SYSTEM AND METHOD FOR ANALYTE MEASUREMENT USING DOSE SUFFICIENCY ELECTRODES

• US 20090045076A1
• Filed: 10/20/2008
• Published: 02/19/2009
• Est. Priority Date: 06/20/2003
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Operations Limited (Roche Holding AG)
• Inventors: Groll, Henning, Burke, David W., Surridge, Nigel A.
• Granted Patent: US 8,663,442 B2
• Time in Patent Office: Days
• US Class Current: 205/792
• CPC Class Codes: G01N 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771

Abstract

A method of measuring an analyte in a biological fluid comprises applying an excitation signal having a DC component and an AC component. The AC and DC responses are measured; a corrected DC response is determined using the AC response; and a concentration of the analyte is determined based upon the corrected DC response. Other methods and devices are disclosed.

Claims

1. A method of determining a dose sufficiency in a test strip for performing a measurement on a biological fluid, comprising:

providing a biological fluid test strip comprising;

a capillary fill chamber extending a length along the test strip,

at least two measurement electrodes in operative communication with the chamber, and

at least two dose sufficiency electrodes in operative communication with the chamber;

applying the biological fluid to the test strip;

applying a dose sufficiency test signal having an AC component to at least one of the dose sufficiency electrodes; and

measuring a response to the dose sufficiency test signal.

2. The method of claim 1, wherein the test signal is an AC signal.

3. The method of claim 1, wherein the response comprises magnitude and phase angle information.

4. The method of claim 1, wherein the response comprises an admittance value.

5. The method of claim 1, wherein the applying a dose sufficiency test signal results in the dose sufficiency electrodes exhibiting an edge effect.

6. The method of claim 1, wherein the AC component has a frequency of about 10 kHz.

7. A method of determining a fill sufficiency in test strip for performing a measurement on a biological fluid comprising:

providing a biological fluid test strip including;

a capillary fill chamber extending a length along the test strip from an intake opening to a terminus,

a measurement zone in the chamber positioned intermediate the opening and the terminus, and

at least two dose sufficiency electrodes in operative communication with the chamber the electrodes positioned intermediate the measurement zone and the terminus;

introducing the biological fluid to the opening effective to cause the fluid to flow toward the terminus whereby the chamber is filled;

applying a test signal having an AC component to at least one of the dose sufficiency electrodes; and

detecting a response or an absence of the response to the test signal effective to indicate the fill sufficiency of the biological fluid.

8. The method of claim 7, wherein the test signal is an AC signal.

9. The method of claim 7, wherein the response comprises magnitude and phase angle information.

10. The method of claim 7, wherein the response comprises an admittance value.

11. A method of determining a dose sufficiency in a test strip for performing a measurement on a biological fluid, comprising:

providing a biological fluid test strip comprising;

a fluid flow intake opening;

a fluid flow terminus;

at least two measurement electrodes disposed on the test strip between the opening and the terminus, the measurement electrodes defining a measurement zone; and

at least two dose sufficiency electrodes defining a gap therebetween and located between the measurement zone and the terminus;

applying the biological fluid to the test strip;

applying a dose sufficiency test signal having an AC component to at least one of the dose sufficiency electrodes; and

measuring a response to the dose sufficiency test signal.

12. The method of claim 11, further comprising:

a capillary fill chamber extending a length along the test strip from the opening to the terminus; and

a reagent disposed in the capillary fill chamber.

13. The method of claim 11, wherein the test signal is an AC signal.

14. The method of claim 11, wherein the response comprises magnitude and phase angle information.

15. The method of claim 11, wherein the response comprises an admittance value.

16. The method of claim 11, wherein the applying a dose sufficiency test signal results in the dose sufficiency electrodes exhibiting an edge effect.

17. The method of claim 11, wherein the AC component has a frequency of about 10 kHz.

18. A method of determining a fill sufficiency in test strip for performing a measurement on a biological fluid comprising:

providing a biological fluid test strip, comprising;

a fluid flow intake opening;

a fluid flow terminus;

a measurement zone positioned intermediate the opening and the terminus, and

at least two dose sufficiency electrodes positioned intermediate the measurement zone and the terminus;

introducing the biological fluid to the opening effective to cause the fluid to flow toward the terminus;

applying a test signal having an AC component to at least one of the dose sufficiency electrodes; and

detecting a response or an absence of the response to the test signal effective to indicate a volume sufficiency of the biological fluid.

19. The method of claim 18, further comprising:

a capillary fill chamber extending a length along the test strip from the opening to the terminus.

