Method for determining hematocrit corrected analyte concentrations

摘要

The method includes: providing a test strip comprising a reference electrode and a working electrode coated with a reagent layer; applying a fluid sample to the test strip for a reaction period; applying a test voltage between the reference electrode and the working electrode; measuring a test current as a function of time; measuring a steady state current value when the test current has reached an equilibrium; calculating a ratio of the test current to the steady state current value; plotting the ratio of the test current to the steady state current value as a function of the inverse square root of time; calculating an effective diffusion coefficient from the slope of the linearly regressed plot of the ratio of the test current to the steady state current value as a function of the inverse square root of time; and calculating a hematocrit-corrected concentration of analyte.

主权项

1. A method of calculating a hematocrit-corrected glucose concentration in a fluid sample, the method comprising:
providing a test strip comprising a reference electrode and a working electrode formed with a plurality of microelectrodes and coated with a reagent layer; applying a fluid sample to the test strip for a reaction period; applying a test voltage between the reference electrode and the working electrode; measuring a test current as a function of time; measuring a steady state current value when the test current has reached an equilibrium; calculating a ratio of the test current to the steady state current value; plotting the ratio of the test current to the steady state current value as a function of the inverse square root of time; calculating an effective diffusion coefficient from the slope of the linearly regressed plot of the ratio of the test current to the steady state current value as a function of the inverse square root of time; substituting the estimated diffusion coefficient into an equation of the form:Cred=Is4⁢⁢n⁢⁢FD⁢⁢rd where:Cred is a reduced mediator concentration;ISS is the steady state current in microamperes;n is the number of electrons exchanged per ion that undergoes an oxidation/reduction reaction;F is Faraday's constant;D is the estimated diffusion coefficient in centimeter2/second; andrd is the radius of the microelectrode in centimeters; generating a calibration curve in which a y-axis is the reduced mediator concentration and an x-axis is a reference analyte concentration; calculating an analyte concentration by subtracting a calibration intercept from the reduced mediator concentration and dividing with a calibration slope; and
estimating a hematocrit-corrected concentration of analyte from the calculating step.