BIPHASIC DEFIBRILLATION WAVEFORM PRODUCTION METHOD AND APPARATUS

摘要

An implantable defibrillator system for generating biphasic waveforms (100) comprises a self-contained human implantable housing containing a capacitor system for storing an electrical charge, a power supply for charging the capacitor system, and a controller for selectively discharging the electrical charge as a biphasic countershock to be delivered through at least two electrodes in response to a sensing of a cardiac dysrhythmia in the human patient. The controller includes a system for controlling a first duration (102) of a first phase (104) of the biphasic countershock such that the discharge of the electrical charge is of a first polarity and the first duration is variable and a system for controlling a second duration (106) of a second phase (108) of the biphasic countershock such that the discharge of the electrical charge is of a second polarity that is opposite from the first polarity and the second duration is fixed.