Patient interface

1. A patient interface for sealed delivery of a flow of air at a continuously positive pressure with respect to ambient air pressure to an entrance to a patient's airways including at least entrance of a patient's nares, wherein the patient interface is configured to maintain a therapy pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure in use, throughout a patient's respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered breathing;

said patient interface comprising:

a frame assembly including a shroud and connectors provided to the shroud, the connectors operatively attachable to headgear;

a cushion assembly provided to the frame assembly, the cushion assembly including a shell and a seal-forming structure provided to the shell and structured to form a seal with a patient's nose and/or mouth,

the shell comprising a different material than the seal-forming structure that is more rigid than the seal-forming structure,

the shell and the seal-forming structure cooperating to form a plenum chamber pressurizable to the therapy pressure, and

the shell including a wall forming at least part of the plenum chamber when the cushion assembly is provided to the frame assembly, and the shell including a circular inlet opening structured to receive the flow of air at the therapy pressure for breathing by the patient; and

an air delivery connector provided to the frame assembly, the air delivery connector operatively connected to an air delivery tube for supplying the flow of air at the therapy pressure along an air flow path to the plenum chamber,

wherein the cushion assembly is structured to releasably connect to the frame assembly independently of the air delivery connector,

wherein the shell of the cushion assembly and the shroud of the frame assembly each comprise a relatively hard material that is more rigid than the seal-forming structure such that engagement between the shell and the shroud provides a hard-to-hard connection,

wherein the air delivery connector is structured to releasably connect to the frame assembly independently of the cushion assembly,

wherein the air delivery connector is structured to releasably connect to the frame assembly via a first retention feature on the frame assembly, and the cushion assembly is structured to releasably connect to the frame assembly via a second retention feature on the frame assembly, and the first and second retention features are separate and distinct from one another,

wherein the first retention feature is arranged outside the plenum chamber of the cushion assembly, and the second retention feature is arranged inside the plenum chamber of the cushion assembly,

wherein a first seal for the air flow path is formed between the air delivery connector and the frame assembly, and a separate second seal is formed between the frame assembly and the cushion assembly, and

wherein the first seal comprises a dynamic diametric seal and a dynamic face seal, and the second seal comprises a static diametric seal and a static face seal.

2. The patient interface according to claim 1 , wherein the air delivery connector includes an elbow assembly.

3. The patient interface according to claim 2 , wherein the elbow assembly is adapted to swivel relative to the frame assembly.

4. The patient interface according to claim 1 , wherein the air delivery connector includes a pair of quick release spring arms structured and arranged to releasably connect to the frame assembly.

5. The patient interface according to claim 1 , wherein the frame assembly includes an upper headgear connector structured to connect to upper straps of the headgear and a lower headgear connector structured to connect to lower straps of the headgear.

6. The patient interface according to claim 5 , wherein the upper headgear connector includes a pair of upper headgear connector arms, each of the pair of upper headgear connector arms including one or more flexible portions structured and arranged to conform to varying facial profiles.

7. The patient interface according to claim 6 , wherein each of the flexible portions includes one or more slots structured to form one or more hinges.

8. The patient interface according to claim 5 , wherein the lower headgear connector includes a pair of lower headgear connector arms, each of the pair of lower headgear connector arms including a magnetic connector structured to connect to a magnetic headgear clip.

9. The patient interface according to claim 8 , wherein each of the lower headgear connector arms comprises a slot structured to form a hinge portion.

10. The patient interface according to claim 1 , wherein the frame assembly is provided in one size and is structured to be selectively engageable with multiple sizes of the cushion assembly.

11. The patient interface according to claim 1 , wherein the frame assembly includes a lockout feature along the air flow path structured and arranged to prevent direct connection or insertion of the air delivery tube.

12. The patient interface according to claim 11 , wherein the lockout feature comprises a plurality of projections structured and arranged to extend towards the air flow path.

13. The patient interface according to claim 11 , wherein the lockout feature comprises a single annular projection structured and arranged to extend towards the air flow path.

14. The patient interface according to claim 1 , wherein the air delivery connector includes an elbow assembly comprising a plurality of vent holes and an anti-asphyxia valve assembly.

15. The patient interface according to claim 1 , wherein the frame assembly is provided in the air flow path.

16. A treatment system used for treatment of sleep disordered breathing, comprising:

the patient interface according to claim 1 ;

a respiratory pressure therapy (RPT) device to supply breathable gas at positive pressure; and

an air delivery tube to pass the breathable gas from the RPT device to the patient interface.

17. The patient interface according to claim 1 , wherein the shell includes an annular flange protruding from the wall, wherein the annular flange forms the circular inlet opening, and wherein the annular flange forms at least part of the static diametric seal and the static face seal.

18. The patient interface according to claim 1 , wherein the first retention feature on the frame assembly comprises an outer annular flange that protrudes forwardly from an anterior side of the shroud, and the second retention feature on the frame assembly comprises an inner annular flange that protrudes rearwardly from a posterior side of the shroud.

19. The patient interface according to claim 18 , wherein the outer annular flange includes a rim along it free end which forms a channel structured to interface with the air delivery connector.

20. The patient interface according to claim 18 , wherein the inner annular flange includes a tab structured to interface with the cushion assembly.