Method and apparatus for humidification of breathable gas by condensation and/or dehumidification

• US 7,525,663 B2
• Filed: 08/19/2005
• Issued: 04/28/2009
• Est. Priority Date: 08/20/2004
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Kwok, Philip Rodney, Darkin, Donald
• Primary Examiner(s): Pham; Hoa Q
• Application Number:
  US11/207,007
• Publication Number:
  US 20060037613A1
• Time in Patent Office: 1,348 Days
• Field of Search: 356432-440, 356/445, 374/28, 250/227.25, 250/221, 250/573, 250/574, 128/203.27, 128/203.26, 128/203.16
• US Class Current: 356/436
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/1055 bacterial
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 16/161 with means for measuring the humidity
• CPC Class Codes: A61M 2205/3673 thermo-electric, e.g. Peltier effect, thermocouples, semi-conductors

Abstract

A method and apparatus for humidifying breathable gas provided to a user includes providing a breathable gas, producing moisture or water derived from ambient environmental surroundings, e.g., via condensation and/or dehumidified air, and directing the breathable gas along an air flow path. The air flow path optionally includes access to at least a portion of the moisture or water for increased humidification of the breathable gas, for delivery to the user.

Claims

1. A condensation sensor arranged to detect condensation, said sensor comprising:

an emitter to emit light towards a location in a mask system or positive airway pressure (PAP) device where condensation is likely to beed or pool; and

a detector structured to receive the emitted light in dependence on the condensation present at the location.

2. The condensation sensor according to claim 1, wherein the emitter and the detector are positioned on a common side of the location, such that the emitted light is reflected from a surface of the location towards the detector if condensation is present.

3. The condensation sensor according to claim 1, wherein the emitter and the detector are positioned on opposite sides of the location, such that the emitted light passes through a surface of the location towards the detector at substantially full intensity if no condensation is present.

4. The condensation sensor according to claim 3, wherein only a portion of the emitted light passes through the surface towards the detector if condensation is present.

5. The condensation sensor according to claim 3, further comprising a controller that receives a light intensity signal from the detector, wherein the controller produces a negative condensation signal if the light intensity signal is equal to or greater than a predetermined full intensity signal, and the controller produces a positive condensation signal if the light intensity signal is less than the predetermined full intensity signal.

6. The condensation sensor according to claim 1, wherein the location is proximate to a bottom of a patient interface of the mask system.

7. The condensation sensor according to claim 1, further comprising a processor configured to determine an amount of condensation proximate to the location.

8. The condensation sensor according to claim 7, wherein the processor is further configured to determine whether the amount of condensation proximate to the location is a therapeutically adequate level of condensation.

9. The condensation sensor according to claim 1, wherein the emitted light is infrared light.

19. A respiratory assistance apparatus, comprising:

a mask;

a flow generator; and

a condensation sensor according to claim 1.

10. A method of detecting condensation, the method comprising:

emitting light towards a location in a mask system or positive airway pressure (PAP) device where condensation is likely to beed or pool via an emitter; and

receiving, via a detector, emitted light emitted via the emitter in dependence on the condensation present at the location.

11. The method according to claim 10, further comprising positioning the emitter and the detector on a common side of the location, such that the emitted light is reflected from a surface of the location towards the detector if condensation is present.

12. The method according to claim 10, further comprising positioning the emitter and the detector on opposite sides of the location, such that the emitted light passes through a surface of the location towards the detector at substantially full intensity if no condensation is present.

13. The method according to claim 12, wherein only a portion of the emitted light passes through the surface towards the detector if condensation is present.

14. The method according to claim 12, further comprising providing a controller arranged to receive a light intensity signal from the detector, wherein the controller is configured to produce a negative condensation signal when the light intensity signal is equal to or greater than a predetermined full intensity signal, and wherein the controller is configured to produce a positive condensation signal if the light intensity signal is less than the predetermined full intensity signal.

15. The method according to claim 10, wherein the location is proximate to a bottom of a patient interface of the mask system.

16. The method according to claim 10, further comprising determining an amount of condensation proximate to the location.

17. The method according to claim 16, further comprising determining whether the amount of condensation proximate to the location is a therapeutically adequate level of condensation.

18. The method according to claim 10, wherein the emitted light is infrared light.