Implantable defibrillator system with capacitor switching circuitry

Claim 1

An improved implantable defibrillator system for producing a capacitive-discharge electrical countershock, the implantable defibrillator system being a self-contained human implantable device including a capacitor means for storing an electrical charge, means for internally charging the capacitor means, means for sensing a cardiac dysrhythmia in a human patient and means for selectively discharging the electrical charge as an electrical countershock to be delivered through at least two implantable discharge electrodes in response to the means for sensing the cardiac dysrhythmia, the improvement comprising: the capacitor means including at least two separate capacitor units, each capacitor unit having a separately electrically accessible anode output and a separately electrically accessible cathode output; and the means for selectively discharging the electrical charge including electronic switching circuitry means electrically connected between at least one output of each capacitor unit and electrically connected between at least one output of each capacitor unit and each of the at least two implantable discharge electrodes for selectively electrically connecting the anode output and the cathode output of the at least two capacitor units to the at least two implantable discharge electrodes to independently establish both a topology and a polarity for the electrical countershock during a discharge period of time when the electrical charge is discharged such that the topology is selectable from the group consisting of a parallel configuration of the capacitor units, a series configuration of the capacitor units, a sequential configuration of the capacitor units, or any combination thereof.