Intravascular blood gas sensing system

• US 4,989,606 A
• Filed: 08/08/1988
• Issued: 02/05/1991
• Est. Priority Date: 01/30/1987
• Status: Expired due to Fees

• Current Assignee: Terumo Cardiovascular Systems Corporation (Terumo Corporation)
• Original Assignee: 3M Company
• Inventors: Hacker, Thomas G., Gehrich, John L., Maxwell, Thomas P.
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): MANUEL, GEORGE C
• Application Number:
  US07/229,617
• Time in Patent Office: 911 Days
• Field of Search: 128/637, 128/634, 128/665, 128/666, 128/DIG. 12, 128/DIG. 13, 364/413.06, 364/413.07, 364/413.08, 364/413.09, 604/4-6
• US Class Current: 600/312
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

An assembly useful in conjunction with a signal transmission means for the measurement of a compositional parameter of the blood of a patient is disclosed. This assembly comprises a housing adapted and sized to be located outside the body of a patient and having a fluid flow passage therethrough into which blood from the patient is passed from a hollow tube, the fluid flow passage being defined by a wall which is substantially impermeable to blood, the housing being adapted to be removeably secured to a signal transmission system such that the housing is capable of being removed from the signal transmission system without disrupting the fluid flow passage; and a sensing element located in the housing in or near the fluid flow passage for providing a signal directly to the signal transmission system in response to a compositional parameter of blood located in the fluid flow passage.

Claims

1. A sensor cassette for use in measuring a compositional parameter of the blood of a patient comprising:

a housing adapted and sized to be located outside the body of the patient and having a fluid flow passage therethrough which is capable of receiving blood from the patient; and

a sensing element located in said housing in or near said fluid flow passage for providing a signal in response to a compositional parameter of blood, said fluid flow passage at or near the location of said sensing element being at least 4.8 times as wide as its depth, the depth of said fluid flow passage extending directly outwardly from said sensing element and the wide direction of said fluid flow passage being substantially perpendicular to both the general direction of fluid flow in said fluid flow passage and to the depth of the fluid flow passage.

2. The senor cassette of claim 1 wherein said sensing element is an optical sensing element.

3. The senor cassette of claim 1 wherein said sensing element is a fluorescent sensing element.

4. The sensor cassette of claim 1 which comprises a plurality of sensing elements in said housing, each of said sensing elements providing a signal in response to a different compositional parameter of blood.

5. The senor cassette of claim 1 wherein said housing includes an indent opening in said fluid flow passage, said indent containing at least a portion of said sensing element.

16. A sensor cassette as defined in claim 1 wherein said housing includes a first housing component having a first recess and a second housing component having a second recess which confronts the first recess, said second housing component being at least partially received in said first recess so that at least a portion of each of said first and second recesses forms at least a portion of said fluid flow passage and a substantially annular space exists between said first and second housing components, and adhesive means located at least partially in said substantially annular space and acting to bond said first and second housing components together.

17. A sensor cassette as defined in claim 16 wherein the first housing component has two holes and the second housing component has two tabs, said tabs being received into said holes, respectively, to form parts of said fluid flow passage adjacent opposite ends of said fluid flow passage.

18. A sensor cassette as defined in claim 16 wherein said first housing component defines a portion of said fluid flow passage and includes first and second tubing fittings for securing first and second segments of hollow tubing to said housing and first portions of first and second fluid flow channels which form end portions of said fluid flow passage, said second housing component defines a portion of said fluid flow passage and includes second portions of said first and second fluid flow channels.

19. A sensor cassette as defined in claim 16 wherein the housing includes first and second tubing fittings located adjacent opposing ends of said fluid flow passage and adapted to hold first and second segments of hollow tubing so that said first and second segments of hollow tubing are oriented in substantially opposing directions substantially perpendicular to the general direction of flow in said fluid flow passage.

