about 10 mm and 50 mm. The distance between the distal end of the at least one light guide and a base of the fluid compartment may be about 7mm. The thickness of the at least one light guide may be about 2.5mm. In some embodiments, the thickness of the at least one light guide may be about 1 to 6mm, 2 to 5mm, 2 to 4mm.

[0043] The at least one light guide may be positioned between the inlet portion and the outlet portion of the humidification chamber.

[0044] The humidification chamber may further include a first curved protrusion positioned above the at least one light guide. The first curved protrusion may be substantially aligned with the input side of the light guide. The first curved protrusion may be configured to collimate the input beam of light for propagation through the input side of the at least one light guide.

[0045] The humidification chamber may further include a second curved protrusion positioned above the at least one light guide. The second curved protrusion may be substantially aligned with the output side of the light guide. The second curved protrusion may be configured to collimate the output beam of light for detection by an optical sensor.

[0046] The at least one light guide may include one or more curved surfaces for redirecting one or more light rays from the input beam of light into the at least one light guide. Each of the one or more curved surfaces may define an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the at least one light guide. The elongate protrusion may be tapered along the lengthwise direction of the at least one light guide.

[0047] The at least one light guide may include a pair of curved surfaces. Each curved surface may be provided on an opposite face of the at least one light guide.

[0048] In some embodiments, the at least one light guide may include two pairs of curved surfaces. One pair of curved surfaces may be provided along the input side of the at least one light guide, and the other pair of curved surfaces may be provided along the output side of the at least one light guide. For each pair of curved surfaces, each curved surface may be provided on an opposite face of the at least one light guide. The curved surfaces for each pair of curved surfaces may be aligned with one another.

[0049] The at least one light guide may be located substantially at or adjacent a central axis of the fluid compartment.

[0050] The body of the humidification chamber may be made of a material having a light transmission percentage of at least 85%. A base of the humidification chamber may be made of metal.

[0051 ] The base of the humidification chamber may include a lip disposed around a circumference of the base so as to facilitate lateral insertion of the humidification chamber into a humidification unit. The humidification unit may include a heater base for heating the fluid in the fluid compartment, and a sensor assembly for transmitting the input beam of light and detecting the output beam of light.

[0052] The deflector may be configured to direct the incoming flow of gases towards the at least one light guide.

[0053] In some embodiments, the humidification chamber may include a first light guide for detecting a minimum level of the fluid in the fluid compartment, and a second light guide for detecting a maximum level of fluid in the fluid compartment, wherein the first light guide is longer than the second light guide.

[0054] The first light guide and the second light guide may be centred about a central axis of the fluid compartment.

[0055] Optionally, at least one of the inlet portion and outlet portion may define a sensor port for receiving a sensor unit therein. The sensor unit may be adapted to detect any one or more of a flow rate, temperature and pressure of a respective incoming flow of gases or outgoing flow of gases.

[0056] In some embodiments, the humidification chamber may further include a seal adapted to fit into the at least one sensor port for receiving the sensor unit therein. The seal may be adapted to provide pneumatic sealing for the respective inlet or outlet portion such that gas flow within the inlet or outlet portion may be isolated from ambient air.

[0057] The seal may be made from resilient material. The seal may be stretchable to engagingly receive the respective sensor unit therein.

[0058] According to another aspect of the invention, there is provided a humidification chamber comprising: a fluid compartment for containing a fluid, and at least one light guide for detecting a level of the fluid in the fluid compartment, the at least one light guide extending into the fluid compartment from a wall of the fluid compartment, wherein the at least one light guide includes a proximal end adjoining the wall of the fluid compartment, and a distal end opposite the proximal end, and wherein the distal end includes a jagged portion, the jagged portion providing a plurality of angled surfaces and/or edges for scattering light rays so as to reduce light rays from propagating along the at least one light guide.

[0059] Advantageously, in the scenario that light from the light guide is refracted into a liquid when the light guide is in contact with the liquid, the jagged portion facilitates scattering of any light rays reflected back towards the at least one light guide from a base of the fluid compartment, to avoid an erroneous water level detection associated with the light guide.

[0060] The at least one light guide may include a pair of opposed angled portions, the pair of angled portions being disposed opposite one another at the distal end of the at least one light guide. Each angled portion may include a downward-facing edge. The jagged portion may include one or more downward-facing edges. Each one of the one or more downward-facing edges of the jagged portion may be disposed at a different orientation to each downward-facing edge of a respective angled portion.

[0061 ] The jagged portion may be disposed between the pair of angled portions. Each angled portion may be disposed at about 45° to a base of the fluid compartment.

[0062] The at least one light guide may extend downwardly into the fluid compartment from a top wall of the fluid compartment. The at least one light guide may include an input side for receiving an input beam of light from an external light source and propagating the input beam of light through the input side of the at least one light guide, and an output side for propagating an output beam of light through the output side of the light guide, the output beam of light being reflected from the input beam of light.

[0063] The output side of the light guide may be parallel and adjacent to the input side of the at least one light guide. [0064] The pair of angled portions may be configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

[0065] The light intensity of the output beam of light may be above a threshold when the light guide is solely in contact with gases. The pair of angled portions may be configured such that the input beam of light is refracted when the at least one light guide is in contact with a liquid such that an output beam of light having light intensity below the threshold or no output beam of light is present for propagation through the output side of the at least one light guide. The threshold may be about 40% of the light intensity of the input beam of light.

[0066] The input beam of light and the output beam of light may be infra-red light.

[0067] The at least one light guide may have a length of between about 10 mm and 50 mm. A distance between the distal end of the at least one light guide and a base of the fluid compartment may be about 7mm. A thickness of the at least one light guide may be about 2.5mm.

[0068] The at least one light guide may be positioned between an inlet portion and an outlet portion of the humidification chamber, the inlet portion for allowing an incoming flow of gases to enter the fluid compartment and the outlet portion for allowing an outgoing flow of gases to exit the fluid compartment.

[0069] The humidification chamber may further include a first curved protrusion positioned above the at least one light guide. The first curved protrusion may be substantially aligned with the input side of the at least one light guide. The first curved protrusion may be configured to collimate the input beam of light for propagation through the input side of the at least one light guide.

[0070] The humidification chamber may further include a second curved protrusion positioned above the at least one light guide. The second curved protrusion may be substantially aligned with the output side of the at least one light guide. The second curved protrusion may be configured to collimate the output beam of light for detection by an optical sensor. [0071 ] The at least one light guide may include one or more curved surfaces for redirecting light rays from the input beam of light into the at least one light guide. Each curved surface may define an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the at least one light guide. The elongate protrusion may be tapered along the lengthwise direction of the at least one light guide.

[0072] The at least one light guide may include a pair of curved surfaces. Each curved surface may be provided on an opposite face of the at least one light guide.

[0073] In some embodiments, the at least one light guide may include two pairs of curved surfaces. One pair of curved surfaces may be provided along the input side of the at least one light guide, and the other pair of curved surfaces may be provided along the output side of the at least one light guide. For each pair of curved surfaces, each curved surface may be provided on an opposite face of the at least one light guide. The curved surfaces for each pair of curved surfaces may be aligned with one another.

[0074] The humidification chamber may include a first light guide for detecting a minimum level of the fluid in the fluid compartment, and a second light guide for detecting a maximum level of the fluid in the fluid compartment, wherein the first light guide is longer than the second light guide.

[0075] The first light guide and the second light guide may be centred about a central axis of the fluid compartment.

[0076] According to another aspect of the invention, there is provided a humidification chamber comprising: a fluid compartment for containing a fluid, and at least one light guide for detecting a level of the fluid in the fluid compartment, the at least one light guide extending into the fluid compartment from a wall of the fluid compartment, wherein the at least one light guide includes a proximal end adjoining the wall of the fluid compartment, and a distal end opposite the proximal end, and wherein the distal end includes a light scattering portion having an uneven surface for scattering stray light. [0077] The scattering portion may include a jagged portion, the jagged portion providing a plurality of angled surfaces and/or edges for scattering stray light so as to reduce stray light rays from propagating along the at least one light guide.

[0078] In one embodiment, the light scattering portion may include a rugged surface for scattering stray light.

[0079] According to a further aspect of the invention, there is provided a humidification chamber comprising: a fluid compartment for containing a fluid, and at least one light guide for detecting a level of the fluid in the fluid compartment, wherein the at least one light guide is located substantially at or adjacent a central axis of the fluid compartment.

[0080] Advantageously, the generally centred location of the at least one light guide allows the humidification chamber to detect a liquid level within the fluid compartment with effective accuracy when the humidification is tilted.

[0081 ] The fluid compartment may have any suitable shape and configuration. In one embodiment, the fluid compartment may have a substantially circular base.

[0082] In some embodiments, the central axis may intersect with an axis of rotation of the fluid compartment. The light guide may be located within a radius of about 10mm from an approximate centre of the fluid compartment through which the central axis passes. An internal diameter of the fluid compartment may be about 100mm to 1 15mm. The internal diameter of the fluid compartment may be about 108mm.

[0083] The at least one light guide may extend downwardly into the fluid compartment from a top wall of the fluid compartment. The at least one light guide may include a proximal end adjoining the top wall of the fluid compartment, and a distal end opposite the proximal end.

[0084] The at least one light guide may further include: an input side for receiving an input beam of light from an external light source and propagating the input beam of light through the input side of the light guide, and an output side for propagating an output beam of light through the output side of the light guide, the output beam of light being reflected from the input beam of light.

[0085] The at least one light guide may include at least one angled portion disposed at the distal end of the at least one light guide. The at least one angled portion may be configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

[0086] The output side of the light guide may be parallel and adjacent to the input side of the light guide.

[0087] The at least one light guide may include a pair of opposed angled portions. The pair of angled portions may be disposed opposite one another at the distal end of the at least one light guide. Each angled portion may be disposed at about 45° to a base of the fluid compartment.

[0088] The pair of angled portions may be configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

[0089] The light intensity of the output beam of light may be above a threshold when the light guide is solely in contact with gases.

[0090] The input beam of light may be refracted when the at least one light guide is in contact with a liquid such that an output beam of light having light intensity below the threshold or no output beam of light is present for propagation through the output side of the at least one light guide. In one embodiment, the threshold may be about 40% of light intensity of the input beam of light.

[0091 ] In one embodiment, the input beam of light and the output beam of light is infra-red light. [0092] The at least one light guide may have a length of between about 10 mm and 50 mm. A distance between the distal end of the at least one light guide and a base of the fluid compartment may be about 7mm. A thickness of the at least one light guide may be about 2.5mm.

[0093] The at least one light guide may be positioned between an inlet portion and an outlet portion of the humidification chamber, the inlet portion for allowing an incoming flow of gases to enter the fluid compartment and the outlet portion for allowing an outgoing flow of gases to exit the fluid compartment.

[0094] The humidification chamber may further include a first curved protrusion positioned above the at least one light guide. The first curved protrusion may be substantially aligned with the input side of the at least one light guide. The first curved protrusion may be configured to collimate the input beam of light for propagation through the input side of the at least one light guide.

[0095] The humidification chamber may further include a second curved protrusion positioned above the at least one light guide. The second curved protrusion may be substantially aligned with the output side of the at least one light guide. The second curved protrusion may be configured to collimate the output beam of light for detection by an optical sensor.

[0096] The at least one light guide may include one or more curved surfaces for redirecting light rays from the input beam of light into the at least one light guide.

[0097] Each curved surface may define an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the at least one light guide. The elongate protrusion may be tapered along the lengthwise direction of the at least one light guide.

[0098] The at least one light guide may include a pair of curved surfaces. Each curved surface may be provided on an opposite face of the at least one light guide.

[0099] The at least one light guide may include two pairs of curved surfaces, one pair of curved surfaces being provided along the input side of the at least one light guide, and the other pair of curved surfaces being provided along the output side of the at least one light guide. For each pair of curved surfaces, each curved surface may be provided on an opposite face of the at least one light guide. The curved surfaces for each pair of curved surfaces may be aligned with one another.

[0100] The humidification chamber may include a first light guide for detecting a minimum level of fluid in the fluid compartment, and a second light guide for detecting a maximum level of fluid in the fluid compartment, wherein the first light guide is longer than the second light guide.

[0101] The first light guide and the second light guide may be centred about a central axis of the fluid compartment.

[0102] In some embodiments, the humidification chamber may further include a fluid directing member proximate the outlet for directing gases towards the outlet.

[0103] In some embodiments, at least one of the inlet portion and outlet portion may define a sensor port for receiving a sensor unit therein. The sensor unit may be adapted to detect any one or more of a flow rate, temperature and pressure of a respective incoming flow of gases or outgoing flow of gases.

[0104] The humidification chamber may further include a seal adapted to fit into the at least one sensor port for receiving the sensor unit therein. The seal may be adapted to provide pneumatic sealing for the respective inlet or outlet portion such that gas flow within the inlet or outlet portion may be isolated from ambient air.

[0105] The seal may be made from resilient material. Moreover, the seal may be stretchable to engagingly receive the respective sensor unit therein.

[0106] According to another aspect of the invention, there is provided a humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet to the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; at least one light guide for detecting a level of the fluid in the fluid compartment; and a deflector configured to direct the incoming flow of gases from the inlet portion towards the at least one light guide. [0107] Directing the incoming flow of gases towards the at least one light guide advantageously reduces build-up of any condensation on the light guide during operation, thereby improving the signal to noise ratio and thus accuracy of the liquid level sensing functionality of the humidification chamber.

[0108] The deflector may be located proximate the inlet. The deflector may be configured to direct a bulk flow of gases from the inlet towards the at least one light guide. The deflector may extend inwardly of the fluid compartment from an inner surface of the humidification chamber.

[0109] An angle between the deflector and a wall of the fluid compartment for a given flow rate of the incoming flow of gases may be based on at least a humidity of an outgoing flow of gasses exiting the fluid compartment via an outlet of the fluid compartment.

[01 10] The angle between the deflector and a top wall of the fluid compartment may be between about 20° and 70°. More specifically, the deflector may extend at an angle of about 30° with respect to a top wall of the fluid compartment.

[01 11 ] The deflector may be sized to substantially correspond with a cross- sectional area of the inlet such that a bulk flow of gases is directed by the deflector towards the at least one light guide. In particular, an area of the deflector may be between about 50% to 150% of the cross-sectional area of the inlet. The deflector may have a thickness of about 1 ,4mm.

[01 12] The at least one light guide may extend downwardly into the fluid compartment from a top wall of the fluid compartment, wherein the at least one light guide includes a proximal end adjoining the top wall of the fluid compartment, and a distal end opposite the proximal end.

[01 13] The at least one light guide may include an input side for receiving an input beam of light from an external light source and propagating the input beam of light through the input side of the at least one light guide, and an output side for propagating an output beam of light through the output side of the at least one light guide, the output beam of light being reflected from the input beam of light. [01 14] The at least one light guide may include at least one angled portion disposed at the distal end of the at least one light guide. The at least one angled portion may be configured to reflecting the output beam of light from the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

[01 15] The output side of the at least one light guide may be parallel and adjacent to the input side of the at least one light guide.

[01 16] The at least one light guide may include a pair of opposed angled portions. The pair of opposed angled portions may be disposed opposite one another at the distal end of the at least one light guide. Each angled portion may be disposed at about 45° to a base of the fluid compartment.

[01 17] The pair of angled portions may be configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

[01 18] The light intensity of the output beam of light may be above a threshold when the light guide is solely in contact with gases.

[01 19] The input beam of light may be refracted when the at least one light guide is in contact with a liquid such that an output beam of light having light intensity below the threshold or no output beam of light is present for propagation through the output side of the at least one light guide.

[0120] The threshold may be about 40% of the light intensity of the input beam of light.

[0121 ] The input beam of light and the output beam of light may be infra-red light.

[0122] The at least one light guide has a length of between about 10mm and 50mm.

[0123] A distance between the distal end of the at least one light guide and a base of the fluid compartment may be about 7mm. A thickness of the at least one light guide may be about 2.5mm. [0124] The humidification chamber may further include an outlet portion for allowing an outgoing flow of gases to exit the fluid compartment. The at least one light guide may be positioned between the inlet portion and the outlet portion of the humidification chamber.

[0125] The humidification chamber may further include a first curved protrusion positioned above the at least one light guide. The first curved protrusion may be substantially aligned with the input side of the light guide. The first curved protrusion may be configured to collimate the input beam of light for propagation through the input side of the light guide.

[0126] The humidification chamber may further include a second curved protrusion positioned above the at least one light guide. The second curved protrusion may be substantially aligned with the output side of the light guide. The second curved protrusion may be configured to collimate the output beam of light for detection by an optical sensor.

[0127] The at least one light guide may include one or more curved surfaces for redirecting light rays from the input beam of light into the at least one light guide. Each curved surface may define an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the at least one light guide. The elongate protrusion may be tapered along the lengthwise direction.

[0128] The at least one light guide may include a pair of curved surfaces. Each curved surface may be provided on an opposite face of the at least one light guide. The at least one light guide may include two pairs of curved surfaces, one pair of curved surfaces being provided along the input side of the at least one light guide, and the other pair of curved surfaces being provided along the output side of the at least one light guide. For each pair of curved surfaces each curved surface may be provided on an opposite face of the at least one light guide. The curved surfaces for each pair of curved surfaces may be aligned with one another.

[0129] The humidification chamber may include a first light guide for detecting a minimum level of fluid in the fluid compartment, and a second light guide for detecting a maximum level of fluid in the fluid compartment, wherein the first light guide is longer than the second light guide. The deflector may be configured to direct a bulk flow of gases from the inlet portion towards the first light guide and/or the second light guide.

[0130] According to a further aspect of the invention, there is provided a kit including a humidification chamber according to any one of the preceding claims, and any one or more of a nasal cannula, an incoming gas flow conduit for connection to the inlet portion of the humidification chamber, and an outgoing gas flow conduit for connection to the outlet portion of the humidification chamber.

[0131 ] The kit may further include a filter.

[0132] In one embodiment, the nasal cannula may include a filter. In one embodiment, the filter may be integral with the nasal cannula.

[0133] According to a further aspect of the invention, there is provided a humidifier including a humidification chamber according to any one of the embodiments described herein.

[0134] The humidifier may further include a humidification unit configured for coupling with the humidification chamber, the humidification unit including a heater base for transferring heat to the fluid compartment of the humidification unit.

[0135] According to a further aspect of the invention, there is provided a respiratory system including a humidification chamber according to any one of the embodiments described herein.

[0136] The respiratory system may further include a flow source for providing the incoming flow of gases to the humidification chamber.

[0137] The flow source may provide the incoming flow of gases at a predetermined flow rate. The predetermined flow rate may be between about 10 L/min to 70 L/min. The predetermined flow rate may be about 70 L/min. The predetermined flow rate may be a high flow rate. [0138] The respiratory system may further include a patient interface. The patient interface may be non-sealing. The patient interface may be a nasal cannula.

[0139] According to a further aspect of the invention, there is provided a humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet of the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; an outlet portion defining an outlet of the fluid compartment for allowing an outgoing flow of gases to exit the fluid compartment; and a channel extending between the inlet and outlet, the channel being configured to provide a passage for a flow of gases from the inlet towards the outlet.

[0140] In particular, the channel may connect the inlet and outlet. As such, the channel may provide a direct passage for the flow of gases from the inlet to the outlet.

[0141] In some embodiments, the channel is located above the fluid compartment.

[0142] The channel may increase a total internal volume of the humidification chamber and reduce a residence time of the flow of gases through the humidification chamber so as to facilitate movement of the flow of gases from the inlet towards the outlet. In other words, a humidification chamber having a channel as disclosed herein may have a larger total internal volume when compared to a humidification chamber without such a channel.

[0143] In some embodiments, the channel may be curved. In some embodiments, the channel may follow a peripheral wall of the fluid compartment.

[0144] In some embodiments, the humidification chamber may include a base, a top portion, and a peripheral wall extending between the base and the top portion, wherein the channel extends outwardly from the top portion.

[0145] In some embodiments, the channel may follow a contour of the peripheral wall. [0146] In some embodiments, at least a portion of a side wall of the channel is flush with, and forms part of, the peripheral wall of the humidification chamber.

[0147] In some embodiments, the humidification chamber may further include a deflector configured to direct the incoming flow of gases from the inlet portion towards the channel.

[0148] The deflector may be located proximate the inlet portion. In some embodiments, the deflector may be configured to direct a bulk flow of gases from the inlet towards the channel.

[0149] In some embodiments, the deflector is partially enclosed. For example, the deflector may be substantially in the form of a scoop.

[0150] In some embodiments, the fluid compartment may include a base, and a peripheral side wall extending around a perimeter of the base. The peripheral side wall may include an inlet adjacent wall portion. The inlet adjacent wall portion may be a portion of the peripheral side wall having a minimum spatial separation from the inlet. The deflector may be configured to direct a bulk flow of gases from the inlet away from the inlet adjacent wall portion.

[0151 ] The peripheral side wall may further include a front wall portion. The front wall portion may be a forward-facing portion of the peripheral side wall when the humidification chamber is in use. The deflector may be configured to direct a bulk flow of gases from the inlet towards the front wall portion.

[0152] In some embodiments, the deflector may be configured to direct a bulk flow of gases from the inlet in a direction generally parallel to a tangential plane of the inlet adjacent wall portion towards the front wall portion. The inlet may be spaced from the inlet adjacent wall portion.

[0153] The channel may provide a low resistance gas flow pathway between the inlet and the outlet. The deflector may be configured to direct a bulk flow of gases from the inlet to the outlet across at least a portion of the channel. The channel may be spaced from the inlet adjacent wall portion. The channel may be generally C-shaped or U-shaped. [0154] The humidification chamber may further include a fluid directing member proximate the outlet for directing gases towards the outlet.

[0155] In some embodiments, either one or both of the inlet portion and the outlet portion may extend substantially horizontally from the fluid compartment.

[0156] In some embodiments, either one or both of the inlet portion and the outlet portion may extend substantially vertically from the fluid compartment.

[0157] In some embodiments, either one or both of the inlet portion and the outlet portion may extend from an upper portion of the fluid compartment. Typically, an upper portion of the fluid compartment may be considered to refer to a portion of the fluid compartment on an upper half of the fluid compartment.

[0158] The inlet and outlet may be disposed adjacent opposite ends of a top portion of the fluid compartment.

[0159] In some embodiments, the inlet portion may be configured to extend at an angle with respect to fluid compartment so as to direct a bulk flow of gases into the channel. In particular, the angle between the inlet portion and a top wall of the fluid compartment may be between about 20° and 70°. More specifically, the inlet portion may extend at an angle of about 30° with respect to a top wall of the fluid compartment.

[0160] In some embodiments, an internal volume of the channel may be smaller than an internal volume of the fluid compartment.

[0161 ] In some embodiments, at least one of the inlet portion and outlet portion may define a sensor port for receiving a sensor unit therein. The sensor unit may be adapted to detect any one or more of a flow rate, temperature and pressure of a respective incoming flow of gases or outgoing flow of gases.

[0162] The humidification chamber may further include a seal adapted to fit into the at least one sensor port for receiving the sensor unit therein. The seal may be adapted to provide pneumatic sealing for the respective inlet or outlet portion such that gas flow within the inlet or outlet portion is isolated from ambient air.

[0163] The seal may be made from resilient material. In some embodiments, the seal may be stretchable to engagingly receive the respective sensor unit therein. [0164] In some embodiments, the fluid compartment may include a base, a top wall portion, and a peripheral wall portion extending between the base and the top portion, wherein an internal volume of the channel is smaller than an internal volume of the fluid compartment as defined by the base, top wall portion and peripheral wall portion of the fluid compartment.

[0165] In some embodiments, the humidification chamber may have a functional liquid capacity of about 400ml. In some embodiments, the humidification chamber may have a functional fluid capacity of about 250 to 350ml.

[0166] It will be understood that the "functional liquid capacity" as used herein refers to the practical or usable amount of liquid that the humidification chamber can hold. It implies that this is the amount of liquid that can be effectively stored within the internal volume of the humidification chamber, taking into account various constraints or limitations of the humidification chamber in its application. In other words, it refers to the usable real-world capacity of humidification chamber, as opposed to its theoretical or maximum liquid capacity, which may not be practical to achieve in use, as described in further detail below.

[0167] The channel and the fluid compartment may form a single continuous internal volume so as to allow a seamless flow of gases between the channel and the fluid compartment. Moreover, the channel may be continuous and provide a substantially uninterrupted passage for the flow of gases from the inlet towards the outlet.

[0168] In some embodiments, the fluid compartment may have a substantially circular base.

[0169] In some embodiments, the humidification chamber may further include one or more guides to provide alignment between the humidification chamber and a sensor module.

[0170] In some embodiments, the one or more guides may include a pair of parallel ribs extending from a top portion of the fluid compartment. [0171 ] Typically, in some embodiments, the humidification chamber may exclude floating mechanisms for enabling measurement of a fluid level within the fluid compartment.

[0172] Moreover, in some embodiments, the humidification chamber may be configured to operate without a connected external water source.

[0173] According to yet another aspect of the invention, there is provided a humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet of the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; an outlet portion defining an outlet of the fluid compartment for allowing an outgoing flow of gases to exit the fluid compartment; a channel extending between the inlet and outlet, the channel being configured to provide a passage for a flow of gases from the inlet towards the outlet, and a deflector configured to direct the incoming flow of gases from the inlet portion towards the channel.

[0174] The deflector may be located proximate the inlet portion. The deflector may be configured to direct a bulk flow of gases from the inlet towards the channel. In some embodiments, the deflector may substantially be in the form of a scoop.

[0175] In some embodiments, the deflector may include a base portion and a side wall portion partially extending around the periphery of the base portion. The base portion of the deflector may be substantially flat.

[0176] The deflector may define an open side opposite the side wall portion. The open side of the deflector may face the channel so as to direct the incoming flow of gases from the inlet portion into the channel.

[0177] In some embodiments, the channel and the fluid compartment may form a single continuous internal volume so as to allow a seamless flow of gases between the channel and the fluid compartment. The channel may be continuous. As such, the channel may provide a substantially uninterrupted passage for the flow of gases from the inlet towards the outlet.

[0178] According to a further aspect of the invention, there is provided a respiratory system including a flow source for providing a flow of gases at a predetermined flow rate, and a humidifier for providing a humidified flow of gases by adding humidity to the flow of gases from the flow source, the humidifier including a heater base, and a humidification chamber as described herein.

[0179] The respiratory system may further include a patient interface for providing the humidified flow of gases to a patient. The patient interface may include a nasal cannula.

