Patent ID: 12201780

4.2 Therapy

4.2.1 Respiratory system

FIG.2ashows an overview of a human respiratory system including the nasal and oral cavities, the larynx, vocal folds, oesophagus, trachea, bronchus, lung, alveolar sacs, heart and diaphragm.

FIG.2bshows a view of a human upper airway including the nasal cavity, nasal bone, lateral nasal cartilage, greater alar cartilage, nostril, lip superior, lip inferior, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

4.3 Patient Interface

FIG.3ashows a patient interface in accordance with one form of the present technology.

4.4 PAP Device

FIG.4ashows a PAP device in accordance with one form of the present technology.

FIG.4bshows a schematic diagram of the pneumatic components of a PAP device in accordance with one form of the present technology. The directions of upstream and downstream are indicated.

It should be understood that a number of components, such as supplementary O24180, anti-spill back valve4160, or the transducer(s)4270are optional. Also, in an alternative arrangement the humidifier5000may be placed in alternative locations for example, upstream of the pneumatic block4020.

4.5 Humidifier

FIG.5ashows a simplified representation of a humidifier connected to a blower and a patient conduit

FIG.5bshows a schematic of a humidifier.

4.6 Breathing Waveforms

FIG.6ashows a model typical breath waveform of a person while sleeping, the horizontal axis is time, and the vertical axis is flow. While the parameter values may vary, a typical breath may have the following approximate values: tidal volume, Vt, 0.5 L, inhalation time, Ti, 1.6 s, peak inspiratory flow, Qpeak, 0.4 L/s, exhalation time, Te, 2.4 s, peak expiratory flow, Qpeak, −0.5 L/s. The total duration of the breath, Ttot, is about 4 s. The person typically breathes at a rate of about 15 breaths per minute (BPM), with Ventilation, Vent, about 7.5 L/s. A typical duty cycle, the ratio of Ti to Ttot is about 40%.

4.7 PAP Device with a Humidifier

FIG.7shows a prior art example of a PAP device4000and a humidifier5000.

FIG.8shows an example of the present technology, showing a PAP device4000and an integrated humidifier5000.

FIGS.9-12show various views of a humidifier reservoir5110in accordance with one aspect of present technology, whereinFIG.9-10show the humidifier reservoir5110in a ‘closed’ configuration,FIG.11shows the humidifier reservoir5110in an ‘open’ configuration, andFIG.12is an exploded view of the humidifier reservoir5110.

FIGS.13-16show the humidifier5000from various perspectives, in particular demonstrating the engagement of the humidifier reservoir5110with the reservoir dock5130.

FIGS.17-19show a time-lapse chart of an exemplary flow path of gas as it enters the humidifier reservoir5110through the inlet5118and exits through the outlet5122after traversing through the inside of the humidifier reservoir5110.

FIGS.20-21show exemplary distributions of pressure/force in the humidifier reservoir5110in various configurations.

FIGS.22-29show varying configurations of the reservoir lid5114, in particular variations in configurations of the inlet tube5124and the outlet tube5126according to aspects of the present technology.

FIGS.30aand30bshow the humidifier reservoir5110and in particular they aim to show the orifice5138according to an example of the present technology.

FIGS.30cand30dshow the humidifier base5112and in particular the sloped profile5139according to an example of the present technology.

FIG.31shows the humidifier reservoir5110and in particular the orifice5138according to an example of the present technology.

FIGS.32-33show the humidifier dock5130and the humidifier reservoir5110, and in particular show the interaction between the lid protrusion5142and the dock locking recess5144according to one aspect of the present technology.

FIG.34show an example of the humidifier reservoir5110according to another example of the current technology, wherein it is configured with a re-filling cap5180and a base, top and variable portion may be affixed together.

FIGS.35-38shows other representations of a humidifier reservoir5110according to an aspect of the present technology, with particular regard to the arrangement of the inlet tube5124and the outlet tube5126.

FIG.39shows a cross-sectional view of a reservoir lid5114and a variable portion in the form of a seal5116according to an aspect of the present technology.

FIG.40shows an example of the humidifier reservoir5110according to another example of the present technology, wherein it is configured with a latch5186.

5 DETAILED DESCRIPTION OF THE INVENTION

Before the present technology is described in further detail, it is to be understood that the technology is not limited to the particular examples described herein, which may vary. It is also to be understood that the terminology used in this disclosure is for the purpose of describing only the particular examples discussed herein, and is not intended to be limiting.

5.1 Treatment Systems

In one form, the present technology comprises apparatus for treating a respiratory disorder. Preferably the apparatus comprises a flow generator or blower for supplying pressurised respiratory gas, such as air, to the patient1000via an air delivery tube leading to a patient interface3000.

5.2 Therapy

In one form, the present technology comprises a method for treating a respiratory disorder comprising the step of applying positive pressure to the entrance of the airways of a patient1000.

5.2.1 Nasal CPAP for OSA

In one form, the present technology comprises a method of treating Obstructive Sleep Apnea in a patient by applying nasal continuous positive airway pressure to the patient.

5.3 Patient Interface3000

A non-invasive patient interface3000in accordance with one aspect of the present technology comprises the following functional aspects a seal-forming structure3100, a plenum chamber3200, a positioning and stabilising structure3300and a connection port3600for connection to an air circuit4170. In some forms a functional aspect may be provided by one or more physical components. In some forms, one physical component may provide one or more functional aspects. In use the seal-forming structure3100is arranged to surround an entrance to the airways of the patient so as to facilitate the supply of air at positive pressure to the airways.

5.4 PAP Device4000

A preferred PAP device4000in accordance with one aspect of the present technology comprises mechanical and pneumatic components4100, electrical components4200and is programmed to execute one or more algorithms4300.FIG.7shows a prior art embodiment of a PAP device4000, which is connectable to a humidifier5000. The PAP device may also be integrated with a humidifier5000so that an external housing4010encases the components that perform the equivalent function of a PAP device4000as well as components that perform the equivalent function of a humidifier5000.

FIG.8shows an example embodiment of such an integrated device comprising a PAP device4000and a humidifier5000. It should be understood that subsequent references to a humidifier5000refers to the integrated device, in particular the components that perform the equivalent function of a humidifier5000.

5.5 Humidifier5000

5.5.1 Humidifier Overview

In one form of the present technology there is provided a humidifier5000comprising a water reservoir5110, a heater plate5120and a water reservoir dock5130.

5.5.2 Humidifier Mechanical Components5100

5.5.2.1 Water Reservoir Dock5130

A water reservoir dock5130may be integrated with the humidifier5000as shown inFIG.13-16. In this arrangement, the reservoir dock5130comprises a breathable gas outlet5168to output a flow of breathable gases to a water reservoir5110, a humidified breathable gas inlet5170to receive the flow of breathable gases that has been humidified in the water reservoir5110, and an air delivery conduit outlet5172to transfer the flow of humidified breathable gases to the air delivery conduit4170. As shown inFIG.14, the water reservoir dock5130may form a cavity5160to receive the water reservoir5110. The cavity5160may include a top portion configured to cover at least a portion of the lid of the reservoir5110and a bottom portion including the heater plate5120(FIG.14). As seen inFIGS.14and16(andFIG.33), the dock cavity5160includes rails5161that are spaced upwardly from the bottom portion. Also, the water reservoir base5112includes shoulders5113with at least one lug5115(as shown, e.g.,, inFIGS.14,30c,30d,33and40).

It should be understood that the reservoir dock5130may be provided separately to a humidifier5000in an alternate arrangement. In such an arrangement, additional interfaces may be used to connect the reservoir dock5130to the humidifier5000.

In another arrangement, a water reservoir dock5130may comprise an opening in a substantially horizontal plane, so that the water reservoir5110may be inserted from above or below the water reservoir dock5130.

5.5.2.2 Water Reservoir5110

FIG.9-12show an example of a water reservoir5110according to the technology, which comprises a reservoir base5112, a reservoir lid5114, and a variable portion5116. As shown in this example arrangement the variable portion5116may also function as a seal between the base5112and the reservoir lid5114. The reservoir forms a cavity formed by a plurality of walls to hold a volume of liquid or water. The cavity of the reservoir5110is configured so that it is able to hold a given, maximum volume of liquid or water, typically several hundred millilitres, for example 300 millilitres (ml), 325 ml, 350 ml or 400 ml, although it is to be understood that other volumes of liquid may be utilised such as 100 ml, 200 ml, 250 ml, 500 ml or more or less.

The lid5114may comprise an inlet5118and an outlet5122. The inlet5118comprises an inlet tube5124and the outlet5122comprises an outlet tube5126. The lid5114may be pivotably connected to the base5112by hinges5158in such a way that it is able to be moved between an open position, as shown inFIG.11, and a closed position, as shown inFIG.9andFIG.10. Reservoir base5112may include a pair of upright supports5159that support a rear edge of an arm of the hinge158, as seen, e.g., inFIGS.10-12. When the water reservoir5110is in its closed configuration, the variable portion5116is put into sealing engagement between the base5112and the lid5114.

The variable portion5116may be provided as part of the reservoir lid5114or as part of the reservoir base5112, or independently of both. The variable portion5116may be engaged with the reservoir lid5114or the reservoir base5112by any number of means including, and not limited to, ultrasonic welding, friction fitting, gluing or by using an intermediate component. The variable portion5116may comprise a carrier5117(as shown inFIG.12).

In an arrangement, the variable portion5116may not be directly engaged with the base5112or lid5114but coupled to one or both of the lid5114and the base5112such that each of the base5112and the lid5114may be formed as two separate parts that are able to be assembled with the variable portion5116coupled therebetween. Alternatively the variable portion5116may be coupled to either the lid5114or the base5112.

In an alternative arrangement the variable portion5116may be located within a wall of the reservoir base5112and/or a wall of the reservoir lid5114rather than being on the edge of either the reservoir base5112or the reservoir lid5114. Thus, in such an arrangement the variable portion would not be between the reservoir base5112and the reservoir lid5114but within the reservoir base5112and/or the reservoir lid5114. There may be more than one variable portion5116to provide more compliance in movement of the reservoir5110.

The reservoir base5112comprises a conducting portion that is configured to couple with a heater plate5120of the humidifier to allow thermal engagement and thermal transfer of heat to the liquid or water within the base. The base may comprise a base upper body5146, a base bottom plate5148, and a conducting portion in the form of a base conductor plate5152, as shown inFIG.12. All or a part of the base conductor plate5152may be made of a different material (e.g. aluminium or another heat conducting metal) than the base upper body5146and/or the base bottom plate5148, which may be made of a plastic or thermoplastic polymer, for example, a polycarbonate material. The base conductor plate5152may comprise of a sealing element5150, which may be integrated to, and/or sealingly connected to both the base upper body5146and the base bottom plate5148to prevent egress of water from the water reservoir5110through its bottom.

It should be appreciated that the reservoir base5112may be constructed in any number of parts. The reservoir base5112may be constructed as a single part made of, for example, aluminium or another heat conducting metal. In another arrangement, the reservoir base5112may be constructed in multiple parts such as two parts comprising a lower component and an upper component. The lower component may include: a reservoir base conductor plate5152, sealing element5150and base bottom plate5148. The base bottom plate is constructed at least in part from a heat conducting material, for example, aluminium or another heat conducting metal. The upper component may include a base upper body5146constructed from, for example, a polycarbonate material. The upper and lower components may be sub-divided to form further arrangements consisting of greater number of parts, for example the sealing element5150may be a separate component.

Water Reservoir-to-Humidifier Connection

When in use, the water reservoir5110is removably coupled with the humidifier5000as shown inFIG.13-16by inserting the water reservoir into the water reservoir dock5130, for example by sliding, so that the inlet5118of the water reservoir5110is configured to receive the flow of breathable air that is output by the PAP device4000, and to direct the flow of breathable air into the water reservoir5110. Moisture is added to the flow of breathable air as the breathable air travels through the reservoir5110, and the humidified flow of breathable air exits the reservoir5110through the outlet tube5126and to the reservoir outlet5122. The reservoir outlet5122is connectable to an air delivery circuit or air delivery conduit4170to deliver the flow of humidified breathable air to the patient1000.

The double-ended arrows inFIG.14andFIG.16show the direction of relative motion, i.e. generally horizontal movement, between the humidifier5000and the water reservoir5110in connecting and disconnection with each other in this arrangement. However, it is noted that the water reservoir5110may be coupled to the humidifier5000by other means such as being inserted into the humidifier in a generally vertical direction. In the illustrated arrangement the reservoir outlet5122is connected to the reservoir dock outlet5168, through which the humidified flow of breathable air travels to the humidifier outlet5172. The humidifier outlet5172is connectable to the air delivery circuit or air delivery conduit4170as indicated inFIG.13by the double-ended arrow. One feature of such an arrangement is that the humidifier reservoir5110must be removed from the reservoir dock5130to fill the humidifier reservoir5110with water. This arrangement may reduce the likelihood of the user over-filling the water reservoir5110over the given, maximum volume of liquid or water, as the humidifier reservoir5110incorporates means to prevent over-filling when the lid5114is in its open position as described further below.

As shown inFIG.16, first and second dock seals5132,5134may be provided to seal the connection between the reservoir inlet5118and the dock5130and the connection between the reservoir outlet5122and the dock5130.

Reservoir Handles

FIG.13-16show an upper handle5154that is located on the reservoir lid5114, and a lower handle5156that is located on the reservoir base5112. These handles are intended to assist the patient1000to grip and hold the water reservoir5110. In the shown arrangement, the handles51545156are located away from the hinges5158such that by holding the reservoir5110by the handles51545156the patient1000imparts forces onto the reservoir5110compressing the variable portion5116, which pushes the lid5114and the base5112towards each other. This compression force may also help maintain the variable portion5116in sealing engagement between the reservoir base5112and the reservoir lid5114. It is to be understood that the handles5154and5156may be placed on other components or areas of the water reservoir5110. A friction grip5166may be provided on a surface of either or both of the handles51545156as shown inFIG.14. The friction grip5166may be constructed from a higher friction material than the primary material used to construct the water reservoir5110. For example, the friction grip5166may be constructed from an elastomeric material such as silicone whereas the water reservoir5110may primarily be constructed from a polycarbonate material.

Reservoir Variable Portion

In the illustrated arrangement, when the water reservoir5110is in use, the variable portion5116is maintained in sealing engagement between the reservoir base5112and the reservoir lid5114. However, as mentioned above the variable portion5116may alternatively be formed as part of the reservoir base5112and/or the reservoir lid5114and not form a seal between the reservoir base5112and the reservoir lid5114. The variable portion5116may be constructed from an elastomeric material such as silicone, TPE, TPE polyester, TPE polyurethane or natural rubber. In choosing the material to be used for the variable portion5116it may be advantageous to choose one that does not experience mechanical relaxation across the range of storage and operational temperatures that the variable portion5116may be exposed to. One example of a material for the variable portion5116which meets these requirements may be silicone.

In the arrangement shown inFIG.15-16, the water reservoir5110is connected with the humidifier5000by placing the water reservoir5110in the water reservoir dock5130. In this arrangement, the heights and shapes of the dock internal cavity5160and the water reservoir5110are such that when the water reservoir5110is engaged with the water reservoir dock5130the variable portion5116is compressed, for example by between about 1 mm and about 5 mm, for example by about 2 mm, about 3 mm or about 4 mm. Thus, the shape of the portion of the water reservoir5110that is inserted into the dock5130is complementary to the shape of the dock cavity5160and the height of the water reservoir5110when variable portion5116is compressed is slightly less than the height of the dock cavity5160to enable the insertion of the water reservoir5110into the dock cavity5160. The variable portion5116may be constructed with a cross-section shape such as one shown inFIG.39. A compressive force is required to sufficiently compress the variable portion to allow relative movement, such as sliding between the water reservoir5110and the water reservoir dock5130. For example a compression force as measured at the handle recesses5154,5156of between about 10 N and about 30 N, or about 20 N, or some other compression force as required to allow insertion of the water reservoir5110into the dock cavity5160. The vertical gap achieved between the water reservoir5110and the dock internal cavity5160may be between about 1 mm and about 5 mm, for example about 2 mm, 3 mm or 4 mm, when the compressive force is applied at the handle recesses and the water reservoir5110is connected with the reservoir dock5130. The water reservoir5110and the reservoir dock5130may be arranged so that the amount of compression in the variable portion5116is reduced once the water reservoir5110is connected with the reservoir dock5130and the patient1000is no longer applying a compressive force. The reduction in compression may be between about 0.5 mm and about 2.5 mm, for example about 1 mm, 1.5 mm or 2 mm.

A reservoir latch5186may be provided on the water reservoir5110, as shown inFIG.39, so that when the reservoir latch5186is engaged, it secures the reservoir lid5114and reservoir base5112together to prevent the reservoir lid5114and the reservoir base5112from separating and maintains the variable portion5116in a compressed state. The latch may also maintain the variable portion5116in sealing engagement between the lid5114and the base5112when the variable portion5116is located between the lid5114and the base5112. The latch5186may be configured to allow further compression of the variable portion5116. This would allow insertion of the water reservoir5110into the reservoir dock5130in the manner described above, and for the variable portion5116to retain its advantageous properties regarding improvements to thermal engagement as described below.

In an alternative arrangement, not shown, the water reservoir5110, may be inserted into the dock cavity5160from a vertical direction rather than using a sliding motion. In such an arrangement the dock cavity of the humidifier5000may comprise a moveable cover portion, such as a lid or top portion, that is at least partially opened to allow insertion of the water reservoir5110and closed following insertion to secure the water reservoir5110within the dock cavity5160.

Air Flow Path

FIG.17-19show an exemplary path of the flow of breathable air through the reservoir5110as it enters through the inlet5118and exits through the outlet5122. The figures are arranged chronologically in three distinct orthogonal views per figure to demonstrate the exemplary flow path visually. In this arrangement the flow of breathable air received through the inlet5118passes through the inlet tube5124(FIG.17), into the internal volume of the water reservoir5110(FIG.18), and then passes through the outlet tube5126to exit the water reservoir5110at the outlet5122(FIG.19) as humidified breathable air.FIG.17-19show the reservoir5110with the lid5114and the base5112in exploded view orientation for clarity, and any flow of the air that occurs in the internal volume of the reservoir5110is shown in dotted lines, and the direction of the arrows shown indicate the general direction of the exemplary flow of breathable air. Although it is noted that the nature of gas or air flow may involve the swirling of air rather than a straight and direct air flow path.

The path of the flow of breathable air demonstrated inFIG.17-19is exemplary only, and is aimed to demonstrate one of many paths that the flow of breathable air may traverse through, namely that it enters the water reservoir5110through the inlet5118and exits through the outlet5122after experiencing some degree of swirling within the volume of the water reservoir5110. A person skilled in the art would understand that the particles or molecules that form the flow of breathable air may not follow a single path within the water reservoir5110due to a number of factors, including, for example, localised turbulence (eddies) or pressure gradients within the water reservoir5110. As a result the cumulative path of the flow of breathable air may comprise any number of paths wherein it experiences various degrees of ‘swirling’ within the water reservoir5110prior to exiting via the outlet tube5126at the outlet5122. It is also possible that some small portion of the flow of breathable air may escape the water reservoir5110as a leak.

Thermal Contact/Engagement

One aspect of this technology is improved thermal contact or engagement between the base5112of the water reservoir and the heater plate5120of the humidifier. The improved thermal contact or engagement may be facilitated by the supply of pressurized gas to the humidifier reservoir5110from a PAP device.

In one arrangement, the water reservoir5110may be configured so that when it is placed in the water reservoir dock5130the reaction to the compression of the variable portion5116, i.e. a force attempting to expand the variable portion5116, pushes the base5112of the water reservoir5110against the heater plate5120to improve the level of thermal engagement between the heater plate5120and the base5112. This occurs as a result of the variable portion5116initially being compressed when it is inserted into the reservoir dock5130as described above, and then the compression is released or reduced allowing the variable portion5116to expand towards its relaxed or uncompressed state. Thus, the variable portion5116is acting like a spring that may be biased to push the reservoir base5112and/or the reservoir lid5114in a direction perpendicular to the heater plate5120until the variable portion5116is in a reduced compressed state. As the reservoir5110is confined within the reservoir dock5130or by some other means the level of compression of the variable portion5116is transferred as a force that encourages improved thermal engagement with the heater plate5020.FIG.20illustrates this effect by indicating the distributed forces or pressures that are applied to the lid5114, variable portion5116and the base5112by the arrows shown.

The force required for compression of the variable portion5116when the water reservoir5110is connected with the humidifier5000is primarily in the direction tangential to the pivoted opening direction of the water reservoir5110, which may be the same direction as the normal to a surface of the conductive portion, and is reacted by the water reservoir dock5130at its contacting points and/or surfaces, thereby pushing the base5112of the water reservoir5110and the heater plate5120together. As a corollary, a decrease of the compression resulting in an increase in height of the variable portion5116will reduce the force between the base5112and the heater plate5120. In other words, varying the height of the variable portion in the reservoir varies a level of thermal engagement between the conductive portion and the heater plate.

The water reservoir5110may be configured so that the direction of thermal engagement with the heater plate5120is in the same direction as the normal direction of a surface of the conductive portion.

The magnitude of this force may be between about 5 N and about 15 N when measured at the heater plate5120when the water reservoir5110is placed in the water reservoir dock5130. However, it should be understood that different configurations of the water reservoir5110may require different magnitudes of compression force. The magnitude of this force may be altered by modifying the design of any or all of the seal5116, the lid5114, the base5112, or the reservoir dock5130. For instance if the variable portion5116was constructed of a material with higher Young's modulus, it would correspondingly increase the magnitude of the force. It should be noted thatFIG.20only shows forces and pressures in the vertical direction.

Furthermore, when the water reservoir5110is connected with the humidifier5000, the pressurized flow of breathable air received from the PAP device pressurizes the interior of the reservoir5110and may further encourage an expansion of the variable portion5116that pushes the base5112of the water reservoir5110against the heater plate5120to improve the level of thermal engagement, or the level of thermal contact, between the heater plate5120and the base5112.FIG.21illustrates this effect by indicating the distributed forces or pressures that are applied to the lid5114and the base5112by the arrows shown. The presence of above-atmospheric pressure within the water reservoir5110is shown to result in forces in the direction of thermal engagement, and is reacted by the water reservoir dock5130at its contacting surfaces, thereby pushing the base5112of the water reservoir5110and the heater plate5120towards each other in the direction of thermal engagement. The magnitude of this force may be between about 5 N and about 15 N when measured at the heater plate5120at 20 cm H2O of pressure. However, it should be understood that different configurations of the water reservoir5110may require different magnitudes of force, which may be achieved by varying the surface area that the pressure acts on, or the effective pressure that acts on the surface. Such changes may be achieved, for example, by a pressure regulating valve. It should be noted thatFIG.21only shows forces and pressures in the vertical direction, as the thermal engagement occurs in the vertical direction. Thus, the variable portion in the reservoir5110enables movement of the reservoir base5112and/or the reservoir lid5114in response to an increase in pressure above atmospheric pressure in the reservoir5110to improve thermal engagement of the reservoir base5112with the heater plate5020. It is envisaged that, in another arrangement, substantially the same effects as those described above may be achieved with a non-opening variable portion of a water reservoir5110. The water reservoir5110and the reservoir dock5130may be substantially arranged so that elasticity or flexibility is provided by an elastomeric material or a joint that allows freedom of movement (e.g. a sliding connection, or a concertina section of pliable plastic or a flexible portion in the water reservoir) in the direction of the heat transfer. In this configuration the lid5114and the base5112may be unconstrained relative to each other in the direction of thermal contact The reservoir5110may then be constrained in the direction of the heat transfer in another manner (e.g. by a water reservoir dock or a similar housing) to create a force that reacts to balance the pressure created in the interior of the reservoir5110by the pressurized flow of breathable air, wherein some of the reaction force may occur at the heater plate5120to improve thermal contact. In such arrangements, another opening to re-fill the water reservoir5110may be introduced on the reservoir5110, such as on the lid5114, and it may comprise a separate seal. Such an opening may be configurable between an open and a closed position, for example, by a cap or a refilling lid.FIG.34shows an example of such an arrangement, including a base5174, a top5176, a variable portion5178and a re-filling cap5180. The base, the top and the variable portion may be affixed together in this arrangement, and in such a case re-filling of the reservoir would be accommodated by the re-filling cap,5180. The re-filling cap5180may be placed such that when the humidifier reservoir5110is engaged with the reservoir dock5130the re-filling cap5180is not accessible. Such an arrangement may preserve the advantage described above, namely that the reservoir5110is not able to be re-filled while it is engaged with the reservoir dock5130. Furthermore, the variable portion5178may be replaced by any mechanism known in the art that is able to accommodate a change in vertical length within a reservoir.

In a yet another alternate arrangement, the pressurized flow of breathable air may be used to improve the level of thermal contact between the humidifier reservoir5110and the heater plate5120by pressurisation or inflation of a chamber, body or surface that acts on the humidifier reservoir5110, which in turn may push the water reservoir5110and the heater plate5120together in the direction of thermal engagement. Similarly the supply of the pressurized flow of breathable air may pressurize or inflate a chamber, body or surface that acts upon the heater plate to push the heater plate5120and water reservoir5110together in the direction of thermal engagement.

The chamber may be arranged on the outside of the reservoir and communicated with the flow of breathable gas. A surface of the chamber may be connected with the reservoir in the direction of thermal engagement so that varying the pressure of the flow of breathable gas in the reservoir varies the size of the chamber and changes a level of thermal engagement between the conductive portion and the heater plate. The chamber being arranged to push the reservoir towards the heater plate5020and/or the heater plate5020towards the reservoir when the size of the chamber increases.

In an alternate arrangement of the reservoir dock5160, wherein the opening is substantially in the horizontal plane and thus the water reservoir5110is inserted from above or below the reservoir dock5160as described above, the water reservoir dock5160may include a retaining mechanism (for example, a lid that closes above the water reservoir5110) to hold the water reservoir5110in its intended position. In such an arrangement, the reservoir dock lid may be configured to compress the variable portion5116which would in turn push the reservoir5110against the heater plate5120. Similarly, the reservoir5110may be configured so that when the reservoir dock lid is closed, and the pressurized flow of breathable air pressurizes the interior of the reservoir5110, it pushes the reservoir lid5114and the reservoir base5112apart that acts on the variable portion to try to expand or un-compress the variable portion, and in turn enhances the level of thermal contact between the reservoir base5112and the heater plate5120.

The level of thermal contact may also be improved using a spring loaded or sprung heater plate as is known in the prior art. The heater plate may be constructed with a convex or domed shape towards the humidifier reservoir5110so that when the humidifier5110is engaged with the reservoir dock5130the convex heater plate is flattened, which generates a clamping force pushing the heater plate5120to the water reservoir5110. Similarly, the conductor plate5152of the water reservoir5110may be domed or convex shaped and be configured to be flattened towards to the heater plate when the water reservoir5110is engaged.in the dock cavity5180of the humidifier5000.

Any one of the above means of improving thermal contact may be used independently of each other, or in any combination thereof, including in combination with any prior art means of achieving or improving thermal engagement between the humidifier reservoir and the heater plate.

Reservoir Inlet/Outlet

In one arrangement, the reservoir inlet5118and the reservoir outlet5122may be oriented horizontally and on the same surface, as shown inFIG.12. The reservoir inlet5118includes an inlet tube5124that extends from the exterior of the reservoir into the interior volume of the reservoir to provide a flow path for the inlet flow of pressurized gas into the reservoir5110. The reservoir outlet5122includes an outlet tube5126that extends from the interior of the reservoir5110to the exterior of reservoir5110to provide a flow path for the outlet flow of humidified pressurized gas from the reservoir5110, as shown inFIG.22.

As shown inFIG.22-23, the reservoir5110may include an end wall5128that is near and opposed to an interior end5125of the inlet tube5124. The inlet tube5124directs the inlet airflow to the inner end wall5128of the reservoir5110thus directing the air to flow across the whole water surface before it reaches an interior end5127of the outlet tube5126and flows out of the outlet5122through the outlet tube5126.FIG.24-27show examples of other arrangements, wherein the reservoir5110may include a turning vane5136which is placed near the interior end5125of the inlet tube5124. The turning vane5136may be formed as an extension of the inlet tube5124as shown inFIG.26-27, or the turning vane5136may be a separate component located adjacent to or coupled with the inlet tube5124. The turning vane may also be profiled as shown inFIG.26-27.

The water reservoir5110is preferably configured to provide tilt spillback protection from the water flowing back through the outlet tube5126or the inlet tube5124. Water egress through the inlet tube5124is particularly undesirable as it may introduce water into the PAP device4000and may damage electronic components (such as an electric motor, a flow sensor or a printed circuit board) from exposure to water. In one arrangement the reservoir5110achieves spillback protection by arranging the inlet tube outlet5125so that when the reservoir5110is rotated by 90 degrees in any direction from its working, horizontal orientation the given maximum volume of water is able to be stored in the reservoir5110without reaching the inlet tube outlet5125.

In another arrangement, the reservoir5110, the axes of inlet tube5124and the outlet tube5126may intersect when viewed from above as shown inFIG.28-29. The inlet tube5124and outlet tube5126are not connected to each other as one of the tubes passes below the other tube, such as the inlet tube5124passes below the outlet tube5126.

This configuration may improve the tilt spillback protection by arranging the inlet tube5124and the outlet tube5126such that when the reservoir5110is tilted to its side (substantially about the axis of the inlet/outlet), and water reaches the lower of the interior end5125of the inlet tube5124or the interior end5127of the outlet tube5126, the water must rise higher to exit the reservoir5110as shown inFIG.29. In comparison, if the inlet tube5124and the outlet tube5126were parallel, when water reaches the lower of the interior end5125of the inlet5124or the interior end5127of the outlet tube5126it would then be able to freely flow out of the reservoir5110through the inlet tube5124or the outlet tube5126.

One example of the above spillback prevention technology arranges the inlet tube5124and the outlet tube5126such that the axes defined by the interior end5125of the inlet5124and the exterior end5190of the outlet5126and the interior end5127of the outlet5126and the exterior end5188of the inlet5124are substantially parallel to each other.

Crossing the inlet tube5124and the outlet tube5126creates a geometric configuration wherein the water level must reach the higher of the inlet and outlet tube interior ends5125,5127to be able to exit the reservoir5110, or the water level must reach the lower of the inlet and outlet tube interior ends5125,5127and extend along the entire length of the inlet tube5124or outlet tube5126to be able to exit the reservoir5110.

Simplified representations of the effects created by crossed inlet and outlet tubing are shown inFIG.35-38(FIG.35-36shows one configuration,FIG.37-38another), wherein the internal surfaces are shown by dotted lines. These figures show alternate arrangements of a water reservoir5110, with an inlet5118and an outlet5122that respectively include an inlet tube5124and an outlet tube5126extending into a cavity or interior volume of the reservoir, and terminating at an interior end5125of the inlet tube5124and an interior end5127of the outlet tube5126respectively.FIG.35-36show a configuration wherein the axes of the tubing substantially intersect when viewed from the side (as shown inFIG.36), andFIG.37-38show an alternate configuration wherein the axes of the tubing are substantially parallel when viewed from the side (as shown inFIG.38). InFIG.35-38, a volume of water5182is assumed to fill approximately half of the volume of the reservoir5110, and is indicated by the dotted lines extending horizontally approximately at the mid-height of the reservoir5110.

When the water reservoir5110is oriented as shown inFIG.35-36, the arrangement of the inlet tube5124and the outlet tube5126requires the water level5184to rise above the entire length of the inlet tube5124to reach the exterior end of the inlet tube or to rise above the interior end5127of the outlet tube5126if any water5182is to exit the water reservoir5110. On the other hand, in the arrangement shown inFIG.36-37the water level5184only needs to rise as high as the lower of the inlet tube5124or the outlet tube5126in order to exit the water reservoir5110. As the water level5184will change as a function of the orientation of the water reservoir5110, this effect of crossing the inlet tube5124and the outlet tube5126may be re-created at any orientation as required by re-orienting the inlet tube5124and the outlet tube5126to suit the shape of the water reservoir5110.

The inlet tube may deliver a supply of breathable gas into the cavity of the reservoir and the outlet tube may deliver a humidified supply of breathable gas from the cavity. The inlet interior end and the outlet interior end are located within the cavity and the inlet exterior end and the outlet exterior end are located in one of the plurality of walls of the cavity. A first axis is defined by the inlet interior end and the inlet exterior end and a second axis is defined by the outlet interior end and the outlet exterior end When the reservoir is tilted approximately 90° to normal working orientation the first axis is on a first angle such that the inlet interior end and the inlet exterior end are positioned at different heights, such that the predetermined maximum volume of water is below at least one of the inlet interior end or the inlet exterior end to prevent spillback of water through the inlet tube. Furthermore, when the reservoir is tilted approximately 90° to normal working orientation the second axis is on a second angle such that the outlet interior end and the outlet exterior end are positioned at different heights, such that the predetermined maximum volume of water is below at least one of the outlet interior end or the outlet exterior end to prevent spillback of water through the outlet tube.

Overfill Prevention

Another aspect of this technology is the inclusion of an overfill protection element configured to prevent filling the reservoir above the maximum volume of water when filling the humidifier reservoir in its open configuration. In one arrangement as seen inFIGS.30aand30b, the overfill protection element may include at least one orifice5138in the water reservoir5110to indicate over-filling. According to this aspect of the technology, when the water reservoir5110is being re-filled with the reservoir lid5114open, over-filling beyond a predetermined level or the maximum capacity or volume for the reservoir5110would cause water to spill out from the orifice5138. The water spilling out through orifice5138indicating that a maximum capacity has been reached and preventing the water reservoir5110from being filled beyond a predetermined level or maximum capacity. Advantageously water would spill out only through the at least one orifice5138rather than from all areas of the water reservoir resulting in less overflow spillage for the user to clean up. Thus, the at least one orifice defines an egress path of water when the predetermined maximum volume of water is exceeded.FIG.30ashow the water reservoir5110in its open configuration, wherein an upper flange of the base5112does not span the perimeter of the entire opening, creating an orifice5138.FIG.30bshows a zoomed in section of the base5112indicating the at least one orifice5138. The at least one orifice5138may be in the form of one or more apertures, holes, slits or slots, or any other form that allows communication of fluid into and out of the water reservoir5110. The at least one orifice5138may be formed in one or more positions around the upper flange of the base5112.

In an alternate arrangement, the overfill protection element may include a sloped profile5139. As shown inFIGS.30cand30d, the reservoir base5112may be arranged so that its side profile has a sloped profile5139in one or more directions. This arrangement may also indicate over-filling when the reservoir base5112is re-filled with liquid or water. In this arrangement, when the reservoir lid5114is in its open configuration, water may spill out at the base of the sloped profile5139rather than from all areas of the reservoir. Thus, the sloped profile defines an egress path of water when the predetermined maximum volume of water is exceeded. Advantages of the above methods may be that over-filling may become more difficult than has been in the prior art, and presents another advantage that in response to attempted over-filling, spillage may occur at more predictable locations.

Another aspect of this technology is that when the water reservoir5110is in its closed position, a seal5192sealingly engages the base5112and the reservoir lid5114and blocks or seals the orifice5138or sloped profile5139preventing fluid communication into and out of the water reservoir5110. One arrangement of this feature is shown inFIG.31, which shows that when the reservoir lid5114is closed (lid not shown in this image), the seal5192sealingly engages with the base5112on the outside of the orifice5138and no longer allows communication of liquid or air into and out of the water reservoir5110through the orifice5138. Similarly the seal5192would engage with the base5112to surround the edges of the sloped profile preventing communication of liquid or air into and out of the water reservoir5110through the sloped profile5139. In some arrangements the seal5192may be integrated with the variable portion5116as described above. Alternatively the seal5192may be a separate seal that may be used in a reservoir with or without a variable portion.

Retaining Clip

The reservoir lid5114may include a means by which the water reservoir5110is to be retained in the water reservoir dock5130once the two members are engaged with each other. In one arrangement a retaining means may be a protrusion, or a clip,5142on the reservoir lid5114as shown inFIGS.32-33.FIGS.32-33show a water reservoir5110and the reservoir dock5130. Here, a protrusion, or a clip,5142on the reservoir lid5114removably engages with a corresponding dock locking recess5144in the water reservoir dock5130when the water reservoir5110is inserted into the water reservoir dock5130. This connection secures the water reservoir5110relative to the water reservoir dock5130. As described above the variable portion5116of the reservoir is compressed to enable insertion of the reservoir into the dock5130. The compression of the variable portion5116allows a portion of the reservoir5110to slide into the dock5130and allows the protrusion or clip5142to slide initially under the outer edge surface of the dock5130to reach the dock locking recess5144. The compression force applied to the reservoir for insertion may then be released to allow the protrusion or clip5142to engage with the dock locking recess5144and securing of the reservoir5110within the dock5130. When the reservoir5110is secured within the dock5130the variable portion5116is no longer in or in a reduced compressed state. Similarly, in order to be able to remove the water reservoir5110from the water reservoir dock5130, the variable portion5116must be compressed as to disengage the lid protrusion5142from the dock locking recess5144. It would be clear to those skilled in the art that in an alternative arrangement the lid protrusion5142may be a recess, and the dock locking recess5144may be a corresponding protrusion. Alternatively one of any number of retaining means that are known in the art may be used to achieve the same means.

5.5.2.3 Heater Plate5120

A heater plate5120is used to transfer heat to the water reservoir5110. The heater plate5120may form a part of the reservoir dock5130, and may be located on or near the base of the humidifier5000as shown inFIG.14. The heater plate5120may be formed, for example, of a nickel chrome alloy or anodised aluminium.

5.6 Glossary

In certain forms of the present technology, one or more of the following definitions may apply. In other forms of the present technology, alternative definitions may apply.

5.6.1 General

Air: Air will be taken to include breathable gases, for example air with supplemental oxygen.

Continuous Positive Airway Pressure (CPAP): CPAP treatment will be taken to mean the application of a supply of air or breathable gas to the entrance to the airways at a pressure that is continuously positive with respect to atmosphere, and preferably approximately constant through a respiratory cycle of a patient. In some forms, the pressure at the entrance to the airways will vary by a few centimeters of water within a single respiratory cycle, for example being higher during inhalation and lower during exhalation. In some forms, the pressure at the entrance to the airways will be slightly higher during exhalation, and slightly lower during inhalation. In some forms, the pressure will vary between different respiratory cycles of the patient, for example being increased in response to detection of indications of partial upper airway obstruction, and decreased in the absence of indications of partial upper airway obstruction.

5.6.2 Humidification System

Water reservoir: A water reservoir, or water tub, or humidifier reservoir, is a chamber that forms a part of the humidification system. It is configured to contain a body of liquid (e.g., water) aimed at imparting additional humidity to the flow of breathable air that passes through the water reservoir. It may comprise an air inlet and an air outlet, as well as a means (such as an opening or an openable lid) of filling the water reservoir with water.

5.6.3 Anatomy of the Respiratory System

Diaphragm: A sheet of muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity, containing the heart, lungs and ribs, from the abdominal cavity. As the diaphragm contracts the volume of the thoracic cavity increases and air is drawn into the lungs.

Larynx: The larynx, or voice box houses the vocal folds and connects the inferior part of the pharynx (hypopharynx) with the trachea.

Lungs: The organs of respiration in humans. The conducting zone of the lungs contains the trachea, the bronchi, the bronchioles, and the terminal bronchioles. The respiratory zone contains the respiratory bronchioles, the alveolar ducts, and the alveoli.

Nasal cavity: The nasal cavity (or nasal fossa) is a large air filled space above and behind the nose in the middle of the face. The nasal cavity is divided in two by a vertical fin called the nasal septum. On the sides of the nasal cavity are three horizontal outgrowths called nasal conchae (singular “concha”) or turbinates. To the front of the nasal cavity is the nose, while the back blends, via the choanae, into the nasopharynx.

Pharynx: The part of the throat situated immediately inferior to (below) the nasal cavity, and superior to the oesophagus and larynx. The pharynx is conventionally divided into three sections: the nasopharynx (epipharynx) (the nasal part of the pharynx), the oropharynx (mesopharynx) (the oral part of the pharynx), and the laryngopharynx (hypopharynx).

5.6.4 Materials

Silicone or Silicone Elastomer: A synthetic rubber. In this specification, a reference to silicone is a reference to liquid silicone rubber (LSR) or a compression moulded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (included in the range of products sold under this trademark), manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless otherwise specified to the contrary, a preferred form of LSR has a Shore A (or Type A) indentation hardness in the range of about 35 to about 45 as measured using ASTM D2240.

Polycarbonate: a typically transparent thermoplastic polymer of Bisphenol-A Carbonate.

5.7 Other Remarks

*A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

Unless the context clearly dictates otherwise and where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit, between the upper and lower limit of that range, and any other stated or intervening value in that stated range is encompassed within the technology. The upper and lower limits of these intervening ranges, which may be independently included in the intervening ranges, are also encompassed within the technology, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the technology.

Furthermore, where a value or values are stated herein as being implemented as part of the technology, it is understood that such values may be approximated, unless otherwise stated, and such values may be utilized to any suitable significant digit to the extent that a practical technical implementation may permit or require it.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present technology, a limited number of the exemplary methods and materials are described herein.

When a particular material is identified as being preferably used to construct a component, obvious alternative materials with similar properties may be used as a substitute.

It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include their plural equivalents, unless the context clearly dictates otherwise.

All publications mentioned herein are incorporated by reference to disclose and describe the methods and/or materials which are the subject of those publications. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present technology is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates, which may need to be independently confirmed.

Moreover, in interpreting the disclosure, all terms should be interpreted in the broadest reasonable manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.

The subject headings used in the detailed description are included only for the ease of reference of the reader and should not be used to limit the subject matter found throughout the disclosure or the claims. The subject headings should not be used in construing the scope of the claims or the claim limitations.

Although the technology herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the technology. In some instances, the terminology and symbols may imply specific details that are not required to practice the technology. For example, although the terms “first” and “second” may be used, unless otherwise specified, they are not intended to indicate any order but may be utilised to distinguish between distinct elements. Furthermore, although process steps in the methodologies may be described or illustrated in an order, such an ordering is not required. Those skilled in the art will recognize that such ordering may be modified and/or aspects thereof may be conducted concurrently or even synchronously.

It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the technology.

6 REFERENCE SIGNS LIST

Not Applicable.

7 CITATIONS

7.1 Patent Literature

7.2 Non-Patent Literature