Apparatus for measuring electrolytes utilizing optical signals related to the concentration of the electrolytes

• US 5,001,417 A
• Filed: 05/25/1988
• Issued: 03/19/1991
• Est. Priority Date: 06/01/1987
• Status: Expired due to Fees

• Current Assignee: Abbott Laboratories North Chicago IL
• Original Assignee: Abbott Laboratories Incorporated
• Inventors: Davis, Charles L., Pumphery, John G., Garrett, Paul E., Spritzer, Lawrence, Pumphrey, Edward G., Clark, Frederic L., Durley, Benton A. III
• Primary Examiner(s): Wieder, Kenneth
• Assistant Examiner(s): Harvey, Jack B.
• Application Number:
  US07/196,120
• Time in Patent Office: 1,028 Days
• Field of Search: 324/71.1, 324/71.5, 324/425, 324/438, 324/96, 324/71.2, 422/64, 422/72, 422/102, 422/68, 357/25, 350/342, 204/406, 204/412, 204/416, 455/617
• US Class Current: 324/71.5
• CPC Class Codes: G01N 33/492 Determining multiple analytes

Abstract

Apparatus for measuring electrolyute concentrations in fluid samples. The apparatus includes an ion selective electrode having a plurality of ion selective detection sites. Each site has an affinity for a preselected electrolyte of interest and generates a potential having a magnitude related to the concentration of the corresponding electrolyte in the sample. A voltage to optical transducer circuit is provided to convert the voltage differentials to optical signals having intensity related to the concentration of the electrolytes in a first embodiment, a digital code related to the concentration of the electrolytes in a second embodiment, and an optical absorption or density value related to the concentration of the electrolytes in a third embodiment. The optical signals are suitable for detection by conventional optical detector apparatus of assay instruments and may be processed using conventional two point linear interpolation techniques to determine the concentrations of the preselected electrolytes.

Claims

1. Apparatus for measuring the concentration of electrolytes in a fluid sample, wherein the components of said apparatus are housed in a single unit, said components comprising:

container means for containing a sample to be measured;

sensor means operative when in fluid contact with a sample to generate an electrical signal having magnitude related to the concentration of at least one preselected electrolyte in said sample;

transducer means in communication with said sensor means and responsive to said electrical signal for generating at least one second signal having a parameter related to said magnitude of said electrical signal;

optical means responsive to said at least one second signal for generating at least one optical signal corresponding to said second signal and representing the concentration of said at least one preselected electrolyte of said sample; and

optical reading means operative te detect said optical signal and measure variations in said optical signal as indicative of the concentration of said at least one preselected electrolyte.

2. The apparatus defined in claim 1 wherein said sensor means includes ion selective electrode means operative to generate at least one analog voltage having magnitude related to the concentration of said at least one preselected electrolyte.

3. The apparatus defined in claim 1 wherein said sensor means includes chemical field effect transistor means operative to generate at least one analog current having magnitude related to the concentration of said at least one preselected electrolyte.

4. The apparatus defined iu claim 1 wherein said sensor means includes chemical field effect transistor means operative to generate at least one analog voltage having magnitude related to the concentration of said at least one preselected electrolyte.

5. The apparatus defined in claim 1 wherein said optical means includes:

optical source means for generating light; and

light valve means responsive to said second signal for absorbing a portion of said light to generate optical signals having a parameter related to the concentration of said at least one preselected electrolyte in said sample.

6. The apparatus defined in claim 1 wherein said optical means comprises light emitting diode means having a selected output wavelength.

7. The apparatus defined in claim 1 wherein said transducer means includes means for converting said at least one electrical signal into a said at least one second signal having duty cycle related to the magnitude of said electrical signal.

8. The apparatus defined in claim 1 wherein said transducer means includes means for converting said at least one electrical signal into a said at least one second signal having frequency related to the magnitude of said electrical signal.

9. The apparatus defined in claim 1 wherein said transducer means includes means for converting said at least one electrical signal into a said at least one second signal having pulse width related to the magnitude of said electrical signal.

10. The apparatus defined in claim 1 wherein said transducer means includes means for converting said at least one electrical signal into a said at least one second signal comprising alternating polarity pulses having magnitude related to the magnitude of said electrical signal.

11. The apparatus defined in claim 1 wherein said sensor means includes a plurality of electrode means attached to a substrate, at least one of which is a common reference electrode and at least one of which is an electrolyte detection electrode including means having an affinity for a preselected electrolyte for generating a plurality of voltage differentials each having magnitude related to the concentration of a preselected electrolyte.

12. The apparatus defined in claim 11 wherein each of said plurality of electrodes except said reference electrode includes means having an affinity for a different preselected electrolyte.

13. The apparatus defined in claim 11 wherein said transducer means includes:

means for sequentially selecting each said electrolyte detection electrode to sequentially generate a plurality of said second signals each having a parameter related to the magnitude of the voltage differential between said electrolyte detection electrode and said common reference electrode; and

means responsive to said means for selecting to sequentially drive said optical means with each of said plurality of second signals to sequentially generate a plurality of optical signals each representing the concentration of a preselected electrolyte in said sample.

14. The apparatus defined in claim 11, including:

vessel means for holding said sample;

interface means connected to said vessel means for mounting said electrode means in fluid-tight communication with said vessel means; and

means forming a fluid-tight area about said reference electrode when said electrode means is mounted to said interface means in a selected storage position and adapted to maintain fluid in contact with said reference electrode when in said storage position.

15. The apparatus defined in claim 1 wherein said optical reading means is in visual alignment with said optical means for directly intercepting the path of said optical signal.

16. The apparatus defined in claim 15 wherein said optical reading means includes a photomultiplier tube.

17. Apparatus for measuring the concentration of electrolytes in a fluid sample wherein the components of said apparatus are housed in a single unit, said components comprising:

container means for containing a sample to be measured;

sensor means mounted in fluid-tight connection with said container means and operative when in fluid contact with said sample to generate at least one electrical signal having magnitude related to the concentration of at least one preselected electrolyte in said sample;

transducer means in communication with said sensor means and responsive to said electrical signal for generating at least one second signal having a parameter related to the magnitude of said electrical signal;

optical means responsive to said at least one second signal for generating at least one optical signal corresponding to said second signal and representing the concentration of said at least one preselected electrolyte in said sample;

optical detector means for reading said at least one optical signal; and

mounting means adapted for use in an automated assay instrument for mounting said sensor means, container means, transducer means, and optical means.

18. The apparatus defined in claim 17 wherein said sensor means includes ion selective electrode means operative to generate at least one electrical voltage signal having magnitude related to the concentration of said at least one preselected electrolyte.

19. The apparatus defined in claim 17 wherein said sensor means includes chemical field effect transistor means operative to generate at least one electrical current signal having magnitude related to the concentration of said at least one preselected electrolyte.

20. The apparatus defined in claim 17 wherein said sensor means includes field effect transistor means operative to generate at least one electrical voltage signal having magnitude related to the concentration of said at least one preselected electrolyte.

21. The apparatus defined in claim 17 wherein said optical means includes light emitting diode means having a selected output wavelength.

22. The apparatus defined in claim 17 wherein said transducer means includes means for converting said at least one electrical signal into a said at least one second signal having duty cycle related to the magnitude of said electrical signal.

23. The apparatus defined in claim 17 wherein said transducer means includes means for converting said at least one electrical signal into a said at least one second signal having frequency related to the magnitude of said electrical signal.

24. The apparatus defined in claim 17 wherein said transducer means includes means for converting said at least one electrical signal into a said at least one second signal having pulse width related to the magnitude of said electrical signal.

25. The apparatus defined in claim 17 wherein said sensor means includes a plurality of electrodes, at least one of which is a common reference electrode and at least one of which is an electrolyte detection electrode including means having an affinity for a preselected electrolyte for generating at least one voltage differential having magnitude related to the concentration of a preselected electrolyte.

