Method to recalibrate continuous glucose monitoring data on-line

In a method of recalibrating continuous glucose monitoring data from a user, operable on a digital processor, an indication from the user that the user has taken a meal is received (806). A self-monitored of blood glucose levels from the user (810) at two separate times during a day corresponding to when the user has taken a meal. A glucose signal is received from a continuous glucose monitoring sensor (818) at times corresponding to the two separate times that the user has taken a meal. Two reconstructed blood glucose values based on the glucose signal from the continuous monitoring sensor at times when the at least two self-monitored of blood glucose levels are received from the user. A linear regression is performed (822) using y = ax + b, wherein x corresponds to the two reconstructed blood glucose values and y corresponds to the two self-monitored of blood glucose levels thereby generating an estimation of a and b. A recalibration signal, including the estimation of a and b, is transmitted to the continuous glucose monitoring sensor (824) based on the linear regression.