Air pressure signal monitoring in apparatus for treating sleep disordered breathing

• US 20040055597A1
• Filed: 08/07/2003
• Published: 03/25/2004
• Est. Priority Date: 02/16/2001
• Status: Active Grant

• Current Assignee: Resmed Limited (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Jones, Richard Llewelyn, Cheung, Andrew, Lithgow, Perry David, Virr, Alexander, Smith, Ian Malcolm
• Granted Patent: US 7,137,388 B2
• Time in Patent Office: Days
• US Class Current: 128/203.12
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2205/21 insensitive to tilting or inclination, e.g. spill-over prevention

Abstract

A humidifier is provided including a first humidifier part, a second humidifier part connectable with the first humidifier part, and a sealing gasket disposed between the first and second humidifier parts. The second humidifier part is configured to hold a volume of liquid therein and the first and second humidifier parts and the sealing gasket define first and second internal passages within the humidifier. The first passage is disposed so as to be exposed to a surface of the volume of liquid and the second passage is isolated from at least one of the first passage and the surface of the volume of liquid. The second passage is configured to communicate with a pressure and/or sound sensing device.

Claims

1. A humidifier (10) comprising:

a first humidifier part (20),

a second humidifier part (24) connectable with the first humidifier part (20), and

a sealing gasket (22) disposed between the first and second humidifier parts (20, 24);

wherein

the second humidifier part (24) is configured to hold a volume of liquid therein, the first and second humidifier parts (20, 24) and the sealing gasket (22) define first and second internal passages (99, 80) within the humidifier (10), and the first passage (99) is disposed so as to be exposed to a surface of the volume of liquid and the second passage (80) being isolated from at least one of the first passage (99) and the surface of the volume of liquid, the second passage (80) being configured to communicate with a pressure and/or sound sensing device.

2. The humidifier (10) according to claim 1, wherein the first and second humidifier parts (20, 24) are separable from one another in a manner such that walls (46, 54, 56) of the first and second internal passages (99, 80) are substantially entirely exposed.

3. The humidifier (10) according to claim 1 or 2, wherein a portion of an internal surface of the first humidifier part (20) defines at least one internal wall of the second internal passage (80).

4. The humidifier (10) according to claim 3, wherein the first humidifier part (20) includes a top wall (52), a peripherally extending side wall (54) extending downwardly from the top wall (52), and an internal wall structure (56) extending downwardly from the top wall (52) generally parallel to and inwardly spaced from the peripherally extending side wall (54), and the internal wall structure (56), portions of the top wall (52), and portions of the peripherally extending side walls (54) define corresponding internal walls of the second internal passage (80).

5. The humidifier (10) according to claim 4, wherein a portion of a surface of the sealing gasket (22) defines a corresponding internal wall of the second internal passage (80).

6. The humidifier (10) according to any of claims 1-5, wherein the first humidifier part (20) includes first and second inlet tubes (16, 18) and an outlet tube (14), the first inlet tube (16) and outlet tube (14) being communicated with the first internal passage (99), and the second inlet tube (18) and the outlet tube (14) being communicated with the second internal passage (80).

7. The humidifier (10) according to claim 6, wherein the outlet tube (14) extends from the internal wall structure (56) of the first humidifier part (20) in such a manner to be communicated with the first internal passage (99) to outside of the humidifier (10), and the second internal passage (80) is communicated with the outlet tube (14) via at least one aperture (62) formed in the outlet tube (14).

8. The humidifier (10) according to claim 7, wherein the at least one aperture (62) is provided by a pair of apertures.

9. The humidifier (10) according to claim 7 or 8, wherein the first inlet tube (16) extends from the internal wall structure (56) of the first humidifier part (20) in such a manner to be communicated with the first internal passage (99) to outside of the humidifier (10), and the second inlet tube (18) extends from the peripherally extending side wall (54) of the first humidifier part (20) in such a manner to be communicated with the second internal passage (80) to the aperture (62) within the outlet tube (14).

10. The humidifier (10) according to claim 9, wherein the second inlet tube (18) is coaxial with and surrounds the first inlet tube (16).

11. The humidifier (10) according to any of claims 1-10, wherein the first and second humidifier parts (20, 24) are formed from a relatively rigid polymer material and the sealing gasket (22) is formed from a relatively resilient material.

12. The humidifier (10) according to any of claims 1-11, further comprising a heater (152) configured to raise a temperature of the volume of liquid within the humidifier (10).

13. The humidifier (10) according to any of claims 1-5 and 11-12, wherein the inlet includes first and second inlet portions directed to the first and second internal passages, respectively.

14. The humidifier (10) according to claim 13, wherein the first and second inlet portions are coaxial.

15. A CPAP apparatus including a humidifier according to any of claims 1-14.

16. A method of determining pressure within a conduit supplying breathable gas from a CPAP apparatus to a patient mask, the method comprising:

providing a humidifier (10) with first and second internal passages (99, 80) therein, wherein the first passage (99) is disposed within the humidifier (10) so as to be exposed to a surface of a volume of liquid present within the humidifier (10) and the second passage (80) is isolated from the first passage (99);

supplying the breathable gas to a first inlet tube (16) of the humidifier (10) in communication with the first internal passage (99) so that breathable gas flowing therethrough is humidified by contact with the volume of liquid and is communicated with an outlet tube (14) of the humidifier (10);

providing an aperture (62) within the outlet tube (14) in communication with the second internal passage (80); and

measuring a pressure within the second internal passage (80) to determine pressure within the outlet tube (14).