[0180] Any suitable patient interface may be provided. In one embodiment, the patient interface may be a sealing patient interface. In another embodiment, the patient interface may be a non-sealing patient interface.

[0181 ] The respiratory system may further include a non-humidified gas conduit for coupling the flow source to the humidifier and providing a passage for the flow of gases from the flow source to the humidifier.

[0182] In some embodiments, the respiratory system may further include a humidified gas conduit for coupling the humidifier to the patient interface and providing a passage for the humidified flow of gases from the humidifier to the patient interface.

[0183] In some embodiments, the humidified flow of gases may have an absolute humidity of about 10mg/L to 45 mg/L. The outgoing flow of gases may have a relative humidity of about 10% to 100%, or about 80% to 100%, or about 100%.

[0184] In some embodiments, the predetermined flow rate of the flow of gases provided by the flow source may be about 5L/min to 90L/min, or 10L/min to 70L/min.

[0185] In some embodiments, the predetermined flow rate of the flow of gases provided by the flow source may be 70 L/min, the outgoing flow of gases 210 may have an absolute humidity of about 20mg/L to 35mg/L and a relative humidity of about 80% to 100%.

[0186] In some embodiments, when the flow of gases provided by the flow source has a flow rate of about 70L/min, the humidified flow of gases may have a humidity of about 20mg/L to 35 mg/L.

[0187] In some embodiments, when the flow of gases provided by the flow source has a flow rate of about 70L/min, the humidified flow of gases may have a humidity of about 30 mg/L.

[0188] According to a further aspect of the invention, there is provided a humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet of the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; an outlet portion defining an outlet of the fluid compartment for allowing an outgoing flow of gases to exit the fluid compartment; and a channel extending between the inlet and outlet, the channel being continuous so as to provide a substantially uninterrupted passage for the flow of gases from the inlet to the outlet.

[0189] In some embodiments, the channel may connect the inlet and outlet. The channel and the fluid compartment may form a single continuous internal volume so as to allow a seamless flow of gases between the channel and the fluid compartment.

[0190] According to a further aspect of the invention, there is provided a system comprising an anaesthesia machine, and a humidifier mounted to the anaesthesia machine, the humidifier comprising a humidification chamber, the humidification chamber being configured to be manually replenishable, and a display module for visually displaying either one or both of an alert and operating parameters in relation to a therapy provided via the humidifier, wherein the humidifier is mounted to the anaesthesia machine such that the display module is greater than about 0.5 to 1 meters from a base of the anaesthesia machine.

[0191] In some embodiments, the humidifier may be mounted to the anaesthesia machine such that the display module is greater than about 0.7 to 1 meters from the base of the anaesthesia machine.

[0192] In some embodiments, the humidifier may be mounted to the anaesthesia machine such that the display module is greater than about 0.7 meters from the base of the anaesthesia machine.

[0193] In some embodiments, the anaesthesia machine may include a monitor. The humidifier may be mounted to the anaesthesia machine such that the display module of the humidifier is generally below the monitor of the anaesthesia machine.

[0194] In some embodiments, the humidifier may be mounted to the anaesthesia machine such that the display module of the humidifier is generally level with or above a top portion of the anaesthesia machine.

[0195] In some embodiments, the anaesthesia machine includes a bellows, and the humidifier is mounted to the anaesthesia machine such that the display module of the humidifier may be generally level with or above a top portion of the bellows.

[0196] In some embodiments, the system may further include a mounting post to enable selective mounting of the humidifier at a variable height relative to the anaesthesia machine, wherein the mounting post has a length of less than about 1 meter.

[0197] In some embodiments, the mounting post may have a length of less than about 0.5 meter. In some embodiments, the mounting post may have a length of about 0.5 to 1 meter.

[0198] In some embodiments, the humidifier may be mounted at or adjacent a top portion of the mounting post.

[0199] In some embodiments, the humidifier may include a graphical user interface, the graphical user interface providing the display module for displaying operating parameters, the operating parameters comprising high flow respiratory support parameters including any one or more of temperature of a flow of gases delivered to a patient, a flow rate of the flow of gases delivered to the patient, a humidify of the flow of gases delivered to the patient, a pressure of the flow of gases delivered to the patient, and a selected respiratory support operating mode.

[0200] The operating parameters may further include any one or more of temperature sensor readings received from one or more sensors mounted at or proximate the patient, at or proximate the humidification chamber, and/or at or proximate a heater base of the humidifier, supply voltage to the humidifier, and power consumption of the heater base of the humidifier.

[0201 ] The graphical user interface may enable user selection of a respiratory support mode from a plurality of available high flow respiratory support modes including any one or more of anaesthesia mode and a specific medical procedure related mode. In some embodiments, the plurality high flow respiratory support modes may further include an infant/paediatric mode and an adult mode.

[0202] The humidifier may be configured to generate one or more alarms to alert a clinician. The one or more alarms may include any one or more of a malfunctioning alarm to indicate that one or more components in the system is not functioning appropriately, and a liquid level alarm to indicate that a liquid level of the humidification chamber is below a minimum threshold.

[0203] In some embodiments, the humidification chamber may be configured to operate without a connected external water source.

[0204] In some embodiments, the humidifier may be configured for use in high flow respiratory support. In particular, the system may further include a flow source for providing a flow of gases to the humidifier. A predetermined flow rate of the flow of gases provided by the flow source may be about 10L/min to 70L/min. [0205] In one embodiment, the flow source may be separate to and independent of the anaesthesia machine. In another embodiment, the flow source may be integrated with and provided by the anaesthesia machine.

[0206] A flow rate controller for controlling a flow rate of gases provided by the flow source may be integrated with, and provided by, the anaesthesia machine.

[0207] It should be noted that any of the features described herein can be combined with one or more other described features in any suitable combination, unless otherwise specified or clearly indicated to the contrary by the context of the specification. The described features may be combined in any suitable manner to produce desired results.

[0208] In order that the invention may be more readily understood and put into practice, one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings.

[0209] It will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

Brief Description of Drawings

[0210] Embodiments of the invention will be described by way of example only and with reference to the drawings, in which:

[0211 ] Figure 1 illustrates a respiratory system for providing humidified gas to a patient including a humidifier having a humidification chamber according to an embodiment of the invention.

[0212] Figure 2A illustrates a perspective view of a humidification chamber according to an embodiment of the invention.

[0213] Figure 2B illustrates a sectional view of the humidification chamber of Figure 2A.

[0214] Figures 3A and 3B illustrate an internal view of the humidification chamber of Figure 2A showing general flow directions of a bulk flow of gases within the humidification chamber according to embodiments of the invention. [0215] Figures 4A and 4B illustrate an internal view of the humidification chamber of Figure 2A showing general flow directions of a bulk flow of gases within the humidification chamber according to other embodiments of the invention.

[0216] Figures 5A and 5B illustrate an internal view of the humidification chamber of Figure 2A showing general flow directions of a bulk flow of gases within the humidification chamber according to further embodiments of the invention.

[0217] Figure 6 illustrates a deflector of the humidification chamber shown in Figure 2A according to one embodiment of the invention.

[0218] Figure 7 illustrates a cross-sectional perspective view of the humidification chamber of Figure 2A showing the deflector of Figure 6 within the humidification chamber.

[0219] Figures 8A and 8B illustrate another perspective view of the humidification chamber of Figure 2A showing an inlet portion of the humidification chamber according to an embodiment of the invention.

[0220] Figures 9A and 9B illustrate yet another perspective view of the humidification chamber of Figure 2A showing an outlet portion of the humidification chamber according to an embodiment of the invention.

[0221 ] Figure 10A and 10B illustrate a perspective and a side (rear) view of the humidification chamber of Figure 2A.

[0222] Figures 1 1 A to 11 H illustrate a humidifier having a humidification chamber of Figure 2A laterally insertable into a humidification unit.

[0223] Figure 12 illustrates a sectional side view of the humidification chamber of Figure 2A having a light guide for fluid level detection according to an embodiment of the invention.

[0224] Figure 13A illustrates a front view of a light guide for detecting fluid level in the humidification chamber of Figure 2A according to an embodiment of the invention.

[0225] Figure 13B illustrates a close-up view of a distal end of the light guide of Figure 13A. [0226] Figure 13C illustrates total internal refection of incident light within the light guide of Figure 13A when the light guide is solely in contact with gases.

[0227] Figure 14 illustrates refraction of incident light from the light guide of Figure 13A when the light guide is in contact with a liquid.

[0228] Figure 15A illustrates a jagged portion at a distal end of the light guide according to one embodiment of the invention.

[0229] Figure 15B illustrates a partial perspective view of a light guide having a jagged portion disposed between opposed angled portions at a distal end of the light guide according to one embodiment of the invention.

[0230] Figure 15C illustrates a further partial perspective view of the light guide shown in Figure 15B.

[0231 ] Figure 15D illustrates a side view of the light guide of Figure 15B.

[0232] Figure 15E illustrates a front view, a bottom view, and an inverted back view of the light guide of Figure 15B to further illustrate the jagged portion.

[0233] Figure 16 illustrates a first curved protrusion and a second curved protrusion used in respect of the light guide of Figure 13A according to an embodiment of the invention.

[0234] Figure 17A illustrates a top view of the humidification chamber of Figure 2A showing the first curved protrusion and second curved protrusion of Figure 16.

[0235] Figure 17B illustrates another top view of the humidification chamber of Figure 2 showing positions for an external light source and a receiver for a humidification unit compatible with the humidification chamber.

[0236] Figure 18 illustrates an example arrangement of the first curved protrusion of Figure 16.

[0237] Figure 19A illustrates a partial top view of the light guide of Figure 13A including one or more curved surfaces according to an embodiment of the invention. [0238] Figure 19B illustrates propagation of light along the light guide between the curved surfaces of Figure 19A.

[0239] Figure 20 illustrates a top view of a pair of light guides, each including two pairs of curved surfaces.

[0240] Figure 21 illustrates an interaction between the incident light and a curved surface.

[0241 ] Figure 22 illustrates a location of the light guide adjacent a central axis of the fluid compartment of the humidification chamber of Figure 2A according to an embodiment of the invention.

[0242] Figure 23A illustrates two light guides within the humidification chamber of Figure 2A according to an embodiment of the invention.

[0243] Figure 23B illustrates a perspective view of the two light guides of Figure 23A.

[0244] Figure 24 illustrates a central location of the two light guides of Figure 23A.

[0245] Figure 25 illustrates a cross-sectional side view of the humidification chamber of Figure 2A when the humidification chamber is tilted at an angle.

[0246] Figure 26A illustrates the humidification chamber of Figure 2A with two light guides located substantially centrally.

[0247] Figure 26B illustrates an impact of tilting the humidification chamber of Figure 26A.

[0248] Figure 27A illustrates a top view of the humidification chamber having a first pair of curved protrusions and a second pair of curved protrusions according to an embodiment of the invention.

[0249] Figure 27B illustrates a top view of the humidification chamber showing locations for two light sources and two receivers relative to the humidification chamber.

[0250] Figure 28 illustrates a kit containing the humidification chamber of Figure 2A. [0251] Figure 29 is a perspective view of a humidification chamber according to another embodiment of the invention.

[0252] Figure 30 is an internal view of the humidification chamber of Figure 29 with a base on the humidification chamber removed.

[0253] Figure 31 is a further internal view of the humidification chamber of Figure 29 with a base on the humidification chamber removed, illustrating the internal configuration of the chamber from a different angle.

[0254] Figure 32 is a cross sectional view of A-A cross-section illustrated in Figure 30, as viewed from a front side of the humidification chamber.

[0255] Figure 33 is a cross sectional view of B-B cross-section illustrated in Figure 30, as viewed from a rear side of the humidification chamber.

[0256] Figure 34 is a perspective view of Figure 32.

[0257] Figure 35 is a cross sectional view of C-C cross-section illustrated in Figure

30, as viewed from an angle to the C-C cross-section.

[0258] Figures 36 to 37 are further perspective view of the humidification chamber of Figure 29.

[0259] Figure 38 is a cross sectional view of D-D cross-section illustrated in Figure 30, as viewed from an angle to the D-D cross-section.

[0260] Figure 39 is a perspective view of the humidification chamber of Figure 29 showing hidden lines.

[0261] Figure 40 is a perspective view of a humidification chamber according to another embodiment.

[0262] Figure 41 is a perspective view of a humidification chamber according to another embodiment.

[0263] Figure 42 is a perspective view of a humidification chamber according to another embodiment. [0264] Figure 43 is a schematic diagram illustrating a system for anaesthesia delivery according to one embodiment.

[0265] Figure 44 illustrates a humidifier according to an embodiment of the invention.

[0266] Figure 45 further illustrates a humidifier according to an embodiment of the invention.

[0267] Figure 46 illustrates an example mounting assembly for a humidifier.

[0268] Figure 47 is an exploded perspective view of the inlet and outlet seals shown in Figures 10A and 10B together with their corresponding sensor units.

[0269] Figure 48 is a partial section view of the inlet portion or outlet portion of a humidification chamber having a sensor port, seal and a biased sensor unit.

[0270] Figure 49 is a section view through one of the seals mounted to a sensor port of the humidification chamber.

[0271] Figure 50 is a top view of the seal of Figure 49, which is substantially the same as the bottom view of the seal.

[0272] Figure 51 is a side view of the seal of Figure 49, which is substantially the same as the opposing side view of the seal.

[0273] Figure 52 is a front view of the seal of Figure 49

[0274] Figure 53 is a rear view of the seal of Figure 49.

[0275] Figure 54 is a perspective view of the seal of Figure 49.

[0276] Figures 55 to 58 illustrate a seal according to another embodiment.

[0277] Figures 59 to 61 illustrate the mounting of the seal of Figures 55 to 58 to a sensor port of a humidification chamber.

[0278] Figures 62 to 72 illustrate seals according to further embodiments. [0279] Figures 73 to 75 illustrate a humidification chamber according to a further embodiment of the invention.

[0280] Figures 76 to 77 illustrate a humidifier including a humidification chamber mounted on a humidification unit according to a further embodiment of the invention.

Detailed Description

[0281 ] Figure 1 illustrates a system/apparatus 10 for providing humidified gas to a patient 16. In separate embodiments, the system/apparatus 10 could be an integrated or a separate component-based arrangement, generally shown in the dotted box 1 1 in Figure 1 . In some configurations the system 10 could be a modular arrangement of the components shown therein. Hereinafter, it will be referred to as a system, but this should not be considered limiting.

[0282] The system 10 comprises a flow source 12 for providing a flow of gas such as oxygen, or a mix of oxygen and one or more other gases. Alternatively, the system can have a connection for coupling to a flow source. As such, the flow source 12 might be considered to form part of the system 10 or be separate to it, depending on context, or even part of the flow source 12 forms part of the system 10, and part of the flow source 12 fall outside the system 10.

[0283] The flow source 12 may be an in-wall supply of oxygen, a tank of oxygen, a tank of other gas and/or a high flow respiratory support system with a blower/flow generator 3. Figure 1 shows a flow source 12 with a flow generator 3 (such as Airvo™ flow generator), with an optional air inlet 6 and optional connection to an oxygen (O2) source 5 (such as a tank or O2 generator) via a shut off valve and/or regulator and/or other gas flow control (all represented as 7), in an embodiment of the invention. In an alternative embodiment, there is no flow generator, but rather the flow source 12 is an in-wall O2 or blended 02/Air supply, optionally with a flow meter. The description from here can refer to either embodiment. The flow source 12 could be one or a combination of a flow generator, O2 source, air source as described. Any valves associated with the flow source 12 could be considered part of the flow source, or external to it, depending on context. The flow source 12 is shown as part of the system 10, although in the case of an external oxygen tank or in-wall source, it may be considered a separate component, in which case the system has a connection port to connect to such flow source 12. The flow source 12 provides an (optionally high) flow of gas 13 that can be delivered to a patient 16 via an outgoing gas flow conduit 14, and patient interface 15 (such as a (non-sealing) nasal cannula or sealing nasal mask).

[0284] A humidifier, for example humidifier 100, (also see Figures 11 C to 1 1 H) may be provided between the flow source 12 and the patient 16 to provide humidification of the delivered gas. It will be appreciated that the humidifier 100 may be integral with or separate from the flow source 12 in various embodiments. One or more sensors 18a, 18b, 18c, 18d, for measuring/detecting parameters such as flow, oxygen fraction, pressure, humidity, temperature, and the like or other sensors can be placed throughout the system and/or at, on or near the patient 16. Alternatively, or additionally, sensors from which such parameters can be derived could be used. In addition, or alternatively, the sensors 18a to 18d can be one or more physiological sensors for sensing patient physiological parameters such as, heart rate, oxygen saturation, partial pressure of oxygen in the blood, respiratory rate, partial pressure of CO2 in the blood. Alternatively, or additionally, sensors from which such parameters can be derived could be used. Other on-patient sensors could comprise EEG sensors, torso bands to detect breathing, and any other suitable sensors. The humidifier 100 provides humidified gases to help maintain the condition of the airways of the patient 16. One or more of the sensors might form part of the system 10, or be external thereto, with the system 10 having inputs for any external sensors.

[0285] The output from the sensors 18a to 18d may be sent to a controller 19 to assist with control of the system 10, including among other things, to vary gas flow to provide an oscillating gas flow.

[0286] As an example, the sensors can comprise a pulse oximeter 18d on the patient for determining the oxygen saturation of the blood. The pulse oximeter provides an analogue or digital electrical signal for the controller 19.

[0287] As another example, the partial pressure of oxygen in the blood could be sensed by using a transcutaneous oxygen monitor/sensor. The oxygen sensor measures the concentration of oxygen and this reading is corrected for temperature to produce an estimated partial pressure for oxygen in the blood. The instrument electronic system provides an analogue or digital signal which directly indicates the partial pressure of blood oxygen, and which is connected to the controller 19.

[0288] As another example, respiratory rate could be sensed using respiratory inductance plethysmography (RIP) with an analogue or digital signal that is connected to the controller 19.

[0289] As a further example, the partial pressure of CO2 in the blood can be sensed using a transcutaneous monitor with an analogue or digital signal that is connected to the controller 19.

[0290] As another example, exhaled CO2 is sensed using an exhaled CO2 sensor. The CO2 partial pressure reading is transmitted to the controller 19 in either analogue or digital form.

[0291 ] Another example is a heart activity sensor for sensing patient heart activity. The controller 19 is connected to receive input from the heart activity sensor (such as a sensor output signal) relating to heart activity of the patient 16. This enables the controller 19 to control gas flow based on the received input from the heart activity sensor.

[0292] A controller 19 is provided, which is coupled to the flow source 12, humidifier 100 and sensors 18a-18d. Controller 19 controls these and other aspects of the system 10.

[0293] The system 10 may also comprise one or more gas flow modulators 59, which can be used to modulate (that is, varying, modify, adjust or otherwise control) parameters of the gas flow. Each gas flow modulator 59 can be provided in the flow source 12 (and the flow source itself can be a gas flow modulator), after the flow source 12 and before the humidifier 100, after the humidifier 100, and/or in any other suitable place in the system 10 to modulate gas flow.

[0294] The controller 19 can operate the flow source 12 to provide the delivered flow of gas. It can also operate the gas flow modulators 59 to control the flow, pressure, volume and/or other parameters of gas provided by the flow source 12 based on feedback from sensors 18a to 18d, or optionally without feedback (e.g., using default settings). The controller 19 can also control any other suitable parameters of the flow source 12 to meet oxygenation requirements.

[0295] The controller 19 can also control the humidifier 100 based on feedback from the sensors 18a - 18d. Using input from the sensors 18a to 18d, the controller 19 can determine oxygenation requirements and control parameters of the flow source 12, gas flow modulators 59 and/or humidifier 100 as required. An input/output interface 20 (such as a display and/or input device) is provided. The input device is for receiving information from a user (e.g. clinician or patient 16) that can be used for determining oxygenation requirements.

[0296] The humidifier 100 may include a humidification chamber 200 and a humidification unit 102 as described herein.

[0297] A humidification chamber 200 according to embodiments described herein is particularly adapted for use in respiratory systems such as CPAP or high flow respiratory gas systems, for example a high flow system for use in anaesthesia procedures. Such a system is shown schematically in Figure 1 . Respiratory systems in which the chamber may be particularly useful are CPAP, BiPAP, high flow respiratory support, varying high flow respiratory support, low flow air, low flow O2 delivery, bubble CPAP, apnoeic high flow (i.e. high flow to anesthetized patients), invasive ventilation and non-invasive ventilation. Further, a humidification chamber 200 as described herein may be useful in systems other than respiratory systems.

[0298] Unless the context suggests otherwise, a flow source provides a flow of gases at a set flow rate. A set flow rate may be a constant flow rate, variable flow rate or may be an oscillating flow rate, for example a sinusoidal flow rate or a flow rate with a step or square wave profile.

[0299] ‘High flow respiratory support’ as used in this disclosure may refer to delivery of gases to a patient at a flow rate of greater than or equal to about 5 or 10 liters per minute (5 or 10 LPM or L/min).

[0300] In some configurations, ‘high flow respiratory support’ may refer to the delivery of gases to a patient at a flow rate of about 5 or 10 LPM to about 150 LPM, or about 15 LPM to about 95 LPM, or about 20 LPM to about 90 LPM, or about 25 LPM to about 85 LPM, or about 30 LPM to about 80 LPM, or about 35 LPM to about 75 LPM, or about 40 LPM to about 70 LPM, or about 45 LPM to about 65 LPM, or about 50 LPM to about 60 LPM. For example, according to those various embodiments and configurations described herein, a flow rate of gases supplied or provided to an interface via a system or from a flow source, may comprise, but is not limited to, flows of at least about 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 1 10, 120, 130, 140, 150 LPM, or more, and useful ranges may be selected to be any of these values (for example, about 20 LPM to about 90 LPM, about 40 LPM to about 70 LPM, about 40 LPM to about 80 LPM, about 50 LPM to about 80 LPM, about 60 LPM to about 80 LPM, about 70 LPM to about 100 LPM, about 70 LPM to about 80 LPM).

[0301 ] The gases delivered will be chosen depending on the intended use of the therapy. Gases delivered may comprise a percentage of oxygen. In some configurations, the percentage of oxygen in the gases delivered may be about 15% to about 100%, 20% to about 100%, or about 30% to about 100%, or about 40% to about 100%, or about 50% to about 100%, or about 60% to about 100%, or about 70% to about 100%, or about 80% to about 100%, or about 90% to about 100%, or about 100%, or 100%.

[0302] High flow respiratory support has been found effective in meeting or exceeding the patient's normal real inspiratory demand, to increase oxygenation of the patient and/or reduce the work of breathing. Additionally, high flow respiratory support may generate a flushing effect in the nasopharynx such that the anatomical dead space of the upper airways is flushed by the high incoming gas flows. This creates a reservoir of fresh gas available of each and every breath, while minimizing re-breathing of carbon dioxide, nitrogen, etc.

[0303] By way of example, the respiratory system 10 of Figure 1 may be a high flow respiratory system. High flow respiratory support may be used as a means to promote gas exchange and/or respiratory support through the delivery of oxygen and/or other gases, and through the removal of CO2 from the patient’s airways. High flow respiratory support may be particularly useful prior to, during or after a medical procedure.

[0304] When used prior to a medical procedure, high gas flow can pre-load the patient with oxygen so that their blood oxygen saturation level and volume of oxygen in the lungs is higher to provide an oxygen buffer while the patient is in a sedated or apnoeic phase during the medical procedure.

[0305] A continuous supply of oxygen helps to sustain healthy respiratory function during medical procedures (such as during anaesthesia) where respiratory function might be compromised (e.g. diminishes or stops). When this supply is compromised, hypoxia and/or hypercapnia can occur. During medical procedures such as anaesthesia and/or general anaesthesia where the patient is unconscious, the patient is monitored to detect when this happens. If oxygen supply and/or CO2 removal is compromised, the clinician may stop the medical procedure and facilitates oxygen supply and/or CO2 removal. This can be achieved for example by manually ventilating the patient through an anaesthetic bag and mask. Additionally or alternatively, a high flow of gases can be provided to the patient’s airway using a high flow respiratory support system.

[0306] Further advantages of high gas flow can include that the high gas flow increases pressure in the airways of the patient, thereby providing pressure support that opens airways, the trachea, lungs/alveolar and bronchioles. The opening of these structures enhances oxygenation, and to some extent assists in removal of CO2.

[0307] The increased pressure can also keep structures such as the larynx from blocking the view of the vocal chords during intubation. When humidified, the high gas flow can also prevent airways from drying out, mitigating mucociliary damage, and reducing risk of laryngospasms and risks associated with airway drying such as nose bleeding, aspiration (as a result of nose bleeding), and airway obstruction, swelling and bleeding. Another advantage of high gas flow is that the flow can clear smoke created during surgery in the air passages. For example, smoke can be created by lasers and/or cauterizing devices.

Humidification chamber and deflector

[0308] Figures 2A and 2B illustrate a perspective view and a sectional view respectively, of a humidification chamber 200 according to one embodiment of the present invention. The humidification chamber 200 comprises a fluid compartment 202, an inlet portion 204 and an outlet portion 208. The fluid compartment 202 is configured to contain a fluid (e.g. liquids and gases). More specifically, the fluid compartment 202 is configured to receive the gas/gases that is/are provided by the flow source 12 and delivered to the humidification chamber 200 via the inlet portion 204. The fluid compartment 202 is also configured to contain a liquid (such as water) to humidify the gas/gases so as to provide humidified gas/gases to the patient 16. The humidified gas/gases exit the humidification chamber 200 via the outlet portion 208 to be provided to the patient 16.

[0309] The gases delivered from the flow source 12 to the humidification chamber 200 through the inlet portion 204 will hereinafter be referred to as an incoming flow of gases as illustrated via arrow 206 in Figure 2A. The humidified gases from the humidification chamber 200 exiting through the outlet portion will hereinafter be referred to as an outgoing flow of gases as illustrated via arrow 210 in Figure 2A.

[0310] The fluid compartment 202 according to one embodiment of the invention has a substantially circular base 212. It will be appreciated that other configurations or shapes for the base of the fluid compartment 202 may be possible without departing from the scope of the claimed invention. For example, the base 212 of the fluid compartment 202 may have a rectangular base, square base, semi-circular base, or any other regular or irregular shaped base.

[0311 ] The humidification chamber 200 also includes a body 214 supported by the base 212. While the body 214 and the base 212 of the humidification chamber 200 are generally circular in Figure 2A, it will be appreciated that the humidification chamber 200 may have other shapes and/or configurations without departing from the scope of the invention, such as, but not limited to cylindrical, elliptical, quadrilateral, or any other regular or irregular shapes. Having a generally circular body 214 may provide an advantage of visibility of the liquid (e.g., water) level from all angles. The base 212 of the humidification chamber has a lip 226 disposed around a circumference of the base 212 to facilitate lateral insertion of the humidification chamber into a humidification unit 102, as explained in more detail below with reference to Figures 1 1 A to 1 1 H. In some embodiments, the humidification chamber 200 may be mounted to a humidification unit in a different manner. Indeed, any suitable mounting mechanism may be used. For example, the humidification chamber may be mounted to the humidification unit by placing the chamber over humidification unit or a portion of the humidification unit. [0312] In some embodiments, the humidification chamber 200 may be a single integral component. In some embodiments, the humidification chamber may comprise separate components mounted together, permanently or detachably, in any suitable manner.

[0313] In an embodiment, the fluid compartment 202 has a liquid capacity of about 350ml. In another embodiment, the fluid compartment 202 has a liquid capacity of about 320ml. In some examples, the internal volume of a humidification chamber 200 may be about 400ml to 500ml. Typically, the internal volume of a humidification chamber 200 may be 450ml. In these humidification chambers 200, the functional liquid capacity may be about 250ml to 350ml. As such, in some embodiments, the ratio of functional liquid capacity of a humification chamber 200 to the chamber’s total internal volume may be roughly (250 to 350ml):(400 to 500ml). In one embodiment, the ratio of functional liquid capacity of a humification chamber 200 to the chamber’s total internal volume may be about 250:450ml.

[0314] As more clearly shown in Figure 2B, the inlet portion 204 defines an inlet 222 of the fluid compartment 202 for allowing the incoming flow of gases 206 to enter the fluid compartment 202. The outlet portion 208 defines an outlet 224 of the fluid compartment 202 for allowing the outgoing flow of gases 210 to exit the fluid compartment 202.

[0315] The humidification chamber 200 further includes a deflector 218 configured to direct the incoming flow of gases 206 from the inlet 222 towards the outlet 224. The deflector 218 is located proximate the inlet 222 as illustrated in Figure 2B. The position, orientation and configuration of the deflector 210 (as discussed in more detail below) is designed to advantageously optimise the residence time of the incoming flow of gases 206 within the fluid compartment 202 to more effectively maximise the time between fluid compartment liquid refills, whilst maintaining a desired level of humidity in the outgoing flow of gases 210. For the humidification chamber 200, the deflector 218 reduces the residence time of the incoming flow of gases 206, when compared with a like humification chamber without a deflector, or with a deflector configured to direct the incoming flow of gases 206 away from the outlet 224. In some humidification chambers, a deflector may be provided to direct the incoming flow of gases 206 away from the outlet (e.g., towards an adjacent side wall 304 of the humidification chamber) to increase a residence time of the gases within the chamber, so as to provide a comparatively higher level of humidity in the outgoing flow of gases 210. The optimal residence time, flow rate of gases, and the level of humidity for a particular humidification chamber is determined based on the specific use case scenario. The residence time for gases in the humidification chamber 200 may be optimised for anaesthetic procedures.

[0316] As shown in Figure 2B, the deflector 218 extends inwardly of the fluid compartment 202 from an inner surface 220 of the humidification chamber 200. In other words, the deflector 218 extends from the inner surface 220 of the humidification chamber 200 and into the fluid compartment 202. In order to direct the incoming flow of gases 206 from the inlet 222 towards the outlet 224 of the humidification chamber 200, the deflector 218 extends from the inner surface 220 of the humidification chamber 200 and into the fluid compartment 202 at an angle.

[0317] As mentioned, such an orientation of the deflector 218 (facing the outlet 224) optimises the residence time of gases within the humidification chamber 200 for some use cases such as for medical procedures where the patient is under a degree of anaesthesia. Optimising the residence time facilitates achievement of a target humidity of the outgoing flow of gases 210 to a desired level to meet humidity requirements of the patient 16 whilst also achieving a rate of water usage in the fluid compartment 202 that is suitable for those use cases. Typically, factors that affect humidity picked up by the incoming flow of gases 206 relate to the length of a path along which the incoming flow of gases 206 travels within the humidification chamber 200, a surface area between the gases and the liquid within the humidification chamber, and a residence time of the gases in the humidification chamber 200. Residence time may also be impacted by the volume of liquid within the fluid compartment 202 and power to a heater base from which heat is passed to the humidification chamber 200.

[0318] In some embodiments, the deflector 218 may be partially enclosed and form an extension of the inlet portion 204, for example as shown in Figures 30 to 35 and described in further detail below. In particular, the deflector 218 may be shaped like a scoop and may be offset from, and/or extend at any suitable angle relative to inner surface 220. [0319] The arrangement and position of deflector 218 in combination with the configuration and dimensions of the humidification chamber 200 enables achievement of consistent humidity output when the flow rate of delivered gases range of between 10 L/min to 70 L/min. Absolute humidity output ranges of interest are typically 10 mg/L to 45 mg/L and more specifically, 20mg/L to 35 mg/L, over the standard flow rate range. In an exemplary embodiment, at a flow rate of 70L/min, humidity value of interest is around 20mg/L to 30mg/L and more specifically 25mg/L to 30mg/L. The outgoing flow of gases may have a relative humidity of about 10% to 100%, or about 80% to100%, or about 100%.

[0320] For a given flow rate of the incoming flow of gases 206 and/or the outgoing flow of gases 210, an angle between the deflector 218 and a wall of the fluid compartment 202 can be determined based on a desired target humidity of the outgoing flow of gases 210. More specifically, the deflector 218 extends from a top wall of the fluid compartment 202 and for a given flow rate of the incoming flow of gases 206 and/or the outgoing flow of gases 210, the angle between the deflector 218 and the top wall (shown as 602 in Figure 6 and explained in more detail below) of the fluid compartment 202 may be based on a desired target humidity of the outgoing flow of gases 210. In other embodiments, for example as shown in Figures 30 to 35, a partially enclosed deflector may be provided. As described in further detail below, a base portion of the deflector may be offset from the top wall, and the angle of the deflector base portion alone may be of less importance in directing the incoming flow of gases 206.

[0321 ] In one embodiment, the angle 604 between the deflector 218 and the top wall 602 of the fluid compartment 202 is between about 20° and 70° (see Figure 6). In this embodiment, the configuration of the deflector 218 may facilitate providing an absolute humidity of outgoing flow of gases between about 10 mg/L and 45 mg/L. As more clearly shown in Figure 6, the angle 604 between the deflector 218 and top wall 602 is such that the deflector 218 serves to direct at least a portion of the incoming flow of gases 206 away from the inlet adjacent wall portion 304 of the fluid compartment 202. As such, the angle 604 is not facing towards the inlet adjacent wall portion 304.

[0322] Changing this angle for a given flow rate may change the residence time of the gases and therefore the humidity output. Hence, the angle between the deflector 218 and the top wall 602 of the fluid compartment 202 is related to the target humidity range (e.g., between 10 mg/L and 45 mg/L).

[0323] In a further embodiment, the angle 604 between the deflector 218 and the top wall 602 of the fluid compartment 202 may be about 30°. In this embodiment, the configuration of the deflector 218 may facilitate providing a target absolute humidity of the outgoing flow of gases between about 10 mg/L and 45 mg/L, and more specifically 30 mg/L. For a fluid compartment 202 having a fluid capacity of 350ml (typically 320ml), with the incoming flow of gases 206/outgoing flow of gases 210 having a flow rate of 70L/min, the time it may take for water in the fluid compartment 202 to become used up may be up to 4 hours, and in some cases may be about 2.5 hours, 1 hour, or 10 to 30 minutes. Typically, the humidification chamber 200 may be particularly suitable for medical procedures having an average duration 30 minutes to 2.5 hours. Additionally, the gas(es) and water temperature, humidity, flow rate and temperature within the humidification chamber 200 may also affect the humidity of the outgoing flow of gases 210.

[0324] Figure 3A illustrates an internal view of the fluid compartment 202 to more clearly show target directions of a bulk flow 302 gases within the humidification chamber 200 according to some embodiments of the present invention. In examples shown in Figure 3A, the humidification chamber 200 has at least one light guide 1102 for water level detection. The deflector 218 is configured to direct a bulk flow 302 of gases from the inlet 222 (partially obstructed by the deflector 218 in Figure 3A) towards the outlet 224 and away from a side wall portion 304 of the fluid compartment 202 proximal to the inlet 222. The side wall portion 304 of the fluid compartment 202 is a section of the side wall of the fluid compartment 202 that is proximal to the inlet 222 and may be opposite to the outlet 224 as can be seen from Figure 3A. In particular, the deflector 218 may be angled and oriented to direct the bulk flow 302 of gases in any direction away from the side wall 304 as illustrated in Figure 3A. In some embodiments, the humidification chamber 200 may not include any light guides.

[0325] Figure 3B illustrates an internal view of the fluid compartment 202 to more clearly show target directions of the bulk flow 302 of gases within the humidification chamber 200 according to further embodiments of the present invention. In the embodiment shown in Figure 3B, the humidification chamber 200 has a first light guide 2302 and a second light guide 2304 for water level detection (which will be discussed in further detail below). Like features in Figure 3B refer to like features previously described in relation to Figure 3A. The deflector 218 may be oriented and configured to direct a bulk flow 302 of gases from the inlet 222 towards the outlet 224 and away from the side wall portion 304 of the fluid compartment 202 proximal to the inlet 222. The side wall portion 304 of the fluid compartment 202 is a section of the side wall of the fluid compartment 202 that is proximal to the inlet 222 and opposite to the outlet 224 as can be seen from Figure 3B.

[0326] Figure 4A illustrates an internal view of the fluid compartment 202 to more clearly show target directions of a bulk flow 404 of gases within the humidification chamber 200 according to other embodiments of the present invention, in which the humidification chamber 200 may have at least one light guide 1102 for water level detection. (In some embodiments, the humidification chamber 200 may not provide any light guides.) The humidification chamber 200 defines a channel 402 for providing a low resistance gas flow pathway between the inlet 222 and the outlet 224. In one embodiment, the channel 402 is located towards the top side of the fluid compartment 202. Moreover, the channel 402 generally occupies one half of the top side of the fluid compartment 202. The deflector 218 may be configured to direct a bulk flow 404 (as shown in Figure 4A) of gases from the inlet 222 towards the outlet 224 across at least a portion of the channel 402. It will be appreciated that in this embodiment, the deflector 218 is also directing the bulk flow 404 of gases from the inlet 222 towards the outlet 224 away from the side wall portion 304 of the fluid compartment 202 proximal to the inlet 222 and opposite to the outlet 224. Further, in this embodiment, the deflector 218 may direct the bulk flow 404 of gases from the inlet 222 towards a section of the side wall proximal to the channel 402. The bulk flow of gases 404 may deflect from the section of the side wall proximal to the channel 402 and travel towards the outlet 224 along a remaining section of the side wall until reaching the outlet 224. Such a flow path is substantially void of intervening structures thereby providing the low resistance pathway for the gases to flow. Residence time of the gases within the fluid compartment 202 may be optimised when flowing in this direction, thereby achieving a desired humidity at the target flow rate for some applications.

[0327] Elaborating further, the residence time of the gases may be reduced when the bulk flow of gases is directed across the channel 402 (toward the channel 402 or towards a section of the side wall proximal to channel 402) when compared to embodiments where the bulk flow of gases is directed away from the channel 402 and/or towards the side wall portion 304 (whilst maintaining all other operating conditions the same), thereby allowing a degree of tuning of the humidification chamber for use in some use cases.

[0328] More specifically, the peripheral side wall 305 extending around the circumference/perimeter of the humidification chamber 200 may include a side wall portion 304 (referred to more specifically herein as an inlet adjacent wall portion 304), an outlet adjacent wall portion 307, a front wall portion 309, and a rear wall portion 31 1 generally opposite the front wall portion 309. As mentioned, the inlet adjacent side wall portion 304 is a section of the peripheral side wall 305 that is proximal to the inlet 222. In particular, the inlet adjacent side wall portion 304 may include a portion of the peripheral side wall 305 having a minimum spatial separation from the inlet 222.

[0329] The outlet adjacent wall portion 307 is typically a section of the peripheral side wall 305 that is proximal to the outlet 224 and may also be opposite to the inlet 222 as shown in Figure 4A. In some embodiments, the outlet adjacent wall portion 307 may be generally opposite the inlet adjacent wall portion 304, however this may not always be the case.

[0330] The front wall portion 309 of the humidification chamber 200 may be outwardly facing (e.g. the portion of the peripheral wall 305 facing away from a humidification unit (e.g. humidification unit 102 as shown in Figures 1 1 A to 11 H) when the chamber 200 is mounted to the humification unit 102 in use. Conversely, the rear wall portion 311 of the humidification chamber 200 may be inwardly facing (e.g. the portion of the peripheral wall 305 facing towards a humidification unit in use. In some embodiments, the front wall portion 309 may be a forward-facing portion of the peripheral side wall 305 in use, and the rear wall portion 31 1 may be a rearward facing portion 309 of the peripheral side wall 305 opposite the front wall portion 309.

[0331 ] In some embodiments, the deflector 218 may be configured to direct the incoming flow of gases 206 towards the front wall portion 309. In particular, the deflector 218 may be configured to direct the incoming flow of gases 206 in a direction generally consistent with or parallel to a tangential plane of the inlet adjacent wall portion 304, and towards the front wall portion 309. In this embodiment, it would be understood that the angle 604 between the deflector 218 and the top wall 602 is nevertheless considered to face away from the inlet adjacent wall portion 304, and not facing towards the inlet adjacent wall portion 304. If a channel 402 is provided, the deflector 218 may also direct the incoming flow of gases 206 into the channel 402 and the channel 402 may direct the bulk flow of gases 404 towards the outlet 224.

[0332] Figure 4B illustrates an internal view of the fluid compartment 202 to more clearly show target directions of a bulk flow 404 of gases within the humidification chamber 200 according to further embodiments of the present invention, in which the humidification chamber has a first light guide 2302 and a second light guide 2304. Like features in Figure 4B refer to like features previously described in relation to Figure 4A. In particular, the deflector 218 is configured to direct the bulk flow 404 of gases from the inlet 222 towards the outlet 224 across at least a portion of the channel 402. In some instances, the bulk flow 404 of gases may contact a section of a side wall of the fluid compartment 202 proximate the channel 402 before travelling along a remaining section of the side wall towards the outlet 224.

[0333] Figure 5A illustrates an internal view of the fluid compartment 202 to more clearly show target directions of the bulk flow 502 of gases within the humidification chamber 200 according to yet another embodiment of the present invention. In this embodiment the humidification chamber 200 may have one light guide 1 102 for water level detection. However, it is to be understood that in some embodiments, the chamber 200 may not provide a light guide. The deflector 218 is configured to direct the bulk flow 502 of gases from the inlet 222 towards the outlet 224 substantially along a direct path between the inlet 222 and the outlet 224. In other words, the deflector 218 is configured to direct the bulk flow 502 of gases from the inlet 222 towards the outlet 224 along a plane that intersects both the inlet 222 and the outlet. In one embodiment, the direct path between the inlet 222 and the outlet 224 is a substantially straight path. It will be appreciated that in this embodiment, the deflector 218 is also directing the bulk flow 502 of gases from the inlet 222 towards the outlet 224 away from the side wall portion 304 of the fluid compartment 202 proximal to the inlet 222 and opposite to the outlet 224. [0334] Figure 5B illustrates an internal view of the fluid compartment 202 to more clearly show target directions of the bulk flow 502 of gases within the humidification chamber 200 according to further embodiments of the present invention, in which the humidification chamber has a first light guide 2302 and a second light guide 2304 for water level detection. Like features in Figure 5B refer to like features previously described in relation to Figure 5A. The deflector 218 is configured to direct the bulk flow 502 of gases from the inlet 222 towards the outlet 224 substantially along a direct path between the inlet 222 and the outlet 224.

[0335] Figure 6 illustrates dimensions of the deflector 218 of the humidification chamber 200 according to one embodiment of the present invention. The deflector 218 has a thickness (Td) 606 of about 0.5 to about 4mm, or about 1 to about 4mm. The angle (Ad) 604 between the deflector 218 and the top wall 602 of the fluid compartment 202 is about 30° (when the target humidity of the outgoing flow of gases is between about 10 mg/L and 45 mg/L). In some embodiments, the angle (Ad) 604 between the deflector 218 and the top wall 602 of the fluid compartment 202 may be between about 0 to 90°, or 20° to 70°. As previously mentioned, the deflector 208 is configured such that the angle (Ad) 604 is facing away from (or not facing towards) the inlet adjacent wall portion 304.

[0336] In some embodiments, the height of the deflector 218 Th is such that the deflector 218 is above an upper liquid level for the humidification chamber, or above a user indicated liquid level. In one embodiment, when the angle (Ad) 604 is about 30°, the height of the deflector 218 Th is about 5mm to 15mm, 7mm to 13mm, or 9mm to 1 1 mm. More specifically, the height of the deflector 218 Th may be about 9mm, 10mm, or 1 1 mm. In one example, the height (Th) is 1 1 mm. In this embodiment, the deflector 218 may have a surface area of between about 50-150%, 75-125%, or 90-1 10% of the cross-sectional area of the inlet 222. More specifically, the deflector 218 may have a surface area of between about 75%, 80%, or 100% of the cross-sectional area of the inlet 222.

[0337] Whilst the deflector 218 in the embodiments shown is illustrated as being generally in the form of a circular disc, it will be understood that in other embodiments, the deflector may have any suitable shape or configuration. For example, the deflector may be flat, curved or bent. The deflector may have any suitable regular or irregular shape.

[0338] It will be understood that to achieve a target humidity, the angle (Ad) 604 may be different to the ranges described herein. The angle (Ad) 604 may be different for different fluid compartment 202 configurations or flow rate of incoming flow of gases 206.

[0339] Figure 7 illustrates a cross-sectional perspective view of the humidification chamber 200. The deflector 218 is sized to substantially correspond with a cross- sectional area 704 of the inlet 222. The deflector 218 and inlet 222 opening can have any suitable shape. For example, the deflector 218 and/or cross-section of the inlet 222 may be generally circular, rectangular, square, triangular, or be of any regular or irregular shape. In one embodiment, the deflector 218 may substantially correspond with a cross-sectional shape of the inlet 222.

[0340] The incoming flow of gases 206 may be directed by the deflector 218 such that the bulk flow (302, 404 or 502) of gases is guided towards the outlet 224. In an embodiment, an area 704 (i.e., surface area) of the deflector 218 is between about 50% to 150%, 75-125%, or 90-1 10%, or more specifically 75%, 80%, or 100% of the cross- sectional area of the inlet 222. The area of the deflector 218 may be beneficial such that a substantial proportion of the incoming flow of gases 206 contact the deflector 218. In an exemplary embodiment, when the cross-sectional area of the inlet 222 is about 340mm², the area 704 of the deflector 218 is about 260mm² (i.e., the area 704 of the deflector is about 75% of the cross-sectional area 704 of the inlet 222). In another embodiment, when the cross-sectional area of the inlet 222 is about 320mm², the area 704 of the deflector 218 is about 260mm² (i.e., the area 704 of the deflector is about 80% of the cross-sectional area of the inlet 222). It will be appreciated that there may be non-substantial variations in the cross-sectional area 702 of the inlet portion 204 along the straight connector 802 (as explained in more detail below) of the inlet portion 204 due to internal features of the inlet portion 204.

[0341 ] Figure 8A illustrates a perspective view of the humidification chamber 200 according to an exemplary embodiment. The inlet portion 204 may include a generally straight connector 802 for connection with an incoming gas flow conduit 2604 (Figure 28) for delivering the incoming flow of gases 206 (i.e., from the flow generator 3) into the fluid compartment 202.

[0342] Figure 8B more clearly shows the generally straight connector 802 directing the incoming flow of gases 206 downwardly (as shown by the arrow 804) into the fluid compartment 202. The incoming flow of gases 206 flow downwardly along the inlet portion 204 to the inlet 222 and into the fluid compartment 202. It will be understood that the inlet portion 204 and outlet portion 208 of the humidification chamber 200 can have any suitable orientation to couple with inlet and outlet conduits of the respiratory system 10. For example, a number of non-exhaustive alternative configurations of the inlet and outlet portions are described below with reference to Figures 40 to 42.

[0343] Figure 9A illustrates a perspective view of the humidification chamber 200 according to an embodiment of the present invention. The outlet portion 208 may include a bent connector 902 for connection with an outgoing gas flow conduit 14 for delivering the humidified outgoing flow of gases 210 away from the fluid compartment 202 (i.e., for delivery to a patient 16). The bent connector 902 is configured to direct the outgoing flow of gases 210 through a bend in the bent connector 902.

[0344] Figure 9B more clearly shows the bent connector 902 directing the outgoing flow of gases 210 from the outlet 224 upwardly (as shown by the arrow 904) out of the fluid compartment 202 and redirecting the outgoing flow of gases 210 through the bend and out of the outlet portion 208 (as shown by the arrow 906). In some examples, the flow of gases may not follow the path illustrated by arrows 904, 906. In an embodiment, the bend in the bent connector 92 is a substantially 90° bend. The configurations of the inlet and outlet portions 204, 208 are exemplary and different configurations of inlet and outlet portions 204, 208 may be used in other embodiments. For example, humidification chamber 200 may comprise an outlet portion 208 that does not comprise a bend.

[0345] As can be seen from Figures 2A, 2B, 7, 8A, 8B, 9A and 9B, the inlet portion 204 and the outlet portion 208 are positioned above the fluid compartment 202. Further, the inlet portion 204 and the outlet portion 208 are located adjacent opposite ends of the humidification chamber 200 above the fluid compartment 202. It will be appreciated that other positions/locations of the inlet portion 204 and the outlet portion 208 may be possible without departing from the scope of the claimed invention. These figures also show the inlet portion 204 being spaced from the outlet portion 208. In an embodiment, the inlet portion 204 is spaced from the outlet portion 208 at a distance of about 30mm to 100mm, 50mm to 80mm or 60mm to 70mm.

[0346] In one or more embodiments, the outgoing flow of gases 210 delivered to the patient 16 has an absolute humidity of between about 10mg/L to 45mg/L. The outgoing flow of gases may have a relative humidity of about 10% to 100%, or about 80% to100%, or about 100%. The incoming flow of gases 206 from the flow source 12 and the outgoing flow of gases 210 delivered to the patient 16 have a flow rate of between about 10L/min to 70L/min. It will be appreciated that the humidity of the outgoing flow of gases 210 and the flow rate of the incoming/outgoing flow of gases 206, 210 may be dependent upon the application of the humidification chamber 200 and/or the system 10. The application may include the provision of high flow respiratory support. In an embodiment, the incoming flow of gases 206 has a flow rate of about 70L/min and the outgoing flow of gases 210 has a humidity of between about 20mg/L to 35mg/L and a relative humidity of about 80% to 100%. In an embodiment, the incoming flow of gases 206 has a flow rate of about 70L/min and the outgoing flow of gases 210 has a humidity of about 30mg/L.

[0347] Figures 10A and 10B further illustrates the humidification chamber 200 according to one embodiment, in which the inlet portion 204 and the outlet portion 208 being positioned above the fluid compartment 202, the inlet portion 204 being spaced from the outlet portion 208 and located adjacent opposite ends of the humidification chamber 200.

[0348] In one embodiment, the humidification chamber 200 may be configured to allow mounting of sensor units thereto so as to detect gas flow characteristics in the chamber 200 such as flow rate, temperature and/or pressure. The inlet portion 204 is provided with an inlet sensor port 205, and the outlet portion 208 is provided with an outlet sensor port 21 1. In some embodiments, more than one sensor port may be provided in each or either of the inlet and outlet portions 204, 208. In some embodiments, the inlet portion 204 and outlet portion 208 may have a different number of sensor ports; for instance, the inlet portion 204 may have one inlet sensor port 205 while the outlet portion 208 may have two sensor ports 211 . [0349] An inlet seal 215 may be mounted to the inlet sensor port(s) 205 and an outlet seal 217 may be mounted to the outlet sensor port(s) 21 1 . Typically, each of the inlet and outlet seals 215, 217 provides pneumatic sealing for a respective inlet and outlet sensor port 205, 21 1 such that the incoming flow of gases 206 and the outgoing flow of gases 210 are respectively isolated from ambient by the seals 215, 217. In other words, the seals 215, 217 substantially close the inlet and outlet sensor ports 205, 21 1 . Accordingly, in the illustrated embodiment, the seals 215, 217 define a barrier that reduces the likelihood of fluid or gas passing through the inlet and outlet sensor ports 205. In some applications, at least one of the seals 215, 217, and optionally each of the seals 215, 217, may be resistant to the passage of water vapor.

[0350] In the embodiment illustrated in Figures 10A and 10B, the inlet seal 215 may include a single terminal to enable insertion of a single sensor unit, and the outlet seal 217 may include two terminals 207, 209 to enable insertion of one or two sensor units. Figure 47 illustrates exemplary sensor unit 219 for insertion into inlet seal 223, and exemplary double sensor unit 221 for insertion into outlet seal 225. It will be appreciated that whilst the inlet seal 223 and outlet seal 225 of Figure 47 are different in configuration to the inlet seal 205 and outlet seal 217 illustrated in Figures 10A and 10B, the functionality of the inlet and outlet seals 223, 225 are substantially similar to those of inlet and outlet seals 215, 217. Moreover, each of the inlet and outlet seals 215, 217 may provide any suitable number of terminals to be compatible with the required sensor unit(s).

[0351 ] In some embodiments, the inlet portion 204 may provide one or more inlet sensor ports to allow mounting of one or more sensor units, and the outlet portion may provide one or more outlet sensor ports 21 1 to allow mounting of one or more sensor units. In some embodiments, either one or both of the inlet and outlet sensor ports may include one or more respective inlet and outlet seals. For example, the outlet sensor port 21 1 may receive two separate outlet seals. Moreover, each of the inlet and outlet seals may provide one or more sensor terminals to receive one or more sensor units, and/or a single sensor unit having multiple sensors.

[0352] In some embodiments, each sensor unit may include one or more sensors. As such, a single inlet or outlet seal having a single sensor terminal may receive a single sensor unit having multiple sensors such that the single sensor unit may be capable of obtaining multiple sensor measurements of flow rate, temperature and/or pressure via the single inlet or outlet seal.

[0353] The inlet seal 215 and the outlet seal 217 can be made from any suitable material. In some applications, the inlet seal 215 and the outlet seal 217 may be formed from a resilient or flexible material. Optionally, at least one of the seals 215, 217 may be formed entirely of a resilient or flexible material. In some applications, at least a portion of at least one of the seals 215, 217 may be formed entirely of a resilient or flexible material. In some applications, one or more of the seals 215, 217 may be formed of a material with a Shore-A hardness of between about 20 and about 60, or between about 30 and about 40. In some applications, one or more of the seals 215, 217 may be formed of Silicone, polyethylene, or thermoplastic polyurethane.

[0354] In some applications, such as that shown in Figure 48, at least a portion of at least one of the seals 215, 217 can be formed with a rigid material. For example, but without limitation, at least a portion of at least one of the seals 215, 217 can be formed of a metal. When at least one of the seals 215, 217 is formed entirely of a rigid material, the seal preferably is configured to provide repeatable contact and thermal conduction between the barrier formed by the seal 215, 217 and an associated sensor. In some embodiments, the seals 215, 217 can be formed of the same material as the chamber 200, can be formed of a different material with a different (optionally higher) thermal conductivity, or a combination thereof. If a combination is used, at least a portion of a tip 401 , or at least a portion exposed to flow of gases within the inlet or outlet portion 204, 208, and in some configurations, the ultimate end of the tip 401 , of the seal may be formed of a material with a higher thermal conductivity (e.g., aluminum, copper). In some configurations, the tip 401 may be positioned such that the seal 215, 217 extends to an axial center of the respective inlet and outlet portion 204, 208. In some configurations, the tip 401 is positioned such that the seal 215, 217 traverses at least half of the transverse dimension of the respective inlet and outlet portion 204, 208. The seals 215, 217 can be formed integrally with the chamber 200 or, for example but without limitation, can be overmoulded, press-fit and glued, co-moulded, or welded thereto.

[0355] In some embodiments, at least one of the seals 215, 217 can be formed of a first, more thermally-conductive portion arranged to receive an end or a sensing portion of the associated sensor 219, 221 and a second, less thermally-conductive or thermally non-conductive portion. The second portion preferably is arranged to reduce or eliminate a conduction or other transmission of heat from the sensing element or tip of the sensor 219, 221 into the surrounding portions of the apparatus. For example, where the associated sensor 219, 221 comprises a thermistor, the second portion preferably generally or substantially thermally isolates the thermistor. In other words, the tip of the thermistor could be arranged in the more thermally-conductive first portion, which can be positioned within the flow of gases that the thermistor is measuring. In some configurations, the less thermally-conductive or thermally non-conductive portion may comprise a different material from the more thermally-conductive portion. In some configurations, a porous material or a foam material can be used in provide improved insulation. In such an arrangement, less heat is conducted from the first portion to the ambient environment through the second portion. The reduced conduction allows the thermistor to provide a more accurate reading of the gas by maximizing or increasing the heat transfer between the first portion and the tip of the thermistor.

[0356] In some embodiments, means may be provided to increase a reliability of a contact between the associated sensor and the tip portion of the seal. For example, in the arrangement of Figure 48, a spring, or any other suitable biasing or cushioning member, may be interposed between a sensor 219, 221 and a cartridge 460 that carries or otherwise supports the sensor 219, 221. In such arrangements, the member 403 (e.g., spring, biasing member or cushioning member) compressed to provide a relatively repeatable force between the end of the sensor 219, 221 and the tip 401 , for example but without limitation. In some applications, a flexible or elastic membrane can connect the tip 401 to the chamber 200. In such configurations, the tip 401 can be displaceable relative to at least some portion of the chamber 200 (including the inlet and outlet portions 204, 208). In other words, the flexible or elastic membrane can stretch with the insertion of the sensor 219, 221 due to contact of the sensor 219, 221 with the tip 401 to provide a generally repeatable force between the end of the sensor 219, 221 and the tip 401 while providing a generally contacting thermal mass at the tip 401.

[0357] In some arrangements, at least one of the seals 215, 217, and optionally both, comprises a feature to retain the seal 215, 217 in position within the respective inlet sensor port 205 and outlet sensor port 21 1 . With reference to Figure 49, the illustrated outlet seal 217 comprises an outer flange 405 and an inner flange 407. As shown in Figure 50, a channel 409 is defined between the outer flange 405 and the inner flange 407. The channel 409 preferably is sized to accommodate a wall 411 of the outlet portion 208. Moreover, the channel 409 may be sized to form a fluid and/or gas tight seal with the wall 411 that surrounds the outlet sensor port 211 .

[0358] Figures 50 to 54 further illustrate the configuration of outlet seal 217. In the configuration illustrated in Figures 49 to 54, a base surface of the channel 409 has a surface that is at least partially curved or sloping to improve the seal between the seal 217 and the wall 411 defining the outlet sensor port 211. In some configurations, such as that shown in Figures 55 to 61 , the base surface can be substantially planar instead of at least partially curved or sloping. Whilst Figures 59 to 61 illustrate a different humidification chamber, it is to be understood that the operation and configuration of the sensor ports, seals and sensor units are consistent with the description herein and can be deployed and used in a humidification chamber of any suitable shape and configuration.

[0359] In some arrangements, at least one of the seals 215, 217 may be permanently or at least semi-permanently attached to the inlet and outlet sensor ports 205, 211. In some arrangements, at least one of the seals 215, 217 can be removable and replaceable. The seals 215, 217 can be configured to have a useable life similar to that of one of the other components. For example, the seals 215, 217 preferably comprise a useable life similar to the chamber 200 such that the chamber 200 and the seals 215, 217 would be disposed of at the same time. In some configurations, especially where the seals 215, 217 are permanently attached to the chamber 200, the seals 215, 217 may have a longer life than the chamber 200 such that the seals 215, 217 are not the limiting component on a life span of the chamber 200.

[0360] In the illustrated configuration, the inner flange 407 has a smaller outer circumference than the outer flange 405. The smaller outer circumference of the inner flange 407 facilitates insertion of the seal 217 into the outlet sensor port 211 . The inner flange 407 of the outlet seal 217 can comprise a sloped surface 425 to further assist with the installation of the outlet seal 217 into the outlet sensor port 211 . While it is possible to slope or taper a surface of the outer flange 407 to facilitate installation, because the illustrated outlet seal 217 is designed to be pressed into the outlet sensor port 21 1 from an external side of the outlet portion 208, the sloped or tapered surface 425 may be positioned on the inner flange 407.

[0361 ] Now reverting to Figure 47, outlet sensor unit 221 is insertable into the outlet seal 225 and inlet sensor unit 219 is insertable into the inlet seal 223. In some configurations, the sensors 219, 221 will not seal the respective inlet and outlet sensor ports 205, 211 if the seals 223, 225 are not positioned within the ports 205, 21 1. As such, the inlet seal 223 and the outlet seal 225 define a barrier that is positioned between the gas flow path and the inlet sensor unit 219 and the outlet sensor unit 221 respectively. With the inlet seal 223 and the outlet seal 225 defining the barrier, the sensor units 219, 221 remain external to the flow path. Because the sensor units 219, 221 remain external to the flow path, sensor units 219, 221 can be reused and need not be cleaned before subsequent reuse. Even though the sensor units 219, 221 remain external to the flow path, however, the sensor units 219, 221 are able to provide measurements of flow characteristics. For instance, the inlet sensor 219 can be used to detect flow rate while the outlet sensor 221 can be used to detect temperature.

[0362] Any suitable components can be used as the sensors for the sensor units 219, 221. For example, thermocouples, resistance temperature detectors, fixed resistors and the like can be used. In the illustrated arrangement, the sensor units 219, 221 comprise thermistors. The inlet sensor 219 may include a single thermistor 427 mounted to a body 429. The sensor unit 219 may be used to sense a temperature of incoming flow of gases 206. As shown in the illustrated arrangement, the temperature sensor unit 219 can be positioned to extend the thermistor 427 into the flow path in the inlet portion 204. In some configurations, the temperature sensor can be positioned in other regions of the humidification system (e.g., on one or more conduits coupled to the inlet and/or outlet portion 204, 208).

[0363] The illustrated outlet sensor unit 221 may comprise a first thermistor 431 and a second thermistor 433 mounted on a single body 435. In some configurations, the first thermistor 431 and the second thermistor 433 can be mounted on separate bodies; however, mounting the first and second thermistors 431 , 433 on the single body 435 improves the accuracy in positioning of the first and second thermistors 431 , 433 relative to each other. As shown in the illustrated arrangement, the outlet sensor unit 221 can be positioned on the outlet portion 408 to extend the two thermistors 431 , 433 into the flow path on the outlet portion 408 so as to detect flow characteristics of the outgoing flow of gases 210. In some configurations, the outlet sensor unit 221 may be positioned in other regions of the humidification system (e.g,. on one or more conduits coupled to the inlet and/or outlet portion 204, 208, or the like).

[0364] Alternative configurations of an inlet or outlet seal are further illustrated in Figures 62 to 72. Further detail in relation to various configurations of sensor ports and inlet/outlet seals are described in international patent publication WO/2013/137753 entitled “RESPIRATORY GAS HUMIDIFICATION SYSTEM”, the entire disclosure of which is incorporated herein by reference.

[0365] Referring back to Figures 10A and 10B, the body 214 of the humidification chamber 200 and the fluid compartment 202 may be made of a material having a light transparency percentage of at least 85%. In one embodiment, the body 214 of the humidification chamber 200 and the fluid compartment 202 are made of a plastic material such as polycarbonate. In other embodiments, thermoplastic polymers such as Acrylonitrile Butadiene Styrene (ABS), or polypropylene, or high density polyethylene (HDPE) may be used. Materials having a light transparency percentage of at least 85% would be substantially transparent. Such materials would provide sufficient optical clarity such that a clinician can easily observe the water level within the humidification chamber 200, and visually confirm the output of the water level detection via optical sensor 1702 (as discussed in further detail below). In some embodiments, the fluid compartment 202 may be opaque/not transparent.

[0366] In some examples, the base 216 of the humidification chamber 200 may be made of a thermally conductive material such as metal. In an embodiment, the base 216 of the humidification chamber 200 is made of aluminium. In other embodiments, base 216 of the humidification chamber 200 is made of stainless steel. Having a thermally conductive base 216 (e.g., in the form of a conductive flat surface) allows better, more efficient heat transfer from a heater base to the humidification chamber 200 when the humidification chamber 200 is placed on the heater base, thereby improving humidification of the gases within the chamber 200. In some alternative embodiments, the humidification chamber may have a base that is not made from thermally conductive material, and liquid in the fluid compartment 202 may be heated using alternative heating means, such as infra-red heating. [0367] As previously mentioned, the lip 226 disposed around the circumference of the base 216 of the humidification chamber 200 facilitates lateral insertion of the humidification chamber 200 into a humidification unit 102 as illustrated in Figures 1 1 A to 1 1 H. The humidification unit 102 (see Figures 1 1 A and 11 B) includes the heater base 104 for heating the fluid (e.g. water) in the fluid compartment 202 by heating the chamber base 216. The humidification unit 102 may additionally include a sensor assembly 106 comprising an external light source 1302 for transmitting light into the fluid compartment 202 and an optical sensor 1702 for detecting light reflected back via the one or more light guides 2302, 2304. In an embodiment, the humidification unit may be a F&P 950 unit, a F&P MR850 unit, F&P 820 unit, F&P MR810 unit. Any other suitable humidification unit may be used with embodiments of the humidification chambers described herein.

[0368] Now referring to Figures 1 1 C to 11 H, when setting up the humidifier 100, the operator or clinician installs the humidification chamber 200 on the heater base 104 by sliding the chamber 200 onto the heater base 104 under a rim edge 108 that facilitates holding the chamber 200 in place. A barrier portion 110 adjacent the heater base 104 and the heater base 104 may be spring loaded in some configurations such that the base 216 of the chamber 200 presses downward upon the barrier portion 1 10 and the heater base 104 during lateral insertion of the humidification chamber 200 into the humidification unit 102 (see Figures 1 1 C to 1 1 E). During lateral insertion, the lip 226 of the chamber 200 may be inserted under the rim edge 108 on opposite sides of the heater base 104. Once the humidification chamber 200 is fully inserted into the humidification unit 102 as shown in Figures 11 F to 1 1 H, the barrier portion 1 10 and heater base 104 may be no longer depressed and the humidification chamber 200 may be retained between the heater base 104 and the rim edge 108 and secured against the humidification unit 102 by the base barrier portion 110. As illustrated in Figures 11 C to 1 1 E, the barrier portion 1 10 may be depressed to enable the base 212 of the humidification chamber 200 to access the heater base 104. Once inserted, the barrier portion 1 10 reverts to a non-depressed position to facilitate holding the humidification chamber 200 in place against the humidification unit 102. This advantageously provides positive feedback that the humidification chamber 200 is properly installed within the humidification unit 102. In some embodiments, the humidification unit 102 may not have a barrier portion 1 10 and the humidification chamber 200 may be held in place by compression between the heater base 114 and the rim edge 108.

[0369] A humidifier 101 according to another embodiment is illustrated in Figures 76 and 77. In humidifier 101 , the humidification chamber 201 may be mounted on top of a humidification unit 103. The humidification chamber 201 may be mounted to the humidification unit 103 via lateral insertion in a similar manner to the humidification unit 102 described with reference to Figures 11 A to 1 1 H. In particular, a resiliently biased tab 105 may be displaced to allow for lateral insertion of the humidification chamber 201 over the humidification unit 103. In the particular embodiment shown in Figures 76 and 77, the humidification chamber 201 may not include any light guides for water level detection, and as such, the humidification unit 103 may not provide any sensor units for water level detection via light guides.

[0370] In some embodiments, humidification chamber 200 may be used without an external water source (e.g. waterbag). The configuration of the fluid compartment 202, the deflector 218, the flow rate of gases of the humidification chamber 200 is such that the humidity of the outgoing flow of gases 210 and the rate of water usage in the humidification chamber 200 is adapted for certain use case scenarios such that the chamber 200 will not require frequent refilling those use case scenarios. In some embodiments, humidification chamber 200 does not comprise a float within the fluid compartment 202 for involvement in the detection of fluid level within the fluid compartment 202.

Light guide(s)

[0371 ] Whilst various embodiments described herein include one or more light guides, it will be understood that in some embodiments, a humidification chamber may be provided without any light guides.

[0372] Figure 12 illustrates a sectional side view of the humidification chamber 200 according to one embodiment of the present invention. The humidification chamber 200 comprises at least one light guide 1 102 for detecting a fluid (i.e. , liquid) level in the fluid compartment 202. The light guide 1102 may extend downwardly into the fluid compartment 202 from the top wall 602 of the fluid compartment 202. In one embodiment, the light guide 1102 extends substantially perpendicularly to the top wall 602 of the fluid compartment 202. The light guide 1 102 may have a length (Li) 1104 of about 10mm to 50mm, 20mm to 50mm, 10mm to 30mm, or 30mm to 50mm, or more specifically 30mm. In one embodiment, the light guide 1102 may have a length of about 15mm. In another embodiment, the light guide 1 102 may have a length of about 40mm. Typically, the light guide 1 102 is symmetrical as more clearly illustrated in Figure 13A. In some embodiments, one or more light guides may extend from a portion of the peripheral side wall 305.

[0373] Figure 13A illustrates a front view of the light guide 1102 for detecting a liquid level in the humidification chamber 200 according to an embodiment of the present invention. The light guide 1 102 includes a proximal end 1308 adjoining the top wall 602 of the fluid compartment 202 and a distal end 1310 opposite the proximal end 1308. The light guide 1102 includes an input side 1302 for receiving an input beam of light 1322 from an external light source 1320 (Figure 13C) and propagating the input beam of light 1322 through the input side 1302 of the light guide 1 102. The light guide 1102 further includes an output side 1304 for propagating an output beam of light 1324 (Figure 13C) through the output side 1304 of the light guide 1 102 for detection by an external light detector 1702.

[0374] As shown in the exemplary embodiment of the light guide 1 102 in Figure 13A, the output side 1304 of the light guide 1 102 is parallel and adjacent to the input side 1302 of the light guide 1 102. While the invention will be explained with respect to such configuration of the input side 1302 and the output side 1304, it will be appreciated that other configurations and/or locations/positions of the input side 1302 and the output side 1304 may be possible without departing from the scope of the invention. For example, in another embodiment (not shown), the output side 1304 may be substantially perpendicular to the input side 1302. In such an embodiment, the light guide 1 102 includes at least one angled portion disposed at the distal end 1310 of the light guide 1 102 and is at an angle of 45° to the base of the fluid compartment 202. The angled portion is configured to reflect the input beam of light 1322 from the input side 1302 of the light guide 1 102 to the output side 1304 of the light guide 1 102 such that the output beam of light 1324 is presented at the output side 1304 when the light guide 1 102 is solely in contact with gases (i.e. , the light guide 1 102 is not in contact with any liquid within the fluid compartment 202). It will be appreciated that in such an embodiment, a receiver or optical detector/sensor for detecting the output beam of light 1324 may be located on a side of the humidification chamber 200 rather than above the humidification chamber 200.

[0375] Returning to the embodiment of the light guide 1 102 as shown in Figure 13A, where the output side 1304 of the light guide 1 102 is parallel and adjacent to the input side 1302 of the light guide 1102, the light guide 1 102 includes a pair of opposed angled portions 1306 disposed opposite one another at the distal end of the light guide 1 102. The pair of opposed angled portions 1306 are aligned with the input side 1302 and the output side 1304 of the light guide, respectively. In one embodiment, the light guide 1 102 has a thickness (Ti) 1318 of about 2.5mm (see Figure 15B).

[0376] Each angled portion 1306 is at about 45° (as shown by 1316 in Figure 13B) to a base of the fluid compartment 202. It will be appreciated that the length of the angled portion(s) may provide tolerance to the location of the input beam of light 1322 to allow for the input beam of light 1322 to be directed onto the 45° angled portion and reflected as the output beam of light 1324 when the light guide 1 102 is not in contact with any liquid in the fluid compartment 202. Accordingly, having a longer surface for the angled portion(s) 1306 may provide more tolerance to the location at which the input beam of light 1322 hits the angled portion(s) 1306. A detector or optical detector/sensor such as a phototransistor (1702 as shown in Figures 13C and 25) for detecting the output beam of light 1324 may be located at a certain distance above the humidification chamber 200. In accordance with the same principals discussed above, the length of the angled portion(s) may also provide tolerance to the location of the detector 1702. Moreover, angled portion(s) having a longer length would effectively increase the width of the input and output sides of the light guide 1 102.

[0377] Figure 13C illustrates reflection of light within the light guide 1 102 according to an embodiment of the present invention. The pair of opposed angled portions 1306 are configured to reflect the input beam of light 1322 (as shown by the line 1326) from the input side 1302 of the light guide 1102 to the output side 1304 of the light guide 1 102 so as to present the output beam of light 1324 at the output side 1304 when the light guide 1 102 is solely in contact with gases (i.e. the light guide 1 102 is not in contact with any liquid within the fluid compartment 202). [0378] The behaviour of the input and output light beams 1322, 1324 as illustrated in Figure 13C follows the principle of total internal reflection (TIR). When the light guide 1 102 is solely in contact with gases (i.e. , the light guide 1 102 is not in contact with any liquid within the fluid compartment 202), total internal reflection occurs when the input beam of light 1322 is incident on an incident surface of one of the angled portions 1306 at an angle a greater than the critical angle of air and the material of the humidification chamber 200. This angle a is relative to a normal to the incident surface of the angled portion 1306. In one embodiment, when the humidification chamber 200 is made of polycarbonate, the input beam of light 1322 is incident on one of the angled portions 1306 at an angle (45°, relative to normal), which is greater than the critical angle of polycarbonate-air boundary (i.e., 39°) (considering the refractive index of polycarbonate = 1 .59 and refractive index of air = 1 .00). Consequently, the light intensity of the output beam of light 1324 may be the same or similar to the light intensity of the input beam of light 1322.

[0379] Typically, the light intensity of the output beam of light 1324 is above a threshold when the light guide 1 102 is solely in contact with gases (i.e., the light guide 1 102 is not in contact with any liquid within the fluid compartment 202). In one embodiment, the threshold is 40% of the light intensity of the input beam of light 1322. In one embodiment, the light generated from the external light source 1320 (and therefore the input beam of light 1322 and the output beam of light 1324) is infra-red (IR) light. Accordingly, the external light source 1320 may be an IR light source/IR LED.

[0380] Figure 14 illustrates refraction of the input light beam 1322 when the light guide 1 102 comes into contact with a liquid such as water 2502. When refraction of the input light beam 1322 occurs in this scenario, an output beam of light 1324 having light intensity below the threshold or no output beam 1324 of light is present for propagation through the output side 1304 of the light guide 1102. When water 2502 is present in the fluid compartment 202, the light guide 1102 may be partially submerged in the water 2502 as shown in Figure 14. The input beam of light 1322 is therefore refracted when it contacts the boundary 1401 between the water 2502 and light guide 1 102. Refraction occurs because the input beam of light 1322 is incident on one of the angled portions 1306 (45°) at an angle, relative to normal to the incident surface, less than the critical angle of liquid and light guide material boundary. In one embodiment, when the light guide 1102 is made from polycarbonate, the input beam of light 1322 is incident on one of the angled portions 1306 at an angle (45°, relative to normal) less than the critical angle of polycarbonate -water boundary (57°) (considering the refractive index of polycarbonate = 1 .59 and the refractive index of water = 1 .33). Consequently, the light intensity of the output beam of light 1324 (if any) will be much lower than the light intensity of the input beam of light 1322. In one embodiment, a distance between the external light source 1320 and the optical sensor 1702 is between about 2mm to 1 1 mm, 4mm to 9mm, or 6mm to 7mm.

[0381 ] During use, an output beam of light 1324 above a predetermined light intensity (e.g. greater than 40% of the light intensity of the input beam of light 1322) is detected by the detector 1702 when the level of liquid in the fluid compartment 202 is below a detection level. No output beam of light 1324 or an output beam of light 1324 having less than a predetermined light intensity (e.g. less than 40% of the light intensity of the input beam of light 1322) is detected by the detector 1702 when the level of liquid in the fluid compartment 202 is above a detection level.

[0382] In some embodiments, an output beam of light 1324 above a first predetermined light intensity (e.g. greater than an upper threshold of 30% of the light intensity of the input beam of light 1322) is detected by the detector 1702 when the level of liquid in the fluid compartment 202 is below a detection level (e.g. the light guide 1 102 is not in contact with any liquid). No output beam of light 1324 or an output beam of light 1324 having less than a second predetermined light intensity (e.g. less than a lower threshold of 20% of the light intensity of the input beam of light 1322) is detected by the detector 1702 when the level of liquid in the fluid compartment 202 is above the detection level. Advantageously, the difference between the upper and lower detection thresholds provides tolerance for any noise which may impact the liquid level detection.

[0383] In some embodiments of the humidification chamber 200 in which a single light guide 1 102 is provided, the single light guide 1102 may be used to detect an upper and/or maximum liquid level or lower and/or minimum liquid level of liquid in the fluid compartment 202. In some embodiments, the single light guide 1 102 may be used to detect a minimum liquid level of liquid in the fluid compartment 202 so as to alert a clinician when the fluid compartment 202 requires refilling. [0384] Any suitable liquid level may be set as the detection level. For example, the detection level may be an upper or lower, maximum or minimum, or any intermediate liquid level of interest. The length of the light guide 1 102 may be determined based on any desirable detection level so as to provide an indication (e.g., visual and/or audible indication) to a user when the detection level is reached.

[0385] When an output beam of light 1324 is present at the output side of the light guide 1 102 for detection by the detector 1702, the detector 1702 senses the light intensity of the output beam of light 1324. A controller associated with the detector 1702 then compares the detected light intensity to the delivered light intensity from the external light source 1302 (e.g., light intensity of the input beam of light 1322) to determine a difference between the detected light intensity (light intensity of the output beam of light 1324) and the delivered light intensity (light intensity of the input beam of light 1322). Based on this difference, the controller can determine whether the light intensity of the detected output beam of light 1322 is above or below a threshold (e.g., 20%, 30% or 40%) as previously described to determine whether the liquid level in the fluid compartment 202 is above or below the detection level.

[0386] One or more light guides may be provided to detect any suitable number of liquid levels. For example, as discussed herein one light guide 1 102 may be provided to detect a single liquid level of interest. Two light guides 2302, 2304 may be provided to detect an upper and lower liquid levels of interest. Similarly, three or more light guides may be provided to detect three or more different liquid levels of interest.

[0387] Once liquid in the fluid compartment 202 moves above or below a detection level, a visual and/or audio indication may be provided in any suitable form. For example, the visual and/or audio indication(s) may be provided in form of one or more alarms, voice message(s), as text messages, images and/or graphs on a graphical interface and the like, or any combination thereof to provide an indication when each detection level is reached. The visual and/or audio indication(s) may be generated by the humidification unit 102 (see Figures 11 A and 1 1 B). For example, the visual indicators may be generated by the graphical user interface 107 of humidification unit 102 as shown in Figure 1 1 A, or graphical user interface 7014 of humification unit 7004 as shown in Figure 45. Jagged portion of light guide

[0388] Figure 15A illustrates a jagged portion 1312 disposed at the distal end 1310 of the light guide 1 102 according to an embodiment of the present invention. The jagged portion 1312 includes a plurality of angled surfaces for scattering light that interacts with the internal surface of the fluid compartment 202. The jagged portion 1312 is intended to scatter any light unintended for propagation in the output side of the light guide, for example any light that may otherwise re-enter the light guide from the fluid compartment 202 (also referred to herein as stray light). The jagged portion 1312 is disposed between the pair of opposed angled portions 1306 of the light guide 1 102. The jagged portion 1312 may have any suitable regular or irregular angled surfaces/edges for scattering stray light so that accuracy of light intensity measurement of the output beam of light 1324 at the output side 1304 of the light guide 1 102 by light detector 1702 is improved. The jagged portion 1312 may scatter stray light within and/or away from the light guide 1102. In one embodiment, the angles of the edges of the jagged portion 1312 is about 20° or 30° or a combination of these angles.

[0389] In the event that any refracted light from the input beam of light 1322 (i.e. light which leaves the light guide 1102 and enters the liquid in the fluid compartment 202) is reflected from the metal base 216 (e.g., aluminium base) of the humidification chamber 200 back towards the light guide 1 102, the jagged portion 1312 serves to scatter this reflected light. This reflected light from the base 216 is scattered to prevent light rays from re-entering (or reduce the amount, or change the direction, of light rays re-entering) the light guide 1 102 to form part of an output beam of light 1324 for detection by an external light detector 1702 provided by the humidification unit 102. The angled surfaces of the jagged portion 1312 are angled such that light is scattered away and not into the light guide 1 102, or if light enters the light guide 1 102, light may be scattered within the light guide 1102 at an angle away from the light detector 1702. Scattering away stray light in this manner advantageously reduces the likelihood of the detector 1702 picking up light reflected off the base 216 of the humidification chamber 200 as falsely indicating that the humidification chamber 200 is empty when it is not. This improves the accuracy of the light intensity detection and the water level sensing.

