Two-pulse systems and methods for determining analyte concentration

• US 20090026094A1
• Filed: 05/06/2008
• Published: 01/29/2009
• Est. Priority Date: 05/11/2007
• Status: Abandoned Application

• Current Assignee: Nipro Diagnostics, Inc.
• Original Assignee: Home Diagnostics Incorporated
• Inventors: Deng, David, Zhang, Yongchao
• Application Number:
  US12/115,804
• Publication Number:
  US 20090026094A1
• Time in Patent Office: Days
• US Class Current: 205/792
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/3273 Devices therefor, e.g. test element readers, circuitry details not specific to biochemical electrodes G01N33/4875

Abstract

Methods and systems for determining the concentration of a analyte in a physiological fluid are provided. The method includes applying at least one first pulse at a first potential and at least one second pulse at a second potential to a sample solution containing an analyte, wherein the first potential and the second potential can be the same polarity and the second potential can be larger than the first potential. The method also includes measuring at least one first current-transient associated with the at least one first pulse and at least one second current-transient associated with the at least one second pulse, determining a ratio between at least one said first current-transient and at least one said second current-transient, wherein said current-transients are measured at a substantially common sampling-time, and determining an analyte concentration of the sample solution based on the ratio of said current-transients.

Claims

1. A method of determining an analyte concentration, comprising:

applying at least one first pulse at a first potential and at least one second pulse at a second potential to a sample solution containing an analyte, wherein the first potential and the second potential are the same polarity and the second potential is larger than the first potential;

measuring at least one first current-transient associated with the at least one first pulse and at least one second current-transient associated with the at least one second pulse;

determining a ratio between at least one said first current-transient and at least one said second current-transient, wherein said current-transients are measured at a substantially common sampling-time; and

determining an analyte concentration of the sample solution based on the ratio of said current-transients.

2. The method of claim 1, wherein the first potential is in a range of about 0.005 volts to about 0.5 volts, and the second potential is in a range of about 0.03 volts to about 3.00 volts.

3. The method of claim 2, wherein the first potential is about 0.05 volts and the second potential is about 0.30 volts.

4. The method of claim 1, wherein the at least one first pulse is applied for a first time-period and the at least one second pulse is applied for a second time-period not the same as the first time-period.

5. The method of claim 4, wherein the first time-period is in a range of about 0.02 seconds to about 2 seconds, and the second time-period is in a range of about 0.5 seconds to about 10 seconds.

6. The method of claim 5, wherein the first time-period is about 0.2 seconds and the second time-period is about 4 seconds.

7. The method of claim 1, wherein in the sampling-time is in the range of about 0.001 seconds to about 1 second.

8. The method of claim 7, wherein in the sampling-time is in the range of about 0.02 seconds to about 0.10 seconds.

9. The method of claim 1, wherein the sample solution includes a physiological fluid and the analyte includes glucose.

10. The method of claim 9, wherein the physiological fluid includes blood.

11. The method of claim 1, wherein at least one said first current-transient and at least one said second current-transient are at least partially generated by a redox reaction.

12. The method of claim 11, wherein the redox reaction is dependent upon a reagent selected from the group consisting of glucose oxidase, glucose dehydrogenase, potassium ferricyanide, and ruthenium hexamine.

13. The method of claim 1, wherein determining the analyte concentration further includes using calibration data.

14. The method of claim 1, further including determining the presence of a sufficient volume of the sample solution.

15. The method of claim 14, wherein the sufficient volume is less than about 1 micro-liter.

16. The method of claim 14, wherein determining the presence of the sufficient solution volume further includes measuring a resistance or impendence across a pair of fill-detect electrodes.

17. The method of claim 1, wherein applying the at least one first pulse and the at least one second pulse includes applying the at least one first pulse and the at least one second pulse across a pair of electrodes.

18. The method of claim 17, wherein measuring at least one said first current-transient and at least one said second current-transient includes measuring at least one said first current-transient and at least one said second current-transient across the pair of electrodes.

19. The method of claim 1, wherein determining the analyte concentration is further based on a steady-state current associated with the at least one second pulse.

20. A method of determining a correction factor, comprising:

applying at least one first pulse at a first potential and at least one second pulse at a second potential to a sample solution containing an analyte, wherein the first potential and the second potential are the same polarity and the second potential is larger than the first potential;

measuring at least one first current-transient associated with the at least one first pulse and at least one second current-transient associated with the at least one second pulse;

determining a first ratio of measured currents between at least one said first current-transient and at least one said second current-transient, wherein said current-transients are measured at a substantially common sampling-time;

determining a second ratio of calculated currents based on a steady-state current associated with the at least one second pulse; and

determining a correction factor based on the first and second ratios.

21. The method of claim 20, wherein the first potential is in a range of about 0.005 volts to about 0.5 volts, and the second potential is in a range of about 0.03 volts to about 3.00 volts.

22. The method of claim 21, wherein the first potential is about 0.05 volts and the second potential is about 0.30 volts.

23. The method of claim 20, wherein the at least one first pulse is applied for a first time-period and the at least one second pulse is applied for a second time-period not the same as the first time-period.

