Patent ID: 7389133

Claim:
A method for continuous monitoring concentration of an analyte by determining the analyte's change over time in the living body of a human or animal, the method comprising: measuring at sequential points in time, measurement values of a measurement variable correlating with a desired concentration of the analyte; measuring the measurement variable as a measurement signal (z t ); determining the change over time of the concentration of the analyte from the measurement signal as a useful signal (y t ) by means of a calibration; providing a filter algorithm in the time domain for determination of the useful signal (y t ) from the measurement signal (z t ), wherein the filter algorithm reduces errors of the useful signal resulting from noise contained in the measurement signal, wherein the filter algorithm includes an operation in which the influence of an actual measurement value on the useful signal is weighted by means of a weighting factor (V); determining a time dependent signal variation parameter (σ t ) related to an actual point of time on the basis of signal variations detected in close chronological relation to the measurement of the actual measurement value; wherein the time dependent signal variation parameter being a measure for signal variations for a period of time preceding an actual measurement value and being determined on the basis of measurement values including values which were measured less than 30 minutes before the measurement of the actual value; and adapting dynamically the weighting factor as a function of the signal variation parameter determined for the point in time of the actual measurement, the weighting factor being changed in such a direction that the influence of the actual measurement value is reduced with increasing standard deviation of the measurement signal.