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