Error detection in analyte measurements based on measurement of system resistance
First Claim
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1. A method for determination of an analyte in a sample comprising the steps of:
- (a) introducing the sample to an electrochemical test strip having working and counter electrodes;
(b) applying a potential difference, Vapp, between the electrodes of the test strip and observing a current signal sufficient to provide an initial determination of analyte in the sample and for a period of time sufficient to determine a plateau current, Iplateau;
(c) switching off the applied potential at time tswitch and determining the magnitude, Vdrop), of a voltage drop arising from series electrode resistance, if present;
(d) calculating a track resistance Rtrack, and comparing the determined magnitude of Rtrack against a predetermined range, and rejecting the test if the magnitude of Rtrack falls outside of the range wherein the value of Rtrack=Vdrop/Iplateau, and(e) if the magnitude is within the predetermined range, correcting the initial determination of analyte to compensate for track resistance and proceeding to display or communicate the result from the corrected determination of analyte.
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Abstract
Measurement of the series track resistance of a working and counter electrode pair in an electrochemical test strip provide error detection for multiple variations in the quality of the test strip, as well as the operation of strip in the test meter. In particular, a single measurement of series resistance can be used to detect and generate an error message when an incorrect reading is likely to result due to (1) damaged electrode tracks, (2) fouled electrode surfaces, (3) dirty strip contacts, or (4) short circuit between the electrodes.
18 Citations
11 Claims
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1. A method for determination of an analyte in a sample comprising the steps of:
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(a) introducing the sample to an electrochemical test strip having working and counter electrodes; (b) applying a potential difference, Vapp, between the electrodes of the test strip and observing a current signal sufficient to provide an initial determination of analyte in the sample and for a period of time sufficient to determine a plateau current, Iplateau; (c) switching off the applied potential at time tswitch and determining the magnitude, Vdrop), of a voltage drop arising from series electrode resistance, if present; (d) calculating a track resistance Rtrack, and comparing the determined magnitude of Rtrack against a predetermined range, and rejecting the test if the magnitude of Rtrack falls outside of the range wherein the value of Rtrack=Vdrop/Iplateau, and (e) if the magnitude is within the predetermined range, correcting the initial determination of analyte to compensate for track resistance and proceeding to display or communicate the result from the corrected determination of analyte. - View Dependent Claims (2, 3, 4, 5, 6, 11)
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7-10. -10. (canceled)
Specification