Medical officer
From Tardis Wiki, the free Doctor Who reference
Medical officer was a UNIT rank. (AUDIO: The Helliax Rift)
Harry Sullivan was seconded to UNIT (PROSE: Harry Sullivan's War) to serve as Medical Officer shortly before the Third Doctor's regeneration. (TV: Planet of the Spiders, Robot)
Marne was a medical officer on Thoros-Beta. (PROSE: Mindwarp)