The counter force of {HEAD ~ the vacuum} resists {TAIL ~ tissue movement} in the direction of electrode penetration 
The counter force of { HEAD ~ the vacuum } resists { TAIL ~ tissue movement } in the direction of electrode penetration
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH