{HEAD ~ An implantable magnet} that can freely turn in {TAIL ~ response} to an external magnetic field, thus avoiding torque and demagnetization on the implantable magnet 
freely turn in
{ HEAD ~ An implantable magnet } that can freely turn in { TAIL ~ response } to an external magnetic field , thus avoiding torque and demagnetization on the implantable magnet
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH