Cushioning structure

1. A patient interface, comprising:

a cushioning structure including at least one hollow chamber filled with first and second discrete and/or layered filling materials, the first filling material being softer and/or more comformable than the second filling material to provide patient comfort in use, and the first filling material adapted to be positioned closer to the patient's face in use; and

a seal forming structure formed in one piece with the cushioning structure, the seal forming structure including a thin membrane flap that is structured to provide a seal to the patient's face, the thin membrane flap including a free end that is spaced from the cushioning structure in its substantially relaxed, unstressed state and is adapted to be responsive to a difference between mask pressure and ambient pressure to effect a seal with a face region of a patient,

wherein the chamber extends only around a portion of the perimeter of the cushioning structure such that the chamber with first and second filling materials is provided in cheek and lip regions of the cushioning structure and a solid silicone portion is provided in a nasal bridge region of the cushioning structure.

2. A patient interface according to claim 1 , wherein spacing between the free end of the thin membrane flap and the cushioning structure is different in different regions of the patient interface.

3. A patient interface according to claim 1 , wherein the cushioning structure and the thin membrane flap include adjacent surfaces that face one another and are spaced apart from one another by a gap.

4. A patient interface according to claim 1 , wherein the first and second filling materials are gel or gel-like materials.

5. A patient interface according to claim 1 , wherein the second filling material provides support and structure to the first filling material.

6. A patient interface according to claim 1 , wherein the cushioning structure and seal forming structure are molded of LSR.

7. A patient interface according to claim 1 , wherein a width of each of the first and second filling materials is the same as a width of the chamber.

8. A patient interface according to claim 1 , wherein the cushioning structure is a nasal cushion, and the chamber with first and second filling materials is provided in cheek and upper lip regions of the cushion.

9. A patient interface according to claim 1 , wherein the first filling material and the second filling material are stacked in an axial direction.

10. A patient interface according to claim 1 , wherein the chamber is oriented, curved, or contoured towards a breathing chamber of the patient interface to encourage bending or rolling towards the breathing cavity in use.

11. A patient interface according to claim 1 , wherein a ratio of height of the first filling material to the second filling material is different in different regions of the cushioning structure along its perimeter.

12. A patient interface according to claim 1 , wherein the first filling material has a Shore 000 hardness in the range of about 10 to about 20 and the second filling material has a Shore 000 hardness greater than about 45.

13. A patient interface according to claim 1 , wherein the first filling material has a Shore 000 hardness in the range of about 10 to about 15 and the second filling material has a Shore 000 hardness in the range of about 50 to about 60.

14. A patient interface according to claim 1 , wherein the seal forming structure is provided along the entire perimeter of the cushioning structure such that the thin membrane flap substantially covers the chamber and solid silicone portion of the cushioning structure.

15. A patient interface according to claim 1 , wherein each of the chamber and the solid silicone portion includes a free end portion that curves inwardly towards a breathing chamber of the patient interface.

16. A patient interface according to claim 1 , wherein walls of the chamber, the thin membrane flap, and the solid silicone portion are molded as a one piece component.

17. A patient interface according to claim 1 , wherein the chamber and the solid silicone portion provide a continuous support and stability structure to the thin membrane flap along the entire perimeter of the cushioning structure.