Method and system for dynamically updating calibration parameters for an analyte sensor

• US 7,618,369 B2
• Filed: 10/02/2006
• Issued: 11/17/2009
• Est. Priority Date: 10/02/2006
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Doniger, Kenneth J., Hayter, Gary, Mazza, John C., Budiman, Erwin S.
• Primary Examiner(s): Mallari; Patricia C
• Assistant Examiner(s): GOLOMB, JORDAN RIVARD
• Application Number:
  US11/537,991
• Publication Number:
  US 20080081977A1
• Time in Patent Office: 1,142 Days
• Field of Search: 600/365, 600/300, 600485-499, 600309-361
• US Class Current: 600/309
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0015 characterised by features of the telemetry system
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence

Abstract

Methods and apparatuses including determining a calibration parameter associated with a detected analyte value, calibrating the analyte value based on the calibration parameter, and dynamically updating the calibration parameter are disclosed. Also provided are systems, kits, and computer program products.

Claims

1. A computer implemented method, comprising:

obtaining a reference data point at a first predetermined time determined based on an analyte sample from an in vitro test strip;

receiving a first data at the first predetermined time from an analyte sensor in fluid contact with an interstitial fluid;

calibrating the first data based on the reference data point using a processor;

receiving a second data at a second predetermined time from the analyte sensor;

updating the calibrated first data based on the second data; and

calibrating the second data.

2. The method of claim 1 wherein the reference data point includes a blood glucose value.

3. The method of claim 1 wherein the first predetermined time includes a calibration time associated with the calibration of one or more of the first data or the second data.

4. The method of claim 1 wherein the first data and the second data includes a respective one of a monitored analyte value.

5. The method of claim 1 wherein calibrating the first data includes:

determining a first rate of change of the first data at the first predetermined time; and

performing a first lag compensation of the first data based on the first rate of change to generate a first lag compensated first data.

6. The method of claim 5 wherein calibrating the first data further includes:

determining a first calibration parameter associated with the first data based on the reference data point and the first lag compensated first data; and

generating a calibrated first data based on the first calibration parameter and the first lag compensated first data.

7. The method of claim 5 wherein updating the calibrated first data includes:

determining a second rate of change of the first data at the first predetermined time based on the second data; and

performing a second lag compensation of the first data based on the second rate of change of the first data to generate a second lag compensated first data.

8. The method of claim 7 wherein calibrating the second data includes:

determining a second calibration parameter associated with the first data based on the reference data point and the second lag compensated first data; and

generating a calibrated second data based on the second calibration parameter and the second lag compensated first data.

9. A computer implemented method, comprising:

determining a calibration parameter associated with a detected analyte value based from an analyte sensor in fluid contact with an interstitial fluid;

calibrating the analyte value based on the calibration parameter to generate a calibrated analyte value using a processor; and

dynamically updating the calibration parameter including updating the calibrated analyte value.

10. The method of claim 9 further including calibrating a second detected analyte value based on the dynamically updated calibration parameter.

11. The method of claim 9 wherein dynamically updating the calibration parameter includes:

determining a rate of change of the detected analyte value; and

generating a lag compensated analyte value based on the rate of change.

12. The method of claim 9 wherein calibrating the analyte value includes:

determining a sensitivity associated with the detected analyte value; and

applying the sensitivity to the lag compensated analyte value.

13. The method of claim 11 wherein dynamically updating the calibration parameter includes:

updating the rate of change of the detected analyte value; and

updating the lag compensated analyte value.

14. The method of claim 13 wherein updating the rate of change includes determining the rate of change of the detected analyte value between a first predetermined time and a second predetermined time.

15. The method of claim 11 wherein calibrating the analyte value includes:

detecting a calibration data;

determining a sensitivity based on the calibration data and the lag compensated analyte value; and

generating a lag compensated and calibrated analyte value.

16. The method of claim 15 wherein the calibration data includes a blood glucose value.

17. An apparatus, comprising:

one or more processing units; and

a memory for storing instructions which, when executed by the one or more processors, causes the one or more processing units to obtain a reference data point at a first predetermined time, receive a first data from an analyte sensor at the first predetermined time, calibrate the first data based on the reference data point;

receive a second data from an analyte sensor at a second predetermined time;

update the calibrated first data based on the second data; and

calibrate the second data.

18. The apparatus of claim 17 wherein the reference data point includes a blood glucose value.

19. The apparatus of claim 17 wherein the first predetermined time includes a calibration time associated with the calibration of one or more of the first data or the second data.

20. The apparatus of claim 17 wherein the first data and the second data includes a respective one of a monitored analyte value.

21. The apparatus of claim 17 wherein the memory is further configured for storing instructions which, when executed by the one or more processing units, causes the one or more processing units to determine a first rate of change of the first data at the first predetermined time, and to perform a first lag compensation of the first data based on the first rate of change to generate a first lag compensated first data.

22. The apparatus of claim 21 wherein the memory is further configured for storing instructions which, when executed by the one or more processing units, causes the one or more processing units to determine a first calibration parameter associated with the first data based on the reference data point and the first lag compensated first data and to generate a calibrated first data based on the first calibration parameter and the first lag compensated first data.

23. The apparatus of claim 21 wherein the memory is further configured for storing instructions which, when executed by the one or more processing units, causes the one or more processing units to determine a second rate of change of the first data at the first predetermined time based on the second data, and to perform a second lag compensation of the first data based on the second rate of change of the first data to generate a second lag compensated first data.

24. The apparatus of claim 23 wherein the memory is further configured for storing instructions which, when executed by the one or more processing units, causes the one or more processing units to determine a second calibration parameter associated with the first data based on the reference data point and the second lag compensated first data, and to generate a calibrated second data based on the second calibration parameter and the second lag compensated first data.