Patent ID: 7132041

Claim:
A method of determining the concentration of an analyte in a fluid test sample, the method comprising the acts of: providing an electrochemical sensor adapted to measure the analyte in the fluid test sample, the electrochemical sensor having a counter electrode and a working electrode; sufficiently covering the counter and working electrodes of the electrochemical sensor with the fluid test sample; applying a first potential between the counter electrode and working electrode for a first predetermined time period; measuring the current between the counter electrode and working electrode at a plurality of intervals during the first predetermined time period; recording the times of at least one measurement during the first predetermined time period; removing or substantially reducing the first potential between the counter electrode and working electrode for a second predetermined time period; applying a second potential between the counter electrode and working electrode for a third predetermined time period; measuring the current between the counter electrode and working electrode at least once during the third predetermined time period; determining the concentration of the analyte in the fluid test sample as a function of the current measured; calculating an index as a mathematical function of the following variables: a measured current of the first predetermined time period a recorded time of the first predetermined time period, and a measured current of the third predetermined time period; comparing the index to at least one predetermined parameter related to the determined concentration of analyte in the fluid test sample to identify when a bias, if any, exceeds a predetermined threshold; and displaying either an error signal or an analyte concentration depending on the comparison between the index and the at least one predetermined parameter.