20. The method of claim 18, wherein the test signal is an AC signal.

21. The method of claim 18, wherein the response comprises magnitude and phase angle information.

22. The method of claim 18, wherein the response comprises an admittance value.

23. A method of determining dosage fill level in a test strip for performing a measurement on a biological fluid comprising:

providing a biological fluid test strip including;

a capillary fill chamber extending a length along the test strip from an opening to a terminus, and

at least two dose sufficiency electrodes in operative communication with the chamber the dose sufficiency electrodes positioned to define a gap between one another;

dosing the test strip with a biological fluid effective to cause the biological fluid to begin to fill the chamber;

applying a test signal having an AC component to at least one of the dose sufficiency electrodes;

measuring a response to the test signal;

determining the dosage fill level based upon the response.

24. The method of claim 23, wherein the test signal is an AC signal.

25. The method of claim 23, wherein the response comprises magnitude and phase angle information.

26. The method of claim 23, wherein the response comprises an admittance value.

27. The method of claim 23, wherein the response varies in correlation with the degree to which the biological fluid bridges the gap.

28. A method of determining a fill level of a biological fluid in a test strip for performing a measurement on the fluid comprising:

providing a test strip including

a capillary fill chamber extending a length along the test strip from an opening to a terminus, and

at least two dose sufficiency electrodes in operative communication with the chamber the dose sufficiency electrodes positioned to define a gap between one another;

introducing the biological fluid to the opening effective to cause the fluid to flow toward the terminus whereby the chamber is filled;

applying a test signal having an AC component to at least one of the dose sufficiency electrodes; and

measuring a response to the test signal;

determining the fill level of the biological fluid based upon the response wherein the response varies in relation to the fill level.

29. The method of claim 28, wherein the test signal is an AC signal.

30. The method of claim 28, wherein the response comprises magnitude and phase angle information.

31. The method of claim 28, wherein the response comprises an admittance value.

32. A system for performing a measurement on a biological fluid, the system comprising:

a test strip comprising;

a capillary fill chamber extending a length along the test strip from an opening to a terminus;

at least two measurement electrodes in operative communication with the chamber; and

at least two dose sufficiency electrodes in operative communication with the chamber;

wherein the dose sufficiency electrodes have first edges substantially parallel to the length of the capillary chamber and second edges substantially perpendicular to the length of the capillary fill chamber with the first edges being of greater length than the second edges; and

a signal generator operable to apply a signal having an AC component to at least one of the dose sufficiency electrodes.

33. The system of claim 32, wherein the signal having an AC component is an AC signal.

34. A system for performing a measurement on a biological fluid, the system comprising:

a test strip comprising;

a capillary fill chamber extending a length along the test strip from an opening to a terminus;

a measurement zone in the chamber positioned intermediate the opening and the terminus, and

at least two dose sufficiency electrodes in operative communication with the chamber the electrodes positioned intermediate the measurement zone and the terminus;

wherein the dose sufficiency electrodes have a first axis substantially parallel to the length of the capillary chamber and a second axis substantially perpendicular to the length of the capillary fill chamber with the first axis being of greater length than the second axis; and

a signal generator operable to apply a signal having an AC component to at least one of the dose sufficiency electrodes.

35. The system of claim 34, wherein the signal having an AC component is an AC signal.

36. A system for performing a measurement on a biological fluid, the system comprising:

a test strip comprising;

a fluid flow path extending a length along the test strip from an opening to a terminus;

at least two measurement electrodes in operative communication with the fluid flow path; and

at least two dose sufficiency electrodes in operative communication with the fluid flow path;

wherein the dose sufficiency electrodes have first edges substantially parallel to the length of the fluid flow path and second edges substantially perpendicular to the length of the fluid flow path with the first edges being of greater length than the second edges; and

a signal generator operable to apply a signal having an AC component to at least one of the dose sufficiency electrodes.

37. The system of claim 36, wherein the signal having an AC component is an AC signal.

38. The system of claim 36, further comprising:

a capillary fill chamber extending a length along the test strip from the opening to the terminus.

39. A system for performing a measurement on a biological fluid, the system comprising:

a test strip comprising;

a fluid flow path extending a length along the test strip from an opening to a terminus;

a measurement zone in the chamber positioned intermediate the opening and the terminus, and

at least two dose sufficiency electrodes in operative communication with the fluid flow path, the electrodes positioned intermediate the measurement zone and the terminus;

wherein the dose sufficiency electrodes have a first axis substantially parallel to the length of the fluid flow path and a second axis substantially perpendicular to the length of the fluid flow path with the first axis being of greater length than the second axis; and

a signal generator operable to apply a signal having an AC component to at least one of the dose sufficiency electrodes.

40. The system of claim 39, wherein the signal having an AC component is an AC signal.

41. The system of claim 39, further comprising:

a capillary fill chamber extending a length along the test strip from the opening to the terminus.

42. A method for performing a measurement on a biological fluid, the method comprising the steps of:

a) providing a test strip comprising;

a capillary fill chamber extending a length along the test strip from an opening to a terminus;

at least two measurement electrodes in operative communication with the chamber; and

at least two dose sufficiency electrodes in operative communication with the chamber;

wherein the dose sufficiency electrodes have first edges substantially parallel to the length of the capillary chamber and second edges substantially perpendicular to the length of the capillary fill chamber with the first edges being of greater length than the second edges; and

b) applying a signal having an AC component to at least one of the dose sufficiency electrodes.

43. The method of claim 42, wherein step (b) comprises applying an AC signal to at least one of the dose sufficiency electrodes.

44. A method for performing a measurement on a biological fluid, the method comprising the steps of:

a) providing a test strip comprising;

a capillary fill chamber extending a length along the test strip from an opening to a terminus;

a measurement zone in the chamber positioned intermediate the opening and the terminus, and

at least two dose sufficiency electrodes in operative communication with the chamber the electrodes positioned intermediate the measurement zone and the terminus;

wherein the dose sufficiency electrodes have a first axis substantially parallel to the length of the capillary chamber and a second axis substantially perpendicular to the length of the capillary fill chamber with the first axis being of greater length than the second axis; and

b) applying a signal having an AC component to at least one of the dose sufficiency electrodes.

45. The method of claim 44, wherein step (b) comprises applying an AC signal to at least one of the dose sufficiency electrodes.

46. A method for performing a measurement on a biological fluid, the method comprising the steps of:

a) providing a test strip comprising;

a fluid flow path extending a length along the test strip from an opening to a terminus;

at least two measurement electrodes in operative communication with the fluid flow path; and

at least two dose sufficiency electrodes in operative communication with the fluid flow path;

wherein the dose sufficiency electrodes have first edges substantially parallel to the length of the fluid flow path and second edges substantially perpendicular to the length of the fluid flow path with the first edges being of greater length than the second edges; and

b) applying a signal having an AC component to at least one of the dose sufficiency electrodes.

47. The method of claim 46, wherein step (b) comprises applying an AC signal to at least one of the dose sufficiency electrodes.

48. The method of claim 46, further comprising:

a capillary fill chamber extending a length along the test strip from the opening to the terminus.

49. A method for performing a measurement on a biological fluid, the method comprising the steps of:

a) providing a test strip comprising;

a fluid flow path extending a length along the test strip from an opening to a terminus;

a measurement zone in the chamber positioned intermediate the opening and the terminus, and

at least two dose sufficiency electrodes in operative communication with the fluid flow path, the electrodes positioned intermediate the measurement zone and the terminus;

wherein the dose sufficiency electrodes have a first axis substantially parallel to the length of the fluid flow path and a second axis substantially perpendicular to the length of the fluid flow path with the first axis being of greater length than the second axis; and

b) applying a signal having an AC component to at least one of the dose sufficiency electrodes.

50. The method of claim 49, wherein step (b) comprises applying an AC signal to at least one of the dose sufficiency electrodes.

51. The method of claim 49, further comprising:

a capillary fill chamber extending a length along the test strip from the opening to the terminus.

52. A system for performing a measurement on a biological fluid, the system comprising:

a test strip comprising;

a capillary fill chamber extending a length along the test strip from an opening to a terminus;

at least two measurement electrodes in operative communication with the chamber; and

at least two dose sufficiency electrodes in operative communication with the chamber;

wherein the dose sufficiency electrodes have first edges substantially parallel to the length of the capillary chamber and second edges substantially perpendicular to the length of the capillary fill chamber with the first edges being of greater length than the second edges; and

a circuit operable to;

a) apply a signal to at least one of the dose sufficiency electrodes;

b) measure a response to the signal; and

c) compare the response to a predetermined threshold to indicate whether the biological fluid substantially fills the capillary fill chamber, wherein the threshold is configured and adapted to prevent false indications of the biological fluid substantially filling the capillary fill chamber.

53. The system of claim 52, wherein the signal is an AC signal.

54. A system for performing a measurement on a biological fluid, the system comprising:

a test strip comprising;

a capillary fill chamber extending a length along the test strip from an opening to a terminus;

a measurement zone in the chamber positioned intermediate the opening and the terminus, and

at least two dose sufficiency electrodes in operative communication with the chamber the electrodes positioned intermediate the measurement zone and the terminus;

wherein the dose sufficiency electrodes have a first axis substantially parallel to the length of the capillary chamber and a second axis substantially perpendicular to the length of the capillary fill chamber with the first axis being of greater length than the second axis; and

a circuit operable to;

a) apply a signal to at least one of the dose sufficiency electrodes;

b) measure a response to said signal; and

c) compare the response to a predetermined threshold to indicate whether the biological fluid substantially fills the measurement zone, wherein the threshold is configured and adapted to prevent false indications of the biological fluid substantially filling the measurement zone.

55. The system of claim 54, wherein the signal is an AC signal.

56. A system for performing a measurement on a biological fluid, the system comprising:

a test strip comprising;

a fluid flow path extending a length along the test strip from an opening to a terminus;

at least two measurement electrodes in operative communication with the fluid flow path; and

at least two dose sufficiency electrodes in operative communication with the fluid flow path;

wherein the dose sufficiency electrodes have first edges substantially parallel to the length of the fluid flow path and second edges substantially perpendicular to the length of the fluid flow path with the first edges being of greater length than the second edges; and

a circuit operable to;

a) apply a signal to at least one of the dose sufficiency electrodes;

b) measure a response to the signal; and

c) compare the response to a predetermined threshold to indicate whether the biological fluid substantially fills the fluid flow path, wherein the threshold is configured and adapted to prevent false indications of the biological fluid substantially filling the fluid flow path.

57. The system of claim 56, wherein the signal is an AC signal.

58. The system of claim 56, further comprising:

a capillary fill chamber extending a length along the test strip from the opening to the terminus.

59. A system for performing a measurement on a biological fluid, the system comprising:

a test strip comprising;

a fluid flow path extending a length along the test strip from an opening to a terminus;

a measurement zone in the chamber positioned intermediate the opening and the terminus, and

at least two dose sufficiency electrodes in operative communication with the fluid flow path, the electrodes positioned intermediate the measurement zone and the terminus;

wherein the dose sufficiency electrodes have a first axis substantially parallel to the length of the fluid flow path and a second axis substantially perpendicular to the length of the fluid flow path with the first axis being of greater length than the second axis; and

a circuit operable to;

a) apply a signal to at least one of the dose sufficiency electrodes;

b) measure a response to said signal; and

c) compare the response to a predetermined threshold to indicate whether the biological fluid substantially fills the measurement zone, wherein the threshold is configured and adapted to prevent false indications of the biological fluid substantially filling the measurement zone.

60. The system of claim 59, wherein the signal is an AC signal.

61. The system of claim 59, further comprising:

a capillary fill chamber extending a length along the test strip from the opening to the terminus.

62. A method of determining dose sufficiency in a test strip for performing a measurement on a biological fluid comprising:

providing a biological fluid test strip, comprising;

a capillary fill chamber extending a length along the test strip from an intake opening to a terminus,

at least two measurement electrodes disposed in the capillary fill chamber between the opening and the terminus, the measurement electrodes defining a measurement zone, and

at least two dose sufficiency electrodes defining a gap therebetween and in operative communication with the capillary fill chamber, the electrodes located between the measurement zone and the terminus;

applying the biological fluid to the opening, whereby the fluid flows from the opening toward the terminus, the flow including a flow front selected from one of a concave, a convex and a substantially flat flow front;

applying a test signal to at least one of the dose sufficiency electrodes;

determining the presence or absence of a response to the test signal above a predetermined threshold, wherein the predetermined threshold is set to indicate whether the biological fluid substantially fills the measurement zone, wherein the threshold is configured and adapted to prevent false indications of the biological fluid substantially filling the measurement zone.

63. The method of claim 62, wherein the test signal is an AC signal.

64. The method of claim 62, wherein the response comprises magnitude and phase angle information.

65. The method of claim 62, wherein the response comprises an admittance value.

66. A method of determining dose sufficiency in a test strip for performing a measurement on a biological fluid comprising:

providing a biological fluid test strip, comprising;

a fluid flow intake opening,

a fluid flow terminus,

at least two measurement electrodes disposed on the test strip between the opening and the terminus, the measurement electrodes defining a measurement zone, and

at least two dose sufficiency electrodes defining a gap therebetween and located between the measurement zone and the terminus;

applying the biological fluid to the opening, whereby the fluid flows from the opening toward the terminus, the flow including a flow front selected from one of a concave, a convex and a substantially flat flow front;

applying a test signal to at least one of the dose sufficiency electrodes;

determining the presence or absence of a response to the test signal above a predetermined threshold, wherein the predetermined threshold is set to indicate whether the biological fluid substantially fills the measurement zone, wherein the threshold is configured and adapted to prevent false indications of the biological fluid substantially filling the measurement zone.

67. The method of claim 66, wherein the test signal is an AC signal.

68. The method of claim 66, wherein the response comprises magnitude and phase angle information.

69. The method of claim 66, wherein the response comprises an admittance value.

70. The method of claim 66, further comprising:

a capillary fill chamber extending a length along the test strip from the opening to the terminus; and

a reagent disposed in the capillary fill chamber.