Contact specific rf therapy balloon

A method of ablating a target tissue region, comprising:

• positioning a medical device having an expandable element proximate the target tissue region, the expandable element including a first plurality of electrodes coupled to a distal portion of the expandable element, and a second plurality of electrodes coupled to a proximal portion of the expandable element;
• transmitting unipolar radiofrequency energy from the first plurality of electrodes;
• measuring an impedance from each electrode of the first plurality of electrodes;
• transmitting bipolar radiofrequency energy from the second plurality of electrodes;
• measuring an impedance from each electrode of the second plurality of electrodes;
• comparing the measured impedance from each electrode of the first plurality of electrodes and the second plurality of electrodes;
• identifying tissue contact areas based on the comparison;
• and
• ablating tissue in contact with the expandable element based on the comparison.

A medical system, comprising:

• a medical device, the medical device including:
• a catheter including a proximal end and a distal end;
• an expandable element coupled to the distal end, the expandable element including a proximal portion and a distal portion, the expandable element defining an exterior surface;
• a first plurality of electrodes coupled to the exterior surface of the distal portion of the expandable element, each of the first plurality of electrodes being selectively operable to transmit unipolar radiofrequency energy;
• a second plurality of electrodes coupled to the exterior surface of the proximal portion of the expandable element, each of the second plurality of electrodes being selectively operable to transmit bipolar radiofrequency energy;
• and
• a control unit having a processor, the processor being operable to:
• transmit unipolar radiofrequency energy from the first plurality of electrodes;
• measure an impedance from each electrode of the first plurality of electrodes;
• transmit bipolar radiofrequency energy from the second plurality of electrodes;
• measure an impedance from each electrode of the second plurality of electrodes;
• compare the measured impedance from each electrode of the first plurality of electrodes and the second plurality of electrodes;
• identify tissue contact areas based on the comparison;
• and
• ablate tissue in contact with the expandable element based on the comparison.