Patent ID: 8682422

Claim:
A cardiac monitor comprising: (a) a sensor adapted to sense an analog signal from a 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) compute a plurality of ST deviations from the digitized waveform, the plurality of ST deviations being characterized by a statistical distribution having a lower boundary and an upper boundary; (ii) storing data pertaining to the plurality of ST deviations in a form that enables characteristics of the statistical distribution to be computed; (iii) locate the lower boundary value of the stored data from said statistical distribution; (iv) form a lower detection threshold that is a function of the difference between the lower boundary value and a preset value; (v) compute a subsequent ST deviation from the digitized waveform; and (vi) apply a test to detect a cardiac event, wherein the test is based on the subsequent ST deviation and the lower detection threshold.