System and method for determination of a concentration of at least one interfering substance and correction of glucose concentration based on the concentration of the interfering substance

摘要

Described are methods and systems to apply a plurality of test voltages to the test strip and measure a current transient output resulting from an electrochemical reaction in a test chamber of the test strip so that an estimated interferent value can be determined so that such interferent value can be used to correct the current transients at specific time points for more accurate glucose concentration determination.

主权项

1. A method of determining an interferent corrected glucose concentration from a fluid sample with a glucose monitor and a biosensor, the method comprising the steps of:
ascertaining historical data relating to at least one interferent in physiological fluid samples by:
determining a historical mean concentration for the at least one interferent including various standards of deviations from a plurality of physiological fluid samples measured separately by a referential interferent sensor at various glucose concentrations;storing the historical mean concentration of the at least one interferent in the plurality of physiological fluid samples;measuring a current output transient of each of the plurality of the physiological fluid samples with respect to time points during a test sequence; andobtaining historical regression of slopes and intercepts, along with coefficients of determination of the current output transient at corresponding time points with respect to the test interval for each sample of the plurality of samples; andretaining as historical data for each time point of the current transient of each of the physiological samples, the following parameters from regression analyses as a function of the at least one interferent concentration at each specific glucose concentration: (a) regression slope, (b) regression intercept, and (c) coefficient of determination associated with the regression slope and regression intercept; depositing a physiological fluid sample in a test chamber of the biosensor to start a test sequence; applying a plurality of potentials to electrodes disposed in the test chamber of the biosensor over a time interval of the test sequence; measuring a current output transient over a plurality of time points during the time interval of the test sequence to provide a measured current output transient for each of the plurality of time points; estimating a glucose concentration of a fluid sample from the measured current output transient of the measuring step; categorizing the estimated glucose concentration into one of plural distinct categories of glucose magnitudes; estimating a plurality of the at least one interferent concentrations at specific time points based on: (a) the measured current output transient; and (b) historical slopes and historical intercepts of current transient output for historical interferent concentrations that have been collected in the one category of glucose magnitudes; determining an estimated mean interferent concentration from the plurality of estimated interferent concentrations from the estimating step; correcting the measured current output transient based on: (a) the measured current output transient at the specific time points during the test sequence, (b) the historical slope at the specific time points during the test sequence from historical data, and (c) historical mean interferent concentration and (d) estimated mean interferent concentration of the estimating step; and calculating a glucose concentration corrected for the presence of at least one interferent based on the measured current output transient that includes the corrected current output transient at the specific time points from the correcting step.