Calibration techniques for a continuous analyte sensor

• US 7,917,186 B2
• Filed: 11/16/2009
• Issued: 03/29/2011
• Est. Priority Date: 12/05/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Goode, Paul V. Jr., Kamath, Apurv Ullas, Brauker, James H., Simpson, Peter C.
• Primary Examiner(s): Marmor, II; Charles A
• Assistant Examiner(s): D'ANGELO, MICHAEL J
• Application Number:
  US12/619,502
• Publication Number:
  US 20100063373A1
• Time in Patent Office: 498 Days
• Field of Search: 600345-347, 600/365
• US Class Current: 600/347
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

Disclosed herein are systems and methods for calibrating a continuous analyte sensor, such as a continuous glucose sensor. One such system utilizes one or more electrodes to measure an additional analyte. Such measurements may provide a baseline or sensitivity measurement for use in calibrating the sensor. Furthermore, baseline and/or sensitivity measurements may be used to trigger events such as digital filtering of data or suspending display of data.

Claims

1. A system for measuring glucose in a host, the system comprising:

a sensor configured to generate a glucose signal indicative of a glucose concentration in a host and configured to generate an auxiliary signal indicative of changes in solute transport across a membrane system of the sensor; and

a processor module configured to calibrate the glucose signal in response to a predetermined change in the auxiliary signal.

2. The system of claim 1, wherein the sensor comprises a first working electrode configured to generate a first signal associated with a glucose concentration in a host and a second working electrode configured to generate a second signal associated with a non-glucose related electroactive compound, wherein the second working electrode is disposed beneath a non-enzymatic portion of the membrane system of the sensor, wherein the first electrode is disposed beneath an active enzymatic portion of the membrane system of the sensor, and wherein the processor module is configured to process the first signal and the second signal to generate the glucose signal indicative of a glucose concentration in the host.

3. The system of claim 1, wherein the sensor comprises a first working electrode configured to generate the glucose signal indicative of a glucose concentration in a host.

4. The system of claim 1, wherein the sensor comprises an auxiliary electrode configured to generate the auxiliary signal indicative of changes in solute transport across a membrane system of the sensor, wherein the auxiliary electrode is configured to measure at least one analyte selected from the group consisting of oxygen, a carboxylic acid, an amino acid, hydrogen, pH, chloride, and combinations thereof.

5. The system of claim 1, wherein the processor module is configured to calibrate the glucose signal based at least in part on an amplitude of the auxiliary signal.

6. The system of claim 1, wherein the processor module is configured to calibrate the glucose signal at a preselected frequency.

7. The system of claim 1, wherein the processor module is configured to calibrate the glucose signal at a frequency based at least in part on a change in the auxiliary signal.

9. The system of claim 1, wherein the glucose signal and the auxiliary signal are each generated by an electrode configured to be located at a same local environment when implanted in a host.

10. The system of claim 9, wherein the glucose signal and the auxiliary signal are generated by electrodes that are juxtapositioned or twisted with or around each other.

11. The system of claim 1, wherein the sensor is configured to continuously generate the glucose signal.

12. The system of claim 1, wherein the sensor is configured to intermittently generate the auxiliary signal.

13. The system of claim 1, wherein the sensor comprises at least one wire.

14. The system of claim 13, wherein the sensor comprises at least two wires juxtapositioned or twisted with or around each other.

15. The system of claim 13, wherein the wire has a width of less than about 0.01 inches.

8. A system for measuring glucose in a host, the system comprising:

a sensor configured to generate a glucose signal indicative of glucose concentration in a host and configured to generate an auxiliary signal indicative of changes in solute transport across a membrane system of the sensor; and

a processor module configured to calibrate the glucose signal at a frequency based at least in part on a change in the auxiliary signal.

16. The system of claim 8, wherein the sensor comprises a first working electrode configured to generate a first signal associated with the glucose concentration in the host and a second working electrode configured to generate a second signal associated with a non-glucose related electroactive compound, wherein the second working electrode is disposed beneath a non-enzymatic portion of the membrane system of the sensor, wherein the first electrode is disposed beneath an active enzymatic portion of the membrane system of the sensor, and wherein the processor module is configured to process the first signal and the second signal to generate the glucose signal indicative of the glucose concentration in the host.

17. The system of claim 16, wherein the sensor comprises a first working electrode configured to generate the glucose signal indicative of the glucose concentration in the host.

18. The system of claim 8, wherein the sensor comprises an auxiliary electrode configured to generate the auxiliary signal indicative of changes in solute transport across a membrane system of the sensor, wherein the auxiliary electrode is configured to measure at least one analyte selected from the group consisting of oxygen, a carboxylic acid, an amino acid, hydrogen, pH, chloride, and combinations thereof.

19. The system of claim 8, wherein the processor module is configured to calibrate the glucose signal based at least in part on an amplitude of the auxiliary signal.

20. The system of claim 8, wherein the processor module is configured to calibrate the glucose signal based at least in part on a change in the auxiliary signal.

21. The system of claim 8, wherein the glucose signal and the auxiliary signal are each generated by an electrode configured to be located at a same local environment when implanted in a host.

22. The system of claim 21, wherein the glucose signal and the auxiliary signal are generated by electrodes that are juxtapositioned or twisted with or around each other.

23. The system of claim 8, wherein the sensor is configured to continuously generate the glucose signal.

24. The system of claim 23, wherein the sensor is configured to intermittently generate the auxiliary signal.

25. The system of claim 8, wherein the sensor comprises at least one wire.

26. The system of claim 25, wherein the sensor comprises at least two wires juxtapositioned or twisted with or around each other.

27. The system of claim 25, wherein the wire has a width of less than about 0.01 inches.