Abstract: A depolarization waveform classifier based on the Modified lifting line wavelet Transform is described. Overcomes problems in existing rate-based event classifiers. A task for pacemaker/defibrillators is the accurate identification of rhythm categories so correct electrotherapy can be administered. Because some rhythms cause rapid dangerous drop in cardiac output, it's desirable to categorize depolarization waveforms on a beat-to-beat basis to accomplish rhythm classification as rapidly as possible. Although rate based methods of event categorization have served well in implanted devices, these methods suffer in sensitivity and specificity when atrial/ventricular rates are similar. Human experts differentiate rhythms by morphological features of strip chart electrocardiograms. The wavelet transform approximates human expert analysis function because it correlates distinct morphological features at multiple scales.

Abstract: An implantable medical device comprises at least two sensing channels for receiving sensed first and second location electrical signals originating from two different locations of a heart. A control unit is connected to the sensing channels and is adapted to process sensed electrical signals originating from first and second locations of the heart. The control unit incorporates an adaptive filter compensator adapted to generate an estimate signal for compensating a far-field contribution of the second location signal to the first location signal, thereby generating an output signal representing a near field signal originating from the first location. A gate is connected to the second location sensing channel and is adapted to enable the adaptive filter compensator only if a predetermined signal is sensed via the second location sensing channel.

Abstract: An apparatus according to the invention for the classification of physiological events has a signal input for the input of a physiological signal representing or constituting a physiological event and a classification unit 1 for classifying the physiological signal on the basis of its signal shape.