Method for automatically and rapidly distinguishing between control and sample solutions in a biosensor strip

• US 8,431,011 B2
• Filed: 01/31/2008
• Issued: 04/30/2013
• Est. Priority Date: 01/31/2008
• Status: Expired due to Fees

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Wang, Yi, Feldman, Benjamin J.
• Primary Examiner(s): Noguerola, Alex
• Application Number:
  US12/023,985
• Publication Number:
  US 20120132540A1
• Time in Patent Office: 1,916 Days
• Field of Search: 20440301-40315, 205/777.5, 205/778, 205/792
• US Class Current: 205/777.5
• CPC Class Codes: A61B 2562/0295 Strip shaped analyte sensors for apparatus classified in A61B5/145 or A61B5/157 disposable multilayered or laminated electrodes G01N27/307; details of handling chemical test elements G01N33/4875
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1468 using chemical or electrochemical methods, e.g. by polarographic means A61B5/1486 takes precedence
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: B01L 2200/148 Specific details about calibrations
• CPC Class Codes: B01L 2200/16 Reagents, handling or storing thereof
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• 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: G01N 33/5302 Apparatus specially adapted for immunological test procedures
• CPC Class Codes: G01N 33/5438 Electrodes

Abstract

The present invention is directed to electrochemical sensors and systems and methods for electrochemically sensing a particular constituent within a fluid through the use of a diagnostic test. The methods provide for automatic discrimination of sample from control or standard solutions. A device and system used to determine a constituent level within a fluid that employ such automatic sample discrimination methods or specially formulated solutions is also provided.

Claims

1. A method of measuring one or more analytes in a fluid, comprising:

introducing a biological fluid sample or control solution into an electrochemical biosensor having a working electrode and two or more electrodes selected from the group consisting of a reference electrode, counter electrode, trigger electrode and dummy electrode;

applying a first voltage across the working electrode and a first electrode selected from the group consisting of a reference electrode, counter electrode, trigger electrode and dummy electrode and obtaining a first measurement;

applying a second voltage across the first electrode and a second electrode selected from the group consisting of a reference electrode, counter electrode, trigger electrode and dummy electrode and obtaining a second measurement;

wherein the first measurement measures an analyte-dependent signal and the second measurement measures a control solution-dependent signal; and

obtaining a reading of the fluid conductivity; and

calculating the current to determine whether the fluid is a biological fluid sample or a control solution.

2. The method of claim 1 wherein the first voltage applied precedes measurement of an analyte and the second voltage applied precedes measurement of the conductivity of the solution.

3. The method of claim 1 wherein the second voltage applied is greater than the first voltage applied.

4. The method of claim 1 wherein the second voltage applied is at least 50 mV.

5. The method of claim 1 wherein the second voltage applied is at least 400 mV.

6. The method of claim 1 wherein the voltage applied preceding the measurement of the analyte is applied across a different pair of electrodes than the voltage applied preceding the measurement of the conductivity of the solution.

7. A control solution for use in the method of claim 1, wherein said control solution has a substantially different ionic strength than that in a sample solution.

8. The control solution of claim 7 wherein the ionic strength is at least about 200 mM, 400 mM, or 600 mM.

9. The control solution of claim 7 wherein addition of a chloride salt is used to increase the ionic strength.

10. The control solution of claim 9 wherein the chloride salt is sodium chloride.

11. A method for automatically discriminating a sample solution from control solution, comprising:

introducing a sample or control solution into an electrochemical biosensor, said biosensor comprising two or more electrodes selected from the group consisting of a reference electrode, counter electrode, trigger electrode and dummy electrode or traces, at least one working electrode, and at least one enzyme reagent;

applying a first voltage between the working electrode and any one of the two or more electrodes selected from the group consisting of a reference electrode, counter electrode, trigger electrode and dummy electrode;

measuring a first current resulting from the first applied voltage;

applying a second voltage between two of the electrodes selected from the group consisting of a reference electrode, counter electrode, trigger electrode and dummy electrode;

measuring a second current resulting from the second applied voltage; and

automatically identifying the sample or control solutions based on the current values.

12. The method of claim 11 wherein the enzyme reagent is deposited onto the working electrode.

13. The method of claim 11 wherein the voltage is applied by a measurement device.

14. The method of claim 11 wherein the current is measured by a measurement device.

15. The method of claim 11 wherein an identifying device automatically identifies the sample or control solutions based on the current values.

16. The method of claim 15, wherein the measurement device measures the concentration of an analyte in a sample solution.

17. The method of claim 16, wherein the sample solution comprises an electrochemically active agent.

18. The method of claim 17, wherein the electrochemically active agent is selected from the group consisting of glucose and ketones.

19. The method of claim 11 wherein the second voltage applied is at least 50 mV.

20. The method of claim 11 wherein the second voltage applied is at least 400 mV.

21. The method of claim 11, wherein said non-working electrodes or traces comprise a conductive metal.

22. The method of claim 11, wherein said electrodes or traces selected from the group consisting of a reference electrode, counter electrode, trigger electrode and dummy electrode comprise Ag/AgCl.

23. The method of claim 11, wherein said first current is temperature dependent and a measured temperature value is used in the step of said identifying the sample or control solution.

24. The method of claim 11, wherein said working electrode is disconnected during the step of measuring said second current.

25. The method of claim 11, wherein the step of automatically discriminating a sample solution from control solution is initiated before or after an analyte determination.

26. A control solution for use in the method of claim 11, wherein said control solution has a substantially different conductivity than that in a sample solution.

27. The control solution of claim 26, wherein the conductivity is substantially higher than that in the sample solution.