[0390] Figure 15B illustrates a perspective view of the light guide 1 102 showing a front face 1502 of the light guide. Figure 15C illustrates another perspective view of the light guide 1102 showing a rear face 1510 of the light guide. Figure 15D illustrates a side view of the light guide 1 102 showing one of the opposed angled portions 1306. In one embodiment, the thickness (Ti) of the light guide 1 102 and the thickness (Ta) of the angled portions are the same.

[0391 ] Figure 15E illustrates a front view of the light guide 1102 showing the front face 1502, a bottom view of the light guide 1102 showing an underside of the light guide 1 102, and an inverted rear view of the light guide 1 102 showing the rear face 1502. As more clearly shown in the bottom view of Figure 15E, the jagged portion 1312 includes a plurality of downward-facing edges 1506. As more clearly shown in Figures 15B and 15E, each angled portion 1306 also includes a respective downward-facing edge 1504. In Figure 15E, the downward-facing edges 1506 of the jagged portion 1312 and the downward-facing edges of the opposed angled portions 1306 are generally aligned between each of the three views. It can be seen that downward-facing edges 1506 of the jagged portion 1312 are disposed at a different orientation to each downward-facing edge 1504 of a respective angled portion 1306. In other words, each downward-facing edge 1504 of a respective angled portion 1306 is not parallel to any of the downwardfacing edges 1506 of the jagged portion 1312 (i.e. , the downward-facing edges 1506 of the jagged portion 1312 and the downward-facing edges 1504 of the angled portions have different orientations). In one embodiment, an angle between the downwardfacing edge of the jagged portion 1312 and the downward-facing edge of a respective angled portion 1306 is about 10° to 30°. Advantageously, the different orientations of the downward-facing edges 1506, 1504 between the jagged portion 1312 and the opposed angled portions 1306 enables more effective scattering of light. In other embodiments the downward-facing edges 1506 of the jagged portion 1312 may be parallel to the downward-facing edges 1504 of the angled portions 1306.

Curved protrusions for collimating and/or focusing light

[0392] Figure 16 illustrates a first curved protrusion 1602 and a second curved protrusion 1604 used in respect of the light guide 1102 of the humidification chamber 200 for collimating light according to an embodiment of the present invention. The first and second curved protrusions 1602, 1604 may be generally dome shaped so as to provide a lens like effect for collimating and focusing the input and output beams of light 1322, 1324 respectively. In particular, a first curved protrusion 1602 may be provided to collimate the input beam of light 1322 from the external light source 1320 (see Figure 18) for propagation though the input side 1302 of the light guide 1 102. Collimating the light from the light source 1320 improves the light intensity of the input beam of light 1322 in the light guide 1 102. This collimation ensures that a substantial proportion of the light rays emitted from the external light source/transmitter 1320 enter into the light guide 1 102 as the input beam of light 1322 and propagate through the entire length of the input side 1302 of the light guide 1102 to make contact with a respective one of the angled portions 1306. This enables the collimated light rays in the input beam of light 1322 to be reflected to the output side 1304 of the light guide 1 102 for propagation as the output beam of light 1324, and for detection by the optical sensor 1702 (see Figure 25) when no water is present. The first curved protrusion 1602 may be positioned above the light guide 1 102 and be substantially aligned with the input side 1302 of the light guide 1 102. In some embodiments, the first curved protrusion 1602 may be integral with the body 214 of the humidification chamber 200, above the light guide 1102 and substantially aligned with the input side 1302 of the light guide 1 102 as shown in Figure 16.

[0393] In some embodiments, a second curved protrusion 1604 may be used in one or more embodiments to collimate the output beam of light 1324 from the output side 1304 of the light guide 1102 for detection by the detector 1702 (as shown in Figure 25). In some embodiments, the second curved protrusion 1604 may be integral with the body 214 of the humidification chamber 200, provided above the light guide 1102 and substantially aligned with the output side 1304 of the light guide 1 102.

[0394] In some embodiments, either the first curved protrusion 1602 or the second curved protrusion 1604 may be provided. In these embodiments, the desired behaviours for the input and output beams of light 1322, 1324 as described above may nevertheless be achievable.

[0395] Figure 17A illustrates a top view of the humidification chamber 200. The first curved protrusion 1602 can be seen positioned proximate the inlet portion 204 of the humidification chamber 200. The input side 1302 of the light guide 1 102 is positioned below/under the first curved protrusion 1602 (and therefore not visible from this top view). The second curved protrusion 1604 can be seen positioned proximate the outlet portion 208 of the humidification chamber 200. The output side 1304 of the light guide 1 102 is positioned below/under the second curved protrusion 1604 (and therefore not visible from this top view).

Light source and light detector

[0396] Figure 17B illustrates another top view of the humidification chamber 200. The external light source/transmitter 1320 can be seen positioned proximate the inlet portion 204 of the humidification chamber 200. The input side 1302 of the light guide 1 102 and the first curved protrusion 1602 are positioned below/under the external light source/transmitter 1320 (and therefore not visible from this top view). The receiver (optical sensor) 1702 can be seen positioned proximate the outlet portion 208 of the humidification chamber 200. The output side 1304 of the light guide 1 102 and the second curved protrusion 1604 are positioned below/under the receiver 1702 (and therefore not visible from this top view). In alternative embodiments, the external light source/transmitter 1320 may be positioned proximate the outlet portion 208 of the humidification chamber 200. In alternative embodiments, the receiver 1702 may be positioned proximate the inlet portion 204 of the humidification chamber 200.

[0397] The channel 402 between the inlet portion 204 and the outlet portion 208 as well as the circular base 212 of the fluid compartment 202 can be seen from Figures 17A, 17B.

[0398] Figure 18 illustrates an example dimension of the first curved protrusion 1602. The first curved protrusion 1602 may be spherical, parabolic or any other suitable shape that aids in collimating the light (e.g. IR light) emitted by the external light source 1320 (e.g.lR LED) through the light guide 1 102. Parameters that affect the collimation of light may include: distance between the external light source 1320 and the first curved protrusion 1602 (Lc), angle of light emitted ([3) and the light cone shape, light guide 1 102 characteristics such as but not limited to the refractive index of the material of which the light guide 1 102 is made (1 .568 for polycarbonate), curvature of the first curved protrusion 1602 and thickness (Tc ) of the first curved protrusion 1602. In some embodiments, the external light source 1320 and the first curved protrusion 1602 may be concentrically aligned to facilitate even collimation of light. An alignment feature (shown as an indent 1704 in Figures 10A, 17A, 17B, 27A, 27B on a top surface of the humidification chamber 200) may be provided to aid in mechanically locating a mating component (e.g. protrusion for location within the indent 1704) on a sensor assembly 106 (see Figures 1 1 A, 1 1 B and 25). The sensor assembly 106 may be provided by the humidification unit 102 for removable coupling to the humidification chamber 200. The sensor assembly may include any one or more of the external light source 1320 or optical sensor 1702. Additionally, the vertical ribs 1002 (see Figures 10A and 10B) on the body 214 of the humidification chamber 200 may guide the sensor assembly into position when the sensor assembly is coupled with the humidification chamber 200.

Curved surface(s) of light guide

[0399] Figure 19A illustrates a partial top view illustrating the input side 1302 of the light guide 1 102. The light guide 1 102 includes a pair of curved surfaces 1902 on opposite sides of the input side 1302 of the light guide 1 102 for redirecting light rays from the input beam of light 1322 into the light guide 1 102. The curved surfaces 1902 can be seen as a curvature (concave bulge) on either side of the light guide 1 102. Whilst not shown in Figure 19A, it will be understood that similar curved surfaces 1902 can be provided on the output side 1304 of the light guide 1 102. On the output side 1304, the curved surfaces 1902 may facilitate capturing and redirecting any stray light rays from the output beam of light 1324 back into the output side 1304 of the light guide 1 102 for propagation along the output side 1304 of the light guide 1 102. Reflection may occur if the light is incident on the curved surfaces 1902 at angles less than the critical angle of the light guide 1 102 material. As more clearly shown in Figure 16, the each of the curved surfaces 1902 define an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the light guide 1102. The elongate protrusion may be tapered along a lengthwise direction of the light guide 1102. The elongate protrusion is also herein referred to as a tapering protrusion.

[0400] Figure 19B illustrates propagation of the input beam of light originating from the external light source 1320 down the input side 1302 of the light guide 1 102 as circular boundaries. The light rays represented by the fourth circle 1321 from the centre may be incident on the curved surfaces 1902 and be reflected back into the light guide 1 102. The light rays depicted by the inner three circles 1323 may travel through the first curved protrusion 1602 (not shown), or directly down the input side 1302 of the light guide 1 102 in embodiments in which a first curved protrusion is not provided. [0401 ] Figure 21 illustrates an interaction between the light and a curved surface 1902. As can be seen from Figure 21 , the curved surface 1902 allows for any light rays incident on the curved surface at an angle of incidence to be reflected at a reflection angle back into the light guide 1102. The curved surfaces 1902 therefore facilitates focusing of the light rays to increase the light intensity of the respective input or output light beam 1322, 1324. Accordingly, loss of light intensity can be minimised by such curved surfaces 1902. It will be appreciated that the light guide 1102 remaining symmetrical/straight can also improve the accuracy and reliability of liquid level sensing. Indeed, any bend in the light guide 1 102 may affect total internal reflection from occurring within the light guide 1 102. The tapering structure defined by each of the curved surfaces 1902 can also provide structural rigidity to the light guide 1 102. For example, the tapering protrusions 1902 may facilitate prevention of warping of the light guide 1 102 after moulding. For the same reason, tapered protrusions 1902 may be provided along the output side 1304 of the light guide 1 102 as well. Other ribs may also be present for providing structural integrity in one or more embodiments in conjunction with or in replacement of the tapered protrusions.

[0402] In embodiments in which the humidification chamber 200 includes two light guides 2302, 2304, each light guide 2302, 2304 may have a pair of curved surfaces 1902. Each curved surface 1902 may be provided on an opposite face of the respective light guide 2302, 2304. Figure 20 illustrates a top view of a pair of light guides 2302, 2304, where each light guide 2302, 2304 includes two pairs of curved surfaces 1902. One pair of curved surfaces 1902 is provided along the input side 1302 of a respective light guide 2302, 2304 and the other pair of curved surfaces 1902 is provided along the output side 1304 of the respective light guide 2302, 2304. For each pair of curved surfaces 1902, each curved surface 1902 is provided on an opposite face of the light guide 2302, 2304. In one or more embodiments, the curved surfaces 1902 for each pair of curved surfaces are aligned with each other. Each of the one or more curved surfaces 1902 define an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the light guide 1 102. The elongate protrusion may be tapered along a lengthwise direction (see Figures 23A to 23B).

[0403] Whilst Figure 20 illustrates the curved surfaces 1902 on a right side of the Figure as being smaller than the other curved surfaces 1902, it will be understood that all curved surfaces 1902 may be the same size in some embodiments, or different sizes in some embodiments.

Location of light guide(s)

[0404] Figure 22 illustrates the location of the light guide 1 102 with respect to the fluid compartment 202. In one embodiment, the light guide 1 102 is located substantially at or adjacent a central axis 2202 of the fluid compartment 202. The central axis 2202 of the fluid compartment 202 refers to an axis passing through a centroid or geometrical centre of the fluid compartment 202. In embodiments where the fluid compartment 202 has a generally circular base, the central axis 2202 may intersect with an axis of rotation. Such a central location for the light guide 1 102 allows for effective liquid level sensing even if the fluid compartment 202 is tilted in use within an expected range (e.g. up to 20 degrees). In one embodiment, the light guide 1 102 is located within a radius (shown as 2204) of about 10mm from an approximate centre of the fluid compartment 202 through which the central axis 2202 passes. In an embodiment, an internal diameter (shown as 2206) of the fluid compartment 202 is around 100mm to 1 15mm and optionally 108mm.

Two light guides in the humidification chamber

[0405] In the embodiment shown in Figure 23A, the humidification chamber 200 illustrates two light guides 2302, 2304. The first light guide 2302 is longer than the second light guide 2304. Each of the light guides 2302, 2304 may include any one or more of the features of the light guide 1 102 as previously described herein.

[0406] The first light guide 2302 is configured to detect a minimum level of fluid (i.e., liquid such as water) in the fluid compartment 202. The second light guide 2304 is configured to detect a maximum level of fluid (i.e., liquid such as water) in the fluid compartment 202. Over-filled fluid compartment 202 poses a safety hazard since there is a risk of water escaping through the outlet portion 208 and subsequently reaching the patient 16. Low-level sensing is equally important to avoid inadequately humidified gas (e.g., air) from being delivered to the patient 16. When a low level of water is detected within the fluid compartment 202, a clinician can be notified to manually refill water (or any other suitable liquid) into the fluid compartment 202. Such refilling may be carried out by delivering water (or any other suitable liquid) from a source (e.g., water bottle/liquid bottle) through optionally the inlet portion 204 having the straight connector 802 or the outlet portion 208. Low-level sensing may be useful in systems where there is no external water source (e.g. water bag) feeding water into the chamber to replenish water levels. In such systems with no external water source, the water supply in the fluid compartment 202 is the only water source available for use in humidification of gases, before refilling is desired.

[0407] In one embodiment, the first light guide 2302 may have a length of about 40mm and the second light guide 2304 may have a length of about 15mm. In one embodiment, a distance between the first light guide 2302 and a base 216 of the humidification chamber 200 is about 2mm to 10mm, 4mm to 8mm, or 5mm to 7mm, or more specifically 5mm, 6mm or 7mm.

[0408] Figure 23B illustrates a perspective view of the two light guides 2302, 2304. As more clearly shown in Figure 23B, a rib 706 extending between the first light guide 2302 and the second light guide 2304 may be provided to improve rigidity of the two light guides 2302, 2304.

[0409] As shown in Figures 23A and 23B, a jagged portion 1312 is provided at the distal end 1310 of the first light guide 2302 for scattering of light as previously described. In alternative embodiments, a jagged portion 1312 may also be provided at the distal end 1310 of the second light guide 2304. In some embodiments, it may not be necessary to provide a jagged portion 1312 on the second light guide 2304 as the distal end 1310 of the second light guide 2304 is further away from the base 216 of the humidification chamber 200 and any light rays reflected from the base 216 of the humidification chamber 200 is unlikely to become incident on the distal end 1310 of the second light guide 2304.

[0410] It will be appreciated that any suitable portion providing an uneven surface between the opposing angled portions 1306 may be used to achieve the same effect of scattering stray light as the jagged portion 1312. In alternative embodiments, the jagged portion 1312 may be replaced by an intermediate portion having an uneven/rugged surface disposed between the opposing angled portions 1306 at the distal end of the at least one light guide 1 102. The uneven surface has an irregular surface finish that serves to scatter light, similar to the function of the jagged portion 1312, as described above. The uneven surface may be achieved by bead blasting a manufacturing tool, or directly etching or indenting the surface.

[0411 ] As shown in Figure 24, the first light guide 2302 and the second light guide 2304 may be centred about a central axis 2402 of the fluid compartment 202. The central axis 2402 of the fluid compartment 202 refers to an axis of rotation passing through a centroid of the fluid compartment 202. In one embodiment, the first light guide 2302 and the second light guide 2304 are located within a radius (shown as 2204) of about 10mm from an approximate centre of the fluid compartment 202 through which the central axis 2402 passes. This configuration advantageously allows effective waterlevel sensing to be achieved even if the humidification chamber 200 is tilted. A circular chamber 200 advantageously provides uniform tilt performance when the chamber is tilted. Typically, a centralised location for the first light guide 2302 and the second light guide 2304 is most optimal for reducing the impact of tilt on effective liquid level sensing. In an exemplary embodiment, a tilt angle in excess of 20° would have little or no impact on the effective fluid level sensing of the humidification chamber 200.

[0412] Figure 25 is a cross-sectional side view schematic of the humidification chamber 200 illustrating the behaviour of liquid in the fluid compartment 202 if the chamber 200 is to be tilted at 20°. In the scenario illustrated in Figure 25, the second light guide 2304 is not in contact with the liquid 2502 within the fluid compartment 202. Accordingly, light from the external light source 1320 will undergo total internal reflection 1326 within the second light guide 2304. As such, an output beam of light 1324 would be detected by the light detector 1702 for the second light guide 2304 thereby indicating that the liquid level is below maximum. The first light guide 2302 is in contact with the liquid 2502 within the fluid compartment 202. Accordingly, refraction of the input beam of light 1322 occurs in the first light guide 2302 and no output beam of light 1324 or an output beam of light having a light intensity lower than a predetermined threshold (less than 40% of the light intensity of the input beam of light 1322) will be detected at the detector 1702 for the first light guide 2302 indicating that the liquid level is above a minimum.

[0413] In some embodiments, the second light guide 2304 may be located proximate the inlet 222 or outlet 224 of the humidification chamber 200. In these embodiments, a maximum liquid level indicator may be triggered when the chamber 200 is subject to tilting. In some embodiments, the first light guide 2302 may also be located proximate the inlet 222 or outlet 224.

[0414] The tilt performance of the humification chamber 200 is further illustrated in Figures 26A and 26B. Figure 26A illustrates the humidification chamber 200 having two light guides 2302, 2304 located substantially centrally of the fluid compartment 202. A liquid 2702 is in contact with the first light guide 2302 but not with the second light guide 2304. Figure 26B illustrates the impact of tilting the humidification chamber 200 of Figure 26A. Due to the substantially central location of the first light guide 2302 and the second light guide 2304, the tilt has very less or no impact on the liquid level sensing of the humidification chamber 200. As illustrated in Figure 26B, despite the tilt, the liquid 2702 remains in contact with the first light guide 2302 but not in contact with the second light guide 2304. The humidification chamber 200 as illustrated in Figures 26A and 26B would detect that the liquid level is between a maximum and a minimum level regardless of the tilting.

[0415] Figure 27A illustrates a top view of the humidification chamber 200 having a first pair of curved protrusions 1602 positioned proximate the inlet portion 204 of the humidification chamber 200, each curved protrusion 1602 positioned above a respective one of the first light guide 2302 and the second light guide 2304. The input side 1302 of the first light guide 2302 and the input side 1302 of the second light guide 2304 are positioned below/under the respective curved protrusions 1602 (and therefore not visible from this top view).

[0416] A second pair of curved protrusions 1604 can be seen positioned proximate the outlet portion 208 of the humidification chamber 200, each curved protrusion 1604 of the second pair of curved protrusions being positioned at the top of a respective one of the first light guide 2302 and the second light guide 2304. The output side 1304 of the first light guide 2302 and the output side 1304 of the second light guide 2304 are positioned below/under the second pair of curved protrusions 1604 (and therefore not visible from this top view). The first pair of curved protrusions 1602 and the second pair of curved protrusions 1604 facilitate collimation of light for input and output beams of light 1322, 1324 respectively in the same way as previously described with reference to Figures 16 to 18. [0417] Figure 27B illustrates another top view of the humidification chamber 200 in which two light guides 2302, 2304 are provided. Two external light sources/transmitters 1320 may be provided by a sensor assembly for positioning proximate the inlet portion 204 of the humidification chamber 200 and above the respective input sides of each of the two light guides 2302, 2304. Two detectors (optical sensors) 1702 may be provided by a sensor assembly for positioning proximate the outlet portion 208 of the humidification chamber 200 and above the respective output sides of each of the two light guides 2302, 2304.

[0418] In various embodiments, the light source 1320, the optical sensor 1720, first curved protrusion 1602 and the second curved protrusion 1604 may be provided by the humidification chamber 200 or each provided separately or in various combinations of integration. In some embodiments, the first and second curved protrusions 1602, 1604 may not be provided. Furthermore, in one or more embodiments, there can be one or more external light sources 1320 and optical sensors 1702 per light guide 1102 or a single external light source 1320 and a single optical sensor 1702 for a plurality of light guides (e.g. a single external light source 1320 and a single optical sensor 1702 for both the first light guide 2302 and the second light guide 2304). In one embodiment, the external light source 1320 and the optical sensor 1702 may be provided in a single removably coupled component that is configured to interact with the light guide(s) 1 102 or 2302, 2304 of the humidification chamber 200.

Deflector to light guide

[0419] As illustrated in Figures 2B to 5B, in embodiments which comprise at least one light guide, the deflector 218 may be configured to direct the incoming flow of gases 206 from the inlet 222 towards the light guide 1 102, or light guides 2302, 2304. In use, condensation may accumulate on the light guide(s) 1 102, 2302, 2304. The accumulation of condensation may impact the propagation of the input and/or output beam of light 1322, 1324 along the light guides 1 102, 2302, 2304 thereby undesirably impacting the accuracy and reliability of liquid level sensing within the chamber 200. Directing the incoming flow of gases 206 to flow over the light guides 1 102, 2302, 2304 can disperse, and reduce the accumulation of, condensation on the light guides 1 102, 2302, 2304 improving the accuracy and reliability of the fluid-level detection. It will be appreciated that configuring the deflector 218 to deflect any portion of the incoming flow of gases 206 to the light guide 1102 (without any intervening structures) will be advantageous to minimise condensation on the light guide 1102.

[0420] A possible advantage of the humidification chamber 200 includes using the humidification chamber 200 for a reasonable period of time without refilling (up to 4 hours) while delivering adequate humidity at a high flow rate (e.g., 30mg/L for a flow rate of 70L/min) and thereby avoiding the need for the chamber to be refilled too frequently. This is useful as it may allow clinicians to focus on their patient 16 without the distraction of frequently having to refill the humidification chamber 200. Another possible advantage of such a humidification chamber 200 is that the optical transparency of the chamber 200 material allows the clinician to visually confirm the level of liquid in the fluid compartment 202.

Furthermore, since the humidification chamber 200 as described in the one or more aspects/embodiments above has a simple construction and can be manufactured in one piece without moving components, a cost-effective humidification chamber 200 with effective liquid-level sensing capabilities can be provided.

Kit

[0421] Figure 28 illustrates a kit 2600 containing the humidification chamber 200 according to any one of the embodiments described herein. The kit 2600 may include an incoming gas flow conduit 2604 for coupling to the inlet portion 204 of the humidification chamber 200. The incoming gas flow conduit 2604 is configured for delivering gases from the flow source 12 to the inlet portion 204 of the humidification chamber 200. The kit 2600 may also include an outgoing gas flow conduit 14 for coupling to the outlet portion 208 of the humidification chamber 200. The outgoing gas flow conduit 14 being configured for delivering the humidified gases from the outlet portion 208 humidification chamber 200 to a patient interface on the patient 16. The kit 2600 may further include a patient interface such as a nasal cannula 15. The nasal cannula 15 may be non-sealing. In an alternative embodiment, the patient interface may be a sealing patient interface, such as nasal pillows or a mask.

[0422] In one embodiment, the kit 2600 may also include a filter 2608. In some embodiments, the filter 2608 may be integral with the nasal cannula 15. In other embodiments, the filter 2608 may be removably couplable with the nasal cannula 15. In some embodiments, the nasal cannula 15 may include the filter 2608.

Raised Channel

[0423] A humidification chamber 3000 according to another embodiment of the present invention is illustrated in Figures 29 to 39. Like features in Figures 29 to 39 refer to those previously described. Similar to previous embodiments described above, the humidification chamber 3000 includes a fluid compartment 202 for containing a fluid such as a liquid (e.g. water) and/or a gas (e.g. oxygen), an inlet portion 204 defining an inlet 222 of the fluid compartment 204 for allowing an incoming flow of gases 206 to enter the fluid compartment 202, an outlet portion 208 defining an outlet 224 of the fluid compartment 202 for allowing an outgoing flow of gases 210 to exit the fluid compartment 202.

[0424] As more clearly seen in Figures 29 to 30, the humification chamber 3000 further includes a channel 402, which extends between the inlet 222 and outlet 224. As more clearly illustrated in Figure 30, the channel 402 may directly connect the inlet 222 and the outlet 224. As such, in the particular embodiment shown, the channel 402 is configured to provide a direct passage for a flow of gases travelling from the inlet 222 towards the outlet 224. In some alternative embodiments, a channel may extend generally between the inlet 222 and the outlet 224 without directly connecting the inlet 222 and the outlet 224, whilst still achieving a reduction in residence time for the flow of gases travelling between the inlet 222 and the outlet 224. It will be understood that the reduction in residence time is relative to a similar humidification chamber without a channel 402.

[0425] Typically, the configuration of the humidification chamber 3000 having the channel 402 optimises (or in other words tunes) a residence time of the flow of gases passing between the inlet 222 and the outlet 224 so as to achieve a desired humidity range. Further tuning of the residence time may be achieved via a deflector as described in various embodiments of the humidification chamber herein.

[0426] Advantageously, the structure and configuration of the channel 402 directly connecting the inlet and outlet provides a substantially unobstructed pathway (passage) for the direct communication of the flow of gases from the inlet 222 to the outlet 224. As further illustrated in Figure 31 , the opening of the inlet 222 may be located within a recess of the channel 402 body at one end of the channel 402. Similarly, the opening of the outlet 224 may be located within the recess of the channel 402 body at an opposite end of the channel 402. By providing a direct connection between the inlet 222 opening and the outlet 224 opening in this embodiment, the channel 402 enhances the movement of the flow of gases so as to provide a direct passageway between the inlet 222 and outlet 224. The configuration of the channel 402 and the created connection between the inlet 222 and outlet 224 may provide seamless and unhindered transfer of gases from the inlet to the outlet, to provide an optimum humidity for the outgoing flow of gases 210 at a desired flow rate.

[0427] In some embodiments, the inlet 222 may be partially located within, entirely within, or entirely externally to, the recess of the channel 402. Similarly, the outlet 224 may be partially located within, entirely within, or entirely externally to, the recess of the channel 402.