20. A sensor cassette as defined in claim 1 wherein said housing includes a first housing component having two holes and a second housing component having two tabs, said tabs being received into said holes, respectively, to form parts of said fluid flow passage adjacent opposite ends of said fluid flow passage.

21. A sensor cassette as defined in claim 20 wherein the first housing component includes first and second tubing fittings located adjacent opposing ends of said fluid flow passage and having tubing retention sections which are oriented in substantially opposing directions substantially perpendicular to the general direction of flow in said fluid flow passage.

22. A sensor cassette as defined in claim 1 wherein said housing includes a first housing component defining a portion of said fluid flow passage, said first housing component includes first and second tubing fittings for securing first and second segments of hollow tubing to said housing and first portions of first and second fluid flow channels which form end portions of said fluid flow passage, said second housing component defining a portion of said fluid flow passage and including second portions of said first and second fluid flow channels.

23. A sensor cassette as defined in claim 1 wherein said housing includes first and second tubing fittings located adjacent opposing ends of said fluid flow passage and adapted to hold first and second segments of hollow tubing so that said first and second segments of hollow tubing are oriented in substantially opposing directions substantially perpendicular to the general direction of flow in said fluid flow passage.

24. A sensor cassette as defined in claim 1 wherein said housing includes first and second housing components defining said fluid flow passage, said fluid flow passage being substantially impermeable to blood, said first housing component being substantially transparent and said sensing element being carried by said substantially transparent first housing component.

6. A sensor cassette for use in measuring a compositional parameter of the blood of a patient comprising:

the housing adapted and sized to be located outside the body of the patient and having a fluid flow passage therethrough into which blood can be received from said patient, said housing including a first housing component having a first recess and a second housing component having a second recess which confronts the first recess, said second housing component being at least partially received in said first recess so that at least a portion of each of said first and second recesses forms at least a portion of said fluid flow passage and a substantially annular space exists between said first and second housing components;

adhesive means located at least partially in said substantially annular space and acting to bond said first and second housing components together; and

a sensing element located in said housing in or near said fluid flow passage for providing a signal in response to a compositional parameter of blood.

7. The senor cassette of claim 6 wherein said sensing element is an optical sensing element.

8. A sensor cassette as defined in claim 6 wherein said first housing component has two holes and said second housing component has two tabs, said tabs being received into said holes, respectively, to form parts of said fluid flow passage adjacent opposite ends of said fluid flow passage.

9. A sensor cassette as defined in claim 6 wherein the housing includes first and second tubing fittings located adjacent opposing ends of said fluid flow passage and adapted to hold first and second segments of hollow tubing so that said first and second segments of hollow tubing are oriented in substantially opposing directions substantially perpendicular to the general direction of flow in said fluid flow passage.

10. A sensor cassette for use in measuring a compositional parameter of the blood of a patient comprising:

a housing adapted and sized to be located outside the body of the patient and having a fluid flow passage therethrough into which blood from said patient can pass, said housing including a first housing component having two holes and a second housing component having two tabs, said tabs being received into said holes, respectively, to form parts of said fluid flow passage adjacent opposite ends of said fluid flow passage; and

a sensing element located in the housing in or near the fluid flow passage for providing a signal in response to a compositional parameter of the blood.

11. A sensor cassette as defined in claim 10 wherein the first housing component includes first and second tubing fittings adjacent opposite ends of the fluid flow passage.

12. A sensor cassette as defined in claim 11 wherein the tubing fittings are adapted to hold first and second segments of hollow tubing so that said first and second segments of hollow tubing are oriented in substantially opposing directions substantially perpendicular to the general direction of flow in said fluid flow passage.

13. A sensor cassette for use in measuring a compositional parameter of the blood of a patient comprising:

a housing adapted and sized to be worn on the body of the patient and having a fluid flow passage therethrough into which blood from said patient can be passed, said housing including first and second tubing fittings located adjacent opposing ends of said fluid flow passage and adapted to hold first and second segments of hollow tubing so that said first and second segments of hollow tubing are oriented in substantially opposing directions substantially perpendicular to the general direction of flow in said fluid flow passage; and

a sensing element located in said housing in or near said fluid flow passage for providing a signal in response to a compositional parameter of blood.