26. The apparatus defined in claim 25 wherein each of said plurality of electrodes except said reference electrode includes means having an affinity for a different preselected electrolyte.

27. The apparatus defined in claim 25 wherein said transducer means includes:

means for sequentially selecting each said electrolyte detection electrode to sequentially generate a plurality of said second signals each having a parameter related to the magnitude of the voltage differential between said electrolyte detection electrode and said common reference electrode; and

means responsive to said means for selecting to sequentially drive said optical means with each of said plurality of second signals to sequentially generate a plurality of optical signals each representing the concentration of a preselected electrolyte in said sample.

28. The apparatus defined in claim 25, including:

vessel means for holding said sample;

interface means connected to said vessel means for mounting said electrode means in fluid-tight communication with said vessel means; and

means forming a fluid-tight area about said reference electrode when said electrode means is mounted to said interface means in a selected storage position and adapted to maintain fluid in contact with said reference electrode when in said storage position.

29. The apparatus defined in claim 17 wherein said container means comprises fluid vessel means for containing said sample and interface means connected to said fluid vessel means for removably mounting said electrode means in fluid communication with said vessel means.

30. The apparatus defined in claim 29 wherein said interface means comprises alignment means adapted to mate with a portion of said electrode means for aligning said electrode means with a selected orientation.

31. The apparatus defined in claim 29 wherein said vessel means include gasket means for engaging said substrate and forming a fluid-tight connection with said substrate about said electrode means when said electrode means is mounted to said interface means.

32. The apparatus defined in claim 17 wherein said mounting means comprises:

adaptor means for mounting said container means and said electrode means as a single unit;

rotatable carousel means having a plurality of sample mounting positions with at least one of said positions being adapted to mount said adaptor means;

electrical mounting means mounted to said carousel means for mounting said transducer means and said optical means; and

electrical connector means for electrically connecting said electrode means and said transducer means.

33. The apparatus defined in claim 32 wherein said container means includes key means and said adaptor means includes key receiving means for receiving the key means of selected container means to mount said selected container means with proper orientation.

34. The apparatus defined in claim 17 wherein said optical detector means is in visual alignment with said optical means for directly intercepting the path of said at least one optical signal.

35. Apparatus for use with centrifugal-type sample analyzer of the type having optical source means for providing a first optical signal and optical detector means for detecting a second optical signal form-measuring the concentration of electrolytes in a fluid sample, comprising:

cartridge means adapted for use in measuring the concentrations of electrolytes in a fluid sample in a centrifugal apparatus;

centrifugal head means capable of rotating about a first axis and adapted to removably hold said cartridge means;

sample container means mounted in said cartridge means for containing a sample;

sensor means mounted in said cartridge means in fluid-tight communication with said sample container means and operative when in fluid contact with said sample to generate at least one electrical signal having magnitude related to the concentration of at least one preselected electrolyte in said sample;

transducer means mounted in said cartridge means in communication with said sensor means and responsive to said at least one electrical signal for generating at least one second signal having a parameter related to the magnitude of said at least one electrical signal; and

optical means mounted in said cartridge means for intercepting the path of said first optical signal and being responsive to said at least one second signal for absorbing a portion of said first optical signal to generate at least one second optical signal having intensity related to the concentration of said at least one preselected electrolyte in said sample.

36. The apparatus defined in claim 35 wherein said sensor means comprises ion selective electrode means operative to generate at least one electrical voltage signal having magnitude related to the concentration of said at least one preselected electrolyte.

37. The apparatus defined in claim 35 wherein said sensor means includes chemical field effect transistor means operative to generate at least one electrical current signal having magnitude related to the concentration of said at least one preselected electrolyte.

38. The apparatus defined in claim 35 wherein said sensor means includes field effect transistor means operative to generate at least one electrical voltage signal having magnitude related to the concentration of said at least one preselected electrolyte.

