Pulsed field ablation catheters with enhanced field smart electrodes

A medical system, comprising:

• a generator configured to generate pulsed electric field (PEF) energy;
• and
• a medical device coupled to the generator, the medical device including:
• an elongate body having a proximal portion and a distal portion;
• a plurality of active electrodes coupled to the distal portion of the elongate body and being configured to electrically couple to the generator and receive a pulse train of PEF energy include low voltage pulses and high voltage pulses;
• an insulator disposed between adjacent ones of the plurality of active electrodes, the insulator being composed of tantalum pentoxide and being configured to prevent delivery of the low voltage pulses and allow delivery of the high voltage pulses;
• and
• at least one passive electrode coupled to the elongate body and disposed on the insulator, the at least one passive electrode is not electrically coupled to the generator during delivery of the pulse train, the at least one passive electrode composed of a conductive material and configured to passively extend or focus an electric field generated by the plurality of active electrodes.

A medical device, comprising:

• an elongate body having a proximal portion and a distal portion;
• a plurality of active electrodes coupled to the distal portion of the elongate body and being configured to electrically couple to a source of pulsed electric field energy and receive a pulse train including low voltage pulses and high voltage pulses, the plurality of active electrodes being composed of tantalum or a tantalum alloy;
• an insulator disposed between adjacent ones of the plurality of active electrodes, the insulator being composed of tantalum pentoxide and being configured to prevent delivery of the low voltage pulses and allow delivery of the high voltage pulses;
• a plurality of passive electrodes coupled to the elongate body and is not electrically coupled to the source of pulsed electric field energy during delivery of the pulse train, the plurality of passive electrodes is composed of a conductive material and configured to passively extend or focus an electric field generated by the plurality of active electrodes;
• and
• one of the plurality of passive electrodes being disposed on an outer surface of the insulator.