qrs complex in the defined segment of the signal curve fig 2 application_number US 80367901 A description as is apparent from fig1 an idealized qrs complex consists of a relatively high amplitude oscillation that initially guides the ecg signal in the q spike away from the zero line 1 in a negative direction afterwards the ecg signal is guided in the r spike into the positive range with a steep rise and with a subsequent steep drop back into the negative range while forming the s spike in reality the ecg signal is accompanied by a certain level of noisiness as indicated in fig1 by the dashed signal curve if this noisy signal is now sampled and converted into discrete signal values in chronological order the sign of each signal value can be determined and a check can be performed as to whether a zero crossing of the ecg signal though the zero line 1 has taken place between these signal values outside the qrs complex a high number of zero crossings occurs in a defined segment n 1 whereas a much lower number of zero crossings is detected during sampling of a segment n 2 in the qrs complex the count of the number of zero crossings may thus be used to detect a qrs complex the ecg signal is sampled and converted into discrete signal values x n in chronological order the sampling rate may be f 360 hz for example i e the ecg signal is converted into a sequence of 360 measuring values per second the detailed sequence of the inventive evaluation method will now be explained.