METHOD AND APPARATUS FOR GENERATING MULTI-PHASE DEFIBRILLATION WAVEFORM BASED ON PULSE WIDTH RATIO

摘要

PURPOSE: To provide a simple circuit scheme for generation of a multi-phase defibrillation by specifying a pulse width percentage for continuous phases in terms of an initial and terminal voltages of the first phase, and a pulsewidth of the first phase in a multi-phase defibrillation waveform. ;CONSTITUTION: An electric circuit 100 for generation of multi-phase defibrillation waveform comprises at least a micro processor 102, a charge control logic circuit 108, a pulse control logic circuit 118, a comparator 120, many switches 81-84, and two electrodes D+, D- for defibrillation implanted in the vicinity of heart 130. The initial voltage level of a capacitor 128 corresponding to the first phase of the formation of multi-phase defibrillation waveform is set and also a ratio of the desired duration time relative to the first phase is set per each phase. The capacitor 128 is charged to the initial voltage level and discharged to the terminal voltage level. The duration and the ratio of the multi- phase waveform in the continuous phase are calculated, by which the discharge of the capacitor 128 is controlled to generate the continuous phase.;COPYRIGHT: (C)1994,JPO