Chief Medical Officer
From Hidden Frontier
The Chief Medical Officer (CMO) is a senior staff-level position who is a Doctor of Medicine with surgical skills.
CMO's aboard a starship or starbase are directly in charge of the sickbay or infirmary, commanding medical department personnel and activities. The CMOs' primary duties are the oversight and maintenance of the overall health and physical fitness of crew and passengers.
In addition to the normal duties of an officer, the CMO also has the power to relieve an officer or crewman, including a superior one, of their duties if in the officer's professional judgment, s/he is medically unfit. In such circumstances, the CMO is expected to have the support of a senior command officer and/or detailed medical documentation to justify this course of action.