Calibration techniques for a continuous analyte sensor

• US 8,428,678 B2
• Filed: 05/16/2012
• Issued: 04/23/2013
• Est. Priority Date: 12/05/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv Ullas, Simpson, Peter C., Brauker, James H., Goode, Paul V. Jr.
• Primary Examiner(s): Mallari, Patricia
• Assistant Examiner(s): D'ANGELO, MICHAEL J
• Application Number:
  US13/473,352
• Publication Number:
  US 20120226121A1
• Time in Patent Office: 342 Days
• Field of Search: 600/309, 600/316, 600345-347, 600/365, 435/4, 435/14, 436/68, 422/50, 422420-429, 20440301-40315, 702/23, 604 64- 66
• US Class Current: 600/345
• 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 method for continuous glucose sensing, the method comprising:

generating a glucose signal associated with a glucose concentration in a host using a continuous glucose sensor;

measuring a sensitivity change of the continuous glucose sensor over a time period, wherein the measured sensitivity change is not based on a reference glucose measurement from a reference glucose monitor; and

determining, using electronic circuitry, a stability of the continuous glucose sensor based on the measured sensitivity change; and

calibrating the glucose signal using the measured sensitivity change.

2. The method of claim 1, wherein measuring a sensitivity change comprises measuring a change in glucose transport through a membrane.

3. The method of claim 1, wherein measuring a sensitivity change comprises measuring an analyte other than glucose.

4. The method of claim 1, wherein measuring a sensitivity change comprises measuring a change in oxygen transport through a membrane.

5. The method of claim 1, wherein measuring a sensitivity change comprises switching, cycling, or pulsing a voltage and evaluating the voltage response.

6. The method of claim 1, wherein measuring a sensitivity change comprises measuring a change in baseline over time.

7. The method of claim 1, wherein measuring a sensitivity change comprises measuring an auxiliary signal.

8. The method of claim 7, wherein the auxiliary signal is indicative of a change in solute transport through a membrane.

9. The method of claim 7, wherein the auxiliary signal is indicative of a change a biointerface of the sensor.

10. A system for continuous glucose sensing, the system comprising:

a continuous glucose sensor configured to generate a glucose signal associated with a glucose concentration in a host; and

electronic circuitry configured to determine a stability of the continuous glucose sensor by measuring a sensitivity change over a time period and to calibrate the glucose signal using the measured sensitivity change, wherein the electronic circuitry is configured to measure the sensitivity change without a reference glucose measurement from a reference glucose monitor.

11. The system of claim 10, wherein the electronic circuitry is configured to measure a sensitivity change by measuring a change in glucose transport through a membrane.

12. The system of claim 10, wherein the electronic circuitry is configured to measure a sensitivity change by measuring an analyte other than glucose.

13. The system of claim 10, wherein the electronic circuitry is configured to measure a sensitivity change by measuring a change in oxygen transport through a membrane.

14. The system of claim 10, wherein the electronic circuitry is configured to measure a sensitivity change by switching, cycling, or pulsing a voltage and evaluating the voltage response.

15. The system of claim 10, wherein the electronic circuitry is configured to measure a sensitivity change by measuring a change in baseline over time.

16. The system of claim 10, wherein the electronic circuitry is configured to measure a sensitivity change by measuring an auxiliary signal.

17. The system of claim 16, wherein the auxiliary signal is indicative of a change in solute transport through a membrane.

18. The system of claim 16, wherein the auxiliary signal is indicative of a change a biointerface of the sensor.