Air delivery conduit

1. A mask assembly for providing a supply of breathable gas at positive pressure, in a range of 2-30 cm H 2 O, to a patient for treatment of sleep disordered breathing, the mask assembly comprising:

a patient interface adapted to form a seal with a patient's face;

a pair of conduits adapted to deliver breathable gas to the patient interface, each conduit being adapted to, in use, extend along a respective side of the patient's head from a position adjacent the patient's nose, between the patient's ear and eye, to a position on top of the patient's head, each conduit having a bottom portion configured to engage the patient interface and a top portion in fluid communication with a supply of breathable gas; and

a back strap adapted to extend around a back of the patient's head between each conduit to support the patient interface in position on the patient's face,

wherein each conduit has a wall that extends from the bottom portion to the top portion,

wherein each wall has a thickness that varies along the length of the conduit, and

wherein, in a cross-sectional view of each conduit, a thickness at every point around a perimeter of the cross-section of each wall at a first location along the length of the respective conduit is different than any thickness around a perimeter of the cross-section of the wall at a second location along the length of the conduit.

2. The mask assembly of claim 1 , wherein the patient interface is a nasal mask.

3. The mask assembly of claim 1 , wherein each conduit comprises silicone.

4. The mask assembly of claim 1 , wherein the patient interface comprises silicone.

5. The mask assembly of claim 1 , wherein the back strap comprises a textile material.

6. The mask assembly of claim 1 , wherein a length of the back strap is selectively adjustable.

7. The mask assembly of claim 1 , wherein each conduit includes a tab portion having a slot to receive a respective end of the back strap.

8. The mask assembly of claim 1 , wherein at least one of the conduits has a conduit width at one end thereof that is greater than a conduit width along a remainder of the respective conduit.

9. The mask assembly of claim 1 , wherein an end of at least one of the conduits is wider than a corresponding width of an intermediate portion of the respective conduit that is between the bottom portion and the top portion of the conduit.

10. The mask assembly of claim 1 , wherein, in use, each conduit is configured to maintain its form in the absence of external force, and to collapse under external force due to the patient rolling onto the conduit.

11. The mask assembly of claim 10 , wherein, when one of the conduits is in a collapsed condition, the other conduit is configured to maintain air supply to the patient interface, in use.

12. The mask assembly of claim 1 , wherein each conduit has a generally D-shaped cross-section.

13. The mask assembly of claim 1 , wherein each conduit has a curvature along it length configured to follow the patient's face.

14. The mask assembly of claim 1 , further comprising an air supply outlet adapted to connect to the supply of breathable gas, wherein the top portion of each conduit is connected to the air supply outlet.

15. The mask assembly of claim 14 , further comprising a cuff provided to at least one of the top portion and the bottom portion of each conduit to facilitate attachment of the respective conduit to at least one of the patient interface and the air supply outlet.

16. The mask assembly of claim 1 , further comprising a reinforcing element provided to the wall of each conduit to provide rigidity to the respective conduit.

17. The mask assembly of claim 1 , wherein, in a cross-sectional view, each wall has a thickness at a first location along a perimeter of the respective conduit that is different than a thickness of the wall at a second location along the perimeter of the conduit.

18. The mask assembly of claim 1 , further comprising an air supply outlet adapted to connect to the supply of breathable gas, wherein the top portion of each conduit is connected to the air supply outlet,

wherein the patient interface is a nasal mask,

wherein patient interface comprises silicone,

wherein a length of the back strap is selectively adjustable, and

wherein each conduit includes a tab portion having a slot to receive a respective end of the back strap,

wherein an end of at least one of the conduits is wider than a corresponding width of an intermediate portion of the respective conduit that is between the bottom portion and the top portion of the conduit,

wherein, in use, each conduit is configured to collapse under external force due to the patient rolling onto the conduit, and

wherein, when one of the conduits is in a collapsed condition, the other conduit is configured to maintain air supply to the patient interface, in use,

wherein each conduit has a generally D-shaped cross-section, and

wherein each conduit has a curvature along its length configured to follow the patient's face.

19. The mask assembly of claim 1 , wherein an end portion of each conduit has a wall thickness, in a cross-sectional view, that is greater than a wall thickness of the remaining length of the conduit,

wherein each conduit has a generally D-shaped cross-section,

wherein the patient interface is a nasal mask,

wherein patient interface comprises silicone, and

wherein a length of the back strap is selectively adjustable.

20. The mask assembly of claim 1 , wherein an end of each conduit has a width, in a cross-sectional view, that is wider than a corresponding width of an intermediate portion of the conduit that is between the bottom portion and the top portion of the conduit,

wherein each conduit has a generally D-shaped cross-section,

wherein the patient interface is a nasal mask,

wherein patient interface comprises silicone,

wherein a length of the back strap is selectively adjustable, and

wherein each conduit includes a tab portion having a slot to receive a respective end of the back strap.

21. The mask assembly of claim 1 , wherein, in a cross-sectional view, each wall has a thickness at a first location along a perimeter of the respective conduit that is different than a thickness of the wall at a second location along the perimeter of the conduit,

wherein an end of each conduit has a width, in a cross-sectional view, that is wider than a corresponding width of an intermediate portion of the conduit that is between the bottom portion and the top portion of the conduit,

wherein each conduit has a generally D-shaped cross-section,

wherein the patient interface is a nasal mask,

wherein patient interface comprises silicone,

wherein a length of the back strap is selectively adjustable, and

wherein each conduit includes a tab portion having a slot to receive a respective end of the back strap.

22. The mask assembly of claim 1 , wherein the bottom portion of each conduit includes a cuff to facilitate attachment of each conduit to the patient interface.

23. The mask assembly of claim 1 , further comprising at least one textile cover that substantially encloses the pair of conduits.

24. The mask assembly of claim 23 , wherein the cover comprises a reinforcing element to provide rigidity to the pair of conduits.

25. The mask assembly of claim 23 , wherein the back strap is integrally formed with the cover.

26. The mask assembly of claim 23 , wherein the back strap is removably attached to the cover.

27. The mask assembly of claim 1 , further comprising at least one textile cover that substantially encloses the pair of conduits,

wherein the cover comprises a reinforcing element to provide rigidity to the pair of conduits, and

wherein the back strap is removably attached to the cover.

28. The mask assembly of claim 1 , wherein the first location along the length of each conduit is located at an end portion of the respective conduit.

29. The mask assembly of claim 1 , wherein the thickness around a perimeter of the cross-section of each conduit, at any point along the length of the conduit, is constant.

30. The mask assembly of claim 1 , wherein the thickness around a perimeter of the cross-section of each conduit, at the first location and the second location, is constant.