During the procedure, {HEAD ~ the surgeon} manipulates active electrode 6 and performs {TAIL ~ directed coagulations} 
During the procedure , { HEAD ~ the surgeon } manipulates active electrode 6 and performs { TAIL ~ directed coagulations }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL