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

摘要

A catheter and catheter system can use energy tailored for remodeling and/or removal of target material along a body lumen, often of atherosclerotic material of a blood vessel of a patient. An elongate flexible catheter body with a radially expandable structure may have a plurality of electrodes or other electrosurgical energy delivery surfaces to radially engage atherosclerotic material when the structure expands. An atherosclerotic material detector system may measure and/or characterize the atherosclerotic material and its location, optionally using impedance monitoring.

主权项

1. A method for characterizing and treating a target tissue in a patient body, the method comprising:
engaging a vessel wall with a plurality of electrodes by expanding a radially expandable structure disposed near a distal end of a catheter body within a blood vessel, the plurality of electrodes being circumferentially distributed about the radially expandable structure, wherein the radially expandable structure comprises a balloon and the plurality of electrodes comprise a plurality of flex circuits mounted on the balloon; energizing a circuit with a tissue characterizing energy, the circuit comprising the plurality of electrodes engaged against the vessel wall, the target tissue and a collateral tissue; characterizing the target tissue and the collateral tissue by measuring a phase angle of the circuit while the circuit is energized with the tissue characterizing energy; determining an appropriate treatment energy from the measured phase angle of the circuit; and energizing the circuit comprising both the target tissue and the collateral tissue with the appropriate treatment energy so that the treatment energy heats the target tissue to a target tissue treatment temperature and heats the collateral tissue to a collateral tissue temperature that is lower than the target tissue treatment temperature, wherein the target tissue of the circuit, if heated by energizing the circuit with a standard RF energy so as to heat the target to the target tissue treatment temperature, would result in the collateral tissue of the circuit being heated to a standard RF collateral tissue temperature that is higher than the collateral tissue temperature.