Unobtrusive nasal mask

1. A patient interface assembly for delivering pressurized breathable gas to a patient, the patient interface assembly comprising:

a patient interface comprising:

a cushion assembly comprising:

a flexible sealing portion comprising a central region around a central orifice and nostril engagement portions extending from the central region on opposite lateral sides of the central orifice that are adapted to engage with and form a seal with opposing sides of the patient's nose; and

a supporting portion that is more rigid than the flexible sealing portion and supports the flexible sealing portion; and

an air delivery tube connector configured to connect an air delivery tube to the cushion assembly; and

a headgear strap configured to support the patient interface on the patient's head, the headgear strap having a central portion that is removably attachable to a central part of the patient interface at a location adjacent to the air delivery tube connector and a pair of side portions extending from the central portion, the headgear strap comprising a rigidizer that adds rigidity to the headgear strap,

wherein the central and side portions of the headgear strap are formed as a single unitary element.

2. The patient interface assembly of claim 1 , wherein the central portion of the headgear strap is configured to be positioned adjacent a base of the flexible sealing portion.

3. The patient interface assembly of claim 1 , wherein the flexible sealing portion comprises an upper lip engagement portion configured to engage and seal with the patient's upper lip.

4. The patient interface assembly of claim 1 , wherein the flexible sealing portion comprises a nose tip engagement portion configured to engage and seal with the patient's nose tip.

5. The patient interface assembly of claim 1 , wherein the air delivery tube connector is attachable to the supporting portion.

6. The patient interface assembly of claim 5 , wherein the air delivery tube connector comprises a gas washout vent.

7. The patient interface assembly of to claim 6 , further comprising the air delivery tube.

8. The patient interface of assembly claim 1 , further comprising:

an air delivery tube connector attached to the supporting portion and configured to connect to an air delivery tube,

wherein the central portion of the headgear strap is configured to be positioned adjacent a base of the flexible sealing portion,

wherein the flexible sealing portion comprises an upper lip engagement portion configured to engage and seal with the patient's upper lip,

wherein the flexible sealing portion comprises a nose tip engagement portion configured to engage and seal with the patient's nose tip,

wherein the air delivery tube connector forms a gas washout vent,

wherein the rigidizer comprises a multilayer structure with one layer being made of fabric, and

wherein distal ends of the side portions of the headgear strap are adapted to be connected to each other by way of a buckle arrangement.

9. The patient interface assembly of claim 1 , wherein the rigidizer comprises a multilayer structure with one layer being made of fabric.

10. The patient interface assembly of claim 1 , wherein distal ends of the side portions of the headgear strap are adapted to be connected to each other by way of a buckle arrangement.

11. The patient interface assembly of claim 1 , wherein the supporting portion is configured to force the flexible sealing portion into engagement with the patient's nose.

12. A patient interface assembly for delivering pressurized breathable gas to a patient, the patient interface assembly comprising:

a patient interface comprising:

a cushion assembly with a central orifice and lateral sides that are adapted to engage with and form a seal with opposite sides of the patient's nose, the cushion assembly comprising:

a flexible sealing portion configured to sealingly engage the patient's nose; and

a supporting portion that is more rigid than the flexible sealing portion and is configured to support the flexible sealing portion;

an air delivery tube connector configured to connect the cushion assembly to an air delivery tube, the air delivery tube connector comprising:

a cushion connection end configured to be connected to the cushion assembly at the central orifice;

a tube connection end opposite the cushion connection end and configured to be connected to the air delivery tube;

an array of gas washout vent openings that extends circumferentially around a top portion of the air delivery tube connector and is configured to disperse gas washout around a perimeter of the air delivery tube connector; and

a circumferential flange between the cushion connection end and the tube connection end, the flange extending parallel to the array of gas washout vent openings; and

a central gas flow passage formed by the cushion assembly and the air delivery tube connector when the air delivery tube connector is attached to the cushion assembly; and

headgear with a central portion and side portions extending from the central portion, the central portion of the headgear being removably attached to the patient interface at a location adjacent to the central gas flow passage,

wherein at least part of the central portion of the headgear is configured to be above the central gas flow passage when the headgear is attached to the patient interface,

wherein the central and side portions of the headgear are constructed in one continuous piece, and

wherein the headgear comprises a rigidizer that adds rigidity to the headgear.

13. The patient interface assembly of claim 12 , wherein the flexible sealing portion comprises an upper lip engagement portion configured to engage and seal with the patient's upper lip.

14. The patient interface assembly of claim 12 , wherein the flexible sealing portion comprises a nose tip engagement portion configured to engage and seal with the patient's nose tip.

15. The patient interface assembly of claim 12 , further comprising the air delivery tube.

16. The patient interface assembly of claim 12 , wherein the flexible sealing portion is configured to cradle the patient's nose.

17. The patient interface assembly of claim 12 , wherein the side portions of the headgear is adapted to be connected to each other by way of a buckle arrangement.

18. The patient interface assembly of claim 12 , wherein the central and side portions of the headgear form a headgear strap.

19. The patient interface assembly of claim 12 , wherein the central portion of the headgear comprises an aperture configured to fit around the central gas flow passage when the headgear is attached to the patient interface.

20. The patient interface assembly of claim 19 , wherein the aperture is C-shaped with its open side facing down in use, and wherein the headgear is configured to be attached to the patient interface by moving the headgear downward onto a top portion of the patient interface.

21. The patient interface assembly of claim 12 , wherein the air delivery tube connector has a substantially tubular form.

22. The patient interface assembly of claim 12 , wherein an opening at the cushion connection end of the air delivery tube connector and an opening at the tube connection end of the air delivery tube connector share the same axis.

23. The patient interface assembly of claim 12 , wherein the flexible sealing portion comprises an upper lip engagement portion configured to engage and seal with the patient's upper lip,

wherein the flexible sealing portion comprises a nose tip engagement portion configured to engage and seal with the patient's nose tip,

wherein the flexible sealing portion is configured to cradle the patient's nose,

wherein the side portions of the headgear is adapted to be connected to each other by way of a buckle arrangement,

wherein the central and side portions of the headgear form a headgear strap,

wherein the central portion of the headgear comprises an aperture configured to fit around the central gas flow passage when the headgear is attached to the patient interface,

wherein the aperture is C-shaped with its open side facing down in use, and wherein the headgear is configured to be attached to the patient interface by moving the headgear downward onto a top portion of the patient interface,

wherein the air delivery tube connector has a substantially tubular form, and

wherein an opening at the cushion connection end of the air delivery tube connector and an opening at the tube connection end of the air delivery tube connector share the same axis.