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