Humidifier with structure to prevent backflow of liquid through the humidifier inlet

• US 20040060559A1
• Filed: 08/07/2003
• Published: 04/01/2004
• Est. Priority Date: 02/16/2001
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Lithgow, Perry David, Jones, Richard Llewelyn, Virr, Alexander, Cheung, Andrew, Smith, Ian Malcolm
• Granted Patent: US 6,935,337 B2
• Time in Patent Office: Days
• US Class Current: 128/204.14
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/109 the humidifying liquid or the beneficial agent
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 2205/21 insensitive to tilting or inclination, e.g. spill-over prevention
• CPC Class Codes: Y10S 261/65 Vaporizers

Abstract

The present invention provides an apparatus (10, 30, 120, 170) for humidifying breathable gas including at least one humidifier part (12, 18, 36, 38, 40) configured to retain a body of liquid therein and defining at least one chamber (14, 16, 74, 76) therein, an inlet (22, 32) communicated with an interior of the at least one humidifier part (12, 18, 36, 38, 40) and connectable to a blower outlet, and an outlet (24, 34) communicated with the interior of the at least one humidifier part (12, 18, 36, 38, 40) and connectable to a patient supply conduit. The at least one chamber (14, 16, 74, 76) is arranged such that liquid from the body of liquid is prevented from exiting the at least one humidifier part (12, 18, 36, 38, 40) through the inlet (22, 32) thereof when the at least one humidifier part (12, 18, 36, 38, 40) is rotated from a working, upright orientation.

Claims

1. An apparatus (10, 30, 120, 170) for humidifying breathable gas comprising:

at least one humidifier part (12, 18, 36, 38, 40) configured to retain a body of liquid therein and defining at least one chamber (14, 16, 74, 76) therein;

an inlet (22, 32) communicated with an interior of the at least one humidifier part (12, 18, 36, 38, 40) and connectable to a blower outlet; and

an outlet (24, 34) communicated with the interior of the at least one humidifier part (12, 18, 36, 38, 40) and connectable to a patient supply conduit,

wherein the at least one chamber (14, 16, 74, 76) is arranged such that liquid from the body of liquid is prevented from exiting the at least one humidifier part (12, 18, 36, 38, 40) through the inlet (22, 32) thereof when the at least one humidifier part (12, 18, 36, 38, 40) is rotated from a working, upright orientation.

2. The apparatus (10, 30, 120, 170) according to claim 1, configured such that liquid from the body of liquid is prevented from exiting the at least one humidifier part (12, 18, 36, 38, 40) through the inlet (22, 32) thereof when the at least one humidifier part (12, 18, 36, 38, 40) is rotated from a working, upright orientation by about 120°

and, preferably when the at least one humidifier part (12, 18, 36, 38, 40) is rotated from a working, upright orientation by between 80 and 110° and

, more preferably when the at least one humidifier part (12, 18, 36, 38, 40) is rotated from a working, upright orientation by about 90°

.

3. The apparatus (10, 30, 120, 170) according to claim 1 or 2, wherein the at least one chamber includes a first chamber (16, 74) having an inlet (22, 32) and an outlet (20, 50), the first chamber inlet (22, 32) being connectable to a blower outlet, and a second chamber (14, 76) having an inlet (20, 50) connected to the first chamber outlet (20, 50), and an outlet (24, 34) connectable to the patient supply conduit, the second chamber (14, 76) having the carrying capacity for the body of liquid, wherein

when the at least one humidifier part (12, 18, 36, 38, 40) is disposed in the working upright orientation, the body of liquid is contained in the second chamber, and

relative positions of the first chamber inlet (22, 32) and outlet (20, 50) and volumes of the first and second chambers (16, 74, 14, 76) are adapted such that, in use, in orientations of the apparatus (10, 30, 120, 170) of up to about 90°

from the working upright orientation, the body of liquid is retained in either (a) the second chamber (14, 76), or (b) the first and second chambers (16, 74, 16, 74) at a level therewithin below a level of the first chamber inlet (20, 50).

