Blood parameter measurement system

• US 4,951,669 A
• Filed: 08/08/1988
• Issued: 08/28/1990
• Est. Priority Date: 01/30/1987
• Status: Expired due to Fees

• Current Assignee: Terumo Cardiovascular Systems Corporation (Terumo Corporation)
• Original Assignee: 3M Company
• Inventors: Maxwell, Thomas P., Hacker, Thomas G.
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): MANUEL, GEORGE C
• Application Number:
  US07/229,703
• Time in Patent Office: 750 Days
• Field of Search: 128/665, 128/637, 128/912, 128/632, 128/634, 604/236, 604/230, 604/181, 604/27, 604/28, 604/154
• 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

Abstract

A parameter of blood is sensed with a system which includes a catheter and a sensor and a volume oscillator element. The catheter has a lumen extending therethrough, a proximal end, a distal end and an opening, adapted to be placed in the blood vessel of a patient. The sensor senses a blood parameter and is adapted to be located outside the patient'"'"'s body in fluid communication with the lumen. The volume oscillator element is in fluid communication with the lumen and is capable of acting to periodically cause blood to enter and exit the lumen. The system is structured so that a flush or anti-clotting solution flows into the patient when the volume oscillator element is inactive. With the volume oscillator activated, blood is moved back and forth in the lumen to expose the sensors to blood so that the blood parameter of interest can be sensed.

Claims

1. An assembly for the sensing of a blood parameter comprising:

a catheter having a proximal end, a distal end, and a lumen extending therethrough, said lumen having an opening in said distal end, said catheter being sized and adapted so that at least said distal end and said opening are receivable within a blood vessel of a patient, said catheter acting to carry a fluid other than blood from a fluid source, through said lumen and opening, and into said patient;

sensor means, in fluid communication with said lumen, for sensing said blood parameter and providing a signal in response thereto;

a multi-legged fitting coupled to said catheter, said multi-legged fitting having two legs which form the only primary fluid flow path through said multi-legged fitting, said sensor means being located in said multi-legged fitting; and

a volume oscillator element in fluid communication with said lumen and being capable of acting to periodically cause blood to enter said lumen and to exit said lumen as desired, said volume oscillator element not interfering with the flow of said fluid through said lumen and opening when said volume oscillator element is inactive.

2. The assembly of claim 1 wherein said volume oscillator element is structured and located so that the operation of said volume oscillator element does not affect the net flow of blood in either direction through said lumen.

3. The assembly of claim 1 which further comprises a conduit for coupling said lumen to said source of fluid whereby said fluid can be supplied to said lumen.

4. The assembly of claim 3 wherein said volume oscillator element is in fluid communication with said conduit.

5. The assembly of claim 1 wherein said sensor means is an optical sensor.

6. The assembly of claim 1 wherein said sensor means is a fluorescence sensor.

7. The assembly of claim 1 which further comprises transmission means for transmitting said signal from said sensor means.

8. The assembly of claim 7 wherein said transmission means comprises an optical fiber.

9. The assembly of claim 1 which further comprises one or more additional sensor means, each of said sensor means sensing a different blood parameter.

10. The assembly of claim 9 which further comprises a plurality of elongated transmission means, each of which is associated with a different one of said sensor means.

11. The assembly of claim 10 wherein each of said sensor means is located at or near a distal end of its associated elongated transmission means.

12. The assembly of claim 10 wherein the number of said sensor means equal sat least three.

13. The assembly of claim 1 wherein said volume oscillator element comprises a piston movable in a chamber to increase or decrease an open volume of said chamber as desired, and a diaphragm movable in response to the increasing or decreasing of said open volume.

14. The assembly of claim 13 wherein said piston is capable of reciprocating in said chamber to increase or decrease the open volume of said chamber as desired.

15. The assembly of claim 14 wherein said piston is motor driven.

16. The assembly of claim 1 wherein said blood parameter is selected from the group consisting of blood gases, pH electrolytes, and glucose.

31. The assembly of claim 1 wherein said multi-legged fitting has a first leg, a second leg, and a third leg, said second and third legs forming said primary fluid flow path through said multi-legged fitting.

32. The assembly of claim 31 wherein said sensor means is located in said first leg.

33. The assembly of claim 31 wherein said sensor means comprises an optical sensor and wherein an optical fiber is associated with said first leg, said optical fiber serving to receive said signal from said optical sensor.

34. The assembly of claim 33 wherein said optical fiber also serves to deliver excitation light to said optical sensor.

17. An assembly for the sensing of a blood parameter comprising:

a catheter having a proximal end, a distal end, and a lumen extending therethrough, said lumen having an opening in said distal end, said distal end having a cross-sectional area of such size that said distal end and said opening are receivable within a blood vessel of a patient;

sensor means for sensing said blood parameter and providing a signal in response thereto, said sensor means being located at a position in said lumen of said catheter at or near the proximal end of said catheter; and

a volume oscillator element in fluid communication with said lumen and being capable of acting to periodically cause blood to enter said lumen and to exit said lumen, wherein the operation of said volume oscillator element does not affect the net flow of blood in either direction through said lumen.

