Emergency Medical Hologram

The Emergency Medical Hologram, or EMH for short, is a sophisticated holographic program in use onboard Starfleet starships and facilities in the late 24th century, particularly beginning 2370, for the specific purpose of assisting the medical staff in times of emergency.

Capabilities
EMHs are programmed with five million possible treatments from the collective information of 2000 medical references and the experience of 47 known individual medical officers, as well has having adaptive programming for situations outside of those in their database. EMHs are only meant to be used as a temporary measure to assist existing medical staff, or in extreme cases, to temporarily replace them until a new doctor is assigned.

History
The program whose formal name is EMH Program AK-1 Diagnostic and Surgical Subroutine Omega-323 was developed by Dr. Lewis Zimmerman on Jupiter Station. Zimmerman's initial proposal for an Emergency Medical Hologram was presented in 2365 to Dr. Beverly Crusher, who at that time was head of Starfleet Medical. Crusher had some reservations to the concept, as it entailed entrusting the life of a living being to a hologram, but she nevertheless gave her support for the initiative to push through. By the time the holographic matrix was completed in 2370, it had to have official approval by Admiral Leonard McCoy, then the highest ranking Starfleet Medical Officer alive.

The Mark I EMH was modelled after Dr. Zimmerman in both physical characteristics and personality. The EMH Mark II was programmed with new physical characteristics and was a much more polite and friendly individual. By 2376 the EMH development had progressed to Mark IV. The Mark IX was online by 2380. This version looked like a young, female with strawberry-blonde hair. Nicknamed "Nina", this model could replicate herself when necessary. A Mark IX was active aboard the USS Enterprise-E in mid 2380.