{TAIL ~ a first electrode} having {HEAD ~ a first pair} of bipolar contacts attached to the expandable balloon; and 
{ TAIL ~ a first electrode } having { HEAD ~ a first pair } of bipolar contacts attached to the expandable balloon ; and
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH