Method Of Calibrating An Analyte-Measurement Device, And Associated Methods, Devices And Systems

• US 20090204340A1
• Filed: 04/09/2009
• Published: 08/13/2009
• Est. Priority Date: 10/31/2003
• Status: Abandoned Application

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Feldman, Benjamin J., McGarraugh, Geoffrey V.
• Application Number:
  US12/421,617
• Publication Number:
  US 20090204340A1
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/0024 for multiple sensor units attached to the patient, e.g. using a body or personal area network
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/6898 Portable consumer electronic devices, e.g. music players, telephones, tablet computers
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick

Abstract

The invention relates to a method for calibrating an analyte-measurement device that is used to evaluate a concentration of analyte in bodily fluid at or from a measurement site in a body. The method involves measuring a concentration, or calibration concentration, of an analyte in blood from an “off-finger” calibration site, and calibrating the analyte-measurement device based on that calibration concentration. The invention also relates to a device, system, or kit for measuring a concentration of an analyte in a body, which employs a calibration device for adjusting analyte concentration measured in bodily fluid based on an analyte concentration measured in blood from an “off-finger” calibration site.

Claims

1. (canceled)

2. A system for monitoring analyte concentration in a biological sample of a host, the system comprising:

a substantially continuous analyte sensor configured to produce a data signal indicative of an analyte concentration in a host during exposure of the sensor to a biological sample;

a reference solution, wherein the system is configured to expose the sensor to the reference solution, and wherein the system is configured to produce a data signal indicative of an analyte concentration in the reference solution during exposure of the sensor to the reference solution; and

a computer system comprising programming configured to determine calibration information and to calibrate a signal associated with a biological sample therefrom, wherein the calibration information comprises steady state information and transient information.

3. The system of claim 2, wherein the reference solution has a known analyte concentration.

4. The system of claim 2, wherein the calibration information is determined from a signal associated with exposure of the sensor to the reference solution and a signal associated with exposure of the sensor to the biological sample.

5. The system of claim 2, wherein the steady state information comprises at least one of sensitivity information and baseline information.

6. The system of claim 5, wherein the steady state information comprises sensitivity information and baseline information.

7. The system of claim 2, wherein steady state information comprises information associated with a signal produced during exposure of the sensor to the reference solution.

8. The system of claim 7, wherein the reference solution comprises a known analyte concentration of about zero, and wherein the steady state information comprises baseline information about the sensor in the reference solution.

9. The system of claim 7, wherein the reference solution comprises a known analyte concentration of more than zero, and wherein the steady state information comprises sensitivity information about the sensor.

10. The system of claim 2, wherein the steady state calibration information comprises reference data from an analyte sensor other than the substantially continuous analyte sensor.

11. The system of claim 2, wherein transient information comprises a rate of change of a signal produced during exposure of the sensor to a step change in analyte concentration.

12. The system of claim 11, wherein the rate of change comprises a rate change of a signal produced during exposure of the sensor to a biological sample of an unknown analyte concentration or an uncalibrated analyte concentration.

13. The system of claim 11, wherein the rate of change comprises a rate change of a signal produced during exposure of the sensor to a biological sample, and wherein steady state information comprises reference data from an analyte sensor other than the substantially continuous analyte sensor.

14. The system of claim 2, wherein transient information comprises response of a signal produced during exposure of the sensor to a change in analyte concentration.

15. The system of claim 14 wherein the response includes an impulse response, and the change in analyte concentration includes a step change in analyte concentration.

16. The system of claim 14, wherein the response is used to determine an offset between a baseline measurement associated with the reference solution and a baseline measurement associated with a biological sample.

17. The system of claim 14, wherein the response is used to determine a time point of a steady state measurement during which an analyte concentration can be obtained.

18. The system of claim 2, wherein the transient information comprises a comparison of steady state information and transient information for a plurality of time spaced signals associated with biological samples of unknown analyte concentration or uncalibrated analyte concentration.

19. The system of claim 18, wherein the comparison of steady state information and transient information is used to determine an offset between a baseline measurement associated with the reference solution and a baseline measurement associated with a biological sample.

20. The system of claim 18, further comprising programming to detect a shift in baseline or sensitivity based on a comparison of steady state information and transient information.

21. The system of claim 20, further comprising programming configured to initiate calibration of the signal to correct for a shift in at least one of baseline and sensitivity based on a comparison of steady state information and transient information.

22. The system of claim 20, further comprising programming configured to calibrate of the signal to correct for a shift in at least one of baseline and sensitivity based on a comparison of steady state information and transient information.

23. The system of claim 2, wherein the programming is configured to calibrate a signal is configured to perform at least one of initial calibration and update calibration.

24. The system of claim 2, wherein the analyte sensor is a glucose sensor.

25. A system for monitoring analyte concentration in a biological sample of a host, the system comprising:

a substantially continuous analyte sensor configured to produce a data signal indicative of an analyte concentration in a host during exposure of the sensor to a biological sample;

a reference solution, wherein the system is configured to expose the sensor to the reference solution, and wherein the system is configured to produce a data signal indicative of an analyte concentration in the reference solution during exposure of the sensor to the reference solution; and

a computer system comprising programming configured to determine calibration information and to calibrate a signal associated with a biological sample therefrom, wherein the calibration information is determined from a signal associated with exposure of the sensor to the reference solution and a signal associated with exposure of the sensor a biological sample, wherein the biological sample is of unknown analyte concentration or uncalibrated analyte concentration.

26. The system of claim 25, wherein the reference solution has a known analyte concentration.

27. The system of claim 25, wherein calibration information comprises steady state information and transient information

28. The system of claim 25, wherein steady state information comprises at least one of sensitivity information and baseline information

29. The system of claim 25, wherein transient information comprises a rate of change of the sensor'"'"'s signal responsive to exposure of the sensor to a change in analyte concentration

30. The system of claim 25, wherein transient information comprises a rate of change of a signal produced during exposure of the sensor to a step change in analyte concentration.

31. The system of claim 25, wherein the analyte sensor is a glucose sensor.

32. A system for monitoring analyte concentration in a biological sample of a host, the system comprising:

a substantially continuous analyte sensor configured to produce a data signal indicative of an analyte concentration in a host during exposure of the sensor to a biological sample;

a reference solution, wherein the system is configured to expose the sensor to the reference solution, and wherein the system is configured to produce a data signal indicative of an analyte concentration in the reference solution during exposure of the sensor to the reference solution; and

a computer system comprising programming configured to determine calibration information and calibrate a signal associated with a biological sample therefrom, wherein the calibration information is determined from at least one of a signal associated with exposure of the sensor to the reference solution and a signal associated with exposure of the sensor to a biological sample, wherein the biological sample is of unknown analyte concentration or uncalibrated analyte concentration.

33. The system of claim 32, wherein the reference solution has a known analyte concentration.

34. The system of claim 32, wherein the computer system further comprises programming configured to diagnose a condition of at least one of the sensor and the host responsive to calibration information.

35. The system of claim 32, wherein calibration information comprises baseline information, and wherein the system comprises programming configured to determine an offset between a baseline associated with a reference solution and a baseline associated with a biological sample.

36. The system of claim 35, wherein the offset is determined by processing an impulse response of the sensor'"'"'s signal during exposure of the sensor to a step change in analyte concentration.

37. The system of claim 35, wherein the offset is determined by a comparison of steady state information and transient information for a plurality of time spaced samples of a biological sample of unknown analyte concentration or uncalibrated analyte concentration.

38. The system of claim 35, wherein the computer system further comprises programming configured to detect an interfering species.

39. The system of claim 38 wherein the interfering species is responsive to a change in the offset above a predetermined amount.

40. The system of claim 35, wherein the computer system further comprises programming configured to diagnose a condition of the host'"'"'s metabolic processes responsive to a change in the offset above a predetermined amount.

41. The system of claim 40, wherein the computer system further comprises programming configured to display or transmit a message associated with the host'"'"'s condition responsive to diagnosing the condition.

42. The system of claim 35, wherein the computer system further comprises programming configured to diagnose an error and fail safe responsive to a change in the offset above a predetermined amount.

43. The system of claim 35, wherein the computer system further comprises programming configured to recalibrate the sensor responsive to a change in the offset above a predetermined amount.

44. The system of claim 32, wherein calibration information comprises sensitivity information, and wherein the system comprises programming configured to diagnose an error responsive to a change in sensitivity above a predetermined amount.

45. The system of claim 32, wherein the computer system further comprises programming configured to calculate an response of a signal produced during exposure of the sensor to a change in analyte concentration, and wherein a time constant for the change is determined from the time of the peak response.

46. The system of claim 45 wherein the response of the signal includes an impulse response.

47. The system of claim 45 wherein the change in analyte concentration includes a step change.

48. The system of claim 45 wherein the time constant for the change includes a time constant for a step change.

49. The system of claim 45 wherein the time of the peak response includes the time of the peak impulse response.

50. The system of claim 45, wherein the step of calculating an response is repeated more than one time, and wherein the computer system further comprises programming configured to diagnose a sensor condition or error responsive to a change in the time constants associated with the plurality of step changes above a predetermined threshold.