[0428] As shown in Figure 29, the channel 402 may be located above the fluid compartment 202 at a top portion (e.g. top wall 602) of the humidification chamber 3000. More specifically, the fluid compartment 202 may include a substantially circular base 212, a top wall 602 and a peripheral wall (also referred to herein as side wall or peripheral side wall) 305 extending between the base 212 and the top wall 602. As such, an internal volume of the fluid compartment 202 may be defined by the base 212, peripheral side wall 305 and the top wall 602. More specifically, the internal volume of the fluid compartment 202 may be defined by the base 212, peripheral side wall 305 and a generally horizontal plane occupied by the top wall 602. As previously mentioned, the fluid compartment 202 can contain any suitable liquid(s) and/or gas(es). In the particular embodiment described herein with reference to Figures 29 to 42, the fluid compartment 202 is generally considered to be distinct to the channel 402, and the recess of the channel 402 is considered to increase the total internal volume of the humidification chamber 3000 by adding to the total internal volume of the fluid compartment 202. Typically, an internal volume of the channel 402 is smaller than the internal volume of the fluid compartment 202.

[0429] As shown in Figure 29, the channel 402 extends outwardly from a top portion of the humidification chamber 3000. Advantageously, the channel 402 extending outwardly from a top portion of the humidification chamber 3000, may provide the humidification chamber 3000 with at least a volume of space that enables a flow of gases to pass between the inlet 222 and the outlet 224 even when the fluid compartment 202 is completely filled with a liquid (e.g. water).

[0430] As the channel 402 is located above the fluid compartment 202 and extends outwardly from the top wall 602, water may be prevented from filling the entire recess of the channel 402 in use (as more clearly illustrated in Figures 30 and 35). Accordingly, the channel 402 creates a passage whereby the flow of gases from the inlet 222 can effectively move to the outlet 224 even when the fluid compartment 202 is filled to a theoretical maximum with water.

[0431 ] In practice, it will be appreciated that the humidification chamber 3000 is not filled to a theoretical maximum in use. In particular, the humidification chamber 3000 may have a functional liquid capacity of about 400ml, or more specifically about 250 to 350ml. The functional liquid capacity of the humidification chamber 3000 is less than the theoretical maximum liquid capacity. It will be understood that the "functional liquid capacity" as used herein refers to the practical or usable or safe amount of liquid that the humidification chamber can hold. It implies that this is the amount of liquid that can be effectively stored within the internal volume of the humidification chamber, taking into account various constraints or limitations of the humidification chamber in its application. In other words, it refers to the usable real-world capacity of humidification chamber, as opposed to its theoretical or maximum liquid capacity, which may not be practical or safe to achieve in use.

[0432] In particular, the humidification chamber 3000 may provide a marking (e.g. a line) across the fluid compartment 202 to indicate the functional liquid capacity of the humidification chamber 3000. The marking may indicate a recommended functional liquid capacity, to provide effective or optimum humidification performance for a particular use case involving a specific procedure and/or having a specific duration (during which humidification is required).

[0433] In some examples, the internal volume of a humidification chamber 3000 may be about 400ml to 500ml. Typically, the internal volume of a humidification chamber 3000 may be 450ml. In these humidification chambers 3000, the functional liquid capacity may be about 250ml to 350ml. As such, in some embodiments, the ratio of functional liquid capacity of a humification chamber 300 to the chamber’s total internal volume may be about (250 to 350ml):(400 to 500ml), or more specifically about 250:450ml.

[0434] The functional liquid capacity may be determined based on various practical use case limitations or restrictions. For example, the humidification chamber 3000 may be subject to a ‘tilt test’ to determine the maximum fluid capacity when the humidification chamber 3000 is tilted to a predetermined degree (e.g. a displacement angle of the humidification chamber 3000 from the horizontal may be a predetermined value, or a predetermined value range) without liquid flowing into or past the opening of the inlet 222 and/or the outlet 224. In some embodiments, the maximum fluid capacity determined by the ‘tilt test’ may guide the determination of the functional liquid capacity of the humidification chamber 3000. The tilt test may also indicate a safe amount of liquid in the humidification chamber 3000 to provide a level of patient safety, so as to ensure that liquid does not flow out of the humidification chamber 3000 and into the incoming gas flow conduit or outgoing gas flow conduit when the humidification chamber 3000 is subject to a predetermined degree of angular displacement.

[0435] Due to the specific configuration of the inlet 222 and outlet 224 openings in conjunction with the raised channel 402 as previously described, a functional fluid capacity of the humidification chamber 3000 may be increased when compared to a humidification chamber without a channel 402 or a humidification chamber having an obstructed channel 402. In other words, the humidification chamber 3000 in accordance with the embodiment shown in Figures 29 to 39, may enable a larger amount of liquid to be contained in the humidification chamber 3000 whilst preventing liquid from entering or flowing into the inlet 222 and/or outlet 224, thereby satisfying the ‘tilt test’. This increased capacity may allow the liquid in the humidification chamber 3000 to last longer in use. In some examples, the humidification chamber 3000 may be used to provide humidification for medical procedures having a duration of about 10 minutes to 4 hours, without the need to refill or top-up the humidification chamber 3000 with water. In some embodiments, the humidification chamber 3000 may be used for multiple medical procedures before it is necessary to refill the chamber 3000 with water. [0436] In the embodiment illustrated, the channel 402 is curved and generally follows a curvature of the peripheral side wall 305 of the fluid compartment 202. In particular, a portion of the channel 402 follows the contour of the peripheral side wall 305 of the fluid compartment 202 such that a portion of a side wall 3002 of the channel 402 is flush with, and forms part of, a portion of the peripheral side wall 305 (Figure 29). In other words, the channel 402 extends outwardly from the bounds of the fluid compartment 202 as defined by the top wall 602 and the peripheral side wall 305.

[0437] As more clearly shown in Figures 30 and 35, the channel 402 and the fluid compartment 202 form a single continuous internal volume so as to allow a seamless flow of gases between the channel 402 and the fluid compartment 202. Moreover, the channel 402 is continuous and provides a substantially uninterrupted passage for the flow of gases from the inlet 222 towards the outlet 224 (Figure 30). In other words, the channel does not have barriers (or other structures) preventing free flow of gases from the inlet 222 towards the outlet 224.

[0438] As more clearly shown in Figure 33, the inlet 222 and outlet 224 are in direct fluid communication with the channel 402. Moreover, the direct fluid communication between the inlet 222, outlet 224 and the channel 402 is created above the generally horizontal plane defined by the top wall 602 of the fluid compartment 202.

[0439] Advantageously, the channel 402 effectively increases a total internal volume of the humidification chamber 3000, and provides direct fluid communication between the inlet 222 and the outlet 224 to facilitate the movement of the flow of gases from the inlet 222 towards the outlet 224. The channel 402 also reduces residence time for the flow of gases travelling from the inlet 222 to the outlet 224 (when compared to a humidification chamber without a channel 402). In this embodiment, the rate of water usage may be decreased (when compared to a humidification chamber without a channel 402), making the humidification chamber 3000 particularly suitable for medical procedures having a specific humidity requirement and an average duration of a specific range. For example, for medical procedures having an average duration of about 10 to 30 minutes. In some embodiments, the humidification chamber 3000 is particularly suitable for medical procedures having an average duration of up to 4 hours. Typically, the humidification chamber 3000 is particularly suitable for medical procedures having an average duration 30 minutes to 2.5 hours. [0440] In some embodiments, the outgoing flow of gases 210 may have an absolute humidity of about 10mg/L to 45 mg/L. The outgoing flow of gases 210 may have a relative humidity of about 10% to 100%, or about 80% to100%, or about 100%. The predetermined flow rate of the flow of gases provided by the flow source may be about 5L/min to about 90L/min, or about 10L/min to about 70L/min, or about 40 L/min to about 70 L/min.

[0441 ] In some embodiments, the predetermined flow rate of the flow of gases provided by the flow source may be 70 L/min, the outgoing flow of gases 210 may have an absolute humidity of about 20mg/L to 35mg/L and a relative humidity of about 80% to 100%.

[0442] In some embodiments, when the flow of gases provided by the flow source has a flow rate of about 70L/min, the humidified flow of gases may have a humidity of about 20mg/L to 35 mg/L. In some embodiments, when the flow of gases provided by the flow source has a flow rate of about 70L/min, the humidified flow of gases may have a humidity of about 30 mg/L.

[0443] Whilst in the embodiment illustrated in Figures 29 to 42, the channel 402 roughly occupies half of a top portion 213 of the humidification chamber 3000, it will be appreciated that in some alternative embodiments, the channel 402 may occupy less than half, or more than half of the top portion 213 of the chamber 3000.

[0444] In some alternative embodiments, the channel 402 may extend outwardly from the peripheral side wall 305 of the humidification chamber 3000.

[0445] Moreover, the channel 402 may be generally C-shaped or U-shaped as shown in Figures 29 and 30. Alternatively, the channel 402 may have one or more angled corners. The cross-sectional area of the channel 402 may be consistent throughout the length of the channel, or variable along the length of the channel.

Partially Enclosed Deflector

[0446] In some embodiments, the humification chamber 3000 may further include a deflector 3004 configured to direct the incoming flow of gases 206 from the inlet portion 204 towards the outlet portion 208 through the channel 402. It is to be understood that in some applications, it may be desirable to provide a humidification chamber 3000 without a deflector. For example, the humidification chamber 3000 may include the fluid compartment and channel 402 without a deflector 3004 at the inlet 222. In other applications, it may be desirable to provide a deflector 3004 at the inlet 222 without a channel 402. In some applications, it may be desirable to provide a humidification chamber 3000 with both the channel 402 and deflector 3004.

[0447] The specific combination of features including either one or both of the channel 402 and deflector 3004 generally depends on the requirements of specific medical procedures. For instance, each of the channel 402 and deflector 3004 may serve to guide a flow of gases from the inlet 222 to the outlet 224, reducing a level of humidity in the outgoing flow of gases 210 and thus reducing rate of water usage for the humidifier (when compared with a chamber without a channel or deflector). As it will be appreciated, different medical procedures will have different durations, and different requirements for humidity and flow rate for the flow of gases delivered to the patient. As such, the humidification chamber 3000 may be flexibly designed with either one or both of the channel 402 and deflector 3004 for different medical procedure applications.

[0448] In the specific embodiment shown in Figures 32 to 35, the deflector 3004 is located directly below the inlet 222 and is partially enclosed (as most clearly illustrated in Figures 34 and 35). In other words, the deflector 3004 is generally shaped like a scoop. Generally, the partially enclosed deflector 3004 may act as an extension of the inlet 222 to direct/guide the incoming flow of gases 206 to the channel 402 such that a bulk flow of gases is directed from the inlet 222 to the outlet 224 via the channel 402.

[0449] In the specific embodiment illustrated in Figures 32 to 35, the deflector 3004 includes a lower portion 3006, and a back portion 3008 partially extending around the periphery of the lower portion 3006. Whilst the lower portion 3006 illustrated is substantially flat, it is to be understood that the lower portion may be curved, or irregular shaped in alternative embodiments. Moreover, the lower portion 3006 (e.g. if flat) may extend at any suitable angle relative to an internal top face 3005 of the humidification chamber 3000. For example, the lower portion 3006 may be offset from, and generally parallel to, the internal top face 3005 of the humidification chamber 3000. [0450] As more clearly shown in Figure 35, the deflector 3006 defines an open side 3010 opposite the back portion 3008 (which defines a closed side 3012 of the deflector 3006). The open side 3010 of the deflector 3004 faces the channel 402 so as to direct the incoming flow of gases 206 from the inlet portion 204 into the channel 402, or adjacent the channel 402. It will be understood that like features of the deflector 3006 refer to those as previously described.

[0451 ] It will be appreciated that the partially enclosed deflector 3006 may also be used in humidification chambers without a channel 402. The direction of the incoming flow of gases 206 may be guided by the orientation of the deflector 3004 and its open side 3010. Moreover, a channel of any suitable shape, position and configuration may be provided. In some embodiments, the channel may extend from a different area of the top portion of the humidification chamber, extend from a portion of the peripheral side wall of the humidification chamber, or a combination thereof.

[0452] As more clearly shown in Figure 36 and 37, the inlet 222 and the inlet portion 204 is spaced/offset from the inlet adjacent wall portion 304. In this embodiment, the incoming flow of gases 206 entering the fluid compartment of the chamber 3000 is generally offset from inlet adjacent wall portion 304. In some humidification chambers where the inlet 222 is not offset from the inlet adjacent wall portion 304, the incoming flow of gases 206 may travel in a direction along or tangential to an inner surface of the inlet adjacent wall portion 304.

[0453] As shown in Figures 30, 31 ,33, 35, 36 and 37, the channel 402 may be integrally formed with the inlet portion 204 and outlet portion 208 such that fluid can flow seamlessly through the inlet 222, channel 402 and outlet 224.

Fluid directing member at the outlet

[0454] According to further embodiments, a humidification chamber 8000 may be provided as shown in Figures 73 to 75. In humidification chamber 8000, like features refer to those previously described, for example with respect to humidification chamber 3000 as shown in Figures 29 to 39. [0455] In addition, the humidification chamber 8000 may include a fluid directing member 8002 adjacent the outlet 224 to direct the bulk flow of gases (for example, from the channel 402) into the outlet portion 208 via the outlet 224.

[0456] The fluid directing member 8002 may take any suitable form. In the embodiment shown in Figures 73 and 74, the fluid directing member 8002 is shaped like a scoop similarly to the partially enclosed deflector 3004. In particular, the fluid directing member 8002 includes a lower portion 8004 and a back portion 8006 partially extending around the periphery of the lower portion 8004, The lower portion 8004 may be flat or curved, disposed at any angle with respect to the top wall 602 of the humidification chamber 8000, be regular or irregular shaped, or any combination thereof. In one embodiment, the lower portion 8004 may be generally parallel with and offset from the top wall 602. The fluid directing member 8002 is partially enclosed by the lower portion 8004 and the back portion 8006. An open side of the fluid directing member 8002 opposite the back portion 8006 receives a flow of gases from the fluid compartment and in particular the channel 402, and directs the gases into the outlet 224. Typically, the open side of the fluid directing member 8002 faces the channel 402.

[0457] Generally, the fluid directing member 8002 serves to direct a bulk flow of gases from the fluid compartment 202 and the channel 402, into the outlet portion 208 via the outlet 224. This arrangement may further serve to reduce the residence time of the flow of gases through the humidification chamber 8000 so as to facilitate movement of the flow of gases from the inlet 222 towards the outlet 224. When used in combination with any one or more of a deflector (e,g, deflector 3004, 218) at the inlet 222, a channel 402, the fluid directing member 8002 may be provided to allow for further variation and adjustment of the residence time of the flow of gases through the humidification chamber 8000, and the humidity of the outgoing flow of gases 210, so as to tailor the humidification chamber 8000 to specific use cases having specific procedural and/or time period requirements.

Alignment Features

[0458] In some embodiments, the humidification chamber 3000 may further include a pair of guides, for example in the form of parallel ribs 3016, 3018 (Figures 32 to 34, 36, 37), extending from the top wall 602 of the fluid compartment 202 to provide alignment between the humidification chamber 3000 and a sensor module (also referred to herein as a sensor assembly) 106.

In some embodiments, the humidification chamber 3000 may be moulded in plastic.

Alternative configurations for Inlet and Outlet

[0459] In some alternative embodiments of the humidification chamber, either one or both the inlet portion and the outlet portion may extend substantially vertically or horizontally from the fluid compartment. For example, as shown in Figure 40, the humidification chamber 4000 includes an inlet portion 4002 which extends generally vertically in a similar way to the humidification chamber 3000 previously described with reference to Figures 29 to 39. The humidification chamber 4000 also includes an outlet portion 4004 which extends generally vertically on an opposite side of the top wall 602 of the fluid compartment 202.

[0460] In some embodiments, the humidification chamber 4000 may include a channel 402 extending between the inlet portion 4002 and the outlet portion 4004. In some embodiments, channel 402 may be configured differently, or the humidification chamber 4000 may not include a channel 402. Moreover, the humidification chamber may include a deflector according to any one of the embodiments as described herein. Alternatively, the humidification chamber 4000 may not provide a deflector.

[0461 ] A further alternative embodiment of a humidification chamber 5000 is shown in Figure 41. Both inlet portion 5002 and outlet portion 5004 of the humidification chamber 5000 extends generally horizontally with respect to an upright position of the humidification chamber 5000. In this embodiment, the respective inlet and outlet (hidden) of the humidification chamber 5000 could be aligned with the channel 402 such that an incoming flow of gases 206 could be directed by the orientation of the inlet portion 5002 and corresponding inlet to direct flow into the channel 402, and to the outlet and outlet portion 5004 creating an outgoing flow of gases 210.

[0462] A further alternative embodiment of a humidification chamber 6000 is shown in Figure 42. Both inlet portion 6002 and outlet portion 6004 of the humidification chamber 6000 extends at an angle with respect to a top wall 602 of the humidification chamber 5000. In this embodiment, the respective inlet and outlet (hidden) of the humidification chamber 6000 may be angled to direct at least a portion of the flow of gases into the channel 402 to achieve a target residence time for the flow of gases based on requirements of a particular medical procedure.

[0463] In particular, the angle between the inlet portion 6002 and a top wall 602 of the fluid compartment may be between about 20° and 70°. More specifically, the inlet portion 6002 may extend at an angle of about 30° with respect to a top wall 602 of the fluid compartment 202.

[0464] In alternative embodiments, the inlet portion 6002 may extend at an angle with respect to the top portion 602, and the outlet portion 6004 extend generally horizontally (or vertically), or vice versa. Moreover, each of the inlet portion 6002 and outlet portion 6004 may extend radially about a respective one of the inlet opening or outlet opening at any suitable orientation, for example to provide a usability benefit.

[0465] The horizontal or angled orientations of the respective inlet portions 5002, 6002 and outlet portions 5004, 6004 may facilitate connections to respective incoming and outgoing gas flow conduits when used in a humification system. As described in further detail below, embodiments of the humidification chamber as described herein may advantageously allow elevated mounting of a humidifier in an overall system for providing respiratory support therapy. When such elevated mounting positions are implemented, the horizontal or angled orientations of the respective inlet portions 5002, 6002 and outlet portions 5004, 6004 may provide more ergonomic and convenient access when conduit connections are made.

[0466] In some embodiments, the respective incoming and/or outgoing gas flow conduits may be pre-attached to the respective inlet portions 5002, 6002 and/or outlet portions 5004, 6004 in a kit. In practice, humidification chamber 4000, 5000, 6000 having the conduit(s) pre-attached may be slid into the humidification unit 102 with a single lateral movement, ready for use, advantageously providing convenience and saving critical clinician time during a medical procedure setup.

[0467] As previously mentioned, the configuration of the humidification chambers described herein optimises the humidity of the outgoing flow of gases for specific medical procedures. System for Providing Respiratory Support including Removably Mounted Humidifier

[0468] A system 7000 for providing respiratory support including an anaesthesia machine (also known as an anaesthesia workstation) according to one embodiment of the invention is illustrated in Figure 43. The system 7000 includes an anaesthesia machine 7002. Typically, the anaesthesia machine 7002 is configurable to receive a gas supply (not shown) for delivering a respiratory support to a patient through piped connections known in the art. The gas supply may include one or more of an anaesthetic gas (e.g. nitric oxide (NO)), oxygen (O2) and air supply. The anaesthesia machine 7002 includes a breathing circuit which delivers gases to the patient and returns expired gases to rebreathing components of the anaesthesia machine 7002.

[0469] One or more vaporizers 7030 convert volatile anaesthetics such as isoflurane and sevoflurane from liquid to vapour, and control introduction of these agents into the breathing circuit in accurately controlled concentration and dosages as required by the user, typically an anaesthetist clinician.

[0470] Integrated into the anaesthesia machine 7002 is a ventilation system which ventilates the patient during induction and after administration of anaesthetic agents to achieve ongoing anaesthesia. A manual ventilation bag is typically used during induction when volatiles are being delivered and prior to the patient being intubated. The compliance of the ventilation bag enables the patient to breathe in and out a fixed volume of gas through a sealing patient interface such as, in the form of a face mask. Once intubated, the ventilation mode changes from manual to mechanical, effectively isolating the manual ventilation bag and associated pressure relief valve from the rebreathing components so that ventilation occurs via a mechanical system. This may involve a collapsible bellows 7032 and/or electronically actuated valves (under control of a controller of the anaesthesia machine) that controls the tidal volume and timing of breaths delivered to the patient through a sealing patient interface such as, in the form of an endotracheal tube or a face mask.

[0471 ] In certain medical procedures, high flow respiratory support may be provided to a patient (e.g. to provide oxygenation and/or CO2 clearance) to extend the safe apnoea time. High flow respiratory support may be provided to the patient before, during, or after delivery of volatile anaesthetics. High flow respiratory support may be provided to the patient before or during the procedure. Typically, gases provided during high flow respiratory support are humidified, for example to provide conditioning to the airways of the patient. As such, it is often desirable to mount a humidifier 7004 to an anaesthesia machine 7002 when providing high flow respiratory support.

[0472] In the embodiment illustrated in Figure 43, the system 7000 further includes a humidifier 7004 mounted to the anaesthesia machine 7002 via a mounting assembly 7006. The configuration of the mounting assembly 7006 will be described in further detail below. The humidifier 7004 includes a humidification unit 7010 and a humidification chamber 7008. The humidification unit 7010 may be the same or similar to the humidification unit 102 previously described with reference to Figures 11 A to 1 1 H.

[0473] The humidification chamber 7008 may be a humidification chamber according to any one of the embodiments described herein. In particular, the humidification chamber 7008 is a manually replenishable chamber. For example, as illustrated in Figure 44, the chamber 7008 can be manually filled with a liquid (e.g. water) by pouring liquid from a bottle 7012 into the fluid compartment 202 via the inlet portion 204. Alternatively, the humidification chamber 7008 may be manually filled by placing the chamber 7008 under a tap, so that water from the tap directly enters the fluid compartment 202 via the inlet portion 204. Typically, the humidification chamber 7008 is configured to operate without a connected external water source such as a connected water bag. As previously mentioned, the humidification chamber 7008 is optimised for use in certain medical procedures, for example with the average procedure duration of about 10 to 30 minutes, or up to a few hours. For these medical procedures, the configuration of the humidification chamber 7008 may be optimised to deliver a flow of gases to the patient at a required humidity range and flow rate range throughout the entire duration of the therapy without the need for refilling. In some embodiments, the humidification chamber 7008 may be used to provide humidification for the duration of multiple procedures without the need for refilling.

[0474] As discussed in further detail below, not having a connected external water source provides additional advantages in relation to the mounting of the humidifier 7004 to the anaesthesia machine 7002. In one example, the humidifier 7004 having a chamber 7008 that is configured to operate without a connected external water source provides the humidifier with 7004 with a greater degree of autonomy and freedom of movement and adjustment with respect to the anaesthesia machine 7002, unencumbered by an external water source connection.

[0475] Moreover, an operator may have a greater degree of control over the amount of water which is added directly into the humidification chamber 7008. For instance, an operator may optionally add less water into the humidification chamber 7008 to reduce the required warm-up time. Smaller, more controllable volumes of water may be more suitable for anaesthetic procedures which have an average duration of about 30 minutes to a few hours. This level of operator adjustable control may be difficult to achieve in a humidifier 7004 that is automatically filled to a predetermined level by an external water source. Not having an externally connected water source (e.g. water bag) also reduces plastic wastage.

[0476] An incoming gas flow conduit 7034 (also referred to herein as a nonhumidified gas conduit) is connectable to the inlet portion of the humidification chamber 7008 for delivering the incoming flow of gases 206 to the humidification chamber 7008, and an outgoing gas flow conduit 7036 (also referred to herein as a humidified gas conduit) is connectable to the outlet portion of the humidification chamber 7008 for delivering the humidified outgoing flow of gases 210 to the patient via a patient interface.

[0477] In some forms, the outgoing gas flow conduit 7036 may be corrugated.

[0478] In some examples, the ridges and grooves of the corrugated outgoing gas flow conduit 7036 comprise a series of annular ridges and grooves. In some forms, the ridges and grooves are helical. Alternatively, the outgoing gas flow conduit 7036 is formed from one or more spirally wound components. In some forms, the outgoing gas flow conduit 7036 comprises two or more spirally wound components. Optionally, the two or more spirally wound components comprise one or more of: an elongate hollow body, and an elongate structural component. In some forms, the elongate structural component comprises heating elements, sensing elements, or both heating and sensing elements. [0479] In some embodiments, the corrugations of the outgoing gas flow conduit 7036 may have an outer diameter of between about 23mm and about 25mm, an inner diameter of between about 20 mm and about 21 mm, and a pitch of about 4.5 mm. However, in other embodiments (with or without corrugations), it is envisaged that these dimensions will vary. For example, the inner diameter may be between about 10 and 30 mm, or between about 15 and 25 mm, or between 19 to 25 mm., or between 10 to 15mm, or about 12mm. For embodiments having corrugations, the minor inner diameter may be between 19 - 22 mm and the major inner diameter may be between 23 - 25 mm. The pitch P may be between 3 to 5 mm, 3.5mm, or 4.5mm. In some embodiments, the pitch may be between about 5 to 10mm, or about 7.5mm.

[0480] The length of the outgoing gas flow conduit 7036 may also vary, for example, the length may be between 1 m and 3 m, between 1 ,5m and 2.5m, or 2.4m.

[0481 ] In the system 7000, the respiratory circuit from the incoming gas flow conduit 7034 to the patient interface may have a resistance to gas flow of 15 - 50 cmH2O at a selected gas flow rate, e.g. 70 L/min. In some forms, the respiratory circuit from the incoming gas flow conduit 7034 to the patient interface may have a resistance to gas flow of 30 - 45 cmH2O at a gas flow rate of 70 L/min. Optionally, the respiratory circuit from the incoming gas flow conduit 7034 to the patient interface may have a resistance to gas flow of about 25 CIT1H2O, or about 30 CIT1H2O, or about 40 CIT1H2O, at a gas flow rate of 70 L/min.

[0482] In some embodiments, an incoming gas flow conduit assembly may include the incoming gas flow conduit 7034 of a predetermined length and one or more connectors at each end of the incoming gas flow conduit 7034. Similarly, an outgoing gas flow conduit assembly may include the outgoing gas flow conduit 7036 of a predetermined length and one or more connectors at each end of the outgoing gas flow conduit 7036.

[0483] As more clearly shown in Figure 45, the humidification unit 7010 further includes a graphical user interface 7014, which provides a display module for visually displaying an alert and/or operating parameters in relation to a respiratory support provided via the humidifier 7004. In some embodiments, the operating parameters may comprise high flow respiratory support parameters including any one or more of temperature of a flow of gases delivered to a patient, a flow rate of the flow of gases delivered to the patient, a humidity of the flow of gases delivered to the patient, a pressure of the flow of gases delivered to the patient, and a selected respiratory support operating mode.

