Respiratory mask having gas washout vent & gas washout vent assembly for a respiratory mask

• US 20060196509A1
• Filed: 04/28/2006
• Published: 09/07/2006
• Est. Priority Date: 05/15/2000
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Virr, Alexander, Crumblin, Geoffrey, Drew, Joanne
• Granted Patent: US 7,926,487 B2
• Time in Patent Office: Days
• US Class Current: 128/206.21
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0633 with forehead support
• CPC Class Codes: A61M 16/0638 in the form of a pivot
• CPC Class Codes: A61M 16/0644 having the means for adjusting its position
• CPC Class Codes: A61M 16/065 in the form of a pivot
• CPC Class Codes: A61M 16/0683 Holding devices therefor
• CPC Class Codes: A61M 16/0816 Joints or connectors
• CPC Class Codes: A61M 16/0825 with ball-sockets
• CPC Class Codes: A61M 16/22 Carbon dioxide-absorbing devices ; Other means for removing carbon dioxidecartridges with absorbing substances for respiratory apparatus A62B19/00
• CPC Class Codes: A61M 2202/0085 product washed out
• CPC Class Codes: A61M 2202/0225 Carbon oxides, e.g. Carbon dioxide
• CPC Class Codes: A61M 2205/42 Reducing noise
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes
• CPC Class Codes: A62B 18/02 Masks gas-masks for animals A62B18/06; masks for welders A61F9/06

Abstract

The present invention provides a vent assembly suitable for use with a respiratory mask of the type used in CPAP treatment. In one embodiment the vent is made of a thin air permeable membrane. Generally, the membrane is thinner than 0.5 mm. The membrane can be made of a hydrophobic material such as polytetrafluoroethylene (PTFE). The membrane can also be fabricated from expanded PTFE. The expanded PTFE membrane is mounted on a polypropylene scrim. The pores of the membrane have a reference pore size of 10 to 15 microns. In an alternative embodiment, the vent assembly includes a vent constructed from stainless steel. In another embodiment the membrane has a superficial cross-sectional area of approximately 500 mm². In another embodiment the vent assembly comprises a membrane attached to a vent frame, the vent assembly forming an insert which can be removeably attached to a mask fame.

Claims

1-14. -14. (canceled)

15. A respiratory mask comprising:

a patient interface structured for communication with a patient'"'"'s airways in use;

a gas inlet to supply pressurized breathable gas in the range of 3-20 cm H₂O to the patient interface; and

a gas washout vent portion having a plurality of holes therein, said holes having a diameter selected to allow adequate CO₂ washout from the patient interface at a lowest end of the pressure range,

wherein said plurality of holes is arranged in a plurality of rows, each said row having at least 3 of said holes, and

wherein each of the holes has a first end positioned on an inside surface of the mask and a second end positioned on an outer surface of the mask, and wherein the first end has a diameter that is larger than a diameter of the second end.

16. A respiratory mask according to claim 15, wherein the patient interface comprises a nasal mask.

17. A respiratory mask according to claim 15, wherein the patient interface comprises nasal prongs or pillows.

18. A respiratory mask according to claim 15, wherein each said hole has a length of about 0.5 mm.

19. A respiratory mask according to claim 15, wherein the plurality of holes includes at least 20 holes.

20. A respiratory mask according to claim 15, wherein the plurality of holes includes at least 30 holes.

21. A respiratory mask according to claim 15, wherein the vent portion is structured such that a total open area of a superficial surface area of the vent portion is about 5-25% or larger.

22. A respiratory mask according to claim 21, wherein the open area is about 5%-15%.

23. A respiratory mask according to claim 15, wherein the open area is greater than 1%.

24. A respiratory mask comprising:

a patient interface;

a breathable gas inlet to provide pressurized gas to the patient interface when the mask is in use; and

a gas washout vent including an air permeable portion to allow gas to exit from the patient interface, wherein the portion has at least ten through holes each having a length, a diameter, and a total open area due to the presence of the holes that are selected to help eliminate or reduce noise while maintaining sufficient CO₂ washout during patient breathing, and

wherein each of the holes has a first end positioned on an inside surface of the mask and a second end positioned on an outer surface of the mask, and wherein the first end has a diameter that is smaller than a diameter of the second end.

25. A respiratory mask according to claim 24, wherein the total open area is about 5% or more.

26. The respiratory mask according to claim 24, wherein the total open area is less than 25%.

27. A respiratory mask according to claim 24, wherein the patient interface comprises a nasal mask.

28. A respiratory mask according to claim 24, wherein the patient interface comprises nasal prongs or pillows.

29. A respiratory mask comprising:

a cushion;

a breathable gas inlet to provide pressurized gas to the patient via the cushion when the mask is in use; and

at least one gas washout vent to allow gas to exit from the mask, wherein the washout vent has at least twenty through holes each having a length and a diameter that are selected to help eliminate or reduce noise while maintaining sufficient CO₂ washout during patient breathing, and

wherein each of the holes has a first end positioned on an inside surface of the mask and a second end positioned on an outer surface of the mask, and wherein the first end has a diameter that is larger than a diameter of the second end.

30. A respiratory mask according to claim 29, wherein each said hole has a length of about 0.5 mm.

31. A respiratory mask according to claim 29, wherein the cushion comprises a nasal mask.

32. A respiratory mask according to claim 29, wherein the cushion comprises nasal prongs or pillows.

33. A respiratory mask according to claim 29, wherein there are at least thirty through holes and the washout vent includes two vent portions.

34. A respiratory mask comprising:

a patient interface having a frame portion and a nose contacting portion in the form of nasal prongs or pillows;

a breathable gas inlet to provide pressurized gas to the patient interface when the mask is in use; and

a gas washout vent portion provided on the frame portion and having at least twenty through holes extending through the frame portion, said holes having a diameter and shape selected to allow gas to quietly exit from the breathing cavity, wherein said holes are arranged in a plurality of rows.

35. A respiratory mask according to claim 34, wherein the plurality of rows includes at least 4 rows each including at least 3 of said holes.

36. A respiratory mask according to claim 35, wherein the plurality of rows includes at least 5 rows each including at least 3 of said holes.

37. A respiratory mask according to claim 34, wherein each of the holes has a first end positioned on an inside the mask and a second end positioned on an outer surface of the mask, and wherein the first end has a diameter that is larger than a diameter of the second end.

38. A respiratory mask according to claim 34, wherein each of the holes has a first end positioned on an inside surface of the mask and a second end positioned on an outer surface of the mask, and wherein the first end has a diameter that is smaller than a diameter of the second end.

39. A respiratory mask according to claim 34, wherein each said hole has a length of about 0.5 mm.

40. A respiratory mask according to claim 34, wherein each hole has a diameter of less than 0.2 mm.

41. A respiratory mask according to claim 34, wherein each hole has a diameter of less than 0.1 mm.

42. A CPAP apparatus comprising:

a blower to generate pressurized gas in the range of 3-20 cm H₂O; and

a mask according to claim 34.

43. A respiratory mask according to claim 34, further comprising an adjustable forehead support provided above the patient interface.

44. A respiratory mask according to claim 34, wherein the vent portion is provided on the frame portion.

45. A respiratory mask according to claim 34, wherein the vent portion is provided on the gas inlet.