18. The assembly of claim 17 wherein the cross-sectional area of said lumen at the position of said sensor means is greater than the cross-sectional of said distal end or of said opening.

19. The assembly of claim 18 wherein said volume oscillator element comprises a piston movable in a chamber to increase or decrease an open volume of said chamber as desired, and a diaphragm movable in response to the increasing or decreasing of said open volume.

20. The assembly of claim 19 wherein said piston is capable of reciprocating in said chamber to increase or decrease the open volume of said chamber as desired.

21. The assembly of claim 20 wherein said piston is motor driven.

22. The assembly of claim 17 wherein said sensor means is an optical sensor.

23. The assembly of claim 17 wherein said sensor means is a fluorescence sensor.

24. The assembly of claim 17 which further comprises transmission means for transmitting said signal from said sensor means.

25. The assembly of claim 24 wherein said transmission means comprises an optical fiber.

26. The assembly of claim 17 which further comprises one or more additional sensor means, each of said sensor means sensing a different blood parameter.

27. The assembly of claim 26 which further comprises a plurality of elongated transmission means, each of which is associated with a different one of said sensor means.

28. The assembly of claim 27 wherein each of said sensor means is located at or near a distal end of its associated elongated transmission means.

29. The assembly of claim 27 wherein the number of said sensor means equals at least three.

30. The assembly of claim 17 wherein said blood parameter is selected from the group consisting of blood gases, pH, electrolytes, and glucose.

35. A probe-catheter assembly comprising:

a probe including sensor means for sensing a parameter of blood and providing a signal in response thereto, elongated transmission means for transmitting said signal from said sensor means, and a multi-legged fitting having a first leg with which said elongated transmission means is associated, and a second leg and a third leg which together form the only primary fluid flow path through said multi-legged fitting; and

a catheter having a proximal end, a distal end, and a lumen extending therethrough, said lumen having an opening in said distal end, said catheter being sized and adapted so that at least said distal end and said opening are receivable within a blood vessel of a patient, said catheter being structured to be coupled to said multi-legged fitting, said sensor means being located in said multi-legged fitting or in said catheter near the proximal end thereof.

36. The probe-catheter assembly of claim 35 wherein said sensor means is located in said first leg.

37. The probe-catheter assembly of claim 36 wherein said first leg at said location of said sensor means has a larger cross-sectional area than the cross-sectional area of said lumen at said distal end.

38. The probe-catheter assembly of claim 35 wherein said sensor means is located in said catheter near the proximal end thereof.

39. The probe-catheter assembly of claim 35 wherein said multi-legged fitting is a Y-fitting.

40. The probe-catheter assembly of claim 35 which further comprises a first coupling component forming part of said catheter and a second coupling component for coupling said catheter to said multi-legged fitting.

41. The probe-catheter assembly of claim 40 wherein said lumen extends through said first coupling component, the cross-sectional area of said lumen within said first coupling component being greater than the cross-sectional area of said lumen at said distal end.

42. The probe-catheter assembly of claim 35 wherein said sensor means is positioned so as to not substantially protrude into said primary fluid flow path.

45. The probe-catheter assembly of claim 35 wherein said sensor means comprises an optical sensor and said elongated transmission means comprises an optical fiber.

46. The probe-catheter assembly of claim 45 wherein said optical sensor is a fluorescence sensor.

43. A probe-catheter assembly comprising:

a probe including sensor means for sensing a parameter of blood and providing a signal in response thereto, elongated transmission means for transmitting said signal from said sensor means, and a fitting including two non-aligned flow path segments which come together at a junction, said two non-aligned flow path segments forming the only primary fluid flow path through said fitting; and

a catheter having a proximal end, a distal end, and a lumen extending therethrough, said lumen having an opening in said distal end, said catheter being sized and adapted so that at least said distal end and said opening are receivable within a blood vessel of a patient, said catheter being coupled to said fitting, said sensor means being located in said fitting at or near said junction.

44. The probe-catheter assembly of claim 43 wherein said sensor means is positioned so as to not substantially protrude into said primary fluid flow path.

47. A method of sensing a parameter of blood comprising:

providing a catheter having a proximal end, a distal end, and a lumen extending therethrough, said lumen having an opening in said distal end, at least said opening of said catheter being positioned within a blood vessel of a patient;

providing sensor means outside the body of said patient in fluid communication with said lumen, said sensor means being capable of sensing a parameter in blood and providing a signal in response thereto;

introducing a flush solution from a flush solution source into said lumen so that there is an interface between blood from the patient and said solution;

providing a volume oscillator element which, when activated, aids in moving said interface back and forth so that said sensor means is exposed to blood for at least a portion of the time that said interface is moving, and continuing the flow of said flush solution from said flush solution source into said lumen when said volume oscillator element is inactive; and

obtaining said signal from said sensor means during the time said sensor is exposed to blood.

48. The method of claim 47 which further comprises allowing said patient'"'"'s heart contractions to partially move said interface.

