CALIBRATION TECHNIQUES FOR A CONTINUOUS ANALYTE SENSOR

• US 20100063373A1
• Filed: 11/16/2009
• Published: 03/11/2010
• Est. Priority Date: 12/05/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv Ullas, Brauker, James H., Simpson, Peter C., Goode, Paul V. JR.
• Granted Patent: US 7,917,186 B2
• Time in Patent Office: Days
• 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 first working electrode configured to generate a first signal associated with a glucose concentration in a host;

an auxiliary electrode configured to generate an auxiliary signal associated with an auxiliary analyte concentration in the host; and

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

2. The system of claim 1, further comprising a second working electrode configured to generate a second signal, wherein the second signal is associated with a non-glucose related electroactive compound, wherein the second working electrode is disposed beneath a non-enzymatic portion of a membrane system on a glucose sensor, wherein the first signal is associated with a glucose related electroactive compound and the non-glucose related electroactive compound, and wherein the first electrode is disposed beneath an active enzymatic portion of the membrane system on the glucose sensor.

3. The system of claim 2, further comprising a subtraction module configured to subtract the second signal from the first signal, whereby a differential signal comprising at least one glucose sensor data point is determined.

4. The system of claim 1, 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 first signal in response to a predetermined change in the auxiliary signal.

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

7. The system of claim 1, wherein the processor module is configured to calibrate the first electrode at a preselected frequency.

8. The system of claim 7, wherein the preselected frequency is based at least in part on a change in the auxiliary signal.

9. The system of claim 1, wherein the first working electrode and the auxiliary electrode are configured to be located at a same local environment when implanted in a host.

10. The system of claim 9, wherein the first electrode and the auxiliary electrode are juxtapositioned with or around each other or are twisted with or around each other.

11. The system of claim 1, wherein the first working electrode is configured to continuously measure the first signal.

12. The system of claim 11, wherein the first working electrode is configured to intermittently measure the first 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 with or around each other or twisted with or around each other.

15. The system of claim 13, wherein the wire has a width of less than about 0.010 inches.