Tuned RF energy and electrical tissue characterization for selective treatment of target tissues

A catheter system for remodeling of a target tissue adjacent a blood vessel of a patient, the catheter system comprising:

• an elongate flexible catheter body having a proximal end and a distal end with an axis therebetween;
• a radially expandable structure coupled to the catheter body;
• a plurality of flex circuits, each of the flex circuits including a polymer substrate attached to an outer surface of the radially expandable structure;
• one or more pairs of bipolar electrodes coupled to each of the flex circuits and being engageable with a vessel wall of the blood vessel;
• a power source electrically coupled to the one or more pairs of bipolar electrodes, the power source configured to energize the one or more pairs of bipolar electrodes with a controlled electrical remodeling energy that heats the target tissue so as to remodel the target tissue without thermally damaging a collateral tissue;
• and
• a processor configured to determine the controlled electrical remodeling energy by monitoring a characteristic of a circuit comprising the one or more pairs of bipolar electrodes engaged against the vessel wall, the target tissue, and the collateral tissue,
• wherein the controlled electrical remodeling energy is such that energizing the circuit heats the target tissue to a target tissue treatment temperature so as to remodel the target tissue and heats the collateral tissue to a collateral tissue temperature that is lower than the target tissue treatment temperature.