A method for determining a regularized estimate of a change rate of a quantitative parameter measured for a biological object of a new subject, the method comprising: - using a device for measuring, for said new subject, said quantitative parameter at a first time T1 and at a second time T2 within a short period of time, wherein the value of the quantitative parameter measured at the first time T1 is denoted Q1 and the value of the quantitative parameter measured at the second time T2 is denoted Q2; - using a processing unit for determining an approximative change rate r of the measured quantitative parameter in function of Q2, Q1, and an interval of time d separating the measurement of Q1 from the measurement of Q2; the method being characterized in that it automatically determines, using the processing unit, the regularized estimate r reg from r reg = 1 − λ r + λ m wherein m is a mean value for said change rate of the quantitative parameter obtained by applying a reference data model to values of said quantitative parameters obtained by measurements of the latter for said biological object of healthy subjects, wherein for each healthy subject, values of the quantitative parameter have been obtained by making a series of said measurements over a long period of time with respect to said short period of time; and λ is computed analytically using an estimate of the variance of the values of the quantitative parameters measured for said healthy subjects. - using a device for measuring, for said new subject, said quantitative parameter at a first time T1 and at a second time T2 within a short period of time, wherein the value of the quantitative parameter measured at the first time T1 is denoted Q1 and the value of the quantitative parameter measured at the second time T2 is denoted Q2; - using a processing unit for determining an approximative change rate r of the measured quantitative parameter in function of Q2, Q1, and an interval of time d separating the measurement of Q1 from the measurement of Q2; the method being characterized in that it automatically determines, using the processing unit, the regularized estimate r reg from r reg = 1 − λ r + λ m wherein m is a mean value for said change rate of the quantitative parameter obtained by applying a reference data model to values of said quantitative parameters obtained by measurements of the latter for said biological object of healthy subjects, wherein for each healthy subject, values of the quantitative parameter have been obtained by making a series of said measurements over a long period of time with respect to said short period of time; and λ is computed analytically using an estimate of the variance of the values of the quantitative parameters measured for said healthy subjects. m is a mean value for said change rate of the quantitative parameter obtained by applying a reference data model to values of said quantitative parameters obtained by measurements of the latter for said biological object of healthy subjects, wherein for each healthy subject, values of the quantitative parameter have been obtained by making a series of said measurements over a long period of time with respect to said short period of time; and λ is computed analytically using an estimate of the variance of the values of the quantitative parameters measured for said healthy subjects.