The application of vacuum draws mucosal tissue against the carrier and prevents movement of the sphincter region while {HEAD ~ the electrode} penetrates {TAIL ~ tissue} 
The application of vacuum draws mucosal tissue against the carrier and prevents movement of the sphincter region while { HEAD ~ the electrode } penetrates { TAIL ~ tissue }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL