Respiratory mask having gas washout vent and gas washout vent assembly for respiratory mask
View Patent ↗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 mm 2 . In another embodiment the vent assembly comprises a membrane attached to a vent frame, the vent assembly forming an insert which can be removably attached to a mask frame.
1. A respiratory mask comprising:
a patient interface structured for conmuinication with a patient's airways in use;
a gas inlet to supply pressurized breathable gas in the range of 3–20 cm H 2 O 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 CO 2 washout at a lowest end of the pressure range, a total open area of a superficial surface area of the vent portion being about 5%, wherein the patient interface includes a mask frame and a cushion provided to the mask frame, the holes in the vent portion have a length of about 0.45 mm.
2. A respiratory mask according to claim 1 , wherein a diameter of each of the holes is less than about 0.2 mm.
3. A respiratory mask according to claim 2 , wherein the diameter is about 0.1 mm.
4. A respiratory mask according to claim 2 , wherein the holes are tapered.
5. A respiratory mask according to claim 2 , wherein the total area of the vent portion is about 322 mm 2 .
6. A respiratory mask according to claim 2 , wherein the holes are laser cut.
7. A respiratory mask according to claim 1 , wherein the vent area is provided to the gas inlet.
8. A respiratory mask according to claim 7 , wherein the gas inlet is formed on a swivel elbow.
9. A respiratory mask according to claim 7 , wherein the gas inlet includes an in-line vent provided with the vent portion.
10. A respiratory mask according to claim 1 , wherein the patient interface includes a nose mask, a nose-mouth mask, a full-face mask, nasal prongs or nasal pillows.
11. 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 a surface area, a thickness, and a plurality of 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 CO 2 washout during patient breathing, wherein the thickness of the portion is less than 3 mm and the total open area is about 5% or greater.
12. The respiratory mask according to claim 11 , wherein the thickness is about 0.5 mm or less.
13. The respiratory mask according to claim 11 , wherein the total open area is 20% or greater.
14. A respiratory mask according to claim 11 , wherein a diameter of each of the holes is about 0.2 mm or less.
15. A respiratory mask comprising:
a patient interface;
a breathable gas inlet to provide pressurized gas to a breathing cavity formed at least in part by the patient interface when the mask is in use; and
a gas washout vent portion having a plurality of holes extending therethrough, each said hole having a diameter selected to allow gas to quietly exit from the breathing cavity, wherein:
the vent portion has a thickness of less than about 3 mm, and
the vent portion is made of a hydrophobic material.
16. A respiratory mask according to claim 15 , wherein the diameter is about 0.2 mm or less.
17. A respiratory mask comprising:
a patient interface structured for communication with a patient's airways in use, the patient interface including a mask frame and a nasal cushion provided to the mask frame;
a gas inlet to supply pressurized breathable gas in the range of 3–20 cm H 2 O to the patient interface; and
a gas washout vent portion provided to the mask frame and having a plurality of holes therein, said holes having a diameter selected to allow adequate CO 2 washout 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, a second end positioned on an outer surface of the mask, and a tapered portion between the first and second ends, and wherein the first end has a diameter that is smaller than a diameter of the second end.
18. A respiratory mask according to claim 17 , wherein plurality of rows includes at least 3 rows.
19. A respiratory mask according to claim 17 , wherein the plurality of rows includes at least 2 rows each having at least 5 of said holes.
20. A respiratory mask according to claim 17 , wherein the plurality of holes includes at least 10 holes.
21. A respiratory mask according to claim 20 , wherein the plurality of holes includes at least 20 holes.
22. A respiratory mask according to claim 21 , wherein the plurality of holes includes at least 30 holes.
23. A respiratory mask according to claim 21 , wherein said vent portion includes at least two discrete portions.
24. A respiratory mask according to claim 17 , 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.
25. A respiratory mask according to claim 24 , wherein the open area is about 5%–15%.
26. A respiratory mask according to claim 17 , wherein the open area is greater than 1%.
27. A respiratory mask according to claim 17 , wherein each said hole has a length of about 0.5 mm.
28. A respiratory mask comprising:
a patient interface structured for communication with a patient's airways in use, the patient interface, including a mask frame and a nasal cushion provided to the mask frame;
a gas inlet to supply pressurized breathable gas in the range of 3–20 cm H 2 O to the patient interface; and
a gas washout vent portion provided to the mask frame and having a plurality of holes therein, said holes having a diameter selected to allow adequate CO 2 washout 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, a second end positioned on an outer surface of the mask, and a tapered portion between the first and second ends, and wherein the first end has a diameter that is larger than a diameter of the second end.
29. A respiratory mask comprising:
a patient interface including a frame portion and a nasal mask;
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 a surface area, a thickness, and a plurality of 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 CO 2 washout during patient breathing, wherein the plurality of holes includes at least 10 holes that extend through the frame portion, and
wherein each of the holes has a first end positioned on an inside surface of the mask, a second end positioned on an outer surface of the mask, and a tapered portion between the first and second ends, and wherein the first end has a diameter that is smaller than a diameter of the second end.
30. A respiratory mask according to claim 29 , wherein the total open area is about 5% or more.
31. The respiratory mask according to claim 30 , wherein the total open area is less than 25%.
32. A respiratory mask according to claim 29 , wherein each said hole has a length of about 0.5 mm.
33. A respiratory mask comprising:
a patient interface including a frame portion and a nasal mask;
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 a surface area, a thickness, and a plurality of 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 CO 2 washout during patient breathing, wherein the plurality of holes includes at least 10 holes that extend through the frame portion, and
wherein each of the holes has a first end positioned on an inside surface of the mask, a second end positioned on an outer surface of the mask, and a tapered portion between the first and second ends, and wherein the first end has a diameter that is larger than a diameter of the second end.
34. A respiratory mask comprising:
a patient interface having a frame portion and a nasal cushion;
a breathable gas inlet to provide pressurized gas to a breathing cavity formed at least in part by the patient interface when the mask is in use; and
a gas washout vent portion provided on the frame and having a plurality of 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:
the vent portion has a thickness of less than about 3 mm, and
the vent portion includes at least 20 of said holes, said holes being 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 6 rows each including at least 3 of said holes.
37. A respiratory mask according to claim 36 , wherein the plurality of rows includes at least 8 rows each including at least 3 of said holes.
38. 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.
39. A respiratory mask according to claim 34 , wherein each of the holes has a first end positioned on an inside surface of the mask, a second end positioned on an outer surface of the mask, and a tapered portion between the first and second ends, and wherein the first end has a diameter that is smaller than a diameter of the second end.
40. A respiratory mask according to claim 34 , wherein each said hole has a length of about 0.5 mm.