Disposable airway adapter for use with a carbon dioxide detector

• US 6,190,327 B1
• Filed: 05/05/1999
• Issued: 02/20/2001
• Est. Priority Date: 05/05/1999
• Status: Active Grant

• Current Assignee: Nonin Medical Incorporated
• Original Assignee: Nonin Medical Incorporated
• Inventors: Johnson, Timothy L., Isaacson, Phillip O., Zinnel, Kathlean Cain, Kratoska, William F.
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): Natnithithadha, Navin
• Application Number:
  US09/305,517
• Time in Patent Office: 657 Days
• Field of Search: 600/529, 600/532, 73/233, 250/339.13, 250/341.1, 250/343, 250/353, 356/437
• US Class Current: 600/529
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices

Abstract

The invention is directed to a disposable airway adapter which includes two optical windows and a reflector, positioned such that radiation transmitted through the first optical window into the airway passage will be reflected by the reflector and be transmitted through the second optical window and out of the airway passage. the disposable airway adapter is for use in connection with a carbon dioxide detector for determining the concentration of carbon dioxide present in the mixture of gases present in the airway passage.

Claims

1. A disposable airway adapter tube comprising:

an adapter tube body defining an airway passage, the adapter tube body including first and second optical windows;

a reflector positioned in the airway passage;

the first and second optical windows being positioned relative to the reflector such that radiation transmitted through the first optical window into the airway passage will be reflected by the reflector and be transmitted through the second optical window and out of the airway passage.

2. The disposable airway adapter tube of claim 1, further in combination with a carbon dioxide detector.

3. The disposable airway adapter tube of claim 2, wherein the carbon dioxide detector is a semi-quantitative device.

4. The disposable airway adapter tube of claim 2, wherein the carbon dioxide detector is a capnometer.

5. The disposable airway adapter tube of claim 1, further in combination with a carbon dioxide detector/pulse oximeter device.

6. The disposable airway adapter tube of claim 2 wherein the radiation transmitted through the first window and out the second window is used to determine the concentration of a designated gas present in the airway passage.

7. The disposable airway adapter tube of claim 6 wherein the measured radiation is at a single wavelength.

8. The disposable airway adapter tube of claim 6 wherein the measured radiation is at two or more wavelengths.

9. The disposable airway adapter tube of claim 1 wherein the adapter tube body is made of a clear molded biocompatible plastic material.

10. The disposable airway adapter tube of claim 1 wherein the first and second optical windows are made of a clear biocompatible plastic material.

11. The disposable airway adapter tube of claim 10 wherein the airway passage is cylindrical and an inside surface of the first and second optical windows is coated with an anti-fog coating.

12. The disposable airway adapter tube of claim 1 wherein the reflector is made of a clear molded biocompatible plastic material and plated with a reflective material.

13. The disposable airway adapter tube of claim 12 wherein the reflective material is an aluminum coating.

14. The disposable airway adapter tube of claim 13 wherein the reflective material is coated with an anti-fog coating.

15. The disposable airway adapter tube of claim 1 wherein the radiation transmitted through the first window and out the second window is used to determine the concentration of a designated gas present in the airway passage.

16. The disposable airway adapter tube of claim 15 wherein the radiation is infrared.

17. The disposable airway adapter tube of claim 16 wherein the designated gas is carbon dioxide.

18. The disposable airway adapter tube of claim 2 wherein the adapter tube body is connected to the carbon dioxide detector, the carbon dioxide detector comprising:

an emitter for transmitting infrared radiation into the airway passage through the first optical window;

an infrared detector for detecting infrared radiation transmitted out of the airway passage through the second optical window;

the carbon dioxide detector including circuitry for determining the amount of infrared radiation absorbed by the carbon dioxide present in a mixture of gases in the airway passage, which is proportional to the carbon dioxide concentration in the mixture of gases.

19. The disposable airway adapter tube of claim 18 further including an optical filter positioned between the infrared detector and the second optical window, the optical filter being most transmissive at a predetermined wavelength.

20. The disposable airway adapter tube of claim 19 in which the optical filter is most transmissive at approximately 4.26 micrometers.

21. The disposable airway adapter tube of claim 18 wherein the angular path of the infrared radiation between the emitter, reflector and detector defines an angle of less than 90°

.

22. The combination of claim 21 wherein the angular path of the infrared radiation between the emitter, reflector and detector defines an angle of approximately 46°

.

23. In combination, a gas detector and a disposable airway adapter tube, the gas detector for determining the concentration of a predetermined gas in a mixture of gases in the airway adapter tube, comprising:

a gas detector including a sensor module;

a disposable airway adapter tube body defining an airway passage, the disposable airway adapter tube body being removably connected to the sensor module, the disposable adapter tube body further including first and second optical windows;

a reflector positioned in the airway passage;

the sensor module including an emitter positioned for transmitting infrared radiation into the airway passage through the first optical window and an infrared detector positioned for detecting infrared radiation transmitted out of the airway passage through the second optical window;

gas concentration circuitry for determining the amount of infrared radiation absorbed by the predetermined gas in the mixture of gases in the airway passage, which is proportional to the gas concentration in the mixture of gases.

24. The combination of claim 23 wherein the predetermined gas is carbon dioxide.

25. The combination of claim 24 further including an optical filter positioned between the infrared detector and the second optical window, the optical filter being most transmissive at a predetermined wavelength.

26. The combination of claim 25 in which the optical filter is most transmissive at approximately 4.26 micrometers.

27. The combination of claim 23 wherein the adapter tube body is made of a clear molded biocompatible plastic material.

28. The combination of claim 23 wherein the first and second optical windows are made of a clear biocompatible plastic material.

29. The combination of claim 28 wherein the airway passage is cylindrical and an inside surface of the first and second optical windows is coated with an anti-fog coating.

30. The combination of claim 29 wherein the reflector is made of a clear molded biocompatible plastic material and plated with a reflective material.

31. The combination of claim 30 wherein the reflective material is an aluminum coating.

32. The combination of claim 31 wherein the reflective material is coated with an anti-fog coating.

33. The combination of claim 23 wherein the sensor module and the disposable airway adaptor are constructed and arranged to snap-fit.

34. The combination of claim 23 wherein the angular path of the infrared radiation between the emitter, reflector and detector defines an angle of less than 90°

.

35. The combination of claim 34 wherein the angular path of the infrared radiation between the emitter, reflector and detector defines an angle of approximately 46°

.

36. A method of measuring a concentration of a designated gas present in a mixture of gases, the method comprising the following steps:

a) connecting a disposable airway adapter to a gas source, the airway adapter defining an airway passage and the airway adapter including first and second optical windows and a reflector positioned in the airway passage, the first and second optical windows being positioned relative to the reflector such that radiation transmitted through the first optical window into the airway passage will be reflected by the reflector and be transmitted through the second optical window and out of the airway passage;

b) transmitting infrared radiation through the first optical window so that it reflects off of the reflector and is transmitted out the second optical window;

c) determining the amount of infrared radiation absorbed by the designated gas in the mixture of gases in the airway passage, which is proportional to the gas concentration in the mixture of gases.