Wire heated tube with temperature control system, tube type detection, and active over temperature protection for humidifier for respiratory apparatus

Patent metadata

Field	Value
Publication number	US-10086158-B2
Application number	US-201414219036-A
Country	US
Kind code	B2
Filing date	Mar 19, 2014
Priority date	Jul 31, 2009
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A PAP system for delivering breathable gas to a patient includes a flow generator to generate a supply of breathable gas to be delivered to the patient; a humidifier including a heating plate to vaporize water and deliver water vapor to humidify the supply of breathable gas; a heated tube configured to heat and deliver the humidified supply of breathable gas to the patient; a power supply configured to supply power to the heating plate and the heated tube; and a controller configured to control the power supply to prevent overheating of the heating plate and the heated tube.

First claim

What is claimed is:

1. A method of preventing overheating in a respiratory system comprising (1) a flow generator configured to pressurize a supply of breathable gas, (2) a humidifier with a heating plate configured to vaporize a supply of water and deliver water vapor to humidify the supply of breathable gas and (3) a tube adapted to deliver the supply of humidified pressurized breathable gas to a patient interface, the method comprising:
sensing an ambient temperature using an ambient temperature sensor;
sensing a temperature of the heating plate using a heating plate temperature sensor;
determining whether a combination of the sensed ambient temperature and the sensed heating plate temperature is implausible; and
preventing heating of the heating plate when the combination of the sensed ambient temperature and the sensed heating plate temperature is determined to be implausible.

2. A method according to claim 1 , wherein determining whether the combination of the sensed ambient temperature and the sensed heating plate temperature is implausible comprises:
comparing the sensed heating plate temperature with a first heating plate threshold; and
comparing the sensed ambient temperature with a first ambient threshold,
wherein the first heating plate threshold is a temperature limit for the heating plate and the first ambient threshold is a temperature limit for the ambient temperature.

3. A method according to claim 2 , wherein a combination of the sensed ambient temperature and the sensed heating plate temperature is determined to be implausible if the sensed heating plate temperature is less than the first heating plate threshold and the sensed ambient temperature is greater than the first ambient threshold.

4. A method according to claim 3 , further comprising:
displaying a first error message when the combination of the sensed ambient temperature and the sensed heating plate temperature is determined to be implausible.

5. A method according to claim 4 , wherein the heating plate is prevented from being heated and the first error message is displayed when the combination of the sensed ambient temperature and the sensed heating plate temperature is determined to be implausible for an elapsed period of time as long as the elapsed period of time is less than a predetermined maximum period of time.

6. A method according to claim 5 , further comprising:
stopping operation of the respiratory system when the combination of the sensed ambient temperature and the sensed heating plate temperature is determined to be implausible for the elapsed time and the elapsed period of time is greater than the predetermined maximum period of time.

7. A method according to claim 6 , further comprising:
displaying a second error message when the combination of the sensed ambient temperature and the sensed heating plate temperature is determined to be implausible for the elapsed period of time and the elapsed period of time is greater than the predetermined maximum period of time.

8. A method according to claim 7 , wherein the first heating plate threshold is between 0° C. and 4° C.

9. A method according to claim 8 , wherein the first heating plate threshold is about 2° C.

10. A method according to claim 7 , wherein the first ambient threshold is between 3° C. and 8° C.

11. A method according to claim 10 , wherein the first ambient threshold is about 5° C.

12. A method according to claim 7 , wherein the predetermined maximum period of time is between 10 minutes and 25 minutes.

13. A method according to claim 12 , wherein the predetermined maximum period of time is about 15 minutes.

14. A method according to claim 3 , further comprising:
preventing heating of the heating plate when the sensed heating plate temperature is less than a second heating plate threshold that is higher than the first heating plate threshold and the sensed ambient temperature is higher than a second ambient threshold that is higher than the first ambient threshold.

15. A method according to claim 14 , further comprising:
preventing heating of the heating plate when the sensed ambient temperature is higher than a third ambient threshold that is higher than the second ambient threshold.

16. A method according to claim 3 , further comprising:
stopping operation of the respiratory system when 1) the sensed heating plate temperature is less than a second heating plate threshold that is greater than the first heating plate threshold and the sensed ambient temperature is higher than a second ambient threshold that is greater than the first ambient threshold or 2) the sensed ambient temperature is higher than a third ambient threshold that is higher than the second ambient threshold.

17. A method according to claim 16 , further comprising:
displaying an error message when 1) the sensed heating plate temperature is less than the second heating plate threshold and the sensed ambient temperature is higher than the second ambient threshold, or 2) the sensed ambient temperature is higher than the third ambient threshold.

18. A method according to claim 17 , wherein the second heating plate threshold is about 25° C.

19. A method according to claim 18 , wherein the second ambient threshold is about 40° C.

20. A method according to claim 17 , wherein the third ambient threshold is between 45° C. and 55° C.

21. A method according to claim 20 , wherein the third ambient threshold is about 50° C.

22. A method according to claim 3 , wherein the tube is a heated tube and the method further comprises:
sensing a temperature of the heated tube using a heated tube temperature sensor; and
comparing the sensed heated tube temperature with the first ambient threshold.

23. A method according to claim 22 , further comprising:
preventing heating of the heated tube when the sensed heated tube temperature is less than the first ambient threshold.

24. A method according to claim 23 , further comprising:
displaying a first error message when the sensed heated tube temperature is less than the first ambient threshold.

25. A method according to claim 24 , wherein the heated tube is prevented from being heated and the first error message is displayed when the sensed heated tube temperature is less than the first ambient threshold for an elapsed period of time as long as the elapsed period of time is less than a predetermined maximum period of time.

26. A method according to claim 25 , further comprising:
stopping operation of the respiratory system when the sensed heated tube temperature is less than the first ambient threshold for the elapsed period of time and the elapsed period of time is greater than the predetermined maximum period of time.

27. A method according to claim 26 , further comprising:
displaying a second error message when the sensed heated tube temperature is less than the first ambient threshold for the elapsed period of time and the elapsed period of time is greater than the predetermined maximum period of time.

28. A method according to claim 22 , further comprising:
preventing heating of the heated tube when a percentage of power supplied from a power supply to the heated tube is equal to or greater than a power percentage threshold for an elapsed period of time and the sensed heated tube temperature is lower than a heated tube threshold for the elapsed period of time, and the elapsed peri

Assignees

• Resmed Ltd

Inventors

• Bath Andrew Roderick
• Richmond Donald Angus
• Row Nathan John
• Zhu Jianhua
• Shadie Timothy Nicholas
• Huby Ronald James
• Dujmovic Ivan Teodor

Classifications

• A61M2205/6018

  providing set-up signals for the apparatus configuration · CPC title

• A61M2205/582

  by tactile feedback · CPC title

• A61M2205/42

  Reducing noise · CPC title

• A61M2016/0027

  pressure meter · CPC title

• A61M16/161

  with means for measuring the humidity · CPC title