[0484] In some embodiments, the operating parameters may further include any one or more of temperature sensor readings received from one or more sensors mounted at or proximate the patient, at or proximate the humidification chamber 7008, and/or at or proximate a heater base 104 of the humidifier 7004, supply voltage to the humidifier 7004, and power consumption of the heater base 104 of the humidifier 7004.

[0485] In some embodiments, the graphical user interface 7014 may enable user selection of a respiratory support mode from a plurality of available high flow respiratory support modes including any one or more of anaesthesia mode and a specific medical procedure related mode. In some embodiments, the respiratory support modes may further include an infant/paediatric mode and an adult mode. The anaesthesia mode and specific medical procedure related mode may be a subset of the adult mode.

[0486] In some embodiments, the humidifier may be configured to generate one or more alarms to alert a clinician. The alarms may be audible alarms and/or visual alarms in the form of diagrams, charts, and/or display messages via the graphical user interface 7014. The one or more alarms may include a malfunctioning alarm to indicate that one or more components in the system 7000 is not functioning appropriately. For example, a malfunctioning alarm may provide an indication when various components of the system are not connected properly (e.g., a conduit is not connected properly to an inlet portion 204 or outlet portion 208 of the humidification chamber 7004), or if one or more components of the system is faulty (e.g. faulty sensor). Moreover, the one or more alarms may include a liquid level alarm to indicate that a liquid level of the humidification chamber 7008 is below a minimum threshold.

[0487] The humidifier 7004 may be mounted to the anaesthesia machine 7002 in any suitable manner. One example mounting assembly 7006 is illustrated in Figure 46. The mounting assembly 7006 includes a mounting base 7016 for connection to the anaesthesia machine 7002 (e.g. via a rail of the anaesthesia machine 7002). The mounting assembly 7006 further includes a pivotable arm 7018 having a first arm portion 7020, and a second arm portion 7022 pivotably mounted to the first arm portion 7020. At one end of the pivotable arm 7018, the arm 7018 is pivotably mounted to the mounting base 7016. At an opposite end the pivotable arm 7018, the arm 7018 includes a sleeve 7026 for adjustably receiving a mounting post 7024 therein. The humidifier 7004 is mounted to the mounting post 7024. To adjust the height of the humidifier 7004 relative to the anaesthesia machine 7002, the mounting location of the humidifier 7004 on the mounting post 7024 may be adjusted. Alternatively, the mounting post 7024 may be slidable within the sleeve 7026 to adjust the height of the humidifier 7004. In some embodiments, the humidifier 7004 may be mounted at or adjacent a top portion of the mounting post 7024.

[0488] The mounting post 7024 can have any suitable length. In some embodiments, the mounting post may have a length of less than about 1 meter. In some embodiments, the mounting post may have a length of less than about 0.5 meter. In some embodiments, the mounting post may have a length of about 0.5 to 1 meter, or about 0.3 to 0.8 meters.

[0489] In other embodiments, the humidifier 7004 may be mounted directly to a rail or other mounting portion of the anaesthesia machine 7002 without a separate mounting assembly 7006. In these embodiments, the humidifier 7004 may be mounted closer to the anaesthesia machine 7002, thereby reducing an overall footprint of the system 7000 and reduces tipping risk.

[0490] Advantageously, not having a connected water source (e.g. water bag) allows the humidifier 7004 to be mounted and elevated and positioned higher up in the system 7000, for example compared to a humidifier that requires a connected water source to be positioned at a certain height above the humidifier for proper operation. The elevated position of the humidifier 7004 with respect to the anaesthesia machine 7002 provides a number of significant benefits, including enhanced visibility, accessibility, and operability of the humidification chamber 7008, the humidifier unit 7010 including the display module 7014. This may significantly improve the ability of the clinician(s) to monitor and manage critical operating parameters associated with the humidifier 7004 and the respiratory support provided in real-time, particularly in time-critical medical procedures. As such, the elevated placement of the humidifier 7004 not only optimises the humidifier’s ergonomics but it may also reduce the time required for the clinician to divert attention away from the patient to monitor critical parameters and operate necessary instrumentation controls, thereby reducing procedural interruptions. Such advantages may contribute to enhanced clinical outcomes, reduced procedure times, and heightened patient safety.

[0491 ] Furthermore, the elevated mounting position of the humidifier 7004 in the system 7000 brings the humidifier 7004 more in line with controls and the display monitor 7026 of the anaesthesia machine 7002, which improves the clinician's workflow by consolidating all essential equipment and controls (e.g. the flowmeter to adjust the flow rate associated with high flow respiratory support) into a single accessible region, conveniently located near or around waist height and at eye level. This elevation eliminates the need for clinicians to reach across or search for instruments, controls, or monitors scattered across the system 7000. Instead, with all critical displays and controls conveniently positioned near or around waist height and at eye level, the clinician gains seamless access to visualise and adjust critical operating parameters of the system 7000 and the associated therapy provided to the patient so as to facilitate operation in a more cohesive and coordinated manner.

[0492] In time critical emergency procedures, the elevated mounting position of the humidifier 7004 may prove invaluable by significantly expediting the mounting process. As it will be appreciated, it may be easier and faster to mount the humidifier 7004 at an ergonomic and convenient height, and without a connected external water bag. In scenarios where it may take too long to properly mount a humidifier, a clinician may decide to proceed with an emergency procedure without the humidifier. As such, providing an easy to use and easy to set up humidifier 7004 may significantly improve patient outcomes, particularly in emergencies.

[0493] In addition, the elevated mounting position of the humidifier 7004 also reduces the required length of the mounting post 7024, further providing a more streamlined design, reducing the overall footprint and potential interference within a workspace (e.g. an operating theatre or sedation suite). [0494] The elevated mounting position of the humidifier 7004 also makes it easier and more ergonomic for an operator to manually fill the humidification chamber 7008, for example, as described herein with reference to Figure 44. In addition, the humidifier 7004 may be elevated to a position which is closer to the patient. Furthermore, the elevation of the humidifier 7004 may be closer to a centre of mass of the anaesthesia machine 7002 and the removal of an elevated waterbag filled with water, further reduces the tipping risk of the system 7000.

[0495] In one embodiment, the humidifier 7004 is mounted to the anaesthesia machine 7002 via the mounting assembly 7006 such that the display module 7014 is greater than about 0.5 to 1 meters from a base of the anaesthesia machine 7002 or from the floor. For example, reference ‘h’ in Figure 43 denotes a height of the display module 7014 relative to a base of the anaesthesia machine 7002.

[0496] In some embodiments, the humidifier 7004 may be mounted to the anaesthesia machine 7002 such that the display module 7014 is greater than about 0.7 to 1 meters from the base of the anaesthesia machine or from the floor (e.g. ‘h’ is greater than 0.7 to 1 meters).

[0497] In some embodiments, the humidifier 7004 may be mounted to the anaesthesia machine 7002 such that the display module 7014 is greater than about 0.7 meters from the base of the anaesthesia machine or from the floor (e.g. ‘h’ is greater than 0.7 meters).

[0498] In some embodiments, the humidifier 7004 may be mounted to the anaesthesia machine 7002 such that the display module 7014 is less than about 1 meter from the base of the anaesthesia machine or from the floor (e.g. ‘h’ is less than 1 meter).

[0499] In some embodiments, the humidifier 7004 may be mounted to the anaesthesia machine 7002 such that the display module 7014 is greater than about 1 meter, or greater than about 1 .1 m, or greater than about 1 .2m, or between about 1 .2m to 1 .5m from the base of the anaesthesia machine or from the floor.

[0500] In the embodiment shown in Figure 43, the anaesthesia machine 7002 includes a monitor 7026. The humidifier 7004 may be mounted to the anaesthesia machine 7002 such that the display module 7014 of the humidifier 7004 is generally below the monitor 7028 of the anaesthesia machine 7002.

[0501 ] In some embodiments, the humidifier 7004 may be mounted to the anaesthesia machine 7002 such that the display module 7014 of the humidifier 7004 is generally level with or above a top portion of the anaesthesia machine 7002.

[0502] In some embodiments, the humidifier 7004 is mounted to the anaesthesia machine 7002 such that the display module 7014 of the humidifier 7004 may be generally level with or above a top portion of the bellows 7032.

[0503] In some embodiments, the humidifier 7004 may be mounted to the anaesthesia machine 7002 such that the display module 7014 of the humidifier 7004 may be generally level with or below a patient’s head (when the patient is lying on a hospital bed) or a head portion of the patient’s hospital bed.

[0504] The humidifier 7004 may be mounted adjacent a left side of the anaesthesia machine 7002 as illustrated in Figure 43. In alternative embodiments, the humidifier 7004 may be mounted adjacent a right side of the anaesthesia machine 7002.

[0505] In some embodiments, the humidifier 7004 may be configured for use in high flow respiratory support. In particular, the system may further include a flow source for providing a flow of gases, for example at a high flow rate, to the humidifier 7004. A predetermined flow rate of the flow of gases provided by the flow source may be about 10L/min to 70L/min. In one embodiment, the flow source may be separate to and independent of the anaesthesia machine. A flow controller for controlling the flow rate of the flow of gases may be integrated with the anaesthesia machine.

[0506] In another embodiment, the flow source may be integrated with and provided by the anaesthesia machine.

[0507] In embodiments in which a high flow module is incorporated into the anaesthesia machine 7002, the elevated mounting of the humidifier 7004 may position the humidifier 7004 closer to the high flow module, which further improves user setup.

Interpretation [0508] This specification, including the claims, is intended to be interpreted as follows:

[0509] Embodiments or examples described in the specification are intended to be illustrative of the invention, without limiting the scope thereof. The invention is capable of being practised with various modifications and additions as will readily occur to those skilled in the art. Accordingly, it is to be understood that the scope of the invention is not to be limited to the exact construction and operation described or illustrated, but only by the following claims.

[0510] Moreover, any feature or element described within one embodiment may be combined with any feature or element as described with respect to any other embodiment detailed within this specification, as deemed suitable and appropriate by those skilled in the art.

[0511 ] The mere disclosure of a method step or product element in the specification should not be construed as being essential to the invention claimed herein, except where it is either expressly stated to be so or expressly recited in a claim.

[0512] The terms in the claims have the broadest scope of meaning they would have been given by a person of ordinary skill in the art as of the relevant date.

[0513] The terms "a" and "an" mean "one or more", unless expressly specified otherwise.

[0514] Neither the title nor the abstract of the present application is to be taken as limiting in any way as the scope of the claimed invention.

[0515] Where the preamble of a claim recites a purpose, benefit or possible use of the claimed invention, it does not limit the claimed invention to having only that purpose, benefit or possible use.

[0516] It should be noted that terms of degree such as “generally”, “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of the modified term if this deviation would not negate the meaning of the term it modifies. [0517] In the specification, including the claims, the term “comprise”, and variants of that term such as “comprises” or “comprising”, are used to mean "including but not limited to", unless expressly specified otherwise, or unless in the context or usage an exclusive interpretation of the term is required.

[0518] Furthermore, the recitation of any numerical ranges by endpoints herein includes all numbers and fractions subsumed within that range (e.g. 1 to 5 includes 1 , 1 .5, 2, 2.75, 3, 3.90, 4, and 5). It is also to be understood that all numbers and fractions thereof are presumed to be modified by the term “about” which means a variation up to a certain amount of the number to which reference is being made if the end result is not significantly changed.

[0519] As used herein, the wording “and/or” is intended to represent an inclusive- or. That is, “X and/or Y” is intended to mean X or Y or both, for example. As a further example, “X, Y, and/or Z” is intended to mean X or Y or Z or any combination thereof.

[0520] Throughout the specification, like reference numerals refer to like features described herein. As such, any instance where features or components are indicated with the same references implies a direct correlation to the similar or identical features or components as previously described in the specification.

[0521 ] The disclosure of any document referred to herein is incorporated by reference into this patent application as part of the present disclosure, but only for purposes of written description and enablement and should in no way be used to limit, define, or otherwise construe any term of the present application where the present application, without such incorporation by reference, would not have failed to provide an ascertainable meaning. Any incorporation by reference does not, in and of itself, constitute any endorsement or ratification of any statement, opinion or argument contained in any incorporated document.

Claims

The claims defining the invention are as follows:

1 . A humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet of the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; an outlet portion defining an outlet of the fluid compartment for allowing an outgoing flow of gases to exit the fluid compartment; and a deflector configured to direct the incoming flow of gases from the inlet portion towards the outlet portion.

2. The humidification chamber of claim 1 , wherein the deflector is located proximate the inlet portion.

3. The humidification chamber of claim 1 or 2, wherein the deflector is configured to direct a bulk flow of gases from the inlet towards the outlet and away from a side wall portion of the fluid compartment proximal to the inlet.

4. The humidification chamber of claim 1 , wherein the fluid compartment includes a base, and a peripheral side wall extending around a perimeter of the base, the peripheral side wall including an inlet adjacent wall portion, the inlet adjacent wall portion being a portion of the peripheral side wall having a minimum spatial separation from the inlet, wherein the deflector is configured to direct a bulk flow of gases from the inlet away from the inlet adjacent wall portion.

5. The humidification chamber of claim 4, the peripheral side wall further including a front wall portion, the front wall portion being a forward -facing portion of the peripheral side wall when the humidification chamber is in use, wherein the deflector is configured to direct a bulk flow of gases from the inlet towards the front wall portion.

6. The humidification chamber of claim 5, wherein the deflector is configured to direct a bulk flow of gases from the inlet in a direction generally parallel to a tangential plane of the inlet adjacent wall portion towards the front wall portion.

7. The humidification chamber of any one of claims 4 to 6, wherein the inlet is spaced from the inlet adjacent wall portion.

8. The humidification chamber of any one of claims 1 to 7, wherein the humidification chamber further defines a channel for providing a low resistance gas flow pathway between the inlet and the outlet, the deflector being configured to direct a bulk flow of gases from the inlet to the outlet across at least a portion of the channel.

9. The humidification chamber of claim 8, wherein the channel is spaced from the inlet adjacent wall portion.

10. The humidification chamber of claim 8 or 9, wherein the channel is generally C-shaped or U-shaped.

1 1 . The humidification chamber of any one of the preceding claims, further including a fluid directing member proximate the outlet for directing gases towards the outlet.

12. The humidification chamber of any one of claims 1 to 7, wherein the deflector is configured to direct a bulk flow of gases from the inlet portion substantially along a direct path between the inlet and the outlet.

13. The humidification chamber according to any one of the preceding claims, wherein the deflector extends inwardly of the fluid compartment from an inner surface of the humidification chamber.

14. The humidification chamber of any one of the preceding claims, wherein an angle between the deflector and a wall of the fluid compartment for a given flow rate of the incoming flow of gases and/or the outgoing flow of gases is based on at least a humidity of the outgoing flow of gasses.

15. The humidification chamber of claim 14, wherein the angle between the deflector and a top wall of the fluid compartment is between about 20° and 70°.

16. The humidification chamber of claim 15, wherein the deflector extends at an angle of about 30° with respect to the top wall of the fluid compartment.

17. The humidification chamber of any one of the preceding claims, wherein the deflector is sized to substantially correspond with a cross-sectional area of the inlet such that a bulk flow of gases is directed by the deflector towards the outlet portion.

18. The humidification chamber of claim 17, wherein an area of the deflector is between about 50% to 150% of the cross-sectional area of the inlet.

19. The humidification chamber of any one of the preceding claims, wherein the deflector has a thickness of about 1 ,4mm.

20. The humidification chamber of any one of the preceding claims, wherein the inlet portion includes a generally straight connector for connection with an incoming gas flow conduit delivering the incoming flow of gases into the fluid compartment.

21. The humidification chamber of claim 20, wherein the generally straight connector directs the incoming flow of gases downwardly into the fluid compartment.

22. The humidification chamber of any one of the preceding claims, wherein the outlet portion includes a bent connector for connection with an outgoing gas flow conduit for delivering the outgoing flow of gases away from the fluid compartment, the bent connector being configured to direct the outgoing flow of gases through a bend in the bent connector.

23. The humidification chamber of claim 22, wherein the bend in the bent connector is a substantially 90° bend.

24. The humidification chamber of claim 22 or 23, wherein the bent connector directs the outgoing flow of gases upwardly out of the fluid compartment and redirects the outgoing flow of gases through the bend.

25. The humidification chamber of any one of the preceding claims, wherein the inlet portion and the outlet portion are positioned above the fluid compartment.

26. The humidification chamber of any one of the preceding claims, wherein the inlet portion is spaced from the outlet portion.

27. The humidification chamber of any one of the preceding claims, wherein the inlet portion and the outlet portion are located adjacent opposite ends of the humidification chamber above the fluid compartment.

28. The humidification chamber of claim 26 or 27, wherein the inlet portion is spaced from the outlet portion at a distance of about 30 to 100 mm.

29. The humidification chamber of any one of the preceding claims, wherein the outgoing flow of gases has an absolute humidity of about 10mg/L to 45 mg/L.

30. The humidification chamber of any one of the preceding claims, wherein the incoming flow of gases and the outgoing flow of gases have a flow rate of about 10L/min to 70L/min.

31 . The humidification chamber of any one of the preceding claims, wherein the incoming flow of gases has a flow rate of about 70L/min, and the outgoing flow of gases has a humidity of about 20mg/L to 35 mg/L.

32. The humidification chamber of any one of the preceding claims, wherein the incoming flow of gases has a flow rate of about 70L/min, and the outgoing flow of gases has a humidity of about 30mg/L.

33. The humidification chamber of any one of the preceding claims, wherein the fluid compartment has a fluid capacity of about 350mL.

34. The humidification chamber of any one of the preceding claims, wherein the fluid compartment has a fluid capacity of about 320mL.

35. The humidification chamber of any one of the preceding claims, wherein the fluid compartment has a substantially circular base.

36. The humidification chamber of any one of the preceding claims, further comprising at least one light guide for detecting a fluid level in the fluid compartment, the at least one light guide extending downwardly into the fluid compartment from a top wall of the fluid compartment, wherein the at least one light guide includes a proximal end adjoining the top wall of the fluid compartment, and a distal end opposite the proximal end.

37. The humidification chamber of claim 36, wherein the at least one light guide includes: an input side for receiving an input beam of light from an external light source and propagating the input beam of light through the input side of the light guide; and an output side for propagating an output beam of light through the output side of the light guide, the output beam of light being reflected from the input beam of light.

38. The humidification chamber of claim 37, wherein the at least one light guide includes at least one angled portion disposed at the distal end of the at least one light guide, the at least one angled portion being configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

39. The humidification chamber of claim 37 or 38, wherein the output side of the at least one light guide is parallel and adjacent to the input side of the at least one light guide.

40. The humidification chamber of claim 38 or 39, wherein the at least one light guide includes a pair of opposed angled portions, the pair of angled portions being disposed opposite one another at the distal end of the at least one light guide.

41 . The humidification chamber of claim 40, wherein each angled portion is at about 45° to a base of the fluid compartment.

42. The humidification chamber of claim 40 or 41 , wherein the pair of angled portions are configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

43. The humidification chamber of any one of claims 37 to 42, wherein light intensity of the output beam of light is above a threshold when the at least one light guide is solely in contact with gases.

44. The humidification chamber of any one of claims 36 to 43, wherein the distal end includes a jagged portion, the jagged portion including a plurality of angled surfaces for scattering light.

45. The humidification chamber of claim 44 when dependent on claim 40, wherein the jagged portion is disposed between the pair of angled portions.

46. The humidification chamber of any one of claims 40 to 42, wherein the pair of angled portions are configured such that the input beam of light is refracted when the at least one light guide is in contact with a liquid such that an output beam of light having light intensity below the threshold or no output beam of light is present for propagation through the output side of the at least one light guide.

47. The humidification chamber of claim 43 or 46, wherein the threshold is 40% of light intensity of the input beam of light.

48. The humidification chamber of any one of claims 37 to 47, wherein the input beam of light and the output beam of light is infra-red light.

49. The humidification chamber of any one of claims 36 to 48, wherein at least one light guide has a length of between about 10 mm and 50 mm.

50. The humidification chamber of any one of claims 36 to 49, wherein a distance between the distal end of the at least one light guide and a base of the fluid compartment is about 7mm.

51 . The humidification chamber of any one of claims 36 to 50, wherein a thickness of the at least one light guide is about 2.5mm.

52. The humidification chamber of any one of claims 36 to 51 , wherein the at least one light guide is positioned between the inlet portion and the outlet portion of the humidification chamber.

53. The humidification chamber of any one of claims 37 to 52, further including a first curved protrusion positioned above the at least one light guide, the first curved protrusion being substantially aligned with the input side of the light guide.

54. The humidification chamber of claim 53, wherein the first curved protrusion is configured to collimate the input beam of light for propagation through the input side of the at least one light guide.

55. The humidification chamber of any one of claims 37 to 54, further including a second curved protrusion positioned above the at least one light guide, the second curved protrusion being substantially aligned with the output side of the light guide.

56. The humidification chamber of claim 55, wherein the second curved protrusion is configured to collimate the output beam of light for detection by an optical sensor.

57. The humidification chamber of any one of claims 37 to 56, wherein the at least one light guide includes one or more curved surfaces for redirecting one or more light rays from the input beam of light into the at least one light guide.

58. The humidification chamber of claim 57, wherein each of the one or more curved surfaces defines an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the at least one light guide.

59. The humidification chamber of claim 58, wherein the elongate protrusion is tapered along a lengthwise direction.

60. The humidification chamber of any one of claims 57 to 59, wherein the at least one light guide includes a pair of curved surfaces, each curved surface being provided on an opposite face of the at least one light guide.

61 . The humidification chamber of any one of claims 57 to 60, wherein the at least one light guide includes two pairs of curved surfaces, one pair of curved surfaces being provided along the input side of the at least one light guide, and the other pair of curved surfaces being provided along the output side of the at least one light guide.

62. The humidification chamber of claim 61 , wherein for each pair of curved surfaces, each curved surface is provided on an opposite face of the at least one light guide.

63. The humidification chamber of any one of claims 60 to 62, wherein the curved surfaces for each pair of curved surfaces are aligned with one another.

64. The humidification chamber of any one of claims 36 to 63, wherein the at least one light guide is located substantially at or adjacent a central axis of the fluid compartment.

65. The humidification chamber of any one of the preceding claims, wherein a body of the humidification chamber is made of a material having a light transmission percentage of at least 85%.

66. The humidification chamber of any one of the preceding claims, wherein a base of the humidification chamber is made of metal.

67. The humidification chamber of any one of claims 37 to 65, wherein a base of the humidification chamber has a lip disposed around a circumference of the base so as to facilitate lateral insertion of the humidification chamber into a humidification unit, the humidification unit including a heater base for heating the fluid in the fluid compartment, and a sensor assembly for transmitting the input beam of light and detecting the output beam of light.

68. The humidification chamber of any one of claims 37 to 67, wherein the deflector is configured to direct the incoming flow of gases towards the at least one light guide.

69. The humidification chamber of any one of the preceding claims, wherein the humidification chamber includes a first light guide for detecting a minimum level of the fluid in the fluid compartment, and a second light guide for detecting a maximum level of fluid in the fluid compartment, wherein the first light guide is longer than the second light guide.

70. The humidification chamber of claim 69, wherein the first light guide and the second light guide are centred about a central axis of the fluid compartment.

71. The humidification chamber according to any one of the preceding claims, wherein at least one of the inlet portion and outlet portion defines a sensor port for receiving a sensor unit therein, wherein the sensor unit is adapted to detect any one or more of a flow rate, temperature and pressure of a respective incoming flow of gases or outgoing flow of gases.

72. The humidification chamber of claim 71 , further including a seal adapted to fit into the at least one sensor port for receiving the sensor unit therein, the seal being adapted to provide pneumatic sealing for the respective inlet or outlet portion such that gas flow within the inlet or outlet portion is isolated from ambient air.

73. The humidification chamber of claim 72, wherein the seal is made from resilient material.

74. The humidification chamber of claim 73, wherein the seal is stretchable to engagingly receive the respective sensor unit therein.

75. A humidification chamber comprising: a fluid compartment for containing a fluid, and at least one light guide for detecting a level of the fluid in the fluid compartment, the at least one light guide extending into the fluid compartment from a wall of the fluid compartment, wherein the at least one light guide includes a proximal end adjoining the wall of the fluid compartment, and a distal end opposite the proximal end, and wherein the distal end includes a jagged portion, the jagged portion providing a plurality of angled surfaces and/or edges for scattering light rays so as to reduce light rays from propagating along the at least one light guide.

76. The humidification chamber of claim 75, wherein the at least one light guide includes a pair of opposed angled portions, the pair of angled portions being disposed opposite one another at the distal end of the at least one light guide, each angled portion including a downward-facing edge, and wherein the jagged portion includes one or more downward-facing edges, each one of the one or more downward-facing edges of the jagged portion being disposed at a different orientation to each downward-facing edge of a respective angled portion.

77. The humidification chamber of claim 76, wherein the jagged portion is disposed between the pair of angled portions.

78. The humidification chamber of claim 76 or 77, wherein each angled portion is at about 45° to a base of the fluid compartment.

79. The humidification chamber of any one of claims 75 to 78, wherein the at least one light guide extends downwardly into the fluid compartment from a top wall of the fluid compartment.

80. The humidification chamber of any one of claims 75 to 79, wherein the at least one light guide includes an input side for receiving an input beam of light from an external light source and propagating the input beam of light through the input side of the at least one light guide, and an output side for propagating an output beam of light through the output side of the light guide, the output beam of light being reflected from the input beam of light.

81. The humidification chamber of claim 80, wherein the output side of the light guide is parallel and adjacent to the input side of the at least one light guide.

82. The humidification chamber of claim 80 when appended to claim 76, wherein the pair of angled portions are configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

83. The humidification chamber of any one of claims 80 to 82, wherein the light intensity of the output beam of light is above a threshold when the light guide is solely in contact with gases.

84. The humidification chamber of claim 80 when appended to claim 76, wherein the pair of angled portions are configured such that the input beam of light is refracted when the at least one light guide is in contact with a liquid such that an output beam of light having light intensity below the threshold or no output beam of light is present for propagation through the output side of the at least one light guide.

85. The humidification chamber of claim 83 or 84, wherein the threshold is 40% of the light intensity of the input beam of light.

86. The humidification chamber of any one of claims 80 to 85, wherein the input beam of light and the output beam of light is infra-red light.

87. The humidification chamber of any one of claims 75 to 86, wherein the at least one light guide has a length of between about 10 mm and 50 mm.

88. The humidification chamber of any one of claims 75 to 87, wherein a distance between the distal end of the at least one light guide and a base of the fluid compartment is about 7mm.

89. The humidification chamber of any one of claims 75 to 88, wherein a thickness of the at least one light guide is about 2.5mm.

90. The humidification chamber of any one of claims 75 to 89, wherein the at least one light guide is positioned between an inlet portion and an outlet portion of the humidification chamber, the inlet portion for allowing an incoming flow of gases to enter the fluid compartment and the outlet portion for allowing an outgoing flow of gases to exit the fluid compartment.

91. The humidification chamber of claim 80, further including a first curved protrusion positioned above the at least one light guide, the first curved protrusion being substantially aligned with the input side of the at least one light guide.

92. The humidification chamber of claim 91 , wherein the first curved protrusion is configured to collimate the input beam of light for propagation through the input side of the at least one light guide.

93. The humidification chamber of claim 91 or 92, further including a second curved protrusion positioned above the at least one light guide, the second curved protrusion being substantially aligned with the output side of the at least one light guide.

94. The humidification chamber of claim 93, wherein the second curved protrusion is configured to collimate the output beam of light for detection by an optical sensor.

95. The humidification chamber of claim 80, wherein the at least one light guide includes one or more curved surfaces for redirecting light rays from the input beam of light into the at least one light guide.

96. The humidification chamber of claim 95, wherein each curved surface defines an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the at least one light guide.

97. The humidification chamber of claim 96, wherein the elongate protrusion is tapered along a lengthwise direction.

98. The humidification chamber of claim 75, wherein the at least one light guide includes a pair of curved surfaces, each curved surface being provided on an opposite face of the at least one light guide.

99. The humidification chamber of claim 80, wherein the at least one light guide includes two pairs of curved surfaces, one pair of curved surfaces being provided along the input side of the at least one light guide, and the other pair of curved surfaces being provided along the output side of the at least one light guide.

100. The humidification chamber of claim 98 or 99, wherein for each pair of curved surfaces each curved surface is provided on an opposite face of the at least one light guide.

101. The humidification chamber of any one of claims 98 to 100, wherein the curved surfaces for each pair of curved surfaces are aligned with one another.

102. The humidification chamber of any one of claims 75 to 101 , wherein the humidification chamber includes a first light guide for detecting a minimum level of the fluid in the fluid compartment, and a second light guide for detecting a maximum level of the fluid in the fluid compartment, wherein the first light guide is longer than the second light guide.

103. The humidification chamber of claim 102, wherein the first light guide and the second light guide are centred about a central axis of the fluid compartment.

104. A humidification chamber comprising: a fluid compartment for containing a fluid, and at least one light guide for detecting a level of the fluid in the fluid compartment, wherein the at least one light guide is located substantially at or adjacent a central axis of the fluid compartment.

105. The humidification chamber of claim 104, wherein the fluid compartment has a substantially circular base.

106. The humidification chamber of claim 104 or 105, wherein the central axis intersects with an axis of rotation of the fluid compartment.

107. The humidification chamber of any one of claims 104 to 106, wherein the light guide is located within a radius of about 10mm from an approximate centre of the fluid compartment through which the central axis passes.

108. The humidification chamber of any one of claims 104 to 107, wherein an internal diameter of the fluid compartment is about 100mm to 1 15mm.

109. The humidification chamber of claim 108, wherein the internal diameter of the fluid compartment is about 108mm.

1 10. The humidification chamber of any one of claims 104 to 109, wherein the at least one light guide extends downwardly into the fluid compartment from a top wall of the fluid compartment, wherein the at least one light guide includes a proximal end adjoining the top wall of the fluid compartment, and a distal end opposite the proximal end.

1 1 1. The humidification chamber of any one of claims 104 to 1 10, wherein the at least one light guide further includes: an input side for receiving an input beam of light from an external light source and propagating the input beam of light through the input side of the light guide, and an output side for propagating an output beam of light through the output side of the light guide, the output beam of light being reflected from the input beam of light.

1 12. The humidification chamber of claim 1 11 , wherein the at least one light guide includes at least one angled portion disposed at the distal end of the at least one light guide, the at least one angled portion being configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

1 13. The humidification chamber of claim 1 1 1 or 112, wherein the output side of the light guide is parallel and adjacent to the input side of the light guide.

1 14. The humidification chamber of claim 1 1 1 when appended to 1 10, wherein the at least one light guide includes a pair of opposed angled portions, the pair of angled portions being disposed opposite one another at the distal end of the at least one light guide.

1 15. The humidification chamber of claim 114, wherein each angled portion is at about 45° to a base of the fluid compartment.

1 16. The humidification chamber of claim 1 14 or 1 15, wherein the pair of angled portions are configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

1 17. The humidification chamber of any one of claims 1 1 1 to 1 16, wherein light intensity of the output beam of light is above a threshold when the light guide is solely in contact with gases.

1 18. The humidification chamber of claim 1 1 1 , wherein the input beam of light is refracted when the at least one light guide is in contact with a liquid such that an output beam of light having light intensity below the threshold or no output beam of light is present for propagation through the output side of the at least one light guide.

1 19. The humidification chamber of claim 117 or 118, wherein the threshold is 40% of light intensity of the input beam of light.

120. The humidification chamber of any one of claims 1 1 1 to 1 19, wherein the input beam of light and the output beam of light is infra-red light.

121. The humidification chamber of any one of claims 104 to 120, wherein the at least one light guide has a length of between about 10 mm and 50 mm.

122. The humidification chamber of claim 1 10, wherein a distance between the distal end of the at least one light guide and a base of the fluid compartment is about 7mm.

123. The humidification chamber of any one of claims 104 to 122, wherein a thickness of the at least one light guide is about 2.5mm.

124. The humidification chamber of any one of claims 104 to 123, wherein the at least one light guide is positioned between an inlet portion and an outlet portion of the humidification chamber, the inlet portion for allowing an incoming flow of gases to enter the fluid compartment via an outlet and the outlet portion for allowing an outgoing flow of gases to exit the fluid compartment via an outlet.

125. The humidification chamber of claim 1 1 1 , further including a first curved protrusion positioned above the at least one light guide, the first curved protrusion being substantially aligned with the input side of the at least one light guide.

126. The humidification chamber of claim 125, wherein the first curved protrusion is configured to collimate the input beam of light for propagation through the input side of the at least one light guide.

127. The humidification chamber of claim 125 or 126, further including a second curved protrusion positioned above the at least one light guide, the second curved protrusion being substantially aligned with the output side of the at least one light guide.

128. The humidification chamber of claim 127, wherein the second curved protrusion is configured to collimate the output beam of light for detection by an optical sensor.

129. The humidification chamber of any one of claims 104 to 128, wherein the at least one light guide includes one or more curved surfaces for redirecting light rays from the input beam of light into the at least one light guide.

130. The humidification chamber of claim 129, wherein each curved surface defines an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the at least one light guide.

131. The humidification chamber of claim 130, wherein the elongate protrusion is tapered along a lengthwise direction.

132. The humidification chamber of any one of claims 129 to 131 , wherein the at least one light guide includes a pair of curved surfaces, each curved surface being provided on an opposite face of the at least one light guide.

133. The humidification chamber of any one of claims 129 to 131 , wherein the at least one light guide includes two pairs of curved surfaces, one pair of curved surfaces being provided along the input side of the at least one light guide, and the other pair of curved surfaces being provided along the output side of the at least one light guide.

134. The humidification chamber of claim 133, wherein for each pair of curved surfaces each curved surface is provided on an opposite face of the at least one light guide.

135. The humidification chamber of claim 133 or 134, wherein the curved surfaces for each pair of curved surfaces are aligned with one another.

136. The humidification chamber of any one of claims 104 to 135, wherein the humidification chamber includes a first light guide for detecting a minimum level of fluid in the fluid compartment, and a second light guide for detecting a maximum level of fluid in the fluid compartment, wherein the first light guide is longer than the second light guide.

137. The humidification chamber of claim 136, wherein the first light guide and the second light guide are centred about a central axis of the fluid compartment.

138. The humidification chamber of claim 124, further including a fluid directing member proximate the outlet for directing gases towards the outlet.

139. The humidification chamber according to claim 124, wherein at least one of the inlet portion and outlet portion defines a sensor port for receiving a sensor unit therein, wherein the sensor unit is adapted to detect any one or more of a flow rate, temperature and pressure of a respective incoming flow of gases or outgoing flow of gases.

140. The humidification chamber of claim 139, further including a seal adapted to fit into the at least one sensor port for receiving the sensor unit therein, the seal being adapted to provide pneumatic sealing for the respective inlet or outlet portion such that gas flow within the inlet or outlet portion is isolated from ambient air.

141. The humidification chamber of claim 140, wherein the seal is made from resilient material.

142. The humidification chamber of claim 141 , wherein the seal is stretchable to engagingly receive the respective sensor unit therein.

143. A humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet to the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; at least one light guide for detecting a level of the fluid in the fluid compartment; and a deflector configured to direct the incoming flow of gases from the inlet portion towards the at least one light guide.

144. The humidification chamber of claim 143, wherein the deflector is located proximate the inlet.

145. The humidification chamber of claim 143 or 144, wherein the deflector is configured to direct a bulk flow of gases from the inlet towards the at least one light guide.

146. The humidification chamber according to any one of claims 143 to 145, wherein the deflector extends inwardly of the fluid compartment from an inner surface of the humidification chamber.

147. The humidification chamber of any one of claims 143 to 146, wherein an angle between the deflector and a wall of the fluid compartment for a given flow rate of the incoming flow of gases is based on at least a humidity of an outgoing flow of gasses exiting the fluid compartment via an outlet of the fluid compartment.

148. The humidification chamber of any one of claims 143 to 147, wherein the angle between the deflector and a top wall of the fluid compartment is between about 20° and 70°.

149. The humidification chamber of claim 148, wherein the deflector extends at an angle of about 30° with respect to the top wall of the fluid compartment.

150. The humidification chamber of any one of claims 143 to 149, wherein the deflector is sized to substantially correspond with a cross-sectional area of the inlet such that a bulk flow of gases is directed by the deflector towards the at least one light guide.

151. The humidification chamber of claim 150, wherein an area of the deflector is between about 50% to 150% of the cross-sectional area of the inlet.

152. The humidification chamber of any one of claims 143 to 151 , wherein the deflector has a thickness of about 1 ,4mm.

153. The humidification chamber of any one of claims 143 to 147, or 150 to 152, wherein the at least one light guide extends downwardly into the fluid compartment from a top wall of the fluid compartment, wherein the at least one light guide includes a proximal end adjoining the top wall of the fluid compartment, and a distal end opposite the proximal end.

154. The humidification chamber of any one of claims 143 to 153, wherein the at least one light guide includes: an input side for receiving an input beam of light from an external light source and propagating the input beam of light through the input side of the at least one light guide, and an output side for propagating an output beam of light through the output side of the at least one light guide, the output beam of light being reflected from the input beam of light.

155. The humidification chamber of claim 154, wherein the at least one light guide includes at least one angled portion disposed at the distal end of the at least one light guide, the at least one angled portion being configured to reflecting the output beam of light from the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

156. The humidification chamber of claim 154 or 155, wherein the output side of the at least one light guide is parallel and adjacent to the input side of the at least one light guide.

157. The humidification chamber of claim 154, wherein the at least one light guide includes a pair of opposed angled portions, the pair of opposed angled portion being disposed opposite one another at the distal end of the at least one light guide.

158. The humidification chamber of claim 157, wherein each angled portion is at about 45° to a base of the fluid compartment.

159. The humidification chamber of claim 157 or 158, wherein the pair of angled portions are configured to reflect the input beam of light from the input side of the at least one light guide to the output side of the at least one light guide so as to present the output beam of light at the output side of the at least one light guide when the at least one light guide is solely in contact with gases.

160. The humidification chamber of any one of claims 154 to 159, wherein the light intensity of the output beam of light is above a threshold when the light guide is solely in contact with gases.

161 . The humidification chamber of any one of claims 154 to 160, wherein the input beam of light is refracted when the at least one light guide is in contact with a liquid such that an output beam of light having light intensity below the threshold or no output beam of light is present for propagation through the output side of the at least one light guide.

162. The humidification chamber of claim 160 or 161 , wherein the threshold is 40% of the light intensity of the input beam of light.

163. The humidification chamber of any one of claims 154 to 162, wherein the input beam of light and the output beam of light is infra-red light.

164. The humidification chamber of any one of claims 143 to 163, wherein the at least one light guide has a length of between about 10 mm and 50 mm.

165. The humidification chamber of any one of claims 143 to 164, wherein a distance between the distal end of the at least one light guide and a base of the fluid compartment is about 7mm.

166. The humidification chamber of any one of claims 143 to 165, wherein a thickness of the at least one light guide is about 2.5mm.

167. The humidification chamber of any one of claims 143 to 166, the humidification chamber further including an outlet portion for allowing an outgoing flow of gases to exit the fluid compartment, wherein the at least one light guide is positioned between the inlet portion and the outlet portion of the humidification chamber.

168. The humidification chamber of any one of claims 154 to 163, further including a first curved protrusion positioned above the at least one light guide, the first curved protrusion being substantially aligned with the input side of the light guide.

169. The humidification chamber of claim 168, wherein the first curved protrusion is configured to collimate the input beam of light for propagation through the input side of the light guide.

170. The humidification chamber of claim 168 or 169, further including a second curved protrusion positioned above the at least one light guide, the second curved protrusion being substantially aligned with the output side of the light guide.

171. The humidification chamber of claim 170, wherein the second curved protrusion is configured to collimate the output beam of light for detection by an optical sensor.

172. The humidification chamber of any one of claims 143 to 171 , wherein the at least one light guide includes one or more curved surfaces for redirecting light rays from the input beam of light into the at least one light guide.

173. The humidification chamber of claim 172, wherein each curved surface defines an elongate protrusion having a lengthwise direction extending along a lengthwise direction of the at least one light guide.

174. The humidification chamber of claim 173, wherein the elongate protrusion is tapered along a lengthwise direction.

175. The humidification chamber of any one of claims 172 to 174, wherein the at least one light guide includes a pair of curved surfaces, each curved surface being provided on an opposite face of the at least one light guide.

176. The humidification chamber of claim 175, wherein the at least one light guide includes two pairs of curved surfaces, one pair of curved surfaces being provided along the input side of the at least one light guide, and the other pair of curved surfaces being provided along the output side of the at least one light guide.

177. The humidification chamber of claim 176, wherein for each pair of curved surfaces each curved surface is provided on an opposite face of the at least one light guide.

178. The humidification chamber of any one of claims 175 to 177, wherein the curved surfaces for each pair of curved surfaces are aligned with one another.

179. The humidification chamber of any one of claims 143 to 178, wherein the humidification chamber includes: a first light guide for detecting a minimum level of fluid in the fluid compartment, and a second light guide for detecting a maximum level of fluid in the fluid compartment, wherein the first light guide is longer than the second light guide.

180. The humidification chamber of claim 179, wherein the deflector is configured to direct a bulk flow of gases from the inlet portion towards the first light guide and/or the second light guide.

181. A kit including a humidification chamber according to any one of the preceding claims, and any one or more of a nasal cannula, an incoming gas flow conduit for connection to the inlet portion of the humidification chamber, and an outgoing gas flow conduit for connection to the outlet portion of the humidification chamber.

182. The kit of claim 181 , further including a filter.

183. The kit of claim 181 , wherein the nasal cannula includes a filter.

184. The kit of claim 181 , wherein the filter is integral with the nasal cannula.

185. A humidifier including a humidification chamber according to any one of claims 1 to 180.

186. The humidifier of claim 185, further including a humidification unit configured for coupling with the humidification chamber, the humidification unit including a heater base for transferring heat to the fluid compartment of the humidification unit.

187. A respiratory system including a humidification chamber according to any one of claims 1 to 180.

188. The respiratory system of claim 187, further including a flow source for providing the incoming flow of gases to the humidification chamber.

189. The respiratory system of claim 188, wherein the flow source provides the incoming flow of gases at a predetermined flow rate.

190. The respiratory system of claim 189, wherein the predetermined flow rate is between about 10 L/min to 70 L/min.

191. The respiratory system of claim 190, wherein the predetermined flow rate is about 70 L/min.

192. The respiratory system of claim 189, wherein the predetermined flow rate is a high flow rate.

193. The respiratory system of claims 187 to 192, further comprising a patient interface.

194. The respiratory system of claim 193, wherein the patient interface is nonsealing.

195. The respiratory system of claim 193, wherein the patient interface is a nasal cannula.

196. A humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet of the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; an outlet portion defining an outlet of the fluid compartment for allowing an outgoing flow of gases to exit the fluid compartment; and a channel extending between the inlet and outlet, the channel being configured to provide a passage for a flow of gases from the inlet towards the outlet.

197. The humidification chamber of claim 196, wherein the channel connects the inlet and outlet.

198. The humidification chamber of claim 196 or 197, wherein the channel is located above the fluid compartment.

199. The humidification chamber of any one of claims 196 to 198, wherein the channel increases a total internal volume of the humidification chamber and reduces a residence time of the flow of gases through the humidification chamber so as to facilitate movement of the flow of gases from the inlet towards the outlet.

200. The humidification chamber of any one of claims 196 to 199, wherein the channel is curved.

201. The humidification chamber of any one of claims 196 to 200, wherein the channel follows a peripheral wall of the fluid compartment.

202. The humidification chamber of any one of claims 196 to 200, including a base, a top portion, and a peripheral wall extending between the base and the top portion, wherein the channel extends outwardly from the top portion.

203. The humidification chamber of claim 202, wherein the channel follows a contour of the peripheral wall.

204. The humidification chamber of claim 202 or 203, wherein at least a portion of a side wall of the channel is flush with, and forms part of, the peripheral wall of the humidification chamber.

205. The humidification chamber of any one of claims 196 to 201 , further including a deflector configured to direct the incoming flow of gases from the inlet portion towards the channel.

206. The humidification chamber of claim 205, wherein the deflector is located proximate the inlet portion.

207. The humidification chamber of claim 205 or 206, wherein the deflector is configured to direct a bulk flow of gases from the inlet towards the channel.

208. The humidification chamber of any one of claims 205 to 207, wherein the deflector is substantially in the form of a scoop.

209. The humidification chamber of any one of claims 205 to 208, wherein the fluid compartment includes a base, and a peripheral side wall extending around a perimeter of the base, the peripheral side wall including an inlet adjacent wall portion, the inlet adjacent wall portion being a portion of the peripheral side wall having a minimum spatial separation from the inlet, wherein the deflector is configured to direct a bulk flow of gases from the inlet away from the inlet adjacent wall portion.

210. The humidification chamber of claim 209, the peripheral side wall further including a front wall portion, the front wall portion being a forward -facing portion of the peripheral side wall when the humidification chamber is in use, wherein the deflector is configured to direct a bulk flow of gases from the inlet towards the front wall portion.

21 1 . The humidification chamber of claim 210, wherein the deflector is configured to direct a bulk flow of gases from the inlet in a direction generally parallel to a tangential plane of the inlet adjacent wall portion towards the front wall portion.

212. The humidification chamber of any one of claims 209 to 211 , wherein the inlet is spaced from the inlet adjacent wall portion.

213. The humidification chamber of any one of claims 209 to 212, wherein the channel provides a low resistance gas flow pathway between the inlet and the outlet, the deflector being configured to direct a bulk flow of gases from the inlet to the outlet across at least a portion of the channel.

214. The humidification chamber of any one of claims 209 to 213, wherein the channel is spaced from the inlet adjacent wall portion.

215. The humidification chamber of any one of claims 196 to 214, wherein the channel is generally C-shaped or U-shaped.

216. The humidification chamber of any one of claims 196 to 215, further including a fluid directing member proximate the outlet for directing gases towards the outlet.

217. The humidification chamber of any one of claims 196 to 216, wherein either one or both the inlet portion and the outlet portion extend substantially horizontally from the fluid compartment.

218. The humidification chamber of any one of claims 196 to 216, wherein either one or both the inlet portion and the outlet portion extend substantially vertically from the fluid compartment.

219. The humidification chamber of any one of claims 196 to 218, wherein either one or both the inlet portion and the outlet portion extend from an upper portion of the fluid compartment.

220. The humidification chamber of any one of claims 196 to 219, wherein the inlet and outlet are disposed adjacent opposite ends of a top portion of the fluid compartment.

221. The humidification chamber of any one of claims 196 to 216, wherein the inlet portion is configured to extend at an angle with respect to fluid compartment so as to direct a bulk flow of gases into the channel.

222. The humidification chamber of any one of claims 196 to 221 , wherein an internal volume of the channel is smaller than an internal volume of the fluid compartment.

223. The humidification chamber according to any one of claims 196 to 222, wherein at least one of the inlet portion and outlet portion defines a sensor port for receiving a sensor unit therein, wherein the sensor unit is adapted to detect any one or more of a flow rate, temperature and pressure of a respective incoming flow of gases or outgoing flow of gases.

224. The humidification chamber of claim 223, further including a seal adapted to fit into the at least one sensor port for receiving the sensor unit therein, the seal being adapted to provide pneumatic sealing for the respective inlet or outlet portion such that gas flow within the inlet or outlet portion is isolated from ambient air.

225. The humidification chamber of claim 224, wherein the seal is made from resilient material.

226. The humidification chamber of claim 225, wherein the seal is stretchable to engagingly receive the respective sensor unit therein.

227. The humidification chamber of any one of claims 196 to 226, wherein the fluid compartment includes a base, a top wall portion, and a peripheral wall portion extending between the base and the top portion, wherein an internal volume of the channel is smaller than an internal volume of the fluid compartment as defined by the base, top wall portion and peripheral wall portion of the fluid compartment.

228. The humidification chamber of any one of claims 196 to 227, wherein the humidification chamber has a functional liquid capacity of about 400ml.

229. The humidification chamber of any one of claims 196 to 227, wherein the humidification chamber has a functional fluid capacity of about 250 to 350ml.

230. The humidification chamber of any one of claims 196 to 229, wherein the channel and the fluid compartment form a single continuous internal volume so as to allow a seamless flow of gases between the channel and the fluid compartment.

231. The humidification chamber of any one of claims 196 to 230, wherein the channel is continuous and provides a substantially uninterrupted passage for the flow of gases from the inlet towards the outlet.

232. The humidification chamber of any one of claims 196 to 231 , wherein the fluid compartment has a substantially circular base.

233. The humidification chamber of any one of claims 196 to 232, further including one or more guides to provide alignment between the humidification chamber and a sensor module.

234. The humidification chamber of claim 233, wherein the one or more guides includes a pair of parallel ribs extending from a top portion of the fluid compartment.

235. The humidification chamber of any one of the preceding claims, wherein the humidification chamber excludes floating mechanisms for enabling measurement of a fluid level within the fluid compartment.

236. The humidification chamber of any one of the preceding claims, wherein the humidification chamber is configured to operate without a connected external water source.

237. A humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet of the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; an outlet portion defining an outlet of the fluid compartment for allowing an outgoing flow of gases to exit the fluid compartment; a channel extending between the inlet and outlet, the channel being configured to provide a passage for a flow of gases from the inlet towards the outlet, and a deflector configured to direct the incoming flow of gases from the inlet portion towards the channel.

238. The humidification chamber of claim 237, wherein the deflector is located proximate the inlet portion.

239. The humidification chamber of claim 237 or 238, wherein the deflector is configured to direct a bulk flow of gases from the inlet towards the channel.

240. The humidification chamber of any one of claims 237 to 239, wherein the deflector is substantially in the form of a scoop.

241 . The humidification chamber of claim 240, wherein the deflector includes a lower portion and a back portion partially extending around the periphery of the lower portion.

242. The humidification chamber of claim 241 , wherein the lower portion of the deflector is substantially flat.

243. The humidification chamber of claim 241 or 242, wherein the deflector defines an open side opposite the back portion, and wherein the open side of the deflector faces the channel so as to direct the incoming flow of gases from the inlet portion into the channel.

244. The humidification chamber of any one of claims 237 to 243, wherein the channel and the fluid compartment form a single continuous internal volume so as to allow a seamless flow of gases between the channel and the fluid compartment.

245. The humidification chamber of any one of claims 237 to 244, wherein the channel is continuous and provides a substantially uninterrupted passage for the flow of gases from the inlet towards the outlet.

246. A respiratory system including a flow source for providing a flow of gases at a predetermined flow rate, and a humidifier for providing a humidified flow of gases by adding humidity to the flow of gases from the flow source, the humidifier including a heater base, and a humidification chamber in accordance with any one of claims 196 to 245.

247. The respiratory system of claim 246, further including a patient interface for providing the humidified flow of gases to a patient.

248. The respiratory system of claim 247, wherein the patient interface includes a nasal cannula.

249. The respiratory system of claim 247, wherein the patient interface is a sealing patient interface.

250. The respiratory system of claim 247, wherein the patient interface is a nonsealing patient interface.

251. The respiratory system according to any one of claims 246 to 250, further including a non-humidified gas conduit for coupling the flow source to the humidifier and providing a passage for the flow of gases from the flow source to the humidifier.

252. The respiratory system according to any one of claims 246 to 250, further including a humidified gas conduit for coupling the humidifier to the patient interface and providing a passage for the humidified flow of gases from the humidifier to the patient interface.

253. The respiratory system of any one of claims 246 to 252, wherein the humidified flow of gases has an absolute humidity of about 10mg/L to 45 mg/L.

254. The respiratory system of any one of claims 246 to 253, wherein the predetermined flow rate of the flow of gases provided by the flow source is about 10L/min to 70L/min.

255. The respiratory system of any one of claims 246 to 254, wherein when the flow of gases provided by the flow source has a flow rate of about 70L/min, the humidified flow of gases has a humidity of about 20mg/L to 35 mg/L.

256. The respiratory system of any one of claims 246 to 254, wherein when the flow of gases provided by the flow source has a flow rate of about 70L/min, the humidified flow of gases has a humidity of about 30 mg/L.

257. A humidification chamber comprising: a fluid compartment for containing a fluid; an inlet portion defining an inlet of the fluid compartment for allowing an incoming flow of gases to enter the fluid compartment; an outlet portion defining an outlet of the fluid compartment for allowing an outgoing flow of gases to exit the fluid compartment; and a channel extending between the inlet and outlet, the channel being continuous so as to provide a substantially uninterrupted passage for the flow of gases from the inlet to the outlet.

258. The humidification chamber of claim 257, wherein the channel connects the inlet and outlet.

259. The humidification chamber of claim 257 or 258, wherein the channel and the fluid compartment form a single continuous internal volume so as to allow a seamless flow of gases between the channel and the fluid compartment.