Patent ID: 6233483
Filing Date: 2001-05-15
Classification: A61N

Abstract:
An implantable cardioverter defibrillator (ICD) for generating a defibrillation waveform for discharge between at least two electrodes implanted in contact with cardiac tissue, said ICD comprising:a first capacitor;a second capacitor;a third capacitor;first switch means for selectively connecting the first, second and third capacitor in a selected one of a series, parallel or series/parallel combination configuration;charging means for charging the first, second and third capacitors to a first voltage;second switch means for selectively connecting the first, second and third capacitors to said at least two electrodes, whereby a charge held on the first, second and third capacitors may be discharged through cardiac tissue in contact with said at least two electrodes; andcontrol means for controlling said first and second switch means to connect said first, second and third capacitors for discharge through said at least two electrodes in accordance with a prescribed time-sequential pattern such that a positive pulse is delivered having a first pulse portion corresponding to the first voltage, followed by at least two pulse portions, each of the at least two pulse portions having a stepped-up voltage which is higher than the first voltage.