24. The method of claim 23, wherein the first time-period is in a range of about 0.02 seconds to about 2 seconds, and the second time-period is in a range of about 0.5 seconds to about 10 seconds.

25. The method of claim 24, wherein the first time-period is about 0.2 seconds and the second time-period is about 4 seconds.

26. The method of claim 20, wherein in the sampling-time is in the range of about 0.001 seconds to about 1 second.

27. The method of claim 26, wherein in the sampling-time is in the range of about 0.02 seconds to about 0.10 seconds.

28. The method of claim 20, wherein the sample solution includes a physiological fluid and the analyte includes glucose.

29. The method of claim 28, wherein the physiological fluid includes blood.

30. The method of claim 20, wherein at least one said first current-transient and at least one said second current-transient are at least partially generated by a redox reaction.

31. The method of claim 30, wherein the redox reaction is dependent upon a reagent selected from the group consisting of glucose oxidase, glucose dehydrogenase, potassium ferricyanide, and ruthenium hexamine.

32. The method of claim 20, wherein determining the correction factor further includes using calibration data.

33. The method of claim 20, further including determining the presence of a sufficient volume of the sample solution.

34. The method of claim 33, wherein the sufficient volume is less than about 1 micro-liter.

35. The method of claim 34, wherein determining the presence of the sufficient solution volume further includes measuring a resistance or impendence across a pair of fill-detect electrodes.

36. The method of claim 20, wherein applying the at least one first pulse and the at least one second pulse includes applying the at least one first pulse and the at least one second pulse across a pair of electrodes.

37. The method of claim 36, wherein measuring at least one said first current-transient and at least one said second current-transient includes measuring at least one said first current-transient and at least one said second current-transient across the pair of electrodes.

38. The method of claim 20, wherein the correction factor is used to modify the steady-state current.

39. The method of claim 38, wherein the modified steady-state current is used to determine the analyte concentration.

40. An analyte testing system, comprising:

a meter system configured to determine an analyte concentration of a sample solution, wherein the meter system is configured to;

apply at least one first pulse at a first potential and at least one second pulse at a second potential to a sample solution containing an analyte, wherein the first potential and the second potential are the same polarity and the second potential is larger than the first potential;

measure at least one first current-transient associated with the at least one first pulse and at least one second current-transient associated with the at least one second pulse;

determine a ratio between at least one said first current-transient and at least one said second current-transient, wherein said current-transients are measured at a substantially common sampling-time; and

determine the analyte concentration of the sample solution based on the ratio of said current-transients.

41. The system of claim 40, wherein the first potential is in a range of about 0.005 volts to about 0.5 volts, and the second potential is in a range of about 0.03 volts to about 3.00 volts.

42. The system of claim 41, wherein the first potential is about 0.05 volts and the second potential is about 0.30 volts.

43. The system of claim 40, wherein the at least one first pulse is applied for a first time-period and the at least one second pulse is applied for a second time-period not the same as the first time-period.

44. The system of claim 43, wherein the first time-period is in a range of about 0.02 seconds to about 2 seconds, and the second time-period is in a range of about 0.5 seconds to about 10 seconds.

45. The system of claim 44, wherein the first time-period is about 0.2 seconds and the second time-period is about 4 seconds.

46. The system of claim 40, wherein in the sampling-time is in the range of about 0.001 seconds to about 1 second.

47. The system of claim 46, wherein in the sampling-time is in the range of about 0.02 seconds to about 0.10 seconds.

48. The system of claim 40, wherein the sample solution includes a physiological fluid and the analyte includes glucose.

49. The system of claim 48, wherein the physiological fluid includes blood.

50. The system of claim 40, wherein at least one said first current-transient and at least one said second current-transient are at least partially generated by a redox reaction.

51. The system of claim 50, wherein the redox reaction is dependent upon a reagent selected from the group consisting of glucose oxidase, glucose dehydrogenase, potassium ferricyanide, and ruthenium hexamine.

52. The system of claim 40, wherein determining the analyte concentration further includes using calibration data.

53. The system of claim 52, wherein the calibration data is stored in a meter or a test strip.

54. The system of claim 40, further including determining the presence of a sufficient volume of the sample solution.

55. The system of claim 54, wherein the sufficient volume is less than about 1 micro-liter.

56. The system of claim 55, wherein determining the presence of the sufficient solution volume further includes measuring a resistance or impendence across a pair of fill-detect electrodes.

57. The system of claim 40, wherein applying the at least one first pulse and the at least one second pulse includes applying the at least one first pulse and the at least one second pulse across a pair of electrodes.

58. The system of claim 57, wherein measuring at least one said first current-transient and at least one said second current-transient includes measuring at least one said first current-transient and at least one said second current-transient across the pair of electrodes.

59. The system of claim 40, wherein determining the analyte concentration is further based on a steady-state current associated with the at least one second pulse.

60. An analyte testing system, comprising:

a meter system configured to determine an analyte concentration of a sample solution, wherein the meter system is configured to;

apply at least one first pulse at a first potential and at least one second pulse at a second potential to a sample solution containing an analyte, wherein the first potential and the second potential are the same polarity and the second potential is larger than the first potential;

measure at least one first current-transient associated with the at least one first pulse and at least one second current-transient associated with the at least one second pulse;

determine a first ratio of measured currents between at least one said first current-transient and at least one said second current-transient, wherein said current-transients are measured at a substantially common sampling-time;

determine a second ratio of calculated currents based on a steady-state current associated with the at least one second pulse;

determine a correction factor based on the first and second ratios; and

determine the analyte concentration of the sample solution based on the correction factor.

61. The system of claim 60, wherein the first potential is in a range of about 0.005 volts to about 0.5 volts, and the second potential is in a range of about 0.03 volts to about 3.00 volts.

62. The system of claim 61, wherein the first potential is about 0.05 volts and the second potential is about 0.30 volts.

63. The system of claim 60, wherein the at least one first pulse is applied for a first time-period and the at least one second pulse is applied for a second time-period not the same as the first time-period.

64. The system of claim 63, wherein the first time-period is in a range of about 0.02 seconds to about 2 seconds, and the second time-period is in a range of about 0.5 seconds to about 10 seconds.

65. The system of claim 64, wherein the first time-period is about 0.2 seconds and the second time-period is about 4 seconds.

66. The system of claim 60, wherein in the sampling-time is in the range of about 0.001 seconds to about 1 second.

67. The system of claim 66, wherein in the sampling-time is in the range of about 0.02 seconds to about 0.10 seconds.

68. The system of claim 60, wherein the sample solution includes a physiological fluid and the analyte includes glucose.

69. The system of claim 68, wherein the physiological fluid includes blood.

70. The system of claim 60, wherein at least one said first current-transient and at least one said second current-transient are at least partially generated by a redox reaction.

71. The system of claim 70, wherein the redox reaction is dependent upon a reagent selected from the group consisting of glucose oxidase, glucose dehydrogenase, potassium ferricyanide, and ruthenium hexamine.

72. The system of claim 60, wherein determining the analyte concentration further includes using calibration data.

73. The system of claim 62, wherein the calibration data is stored in a meter or a test strip.

74. The system of claim 60, further including determining the presence of a sufficient volume of the sample solution.

75. The system of claim 74, wherein the sufficient volume is less than about 1 micro-liter.

76. The system of claim 75, wherein determining the presence of the sufficient solution volume further includes measuring a resistance or impendence across a pair of fill-detect electrodes.

77. The system of claim 60, wherein applying the at least one first pulse and the at least one second pulse includes applying the at least one first pulse and the at least one second pulse across a pair of electrodes.

78. The system of claim 77, wherein measuring at least one said first current-transient and at least one said second current-transient includes measuring at least one said first current-transient and at least one said second current-transient across the pair of electrodes.

79. The system of claim 60, wherein the correction factor is used to modify the steady-state current.

80. The system of claim 79, wherein the modified steady-state current is used to determine the analyte concentration.

81. A calibration method, comprising;

applying a standard solution to a first test strip;

applying at least one first pulse at a first potential and at least one second pulse at a second potential to the standard solution, wherein the first potential and the second potential are the same polarity and the second potential is larger than the first potential;

measuring at least one first current-transient associated with the at least one first pulse and at least one second current-transient associated with the at least one second pulse;

determining a ratio between at least one said first current-transient and at least one said second current-transient, wherein said current-transients are measured at a substantially common sampling-time; and

determining calibration data based at least in part on the ratio of said current-transients.

82. The method of claim 81, wherein the standard solution contains an analyte of known concentration and the calibration data includes data representative of the analyte concentration.

83. The method of claim 81, further including displaying the calibration data to a user.

84. The method of claim 83, wherein the calibration data is displayed to the user by a meter configured to receive the first test strip.

85. The method of claim 81, wherein the calibration data is determined as part of a manufacturing process.

86. The method of claim 85, further including manufacturing a second test strip associated with the manufacture of the first test strip.

87. The method of claim 86, wherein the manufacturing process further includes encoding the calibration data on the second test strip.

88. A calibration method, comprising;

applying a standard solution to a first test strip;

applying at least one first pulse at a first potential and at least one second pulse at a second potential to the standard solution, wherein the first potential and the second potential are the same polarity and the second potential is larger than the first potential;

measuring at least one first current-transient associated with the at least one first pulse and at least one second current-transient associated with the at least one second pulse;

determining a first ratio between at least one said first current-transient and at least one said second current-transient, wherein said current-transients are measured at a substantially common sampling-time;

determining a second ratio of calculated currents based on a steady-state current associated with the at least one second pulse; and

determining calibration data based at least in part on the first and second ratios.

89. The method of claim 88, wherein the standard solution contains an analyte of known concentration and the calibration data includes data representative of the analyte concentration.

90. The method of claim 88, further including displaying the calibration data to a user.

91. The method of claim 90, wherein the calibration data is displayed to the user by a meter configured to receive the first test strip.

92. The method of claim 88, wherein the calibration data is determined as part of a manufacturing process.

93. The method of claim 92, further including manufacturing a second test strip associated with the manufacture of the first test strip.

94. The method of claim 93, wherein the manufacturing process further includes encoding the calibration data on the second test strip.