Analyte sensors and methods

• US 7,822,557 B2
• Filed: 10/31/2006
• Issued: 10/26/2010
• Est. Priority Date: 10/31/2006
• Status: Active Grant

• Current Assignee: Abbott Care Diabetes, Inc.
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Feldman, Benjamin J., Chen, Ting
• Primary Examiner(s): BORIN, MICHAEL L
• Application Number:
  US11/555,167
• Publication Number:
  US 20080102441A1
• Time in Patent Office: 1,456 Days
• Field of Search: None
• US Class Current: 702/23
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/26 by investigating electrochemical variables; by using electrolysis or electrophoresis
• CPC Class Codes: G01N 27/3273 Devices therefor, e.g. test element readers, circuitry details not specific to biochemical electrodes G01N33/4875

Abstract

Methods of determining analyte concentration. The methods use a fraction of the predicted total charge, from analyte electrolysis, instead of using time, for determination of a data collection endpoint. The total charge is then extrapolated from the data collection endpoint. The analyte concentration is determined from the total charge.

Claims

1. A method for determining the concentration of an analyte in a sample, the method comprising:

applying a sample to an analyte sensor, wherein the analyte sensor comprises a working electrode and a counter electrode;

applying a current to the working electrode and counter electrode;

measuring a predetermined amount of a current decay for the current;

predicting a first total signal value for complete reaction of the analyte from the measured current decay;

determining a data collection endpoint, wherein the data collection endpoint is a predetermined percentage of the predicted first total signal value;

measuring current decay until the data collection endpoint;

calculating a second total signal value at the data collection endpoint; and

determining the concentration of the analyte based on the calculated second total signal value and the measured current decay until the data collection endpoint.

2. The method of claim 1, wherein the first total signal value is the sum of a measured signal and an extrapolated signal.

3. The method of claim 2, wherein the signal is charge and the reaction is electrolysis, and the method comprises:

predicting a total charge for complete electrolysis.

4. The method of claim 3, wherein the electrolysis comprises coulometry.

5. The method of claim 3, further comprising:

determining a predicted charge from an extrapolated linear current decay made at the data collection endpoint.

6. The method of claim 5, wherein determining the predicted charge comprises:

integrating the extrapolated linear current decay made at the data collection endpoint and the measured current decay prior to the data collection endpoint to determine the total charge.

7. The method of claim 3, wherein electrolysis comprises amperometry.

8. The method of claim 3, wherein electrolysis comprises potentiometry.