Patent ID: 8855752

Claim:
A cardiac monitor comprising: (a) a sensor for sensing an analog signal from a human heart; (b) a device coupled to the sensor, the device having an analog-to-digital circuit system contained therein for digitizing the analog signal to produce a digitized waveform; (c) a processor electrically coupled to the analog-to-digital circuit system, said processor configured to: (i) detect a QRS complex within the digitized waveform, the QRS complex characterized by having an R wave; (ii) determine the location of a fiducial point within the QRS complex; (iii) perform a search for a point outside the QRS complex that meets a slope based criterion; (iv) if a qualifying point is found that meets the slope based criterion, determine a location of a non-QRS point within an adaptive window that is defined by a plurality of window parameters; (v) update at least one of plurality of window parameters based on the location of the non-QRS point; and (vi) repeat step (iv) for a different QRS complex with the adaptive window updated at least in part according to step (v).