49. The method of claim 47 wherein said interface is moved back and forth over said sensor means.

50. The method of claim 47 wherein said introducing step includes introducing said flush solution into said lumen to produce a net flow of said solution through said opening and into said blood vessel of said patient.

51. The method of claim 47 which further comprises deactivating said volume oscillator element for a desired time period, and taking a blood pressure reading while said volume oscillator element is inactive.

52. The method of claim 47 wherein the action of said volume oscillator element does not affect the net flow of blood in either direction through said lumen.

53. The method of claim 47 further comprising the step of continuing the flow of said flush solution from said flush solution source into said lumen when said volume oscillator element is active or inactive.

54. A method of sensing a parameter of blood comprising:

providing a catheter having a proximal end, a distal end, and a lumen extending therethrough, said lumen having an opening in said distal end, at least said opening of said catheter being positioned within a blood vessel of a patient;

providing sensor means outside the body of said patient in fluid communication with said lumen, said sensor means being capable of sensing a parameter of blood and providing a signal in response thereto;

introducing an anti-clotting solution into said lumen from an anti-clogging solution source through a variable volume solution-introducing system so that there is a net flow of said anti-clogging solution through said opening into said blood vessel of said patient; and

providing a volume oscillator element in fluid communication with said solution-introducing system which volume oscillator element, when activated, aids in moving blood from said blood vessel through said opening and into said lumen so as to expose said sensor means to blood and obtain a signal in response to said parameter of said blood, and continuing the flow of said anti-clotting solution from said anti-clotting solution source into said lumen when said volume oscillator element is active or inactive.

55. The method of claim 54 which further comprises allowing the pressure generated by the patient'"'"'s heart contractions to partially move said blood back and forth in said lumen.

56. The method of claim 54 wherein the action of the volume oscillator element does not affect the net flow of blood in either direction through said lumen.

57. The method of claim 54 which further comprises deactivating said volume oscillator element for a desired period of time, and taking a blood pressure reading while said volume oscillator element is inactive.

58. An assembly for the sensing of a blood parameter comprising:

a catheter having a proximal end, a distal end, and a lumen extending therethrough, said lumen having an opening in said distal end, said catheter being sized and adapted so that at least said distal end and said opening are receivable within a blood vessel of a patient, said catheter acting to carry a fluid other than blood from a fluid source, through said lumen and opening, and into said patient;

sensor means, in fluid communication with said lumen, for sensing said blood parameter and providing a signal in response thereto, said sensor means being located in said catheter near the proximal end thereof; and

a volume oscillator element in fluid communication with said lumen and being capable of acting to periodically cause blood to enter said lumen and to exit said lumen as desired, said volume oscillator element not interfering with the flow of said fluid through said lumen and opening when said volume oscillator element is inactive.

59. The assembly of claim 58 wherein said sensor means is an optical sensor.

60. The assembly of claim 58 wherein said sensor means is a fluorescence sensor.

61. The assembly of claim 58 wherein said blood parameter is selected from the group consisting of blood gases, pH, electrolytes, and glucose.

62. The assembly of claim 58 further comprising a multi-legged fitting coupled to said catheter, said multi-legged fitting having a first leg, a second leg, and a third leg, said second and third legs forming the only primary fluid flow path through said multi-legged fitting.

63. The assembly of claim 62 wherein said sensor means comprises an optical sensor and wherein an optical fiber is associated with said first leg, said optical fiber serving to receive said signal from said optical sensor.

64. An assembly for the sensing of a blood parameter comprising:

a catheter having a proximal end, a distal end, and a lumen extending therethrough, said lumen having an opening in said distal end, said catheter being sized and adapted so that at least said distal end and said opening are receivable within a blood vessel of a patient, said catheter acting to carry a fluid other than blood from a fluid source, through said lumen and opening, and into said patient;

sensor means for sensing said blood parameter and providing a signal in response thereto, said sensor means being adapted to be located outside the body of said patient in fluid communication with said lumen; and

a volume oscillator element in fluid communication with said lumen and being capable of acting to periodically cause blood to enter said lumen and to exit said lumen as desired, said assembly allowing the flow of said fluid into said lumen when said volume oscillator element is active or inactive.

65. The assembly of claim 64 wherein said sensor means is an optical sensor.

66. The assembly of claim 64 wherein said sensor means is a fluorescence sensor.

67. The assembly of claim 64 wherein said blood parameter is selected from the group consisting of blood gases, pH, electrolytes, and glucose.

68. The assembly of claim 64 further comprising a multi-legged fitting coupled to said catheter, said multi-legged fitting having a first leg, a second leg, and a third leg, said second and third legs forming the only primary fluid flow path through said multi-legged fitting.

69. The assembly of claim 68 wherein said sensor means is located in said first leg.

70. The assembly of claim 68 wherein said sensor means comprises an optical sensor and wherein an optical fiber is associated with said first leg, said optical fiber serving to receive said signal from said optical sensor.

71. The assembly of claim 64 wherein said sensor means is located in said catheter near the proximal end thereof.