Patient interface and method for making same

1. A frame assembly for a patient interface for delivery of a supply of pressurised air or breathable gas to an entrance of a patient's nasal airways only, the frame assembly comprising:

a ring member;

a pair of lower arms, each of the pair of lower arms extending from a respective one of a pair of lower arm connection points radially positioned on the ring member;

a joining member extending posteriorly from the ring member at an upper position on the ring member; and

a pair of upper arms extending from an upper arm connection point at a distal end of the joining member such that the pair of lower arm connection points are spaced apart or offset in a position anterior from the upper arm connection point, each of the pair of upper arms structured and arranged to arch or curve in a superior direction from the upper arm connection point so that each of the pair of upper arms is adapted to extend across a cheek and below an eye of a patient's face in use,

wherein the upper arm connection point and lower arm connection points are spaced apart or offset at a predetermined distance to at least partly define a moment arm providing a maximum tilting range for the frame assembly relative to the patient's face, and

wherein the moment arm provides a center of rotation or pivot point of the frame assembly at a lower side of the frame assembly when a force is applied to the pair of upper arms and translated to the upper arm connection point in use.

2. The frame assembly of claim 1 , wherein each of the pair of upper arms is releasably engageable with a respective one of a pair of upper headgear straps and the pair of upper arms direct a tension vector of the pair of upper headgear straps in a direction substantially parallel to the Frankfort horizontal direction and avoid extending across the patient's ears.

3. The frame assembly of claim 1 , wherein the upper arm connection point is at an upper most position on the ring member, and the lower arm connection points are positioned about 80° to about 160° from the upper arm connection point.

4. The frame assembly of claim 3 , wherein the lower arm connection points are positioned about 90° from the upper arm connection point.

5. The frame assembly of claim 1 , wherein the pair of upper arms are spaced apart from each other to accommodate a plurality of sizes for a cushion assembly that is releasably attachable to the frame assembly.

6. The frame assembly of claim 1 , wherein each of the pair of upper arms is more flexible in the sagittal plane than other planes to accommodate various patient face widths.

7. The frame assembly of claim 1 , wherein the pair of upper arms are more flexible than the pair of lower arms.

8. The frame assembly of claim 1 , wherein each of the pair of upper arms has a distal free end having a magnet.

9. The frame assembly of claim 1 , wherein each of the pair of upper arms includes an upper headgear connection point adapted to connect to an upper headgear strap, and each of the pair of upper arms are structured and arranged to arch or curve in the superior direction from the upper arm connection point so that each of the pair of upper arms are adapted direct the upper headgear strap between the eye and ear of the patient.

10. The frame assembly of claim 1 , wherein the ring member comprises a connection port for connection to an air circuit, and the center of rotation or pivot point is spaced apart in a position inferior from the connection port.

11. The frame assembly of claim 1 , wherein each of the pair of lower arms has a distal free end having a magnet.

12. The frame assembly of claim 11 , wherein the magnet is fully encased within each of the pair of lower arms.

13. The frame assembly of claim 12 , wherein encasement of the magnet provides a raised surface extending anteriorly, and the raised surface enables a mechanical engagement to a circumferential edge of a headgear clip.

14. The frame assembly of claim 13 , wherein the magnet and the raised surface have a substantially circular or oval cross-section which enables the headgear clip to rotate relative to each of the pair of lower arms when magnetically engaged to minimise a lower headgear strap from twisting when headgear tension is applied.

15. The frame assembly of claim 1 , wherein the ring member has a multi-hole vent radially disposed around a connection port for connection to an air circuit.

16. The frame assembly of claim 15 , wherein the air circuit comprises a gas delivery tube with a cuff that is connected to the ring member, the ring member having a radial wall projecting posteriorly that segregates a flowpath of pressurised air from a flowpath of exhaust via the multi-hole vent to reduce cyclic noise.

17. The frame assembly of claim 16 , wherein the cuff is non-rotatably connected to the ring member.

18. The frame assembly of claim 16 , wherein the cuff is permanently connected to the ring member via mechanical interlock.

19. The frame assembly of claim 1 , wherein the frame assembly is releasably engageable with a cushion assembly, the cushion assembly comprising:

a retaining structure for repeatable engagement with and disengagement from a frame member; and

a seal-forming structure permanently connected to the retaining structure, the seal-forming structure serving both nares of the patient with a single orifice;

wherein the seal-forming structure is made from a first material and the retaining structure is made from a second material that is different from the first material and is more rigid than the first material; and

wherein an increase in air pressure within the cushion assembly causes a sealing force between the seal-forming structure and the frame member to increase.

20. The frame assembly of claim 19 , wherein the seal-forming structure has a substantially flat lower wall to alleviate pressure on the patient's upper lip.

21. The frame assembly of claim 19 , wherein the frame member and the retaining structure are comprised of a semi-rigid material to provide a releasable hard-to-hard connection.

22. The frame assembly of claim 19 , wherein the cushion assembly comprises a sealing lip that seals against the frame member when the retaining structure and frame member are attached to one another, and when air pressure increases within the cushion assembly, the sealing force is increased.

23. The frame assembly of claim 1 , further comprising a tube for the delivery of the supply of pressurised air or breathable gas, the tube being connected to the frame assembly without a swivel elbow.

24. The frame assembly of claim 23 , wherein the tube is permanently connected to the frame assembly.

25. A patient interface for sealed delivery of a flow of breathable gas at a continuously positive pressure with respect to ambient air pressure to an entrance to the 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 4cmH 2 O to about 30 cmH 2 O above ambient air pressure in use, throughout the patient's respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered breathing;

said patient interface comprising:

a cushion assembly including a seal-forming structure adapted to form a seal against the patient's airways and a plenum chamber pressurised at a pressure above ambient pressure in use;

a positioning and stabilising structure to maintain the cushion assembly in sealing contact with an area surrounding an entrance to the patient's airways while maintaining a therapeutic pressure at the entrance to the patient's airways;

a gas washout vent configured to allow a flow of patient exhaled CO 2 to an exterior of the patient interface to minimise rebreathing of exhaled CO 2 by the patient; and

the frame assembly according to claim 1 .

26. Apparatus for treating a respiratory disorder comprising:

a patient interface as claimed in claim 25 ;

an air circuit; and

a source of air at positive pressure.