SYSTEM AND METHOD FOR DETERMINING AN ABUSED SENSOR DURING ANALYTE MEASUREMENT

• US 20090292489A1
• Filed: 07/17/2009
• Published: 11/26/2009
• Est. Priority Date: 06/20/2003
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Operations Limited (Roche Holding AG)
• Inventors: Burke, David W., Kuhn, Lance S., Maxwell, James
• Granted Patent: US 8,377,707 B2
• Time in Patent Office: Days
• US Class Current: 702/65
• CPC Class Codes: G01N 27/02 by investigating impedance
• CPC Class Codes: G01N 27/121 for determining moisture content, e.g. humidity, of the fluid moisture content of the tested material G01N27/048
• CPC Class Codes: G01N 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/112499 with sample on test slide
• CPC Class Codes: Y10T 436/142222 Hetero-O [e.g., ascorbic acid, etc.]
• CPC Class Codes: Y10T 436/143333 Saccharide [e.g., DNA, etc.]
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

A method of measuring an analyte in a biological fluid comprises applying an excitation signal having a DC component and an AC component. The AC and DC responses are measured; a corrected DC response is determined using the AC response; and a concentration of the analyte is determined based upon the corrected DC response. Other methods and devices are disclosed.

Claims

1. A method of detecting whether a sensor is aged beyond a specified sensor life, comprising:

performing an EIS procedure between at least two electrodes of the sensor;

calculating an impedance value between the electrodes; and

comparing the impedance value against a threshold to determine if the sensor has aged beyond the specified sensor life.

2. The method of claim 1, wherein the EIS procedure is performed regularly at fixed intervals during the specified sensor life.

3. The method of claim 1, further comprising:

comparing the impedance value against an another threshold to determine if the sensor is failing.

4. The method of claim 1, wherein the EIS procedure includes applying a combination of a DC bias and an AC voltage of varying frequencies.

5. The method of claim 1, wherein the EIS procedure is a potential step.

6. A method of preventing a user from bypassing a limit placed on a specified operating life of a sensor by disconnecting and reconnecting the sensor, comprising:

checking a characteristic of the sensor to see if the sensor is used prior to the connection of the sensor; and

rejecting the sensor if the sensor is determined to have been used before.

7. The method of claim 6, wherein the step of checking the characteristic of the sensor comprises performing an EIS procedure and calculating an impedance value.

8. A program for detecting whether a sensor is aged beyond a specified sensor life comprising a computer usable media including at least one computer program embedded therein that is capable or causing at least one computer to perform:

performing an EIS procedure between at least two electrodes of the sensor;

calculating an impedance value; and

comparing the impedance value against a threshold to determine if the sensor has aged beyond the specified sensor life.

9. The program of claim 8, wherein the EIS procedure is performed regularly at fixed intervals during the specified sensor life.

10. The program of claim 8, further comprising:

comparing the impedance value against an another threshold to determine if the sensor is failing.

11. The program of claim 8, wherein the EIS procedure includes applying a combination of a DC bias and an AC voltage of varying frequencies.

12. The program of claim 8, wherein the EIS procedure is a potential step.