acquisition part may receive ecg data from a recorded data source for analysis but preferably receives the data real time on line through the electrodes 25 that are connected to a patient as used herein patient means an animal and most likely a human the medical device further includes an analysis unit or module 40 which in turn consists of processing compression storage and comparison units fig2 the processing unit 41 can be a typical computer or personal computer of the type available from many vendors such as ibm and hewlett packard the processing unit 41 is programmed to detect a plurality of characteristic points such as the onset peak and offset of p q r s t u waves and computes the characteristic parameters or primary elements which include amplitudes of the said waves and st segment duration of pq qrs and qt intervals the processing unit 41 has a programmable microprocessor that can be programmed to modify or change the set of primary elements or to adjust their search criteria this allows individual adjustment of the characteristic points which in turn increases the accuracy of detection of the primary elements for instance in signals with biphasic t wave two t peaks should be detected whereas monophasic t wave requires detection of a single t peak furthermore the criteria for determining the offset of biphasic t wave are different from the criteria for the offset of monophasic t wave individual adjustment of the primary elements and their search criteria increases the accuracy of the detection of characteristic points.