{HEAD ~ a rotor} cooperating with {TAIL ~ said stator} to pump blood axially through said pump 
cooperating with
{ HEAD ~ a rotor } cooperating with { TAIL ~ said stator } to pump blood axially through said pump
HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH