Humidifier and/or flow generator for CPAP device

1. A positive airway pressure device configured to deliver a pressurized flow of respiratory gas to a patient's airways, the positive airway pressure device comprising:

a flow generator comprising a blower configured to pressurize the flow of respiratory gas and a blower wall with a blower discharge path configured to convey the pressurized flow of respiratory gas from the blower;

a flexible face seal connected to the blower wall, the flexible face seal comprising an aperture and a lip curling inwardly from a perimeter of the flexible face seal toward the aperture;

a tub configured to hold a body of water and humidify the pressurized flow of respiratory gas, the tub comprising a heat conducting base plate and a tub side wall, the tub side wall having a substantially flat portion that surrounds an air opening that is substantially co-planar with the substantially flat portion;

a base that supports both the flow generator and the tub and comprises a floor with a heater plate, the tub being removable from the base by moving the tub in a first direction and being receivable by the base by moving the tub in a second direction opposite the first direction to engage the flexible face seal; and

a guide assembly comprising a pair of flange portions and a pair of C-shaped channel portions, each of the C-shaped channel portions being configured to receive a respective one of the pair of flange portions,

wherein the heater plate of the base is positioned to engage the heat conducting base plate of the tub when the tub is received by the base,

wherein the substantially flat portion of the side wall that surrounds the air opening of the tub is arranged to engage the lip of the flexible face seal upon the tub being fully received by the base,

wherein the tub and the flexible face seal are configured so that no part of the tub enters the aperture of the flexible face seal when the tub is fully received by the base,

wherein the base is configured so that the tub is automatically secured on the base when the tub fully slides into place and contacts with flexible face seal, and

wherein the tub is configured to be released from the base by way of pressing down on a resiliently biased surface.

2. The positive airway pressure device of claim 1 , further comprising a securing catch configured to releasably retain the tub on the base, the securing catch being pivotable and being configured to produce a clicking sound when the tub is fully received by the base.

3. The positive airway pressure device of claim 1 , wherein the tub further comprises a conduit configured to convey the pressurized flow of respiratory gas from the air opening of the tub to an interior of the tub.

4. The positive airway pressure device of claim 1 , wherein the flexible face seal comprises an elastomeric portion that includes the lip and comprises a rigid portion that is a permanent part of the blower discharge path, the rigid portion being plastic and the elastomeric portion being silicone.

5. The positive airway pressure device of claim 1 , wherein the flow generator further comprises a housing and the entirety of the blower discharge path is within the flow generator housing.

6. The positive airway pressure device of claim 1 , wherein the lip of the flexible face seal is configured to be pressed against the tub side wall when the flexible face seal is pressurized.

7. The positive airway pressure device of claim 1 , wherein each of the C-shaped channel portions is positioned so that a bottom part of the C-shaped channel portion is lower than the heat conducting base plate of the tub when the tub is laterally received by the base, and wherein each of the C-shaped channel portions comprises a vertical wall that laterally extends in a direction that is parallel to the direction in which the tub is received by the base.

8. The positive airway pressure device of claim 1 , wherein the resiliently biased surface comprises a groove, and the tub is configured to be released from the base by way of pressing down on the groove.

9. The positive airway pressure device of claim 1 , wherein the flow generator is separable from the base.

10. The positive airway pressure device of claim 1 , further comprising a securing catch configured to releasably retain the tub on the base,

wherein the securing catch is pivotable,

wherein the tub further comprises a conduit configured to convey the pressurized flow of respiratory gas from the air opening of the tub to an interior of the tub,

wherein the flexible face seal comprises an elastomeric portion that includes the lip and comprises a rigid portion that is a permanent part of the blower discharge path,

wherein the rigid portion of the flexible face seal is plastic and the elastomeric portion of the flexible face seal is silicone,

wherein the flow generator further comprises a housing and the entirety of the blower discharge path is within the flow generator housing,

wherein the lip of the flexible face seal is configured to be pressed against the tub side wall when the flexible face seal is pressurized,

wherein each of the C-shaped channel portions is positioned so that a bottom part of the C-shaped channel portion is lower than the heat conducting base plate of the tub when the tub is laterally received by the base, and

wherein each of the C-shaped channel portions comprises a vertical wall that laterally extends in a direction that is parallel to the direction in which the tub is received by the base.

11. The positive airway pressure device of claim 1 , wherein the tub is configured to separate from the flexible face seal upon being removed from the base.

12. The positive airway pressure device of claim 1 , further comprising:

a securing catch assembly comprising a first spring and being configured to secure the tub within the base upon the tub being fully received by the base, the securing catch assembly further comprising a catch and a manually depressable portion that is downwardly pressable against the bias of the first spring to move the catch from a securing position, in which the tub is secured against horizontal movement relative to the base, to a release position in which the tub is horizontally slidable to remove the tub from the base; and

a second spring configured to bias the heater plate towards the heat conducting base plate, the first and second springs being different from one another.

13. The positive airway pressure device of claim 1 , wherein the flexible face seal is positioned at an outlet end of the blower discharge path,

wherein the air opening is an inlet air opening,

wherein the tub is horizontally removable from the base by sliding the tub away from the blower wall and is horizontally receivable by sliding the base toward the blower wall,

wherein the guide assembly is configured to prevent the tub from being removed from the base in a vertical direction, and

wherein the C-shaped channel portions oppose each other and each of the C-shaped channel portions comprises an open side that faces the other C-shaped channel portion.

14. A positive airway pressure treatment system comprising:

the positive airway pressure device of claim 1 ; and

an air delivery tube,

wherein the positive airway pressure device further comprises an air delivery tube connector configured to be connected to the air delivery tube.

15. The positive airway pressure treatment system of claim 14 , further comprising a patient interface that is connectable to the air delivery tube.

16. A positive airway pressure device configured to deliver a pressurized flow of respiratory gas to a patient's airways, the positive airway pressure CPAP device comprising:

a flow generator portion comprising a blower configured to pressurize the flow of respiratory gas, a blower discharge path configured to convey the pressurized flow of respiratory gas from the blower, and a flexible face seal positioned at an outlet end of the blower discharge path, the flexible face seal comprising an aperture and a lip curling inwardly from a perimeter of the flexible face seal toward the aperture;

a humidifier portion configured to humidify the pressurized flow of respiratory gas, the humidifier portion and the flow generator portion sharing a common base, the humidifier portion comprising a heater plate;

a tub configured to hold a body of water, the tub comprising a heat conducting base plate and a side wall, the side wall having a substantially flat portion that surrounds an air inlet opening, the air inlet opening being substantially co-planar with the substantially flat portion; and

a securing catch assembly comprising a first spring and being configured to secure the tub within the humidifier portion upon the tub being fully received by the humidifier portion, the securing catch assembly having a catch and a manually depressable portion that is downwardly pressable against the bias of the first spring to move the catch from a securing position, in which the tub is secured against horizontal movement relative to the base, to a release position in which the tub is removable from the base,

wherein the heater plate of the humidifier portion is positioned to engage the heat conducting base plate of the tub when the tub is received by the humidifier portion,

wherein the substantially flat portion of the side wall that surrounds the air inlet opening of the tub is arranged to engage the lip of the flexible face seal upon the tub being fully received by the humidifier portion, and

wherein the tub and the flexible face seal are configured so that no part of the tub enters the aperture of the flexible face seal when the tub is fully received by the humidifier portion.

17. The positive airway pressure device of claim 16 , further comprising a second spring configured to bias the heater plate towards the heat conducting base plate, the first and second springs being different from one another.

18. The positive airway pressure device of claim 16 , wherein the tub further comprises an air outlet, a base, a top part connected to the base, and a conduit configured to convey the pressurized flow of respiratory gas from the air inlet opening of the tub to an interior of the tub, and wherein the air inlet opening and the air outlet are formed on the top part of the tub.

19. The positive airway pressure device of claim 16 , further comprising a guide that prevents the tub from being removed from the humidifier portion in a vertical direction, the guide comprising at least one C-shaped channel portion, each said C-shaped channel portion comprising an inwardly facing open side.

20. The positive airway pressure device of claim 16 , wherein the securing catch assembly is pivotable.

21. The positive airway pressure device of claim 16 , wherein the flexible face seal comprises an elastomeric portion that includes the lip and comprises a rigid portion that is a permanent part of the blower discharge path.

22. The positive airway pressure device of claim 21 , wherein the rigid portion of the flexible face seal is plastic and the elastomeric portion of the flexible face seal is silicone.

23. The positive airway pressure device of claim 16 , wherein the flow generator portion further comprises a housing and the entirety of the blower discharge path is within the housing.

24. The positive airway pressure device of claim 16 , wherein the lip of the flexible face seal is configured to be pressed against the side wall of the tub when the flexible face seal is pressurized.

25. The positive airway pressure device of claim 16 , wherein the flow generator portion is separable from the humidifier portion.

26. The positive airway pressure device of claim 16 , further comprising:

a guide that prevents the tub from being removed from the humidifier portion in a vertical direction, the guide comprising at least one C-shaped channel portion, each said C-shaped channel portion comprising an inwardly facing open side; and

a second spring configured to bias the heater plate towards the heat conducting base plate, the first and second springs being different from one another,

wherein the tub further comprises:

an air outlet;

a base; a top part connected to the base; and

a conduit configured to convey the pressurized flow of respiratory gas from the air inlet opening of the tub to an interior of the tub,

wherein the air inlet opening and the air outlet are formed on the top part of the tub,

wherein the securing catch assembly is pivotable,

wherein the flexible face seal comprises an elastomeric portion that includes the lip and comprises a rigid portion that is a permanent part of the blower discharge path,

wherein the rigid portion of the flexible face seal is plastic and the elastomeric portion of the flexible face seal is silicone,

wherein the flow generator portion further comprises a housing and the entirety of the blower discharge path is within the housing, and

wherein the lip of the flexible face seal is configured to be pressed against the side wall of the tub when the flexible face seal is pressurized.

27. The positive airway pressure device of claim 16 , wherein the tub is secured against horizontal movement relative to the base, to a release position in which the tub is horizontally slidable to remove the tub from the base.

28. The positive airway pressure device of claim 16 , wherein the tub is configured to separate from the flexible face seal upon being removed from the base.

29. A positive airway pressure treatment system comprising:

the positive airway pressure device of claim 16 ; and

an air delivery tube,

wherein the positive airway pressure device further comprises an air delivery tube connector configured to be connected to the air delivery tube.

30. The positive airway pressure treatment system of claim 29 , further comprising a patient interface that is connectable to the air delivery tube.