39. The apparatus defined in claim 35 wherein said optical means comprises liquid crystal light valve means having crystal polarization responsive to said second signal for absorbing a portion of said first optical signal related to the value of said second signal to generate said at least one second optical signal having intensity related to the concentration of said at least one preselected electrolyte in said sample.

40. The apparatus defined in claim 35 wherein said sample container means includes:

a plurality of sample chambers formed in said cartridge means in sequential fluid communication for containing a plurality of samples to be tested;

a fluid-tight sensor mounting well for containing said sensor means;

at least one of said sample chambers being in fluid communication with said mounting well; and

a waste chamber in fluid communication with said mounting well;

said chambers being arranged so that when said centrifugal head means is rotated about said axis and wherein said centrifugal head means further includes means to rotate said cartridge means about a second axis said plurality of samples are conducted sequentially into fluid contact with said sensor means.

41. The apparatus defined in claim 35 wherein said electrode means includes a plurality of electrodes, at least one of which is a common reference electrode and at least one of which is an electrolyte detection electrode including means having an affinity for a preselected electrolyte for generating at least one electrical voltage signal having magnitude related to the concentration of a preselected electrolyte in the sample.

42. The apparatus defined in claim 41 wherein each of said plurality of electrodes except said reference electrode includes means having an affinity for a different preselected electrolyte.

43. The apparatus defined in claim 35 wherein said transducer means includes means for converting said at least one electrical signal into at least one second signal comprising alternating polarity pulses each having magnitude related to the magnitude of said electrical signal.

44. The apparatus defined in claim 43 wherein said transducer means includes means for applying said alternating polarity pulses to drive said optical means.

45. Apparatus for measuring the concentration of electrolytes in a fluid sample, wherein the components of said apparatus are housed in a single unit, said components comprising:

container means for containing a fluid sample;

sensor means mounted in fluid communication with said container means and operative when in fluid contact with a sample to generate an analog signal having a parameter with value related to the concentration of a preselected electrolyte in said sample;

transducer means in communication with said sensor means for generating a digital signal having value related to the value of the parameter of said analog signal;

optical means responsive to said digital signal for generating an optical signal corresponding to said digital signal to provide an optical indication of the concentration of said preselected electrolyte in said sample; and

optical reading means operative to detect and measure said optical signal as indicative of the concentration of said preselected electrolyte.

46. The apparatus defined in claim 45 wherein said sensor means includes ion selective electrode means operative to generate an analog voltage having magnitude related to the concentration of said preselected electrolyte.

47. The apparatus defined in claim 45 wherein said sensor means includes chemical field effect transistor means operative to generate an analog current having magnitude related to the concentration of said preselected electrolyte.

48. The apparatus defined in claim 45 wherein said sensor means includes chemical field effect transistor means operative to generate an analog voltage having magnitude related to the concentration of said preselected electrolyte.

49. The apparatus defined in claim 45 wherein said sensor means includes a plurality of sensor means each operative to generate an analog signal having a parameter with value related to the concentration of a preselected electrolyte in said sample;

wherein said transducer means includes means for sequentially selecting each of said sensor means to sequentially generate a plurality of said digital signals each having value related to the value of the parameter of the analog signal generated by the selected sensor means;

wherein said optical means is responsive to each of said plurality of digital signals to generate a corresponding plurality of optical signals; and

wherein said optical reading means is responsive to each of said optical signals.

50. The apparatus defined in claim 45 including container means mounted in fluid communication with said sensor means for holding said sample in fluid contact with said sensor means.

51. The apparatus defined in claim 50 wherein said container means includes means for forming a fluid-tight seal with said sensor means.

52. The apparatus defined in claim 46 wherein said mounting means comprises:

adaptor means for mounting said container means and said electrode means as a single unit;

rotatable carousel means having a plurality of sample mounting positions with at least one of said positions being adapted to mount said adaptor means;

electrical mounting means mounted to said carousel means for mounting said transducer means and said optical means; and

electrical connector means for electrically connecting said electrode means and said transducer means.

