Multiple function airway adapter

• US 6,312,389 B1
• Filed: 06/05/1998
• Issued: 11/06/2001
• Est. Priority Date: 07/15/1996
• Status: Expired due to Term

• Current Assignee: RIC INVESTMENTS LLC (Koninklijke Philips N.V.)
• Original Assignee: NTC Technology, Inc. (Dixtal Medical, Inc.)
• Inventors: Orr, Joseph A., Rich, David R., Kofoed, Scott A.
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US09/092,260
• Time in Patent Office: 1,250 Days
• Field of Search: 600/529, 600/534, 600/538, 600/532, 73/233
• US Class Current: 600/532
• CPC Class Codes: A61B 5/083 Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
• CPC Class Codes: G01F 1/40 Details of construction of the flow constriction devices
• CPC Class Codes: G01F 1/42 Orifices or nozzles
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10

Abstract

An intergrated airway adapter capable of monitoring CO₂ concentration in real time, breath by breath, using infrared absorption techniques and monitoring respiratory flow with differential pressure flowmeters under diverse inlet conditions through improved sensor configurations which minimize phase tag and dead space within the airway adapter.

Claims

1. An integrated airway adapter providing a CO₂ concentration monitoring capability and a differential pressure measurement capability for determining respiratory gas flow, said integrated airway adapter comprising:

a housing having a bore and a longitudinal axis;

a first pressure port and a second pressure port opening into said bore and structure communicating with said first pressure port and said second pressure port exterior to said housing for detecting a pressure differential in respiratory gas flowing through said housing bore;

a structure located within said housing bore for creating said pressure differential;

a detection chamber defined within said housing at least partially between said first pressure port and said second pressure port, said detection chamber communicating with said bore; and

a pair of windows located on opposing sides of said detection chamber and aligned along an optical path traversing the detection chamber,

each of said pair of windows being optically compatible to allow a beam of infrared radiation originating on one side of said detection chamber to traverse said respiratory gas when located in said detection chamber to be received by a detecting system to determine a CO₂ concentration in said respiratory gas.

2. The integrated airway adapter of claim 1, wherein said first and second pressure ports face substantially perpendicular to said longitudinal axis of said housing.

3. The integrated airway adapter of claim 1, wherein said pair of windows are fabricated from a segment of infrared radiation transmitting polymer.

4. The integrated airway adapter of claim 3, wherein said infrared radiation transmitting polymer is malleable.

5. The integrated airway adapter of claim 4, wherein said infrared radiation transmitting polymer is a biaxially oriented polypropylene.

6. The integrated airway adapter of claim 1, wherein said structure for creating said pressure differential comprises at least one strut with at least one of said first pressure port and second pressure port disposed therein.

7. The integrated airway adapter of claim 6, wherein said at least one strut has a restriction member disposed thereon which is oriented with a face surface substantially perpendicular to a direction of said respiratory gas flow.

8. The integrated airway adapter of claim 7, wherein said restriction member includes a planar disk shape member.

9. The integrated airway adapter of claim 6, wherein said at least one strut is tapered toward one end of said detection chamber.

10. The integrated airway adapter of claim 1, wherein said first pressure port is located proximate one end of said detection chamber and said second pressure port is located proximate another end of said detection chamber.

11. The integrated airway adapter of claim 10, wherein said structure for creating said pressure differential comprises a first strut proximate one end of said detection chamber with said first pressure port and a second strut proximate another end of said detection chamber with second pressure port disposed therein.

12. The integrated airway adapter of claim 11, wherein at least one of said first strut and said second strut has a restriction member disposed thereon which is oriented with a face surface substantially perpendicular to a direction of said respiratory gas flow through said housing bore.

13. The integrated airway adapter of claim 11, wherein at least one of said first strut and said second strut is tapered toward one end of said detection chamber.

14. The integrated airway adapter of claim 1, further comprising

a strut diametrically disposed and longitudinally extending within said housing bore, said strut having a first end face, a second end face, a first side face, a second side face, an axial length along the longitudinal axis of said housing, and material affixed thereto to restrict said respiratory gas flow through said housing bore;

first and second longitudinally spaced notches in said strut located proximate said longitudinal axis of said housing for allowing said respiratory gas flow thereinto from said bore, said first notch extending from said first end face axially inward into said strut and from said first side face to said second side face, said second notch extending from said second end face axially inward into said strut and from said first side face to said second side face; and

said first and second pressure ports respectively opening into said first and second notches from first and second lumens contained within said strut and extending to an exterior of said housing.

15. The integrated airway adapter of claim 14, wherein said first and second longitudinally spaced notches in said strut each include a curved back wall surface portion.

16. The integrated airway adapter of claim 15, wherein said first and second longitudinally spaced notches extend longitudinally into said strut at least as far as longitudinally innermost extents of said first and second pressure ports.

17. The integrated airway adapter of claim 14, wherein said first and second longitudinally spaced notches have heights perpendicular to said longitudinal axis of said housing less than or equal to about four-tenths of a height of said strut, taken in the same direction.

18. The integrated airway adapter of claim 14, wherein said strut has a cross-sectional area of at least about ten percent of that of the bore of said housing at a location of said strut.

19. The integrated airway adapter of claim 14, wherein said bore of said housing is constricted adjacent a bore wall proximate the location of a portion of said strut.

20. The integrated airway adapter of claim 19, wherein said constriction of said bore comprises a reduction in bore diameter proximate the location of a portion of said strut.

21. The integrated airway adapter of claim 14, wherein said housing bore proximate one longitudinal extent of said strut is greater in diameter than said housing bore proximate another longitudinal extent of said strut.

22. The integrated airway adapter of claim 14, wherein said strut includes first and second longitudinal ends oriented perpendicular to said longitudinal axis of said housing.

23. The integrated airway adapter of claim 22, wherein the first and second longitudinal ends of said strut are rounded.

24. The integrated airway adapter of claim 14, wherein said bore of said housing is constricted between said first and second pressure ports.

25. The integrated airway adapter of claim 24, wherein said constriction is provided by said material and comprises transversely orient lands extending laterally outwardly from said strut.

26. The integrated airway adapter of claim 1, wherein said structure for creating said pressure differential defines at least one boundary of said detection chamber.