Patent ID: 8620414
Filing Date: 2013-12-31
Classification: A61B,A61N,G16H

Abstract:
1. A medical device system for classifying a patient's risk for arrhythmias, comprising: an electrode to sense a cardiac electrogram (EGM) signal comprising a plurality of T-wave signals; sensing circuitry coupled to the electrode to receive and filter the EGM signal; and a processor coupled to the sensing circuitry and configured to: select a first pair of T-wave signals from the plurality of T-wave signals, the selected first pair comprising a first T-wave signal and a second T-wave signal, the second T-wave signal occurring consecutively after the first T-wave signal, determine a feature of the first T-wave signal and a feature of the second T-wave signal, compute a first difference between the feature of the first T-wave signal and the feature of the second T-wave signal, select a second pair of T-wave signals occurring after the first pair of T-wave signals, the selected second pair comprising a third T-wave signal and a fourth T-wave signal, the fourth T-wave signal occurring consecutively after the third T-wave signal, determine a feature of the third T-wave signal and a feature of the fourth T-wave signal, determine a second difference between the feature of the third T-wave signal and the feature of the fourth T-wave signal, compare the first difference and the second difference, detect a T-wave alternans phase reversal of a T-wave morphology from an A-B order to a B-A order in response to comparing the first difference and the second difference, and classify the patient's arrhythmia risk in response to detecting the phase reversal.