53. The apparatus defined in claim 45 wherein said transducer means includes:

pulse generator means responsive to said analog signal for generating a plurality of pulses; and

counter means for counting said pulses to generate said digital signal comprising a count value related to the concentration of said preselected electrolyte in said sample.

54. The apparatus defined in claim 53 wherein said transducer means includes means for converting said digital signal to a bit-serial digitally-encoded pulse train for communication to said optical means.

55. The apparatus defined in claim 53 wherein said pulse generator means includes means responsive to said analog signal for generating a plurality of pulses with duty cycle related to said parameter of said analog signal.

56. The apparatus defined in claim 55 wherein said counter means includes means for counting said pulses over a predetermined time interval to generate said digital signal.

57. The apparatus defined in claim 45 wherein said optical reading means is in visual alignment with said optical means for directly intercepting the path of said optical signal.

58. Apparatus for measuring the concentration of an electrolyte in a fluid sample, wherein the components of said apparatus are housed in a single unit, said components comprising:

container means for containing a fluid sample;

sensor means mounted in fluid communication with said container means and operative when in fluid contact with said sample to generate an analog signal having a parameter with a value related to the concentration of a preselected electrolyte in said sample;

transducer means in communication with said sensor means for generating a first digital signal having a value related to the value of the parameter of said analog signal;

optical means responsive to said first digital signal for generating an optical signal corresponding to said first digital signal;

optical detector means responsive to said optical signal for generating a second digital signal corresponding to said first digital signal and providing an indication of the concentration of said preselected electrolyte in said sample; and

means adapted for mounting in an automated assay instrument for mounting said container means sensor means, transducer means, and optical means.

59. The apparatus defined in claim 58 wherein said sensor means includes ion selective electrode means operative to generate an analog voltage having magnitude related to the concentration of said preselected electrolyte.

60. The apparatus defined in claim 58 wherein said sensor means includes chemical field effect transistor means operative to generate an analog current having magnitude related to the concentration of said preselected electrolyte.

61. The apparatus defined in claim 58 wherein said sensor means includes chemical field effect transistor means operative to generate an analog voltage having magnitude related to the concentration of said preselected electrolyte.

62. The apparatus defined in claim 58 wherein said sensor means includes a plurality of sensor means each operative to generate an analog signal having a parameter with value related to the concentration of a preselected electrolyte in said sample;

wherein said transducer means includes means for sequentially selecting each of said sensor means to sequentially generate a plurality of said first digital signals each having value related to the value of the parameter of the analog signal generated by the selected sensor means;

wherein said optical means is responsive to each of said plurality of first digital signals to generate a corresponding plurality of optical signals; and

wherein said optical detector means is responsive to each of said optical signals to generate a plurality of second digital signals, each providing an indication of the concentration of a said preselected electrolyte in said sample.

63. The apparatus defined in claim 58 including container means mounted in fluid communication with said sensor means for holding said sample in fluid contact with said sensor means.

64. The apparatus defined in claim 63 wherein said container means includes means for forming a fluid-tight seal with said sensor means.

65. The apparatus defined in claim 58 wherein said transducer means includes:

pulse generator means responsive to said analog signal for generating a plurality of pulses; and

counter means for counting said pulses to generate said digital signal comprising a digital count value related to the concentration of said preselected electrolyte in said sample.

66. The apparatus defined in claim 65 wherein said transducer means includes means for converting said digital signal to a bit-serial digitally-encoded pulse train for communication to said optical means.

67. The apparatus defined in claim 65 wherein said pulse generator means includes means responsive to said analog signal for generating a plurality of pulses with duty cycle related to said parameter of said analog signal.

68. The apparatus defined in claim 67 wherein said counter means includes means for counting said pulses over a predetermined time interval to generate said digital signal.

69. The apparatus defined in claim 58 wherein said optical detector means is in visual alignment with said optical means for directly intercepting the path of said optical signal.