NZ778731B2 - Patient Interface With A Seal-Forming Structure Having Varying Thickness - Google Patents

Abstract

cushion assembly for 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 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 4 cmH2O to about 30 cmH2O above ambient air pressure in use, throughout the patient's respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered breathing, the cushion assembly comprising: an elastomeric seal-forming structure that is shaped to be bisected by a sagittal plane having a line that is tangent to the elastomeric seal-forming structure at a superior tangent point and at an inferior tangent point, wherein a saddle-shaped superior region of the elastomeric seal-forming structure straddles the sagittal plane and includes the superior tangent point, wherein the elastomeric seal-forming structure transitions in a cylinder-shaped superior region from the saddle-shaped region to a dome-shaped superior region offset from the sagittal plane, and wherein an elastomeric wall thickness of the elastomeric seal-forming structure is greater in the cylinder-shaped superior region than in the saddle-shaped superior region and the dome-shaped superior region.

Claims (14)

1. A cushion assembly for 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 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 4 cmH2O to about 30 cmH2O above ambient air pressure in use, throughout the patient’s respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered breathing, the cushion assembly comprising: an elastomeric seal-forming structure that is shaped to be bisected by a sagittal plane having a line that is tangent to the elastomeric seal-forming structure at a superior tangent point and at an inferior tangent point, wherein a saddle-shaped superior region of the elastomeric seal-forming structure straddles the sagittal plane and includes the superior tangent point, wherein the elastomeric seal- forming structure transitions in a cylinder-shaped superior region from the saddle-shaped region to a dome-shaped superior region offset from the sagittal plane, and wherein an elastomeric wall thickness of the elastomeric seal-forming structure is greater in the cylinder-shaped superior region than in the saddle-shaped superior region and the dome- shaped superior region.

2. The cushion assembly of claim 1, wherein the thickened elastomeric wall in the cylinder- shaped superior region is configured to reduce crinkling of the saddle-shaped superior region when the saddle-shaped superior region is subject to a compressive force.

3. The cushion assembly of any one of claims 1 to 2, wherein the elastomeric wall thickness in the cylinder-shaped superior region increases in the direction of the curvature of the cylinder- shaped superior region.

4. The cushion assembly of any one of claims 1 to 3, wherein the elastomeric wall thickness in the dome- shaped superior region increases in the same direction as the cylinder-shaped superior region.

5. The cushion assembly of any one of claims 1 to 4, wherein the elastomeric seal- forming structure comprises a saddle-shaped inferior region that includes the inferior tangent point.

6. The cushion assembly of claim 5, wherein the saddle-shaped superior region and the saddle-shaped inferior region have the same elastomeric wall thickness.

7. The cushion assembly of any one of claims 5 to 6, wherein the elastomeric wall thickness of the elastomeric seal-forming structure is invariable within a continuous portion of the elastomeric seal-forming structure extending from the saddle-shaped inferior region to the saddle-shaped superior region.

8. The cushion assembly of any one of claims 5 to 7, wherein the elastomeric seal- forming structure further comprises a dome-shaped inferior region positioned between the saddle-shaped inferior region and the dome-shaped superior region.

9. The cushion assembly of claim 8, wherein the elastomeric seal-forming structure further comprises a cylinder-shaped side region that connects the dome-shaped inferior region to the dome-shaped superior region.

10. The cushion assembly of claim 9, wherein an elastomeric wall thickness of the cylinder- shaped side region and the dome-shaped inferior region is greater than an elastomeric wall thickness in the saddle-shaped superior region and the saddle-shaped inferior region.

11. The cushion assembly of any one of claims 9 to 10, wherein the dome-shaped superior region and the cylinder-shaped side region transitions into a loop structure that curves in the direction of the curvature of the cylinder-shaped side region.

12. The cushion assembly of claim 11, wherein an elastomeric wall thickness of the loop structure increases in a direction away from the cylinder-shaped side region.

13. A patient interface comprising: the cushion assembly of any one of claims 1 to 12; a rigid shell removably connected to the cushion assembly; and headgear removably attached to the rigid shell.

14. A CPAP system comprising: a patient interface according to claim 13; a flow generator configured to pressurize a flow of gas; and an air delivery tube configured to deliver the pressurized gas to the patient interface.