Neck strap, crown strap assembly and headgear for a breathing mask

1. Neck strap for a headgear, comprising:

a one-piece main body adapted to engage a patient's neck, the main body including:

first and second lower connection portions adapted to connect to respective first and second lower mask connection straps, and

first and second upper connection portions adapted to connect to respective first and second lateral crown straps,

wherein the main body comprises two opposing major side edges and two opposing minor side edges that interconnect the opposing major side edges,

wherein the first upper connection portion and the first lower connection portion are located along a first of the two opposing minor side edges, and wherein the second upper connection portion and the second lower connection portion are located along a second of the two opposing minor side edges, and

wherein, in a flat state of the main body, each of the opposing major side edges comprises a curved portion.

2. The neck strap according to claim 1 , wherein each curved portion is concave.

3. The neck strap according to claim 1 , wherein the neck strap has at least partially a reduced width between the two opposing major side edges in the curved portion.

4. The neck strap according to claim 1 , wherein the first and/or second lower connection portion extends parallel to an adjacent portion of the respective minor side edge, and/or wherein the first and/or second upper connection portion extends parallel to an adjacent portion of the respective minor side edge.

5. The neck strap according to claim 4 , wherein the first and second upper connection portions and/or the adjacent portions of the minor side edges are adapted to be oriented in an acute angle to a main axis of extension of the respective first and second lateral crown straps.

6. The neck strap according to claim 1 , wherein the first and/or second lower connection portion and/or respective portions of the minor side edges is/are adapted to be oriented substantially perpendicular to a main axis of extension of the respective first and/or second lower mask connection strap.

7. The neck strap according to claim 1 , wherein the neck strap is symmetrical to a first axis, wherein the first axis in an application position is parallel to the sagittal plane of a patient.

8. The neck strap according to claim 7 , wherein the neck strap includes a second axis that extends perpendicular to the first axis.

9. The neck strap according to claim 8 , wherein a width perpendicular to the second axis of the neck strap is lowest between the curved portion of the two opposing major side edges of the main body.

10. The neck strap according to claim 1 , wherein the major side edges and/or the minor side edges are rounded.

11. A three-dimensionally formed crown strap assembly for a headgear, comprising:

a top crown strap,

first and second lateral crown straps, and

the neck strap according to claim 1 .

12. The crown strap assembly according to claim 11 , wherein the crown strap assembly has a generally round three-dimensional shape adapted to cup the parietal bone and occipital bone of the patient's head in use.

13. Headgear, comprising:

the crown strap assembly according to claim 11 , and

upper mask connection straps.

14. 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 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 cmH 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 seal-forming structure adapted to form a seal against the patient's airways;

a positioning and stabilising structure to maintain the seal-forming structure 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 plenum chamber pressurised at a pressure above ambient pressure in use; and

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;

wherein the positioning and stabilising structure includes a headgear including a crown strap assembly, first and second upper connection straps provided to the crown strap assembly and adapted to connect to respective upper headgear connectors of the patient interface, and first and second lower connection straps provided to the crown strap assembly and adapted to connect to respective lower headgear connectors of the patient interface,

the crown strap assembly including the neck strap according to claim 1 , first and second lateral crown straps and a top crown strap adapted to cup the parietal bone and the occipital bone of the patient's head.

15. The neck strap according to claim 1 , wherein the main body is adapted to extend in a common plane when laying on a flat surface, and each of the opposing major side edges comprises the curved portion when the neck strap is laying on the flat surface.

16. The neck strap according to claim 1 , wherein each of the two opposing major side edges is longer than each of the two opposing minor side edges.

17. The neck strap according to claim 1 , wherein a width between the two opposing major side edges in the curved portion is less than a width between the two opposing minor side edges.