Bridge PFA biphasic generator for electroporation using finite energy transfer

An electrode channel for generating biphasic waveforms for irreversible electroporation, comprising:

• a charge transfer source circuit including a source capacitor and configured to receive an input voltage and a pulse train which causes pulses of the input voltage to be applied to the source capacitor, thereby charging the source capacitor to a source voltage;
• a charge transfer load circuit including a load capacitor;
• a switching circuit coupled to the charge transfer source circuit and the charge transfer load circuit;
• a first electrode coupled to the switching circuit;
• and
• a second electrode coupled to the switching circuit and the load capacitor;
• wherein the switching circuit further includes a plurality of spark gap switches configured to be activated by trigger signals to generate a biphasic waveform including a positive phase wherein the source voltage of the source capacitor is discharged through tissue in contact with the first and second electrodes to charge the load capacitor, and a negative phase wherein the load capacitor is discharged through the tissue.

A method for generating a biphasic waveform for application in irreversible electroporation, comprising:

• applying a voltage supply to a source capacitor to charge the source capacitor to a source voltage;
• triggering a first spark gap switch coupled to the source capacitor through a first inductor to discharge the source voltage as an applied voltage through a pair of electrodes in contact with tissue and to charge a load capacitor to a load voltage;
• after a first time period beginning at the triggering of the first spark gap switch, triggering a second spark gap switch coupled to the source capacitor through a second inductor to shunt delivery of the applied voltage;
• after a second time period beginning at the triggering of the second spark gap switch, triggering a third spark gap switch to provide a path for discharging the load voltage of the load capacitor through the pair of electrodes and a third inductor to ground;
• and
• after a third time period beginning at the triggering of the third spark gap switch, triggering a fourth spark gap switch to shunt delivery of the load voltage.