Mask and vent assembly therefor

• US 7,845,354 B2
• Filed: 11/19/2002
• Issued: 12/07/2010
• Est. Priority Date: 02/10/1997
• Status: Expired due to Fees

• Current Assignee: Resmed Limited (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Lithgow, Perry David, Kwok, Philip Rodney
• Primary Examiner(s): Erezo; Darwin P
• Application Number:
  US10/298,845
• Publication Number:
  US 20030079751A1
• Time in Patent Office: 2,940 Days
• Field of Search: 128/207.12, 128/207.13, 128/207.16, 128/205.25, 128/205.11, 128/205.24, 128/203.11, 128/202.27, 128/204.18, 128/201.25, 128/206.12, 128/206.21
• US Class Current: 128/207.12
• CPC Class Codes: A61D 7/00 Devices or methods for introducing solid, liquid, or gaseous remedies or other materials into or onto the bodies of animals for reproduction or fertilisation A61D19/00 ; devices for implanting pellets, radon seeds or the like A61M37/0069
• CPC Class Codes: A61M 16/0057 Pumps therefor
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0683 Holding devices therefor
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 2205/42 Reducing noise
• CPC Class Codes: A62B 18/02 Masks gas-masks for animals A62B18/06; masks for welders A61F9/06
• CPC Class Codes: A62B 18/10 Valves
• CPC Class Codes: B23P 11/02 by first expanding and then shrinking or vice versa, e.g. by using pressure fluids; by making force fits
• CPC Class Codes: Y10T 29/49872 Confining elastic part in socket

Abstract

A mask (10) for use with a system for supplying breathable gas pressurised above atmospheric pressure to a human or animal'"'"'s airways. The mask (10) includes a mask shell (12) which is, in use, in fluid communication with a gas supply conduit and a gas washout vent assembly (20). The gas washout vent assembly (20) includes at least one gas washout orifice (22) extending from a first side of the vent assembly (20) positioned, in use, adjacent the human or animal'"'"'s face and a second side positioned, in use, adjacent the atmosphere. The cross-sectional area of the orifice (22) at the first side is larger than the cross-sectional area of the orifice (22) at the second side.

Claims

1. A CPAP mask assembly for use with a system for supplying breathable gas pressurized above atmospheric pressure to a human or animal, the CPAP mask assembly including:

a mask having an inlet tube that is, in use, adapted to be in fluid communication with a gas supply conduit, said mask including a shell made of an elastomeric material, the shell being provided with a sealing membrane to provide a gas tight seal with the user in use, the shell and the sealing membrane defining a breathing chamber of the mask; and

a vent array provided as part of the shell, the vent array including four or more gas washout orifices extending through the elastomeric material of the shell, the orifices extending from an inner side of the vent assembly placed, in use, adjacent the human or animal'"'"'s face to an outer side placed, in use, adjacent atmosphere, the gas washout orifices being open in use,

wherein a cross-sectional area of each orifice at the inner side of the vent assembly is larger than a cross-sectional area of the orifice at the outer side of the vent assembly, each orifice having a transition portion that decreases in size from the inner side to the outer side, each said orifice being in communication with a source of pressurized gas in use.

2. A CPAP mask assembly as claimed in claim 1, wherein each of said orifices is separated from each of adjacent ones of said orifices by at least the diameter of the orifice at the outer side.

3. A CPAP mask assembly as claimed in claim 1, wherein the elastomeric material comprises silicone.

4. A CPAP mask assembly as claimed in claim 1, wherein an axis defined within the orifice extends substantially linearly from the inner side of the vent assembly to the outer side of the vent assembly.

5. A CPAP mask assembly as claimed in claim 1, wherein a thickness of the vent assembly is greater than an inner diameter of the orifice.

6. A mask assembly as claimed in claim 5, wherein a ratio of the thickness of the vent assembly to an outer diameter of the orifice is about 2.

7. A CPAP mask assembly as claimed in claim 1, wherein the orifice includes a cross-sectional contour that remains substantially constant in size upon application of pressurized gas at a level suitable for CPAP treatment.

8. A CPAP mask assembly as claimed in claim 1, wherein a ratio of an inner diameter at the inner side of the orifice to an outer diameter at the outer side of the orifice is about 2.

9. A CPAP mask assembly as claimed in claim 1, wherein the gas washout orifice is open in use at least during the inhalation and exhalation phases of the user'"'"'s breathing cycle.

10. A CPAP mask assembly as claimed in claim 1, wherein the four orifices are arranged in the general shape of a square.

11. A CPAP mask assembly as claimed in claim 1, wherein the mask includes a slotted lug on each side thereof for connecting the mask to a headgear strap to retain the mask in place relative to the user in use.

12. A CPAP mask assembly as claimed in claim 1, wherein the orifices are provided in two distinct groups on spaced and discrete lateral portions of the mask.

