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