a) inserting the end effector into the mouth of a patient and translating the end effector to the esophagus or {HEAD ~ the stomach} of {TAIL ~ the patient} 
of
a ) inserting the end effector into the mouth of a patient and translating the end effector to the esophagus or { HEAD ~ the stomach } of { TAIL ~ the patient }
OTH OTH OTH 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 TAIL