4. The apparatus (10, 30, 120, 170) according to claim 3, wherein a volume of the second chamber (14, 76) is larger than a volume of the first chamber (16, 74).

5. The apparatus (10, 30, 120, 170) according to claims 3 or 4, wherein the first chamber (16, 74) is located substantially above the second chamber (14, 76) in the working upright orientation of the apparatus (10, 30, 120, 170).

6. The apparatus (10, 30, 120, 170) according to any of claims 3-5, wherein the first chamber inlet (22, 32) and outlet (20, 50) are diagonally opposed across the first chamber (16, 74).

7. The apparatus (10, 30, 120, 170) according to any of claims 3-6, wherein the second chamber outlet (24, 34) is located closer to the first chamber outlet (20, 50) than the first chamber inlet (22, 32).

8. The apparatus (10, 30, 120, 170) according to any of claims 3-7, wherein at least a portion of a base (62, 178) of the second chamber (14, 76) is made of a heat conducting material.

9. The apparatus (10, 30, 120, 170) according to claim 8, wherein the heat conductive portion is in the form of a metallic cap (174) which covers an opening (176) of the base (62, 178).

10. The apparatus (10, 30, 120, 170) according to any of claims 3-9, wherein the at least one humidifier part (12, 18, 36, 38, 40) includes a top cover (36), a base (40), and a divider (18, 38) disposed between the top cover (36) and base (40), wherein the base (40) defines a receptacle (60) formed therewithin, which retains the body of liquid in the working orientation of the apparatus (10, 30, 120, 170).

11. The apparatus (10, 30, 120, 170) according to claim 10, wherein the top cover (36) and the divider (18, 38) together define the first chamber (16, 74) and the receptacle (60) and the divider (18, 38) together form the second chamber (14, 76).

12. The apparatus (10, 30, 120, 170) according to claim 11, wherein the first chamber inlet (22, 32) and the second chamber outlet (24, 34) are formed in the top cover (36) and the first chamber outlet (20, 50) and the second chamber inlet (20, 50) are formed in the divider (18, 38), the first chamber outlet (20, 50) and the second chamber inlet (20, 50) being defined by a single aperture (20, 50) in the divider (18, 38) which communicates the first and second chambers (16, 74, 14, 76).

13. The apparatus (10, 30, 120, 170) according to any of claims 10-12, wherein the divider (18, 38) defines first and second sections (42, 44), the first section (44) together with the top cover (36) defining the first chamber (74).

14. The apparatus (10, 30, 120, 170) according to any of claims 10-13, wherein the divider (18, 38) includes a plurality of apertures (52), separated by ribs (54), which provide fluid communication from the second chamber (14, 76) to the second chamber outlet (24, 34) formed in the top cover (36).

15. The apparatus (10, 30, 120, 170) according to any of claims 10-14, wherein the top cover (36) and the base (40) are formed from a relatively rigid polymer material and the divider (18, 38) is formed from a relatively resilient material.

16. The apparatus (10, 30, 120, 170) according to any of claims 3-15, wherein (i) the first chamber inlet (22, 32) is connected to a blower outlet, (ii) the first chamber outlet (20, 50) is connected to the second chamber inlet (20, 50), (iii) the second chamber outlet (24, 34) is connected to the patient supply conduit, and (iv) a portion of the second chamber (14, 76) below and behind the second chamber inlet (20, 50) defines a volume thereof greater than a volume of the body of liquid.

17. The apparatus (10, 30, 120, 170) according to any of claims 3-16, wherein a portion of the second chamber (14, 76) between the first chamber inlet (22, 32) and the second chamber inlet (20, 50) and below the second chamber inlet (20, 50) defines a volume thereof greater than the volume of the body of liquid.

18. The apparatus (10, 30, 120, 170) according to any of claims 3-16, wherein portions of the first chamber (16, 74) and second chamber (14, 76) between the first chamber inlet (22, 32) and the second chamber outlet (24, 34) define a volume thereof greater than the volume of the body of liquid.

19. A CPAP apparatus including an apparatus (10, 30, 120, 170) for humidifying breathable gas according to any of claim 1-18.