13. A CPAP mask assembly as claimed in claim 1, wherein the vent assembly includes at least six gas washout orifices.

14. A CPAP mask assembly as claimed in claim 1, wherein a ratio of the cross-sectional area of the inner side of the orifice to the cross-sectional area of the outer side of the orifice is about 2:

1.

15. A CPAP mask assembly as claimed in claim 1, wherein each of said orifices is separated from each of adjacent ones of said orifices by at least a diameter of the orifice at the outer side.

16. A CPAP mask assembly for use with a system for supplying breathable gas pressurized above atmospheric pressure to a human for treatment of obstructive sleep apnea, the CPAP mask assembly comprising:

a mask including a rigid plastic shell and a flexible seal to seal against the human in use; and

a vent assembly provided to exhaust CO₂-laden gas from the mask or a conduit provided to the mask, the mask or conduit including an opening delineated by a rim, the vent assembly comprising an insert attached to the mask or conduit and including a plurality of gas washout orifices, each orifice extending from an inner side of the insert to an outer side of the insert, each orifice being open in use,

wherein at least one portion of the insert includes an inner flange portion defining a first surface that engages an inner surface of the mask or conduit, and an outer flange portion defining a second surface that engages an outer surface of the mask or conduit, the first and second surfaces defining a recess or groove therebetween to receive the rim of the mask or conduit to retain connection between the insert and the mask or conduit, and

wherein a cross-sectional area of each orifice at the inner side of the insert is larger than a cross-sectional area of the orifice at the outer side of the insert.

17. A CPAP mask assembly as claimed in claim 16, wherein the insert comprises a material that is different from a material of the rim.

18. A CPAP mask assembly as claimed in claim 17, wherein the insert is less rigid compared to the material of the rim.

19. A CPAP mask assembly as claimed in claim 16, wherein a thickness of the vent assembly is greater than an inner diameter of each orifice.

20. A CPAP mask assembly as claimed in claim 16, wherein each orifice includes a cross-sectional contour that remains substantially constant in size upon application of pressurized gas at a level suitable for CPAP treatment.

21. A CPAP mask assembly as claimed in claim 16, wherein each orifice includes a cross-sectional contour that remains substantially constant in size upon application of pressurized gas less than about 18 cmH₂O.

22. A CPAP mask assembly as claimed in claim 16, wherein each orifice includes a cross-sectional contour that remains substantially constant in size upon application of pressurized gas in the range of 4-18 cmH₂O.

23. A CPAP mask assembly as claimed in claim 16, wherein each orifice includes a cross-sectional contour that remains substantially constant in size upon application of pressurized gas in the range of 5-15 cmH₂O.

24. A CPAP mask assembly as claimed in claim 16, wherein a ratio of a diameter at the inner side of each orifice to a diameter at the outer side of the orifice is about 2:

1.

25. A CPAP mask assembly as claimed in claim 16, wherein the mask includes a nose mask.

26. A CPAP mask assembly as claimed in claim 16, wherein the vent assembly includes six orifices.

27. A CPAP mask assembly as claimed in claim 26, wherein a length of each said orifice is greater than an inner diameter at the inner side of each said orifice.

28. A CPAP mask assembly as claimed in claim 16, wherein the shell includes a slotted lug on each side thereof for connecting the mask to a headgear strap to retain the mask in place relative to the user in use.

29. A CPAP mask assembly as claimed in claim 16, wherein each orifice includes a transition portion between the inner and outer sides that has a cross-sectional size or area that varies or tapers along at least a portion of a length thereof.

30. A CPAP mask assembly as claimed in claim 16, wherein each said orifice has a substantially round cross section along its length.

31. A CPAP mask assembly as claimed in claim 16, wherein the insert includes all of the orifices.

32. A CPAP mask assembly as claimed in claim 16, wherein the insert includes three or more gas washout orifices.

33. A CPAP mask assembly as claimed in claim 26, wherein the insert includes four or more gas washout orifices.

34. A CPAP mask assembly as claimed in claim 16, wherein the insert is provided to the mask.

35. A CPAP mask assembly as claimed in claim 16, wherein the insert is provided to the conduit.

36. The CPAP mask assembly as claimed in claim 16, wherein insert has a thickness that is greater than a surrounding thickness of the mask.

37. A CPAP mask assembly as claimed in claim 16, wherein the first and second surfaces, respectfully, extend at substantially right angles relative to a longitudinal axis of the washout orifices.

38. A CPAP mask assembly as claimed in claim 16, wherein a thickness of the recess or groove is approximately equal to a thickness of each of the inner and outer flange portions.

39. A CPAP mask assembly as claimed in claim 16, wherein the insert is sufficiently flexible to allow the insert to be squeezed through the opening after which it expands to engage the rim.

40. A CPAP mask assembly as claimed in claim 16, wherein the shell is made of polycarbonate.

41. A CPAP mask assembly as claimed in claim 16, wherein the mask includes an inlet tube.