Method of Calibrating an Analyte-Measurement Device, and Associated Methods, Devices and Systems

• US 20110004084A1
• Filed: 09/17/2010
• Published: 01/06/2011
• 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:
  US12/885,379
• Publication Number:
  US 20110004084A1
• Time in Patent Office: Days
• US Class Current: 600/347
• 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. An apparatus for use in calibrating a signal from a subcutaneous sensor, the apparatus comprising:

one or more processors;

a memory for storing instructions which, when executed by the one or more processors, causes the one or more processors to receive a calibration measurement from a calibration sensor placed in contact with capillary blood from an off-finger calibration site within a body, to evaluate whether the calibration measurement is within a predetermined range of analyte concentration, and to determine that the calibration measurement is suitable for use in converting an analyte signal from the subcutaneous sensor into an analyte concentration if the calibration measurement is within the predetermined range.

2. The apparatus of claim 1, wherein the analyte is glucose and the predetermined range is from about 60 mg/dL to about 350 mg/dL.

3. The apparatus of claim 1, wherein the analyte is glucose.

4. The apparatus of claim 1, wherein the calibration site is located in an arm of the body.

5. The apparatus of claim 1, wherein the calibration site is located in a leg of the body.

6. The apparatus of claim 1, wherein the subcutaneous sensor is located in an arm of the body.

7. The apparatus of claim 1, wherein the subcutaneous sensor is located in the abdomen of the body.

8. The apparatus of claim 1, wherein the subcutaneous sensor is located in one region of the body and the calibration site is located in another region of the body.

9. The apparatus of claim 1, wherein each of the subcutaneous sensor and the calibration site is located in substantially one region of the body.

10. The apparatus of claim 1, wherein the subcutaneous sensor is sufficient for electrochemically determining a concentration of an analyte.

11. The apparatus of claim 1, wherein the instructions for receiving the calibration measurement comprises instructions for determining the calibration measurement electrochemically.

12. The apparatus of claim 1, wherein the instructions for receiving the calibration measurement comprises instructions for determining the calibration measurement in less than or equal to about 1 μ

L of blood.

13. The apparatus of claim 1, wherein the instructions for receiving the calibration measurement comprises instructions for determining the calibration measurement in less than or equal to about 0.5 μ

L of blood.

14. The apparatus of claim 1, wherein the instructions for receiving the calibration measurement comprises instructions for determining the calibration measurement in less than or equal to about 0.2 μ

L of blood.

15. The apparatus of claim 1, wherein the instructions for receiving the calibration measurement comprises instructions for determining the calibration measurement within about five minutes after the subcutaneous sensor is inserted at a measurement site.

16. The apparatus of claim 1, wherein the instructions for receiving the calibration measurement comprises instructions for determining the calibration measurement within about one hour after the subcutaneous sensor is inserted at a measurement site.

17. The apparatus of claim 1, wherein the instructions for receiving the calibration measurement comprises instructions for determining the calibration measurement within about three hours after the subcutaneous sensor is inserted at a measurement site.

18. The apparatus of claim 1, wherein the instructions for receiving the calibration measurement comprises instructions for determining the calibration measurement within about twenty-four hours after the subcutaneous sensor is inserted at a measurement site.

19. The apparatus of claim 1, further comprising instructions which, when executed by the one or more processors, causes the one or more processors to receive at least one analyte signal from the subcutaneous sensor.

20. The apparatus of claim 19, further comprising instructions which, when executed by the one or more processors, causes the one or more processors to evaluate the analyte signal based on a predetermined range for a rate of change in analyte concentration over a predetermined period.

21. The apparatus of claim 20, wherein the analyte is glucose and the predetermined range is up to about 2 mg/dL per minute in any direction.

22. The apparatus of claim 20, further comprising instructions which, when executed by the one or more processors, causes the one or more processors to repeat receiving an analyte signal, receiving a calibration measurement or evaluating, or any combination thereof, until the analyte signal, the calibration measurement or both are suitable for use in converting an analyte signal from the subcutaneous sensor into an analyte concentration.

23. The apparatus of claim 22, further comprising instructions which, when executed by the one or more processors, causes the one or more processors to determine a sensitivity based on a ratio of the analyte signal and the calibration measurement when the analyte signal, the calibration measurement or both are suitable for use in converting an analyte signal from the subcutaneous sensor into an analyte concentration.

24. The apparatus of claim 23, wherein the ratio falls within a predetermined range associated with a code associated with the subcutaneous sensor.

25. The apparatus of claim 23, further comprising instructions which, when executed by the one or more processors, causes the one or more processors to convert an analyte signal from the analyte sensor to an analyte concentration based on the sensitivity.

26. The apparatus of claim 1, wherein the subcutaneous sensor comprises a working electrode and a counter electrode.

27. The apparatus of claim 26, wherein the working electrode comprises a glucose-responsive enzyme.

28. The apparatus of claim 26, wherein the working electrode comprises a redox mediator.

29. The apparatus of claim 28, wherein the redox mediator comprises a complex selected from the group consisting of a ruthenium-containing complex and an osmium-containing complex.

30. The apparatus of claim 28, wherein the redox mediator is non-leachable with respect to the working electrode.

31. The apparatus of claim 28, wherein the redox mediator is immobilized on the working electrode.

32. The apparatus of claim 1, wherein the subcutaneous sensor and the calibration sensor are physically or wirelessly associated.