1. A monitoring device for monitoring and evaluation of a physiological signal including a cardiac electrogram to detect physiological events and/or categorize physiological events and discriminate them from each other by way of comparison to prototype events comprising: a monitoring device comprising a signal preprocessing stage having an input for a digitized physiological signal being a digital representation of a time course of a physiological signal; said signal preprocessing stage comprising an event-detector that is adapted to determine a fiducial point for at least one segment of said physiological signal by detecting reoccurring characteristic features within said physiological signal including R-waves or p-waves; said monitoring device further comprising a wavelet coefficient generation stage that is adapted to perform a modified lifting line wavelet transformation on a segment of said physiological signal relative a selected fiducial point in a signal segment to thus generate wavelet transformation coefficients as features of said digitized physiological signal; a feature evaluation stage that is adapted to perform a reduction of features of said digitized physiological signal by selecting those wavelet transformation coefficients that have been determined to be most characteristic of prototype events from each other by means of a receiver operation characteristics curve analysis; a feature threshold memory comprising a threshold value for each selected feature of a prototype event, said threshold value being determined by said receiver operation characteristics curve analysis; and, a comparator stage connected to said feature threshold memory and being adapted to compare said selected features of an actual digitized physiological signal to corresponding threshold values for a prototype event and to assign said actual digitized physiological signal to a prototype event category if each or a majority of said selected features of said actual digitized physiological signal is within a threshold defined by a corresponding one of said threshold values.