14. The sensor cassette of claim 13 wherein said mutually substantially opposing directions are substantially coplanar.

15. A sensor cassette for use in measuring a compositional parameter of the blood of a patient comprising:

a housing adapted and sized to be located outside the body of the patient and having a fluid flow passage therethrough into which blood from said patient can be passed, said housing including first and second housing components defining said fluid flow passage, said fluid flow passage being substantially impermeable to blood, said first housing component being substantially transparent; and

an optical sensing element carried by said substantially transparent first housing component in or near said fluid flow passage for providing an optical signal through said first housing component in response to a compositional parameter of blood.

25. An assembly for use in measuring a compositional parameter of blood comprising:

a housing having a fluid flow passage extending therethrough and first and second opposite sides;

a tube;

means on said housing for coupling the housing to the tube with the tube in communication with said fluid flow passage whereby blood can be conducted to the fluid flow passage;

said housing having wall means defining an external recess on said first side of the housing;

a sensing element carried by said wall means for providing a signal in response to a compositional parameter of the blood;

signal transmission means for transmitting said signal away from the housing, a portion of said signal transmission means being receivable in said recess; and

coupling means carried by the signal transmission means for engaging said second side of said housing to releasably couple the housing to the signal transmission means.

26. An assembly as defined in claim 25 wherein said coupling means includes a coupling member pivotally mounted on the signal transmission means and pivotable between a locking position in which the coupling member engages said second side of said housing to releasably couple the housing to the signal transmission means and a releasing position in which the housing can be removed from the signal transmission means.

27. An assembly as defined in claim 25 wherein the sensing element is optical and the wall means is substantially transparent at the sensing element.

28. The assembly of claim 25 wherein said sensing element is an optical sensing element.

29. The assembly of claim 25 wherein said sensing element is a fluorescent sensing element.

30. The assembly of claim 25 including a plurality of sensing elements, each of said sensing elements providing a signal to a signal transmission means in response to a different compositional parameter of blood located in said fluid flow passage.

31. The assembly of claim 25 which further comprises volume oscillator means in fluid communication with said fluid flow passage for urging blood to flow in said fluid flow passage.

32. The assembly of claim 25 wherein said housing includes an indent open to said fluid flow passage, said indent containing at least a portion of said sensing element.

33. The assembly of claim 25 wherein the cross-sectional area of said fluid flow passage at or near the location of said sensing element is less than about 10 times the largest cross-sectional area of said tube available for fluid flow.

34. The assembly of claim 25 wherein the cross-sectional area of said fluid flow passage at or near the location of said sensing element is less than about 3 times the largest cross-sectional area of said tube available for fluid flow.

35. A sensor cassette for use in measuring a compositional parameter of the blood of a patient comprising:

a housing adapted and sized to be located outside the body of the patient and having a fluid flow passage extending therethrough, said fluid flow passage being elongated along an axis of elongation and having first and second ports at opposite ends of the fluid flow passage and located along the axis of elongation, said fluid flow passage being capable of receiving blood from the patient through one of said ports;

a plurality of sensing elements located in said housing along the axis of elongation in or near said fluid flow passage, each of said sensing elements being capable of providing a signal in response to a different compositional parameter of blood; and

said fluid flow passage at or near the location of said sensing element being at least two times as wide as its depth, the depth of said fluid flow passage extending directly outwardly from said sensing element and the wide direction of said fluid flow passage being substantially perpendicular to both the general direction of fluid flow in said fluid flow passage and to the depth of the fluid flow passage.

36. An assembly including the sensor cassette of claim 35 and first and second conduits coupled to the sensor cassette in communication with the first and second ports, respectively, the cross-sectional area of the fluid flow passage being about 2.2 times the largest cross-sectional area of either of said conduits available for fluid flow.