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For the EMH from the USS Voyager, see The Doctor.


The Emergency Medical Hologram or EMH is a sophisticated holographic program used upon Starfleet starships and facilities in the late 24th century to assist medical staff in times of emergency. The program whose formal name is EMH Program AK-1 Diagnostic and Surgical Subroutine Omega-323 was developed by Doctor Lewis Zimmerman on Jupiter Station. (VOY episodes: "Lifesigns", "The Cloud", "Projections", "Inside Man", "Life Line", DS9 episode: "Doctor Bashir, I Presume")

History and specifications

EMHs are programmed with five million possible treatments from the collective information of 2000 medical references and the experience of 47 individual medical officers, as well as having adaptive programming for situations outside of those in their database. EMHs are only meant to be used a temporary measure to assist existing medical staff, or in extreme cases, to temporarily replace them until a new doctor is assigned. (VOY episodes: "Caretaker", "Future's End, Part I")

Mark I

Work on the EMH program began as far back as the year 2360 which was conducted by Starfleet Medical, though information on it was known only to a few individuals. (ST - The Lost Era novel: Catalyst of Sorrows)

Zimmerman's initial proposal for an Emergency Medical Hologram was presented in 2365 to Doctor Beverly Crusher, Chief medical officer of the USS Enterprise-D. (VOY short story: "Bedside Matters")

By the time the holographic matrix was completed in 2370, it had to have official approval by Leonard McCoy. (TOS - Strange New Worlds II short story: "Doctors Three")

The Mark I EMH was modelled on Doctor Zimmerman, in both its physical characteristics and personality. This was considered a flaw in the program's design by many Starfleet medical personnel, including Doctor Elizabeth Lense of the USS Lexington. (SCE eBook: War Stories, Book 1)

Lense later came to appreciate the Mark I EMH's lack of simulated emotionalism. (SCE eBook: Out of the Cocoon)

Starfleet thought the Mark I's personality was too abrasive. (DS9 short story: "So a Horse Walks into a Bar...")

Given these reactions, the Mark I was quickly replaced on many ships by newer versions. (VOY episode: "Life Line")

The existing Mark I EMHs were reprogrammed for more menial tasks, such as scrubbing plasma conduits and mining dilithium ore. (VOY episode: "Author, Author")

Several Mark I EMHs continued to serve in their intended roles, including "The Doctor" of the USS Voyager and the EMH on the USS Equinox: both vessels being stranded in the Delta Quadrant, did not, of course, have access to upgraded versions. (VOY novelization: Equinox)

A Mark I EMH also remained on the USS Enterprise-E into 2379, as Chief medical officer Doctor Beverly Crusher preferred it to later versions. Although Doctor Crusher had previously mentioned that she had sworn to never use the EMH. (TNG movie: First Contact, TNG - A Time to... novel: A Time to Sow)

The USS Destiny also had a Mark I EMH. (DS9 short story: "Second star to the right...")

The Soong Foundation discovered that more than 600 EMH Mark I models were put into servitude by Starfleet mining dilithium. Soong Foundation attorney Alyssa Cogley-Shaw sued for an injunction for Starfleet to reveal the status of all of its holographic programs. She claimed this was the slavery of sentient lifeforms, but Starfleet appealed the injunction claiming that the Mark I models are photonic tools. (STO novel: The Needs of the Many)

Later versions

EMH Mark II in 2374.

The EMH Mark II was programmed with new physical characteristics and to be a much more polite and friendly individual, although some felt it was too skittish. New starship classes such as the Prometheus-class were fitted with shipwide holographic projection systems so that EMHs could attend emergencies outside of sickbay. (VOY episode: "Message in a Bottle", DS9 short story: "So a Horse Walks into a Bar...")

The EMH Mark III came into general use during the height of the Dominion War, and included stringent security protocols. It also featured an improvement of its personality subroutine over the previous models. However, following the end of the war, these security measures came to be viewed as a hindrance to effective caregiving. (TNG novel: Losing the Peace)

The EMH Mark IV came into use in early 2376, replacing the Mark III. (VOY episode: "Life Line"; TNG novel: Losing the Peace)

EMH Mark VI in 2409.

The EMH Mark VI usage was unknown though it was still in operation on starships by 2409 as seen on the USS Khitomer. This version had pale, blueish skin and a personality similar to that of the Mark I. (ST video game: Star Trek Online)

The EMH Mark IX was online by 2380. This version looked like a young, female with strawberry-blonde hair, and could replicate herself as necessary. A Mark IX nicknamed "Nina" was active aboard the Enterprise in mid 2380. (TNG novel: Greater Than the Sum)

Nina was often used following heavy combat, especially during the Borg Invasion of 2381. (ST - Destiny novel: Mere Mortals)

Following a refit in early 2386, the USS Titan was equipped with a Mark IX. (TTN novel: Sight Unseen)

The EMH Mark XI was in use by 2381. (VOY novel: Full Circle)



Emergency holographic programs
emergency holograms Command (ECH)Conn (ECH)Counseling (ECH)Engineering (EEH)Hospitality (EHH)Medical (EMH)Navigational (ENH)Tactical (ETH)Security (ESH)Security Gorn (ESG) Federation icon image. Starfleet icon image.
related technology Emergency Hologram basic installationEmergency Medical Android (EMA)Jupiter Station Diagnostic Program Alpha-11Long-term Medical Holographic program (LMH)
Photonic and holographic personnel
Emergency holographic programs positions Command (ECH)ConnCounselingEngineeringHospitality (EHH)Medical (EMH) (25th century EMH Mk I) • Navigational (ENH)R&D (Energy Weapons OfficerMatter-Antimatter SpecialistQuartermaster) • Security (ESH) (Security Gorn (ESG)) • Tactical (Holo Leeta) • Entertainment (OrionVulcan) • Hamlet programsholographic bridge officers (TOS • DS9 • others) • holographic Exocomps (holographic combat drone) • Long-term Medical (LMH)personal Karemma trader UFP emblem. Seal of the Federation Starfleet.
notable versions and variants Medical Android (EMA)EmmetEmmettHolo Leeta (Dabo LeetaMirror Admiral) • Diagnostic Program ("Dr. Zimmerman")The DoctorMedical Consultant Program (MCP, Beta-1)Photonic Engineering Officer CandidatePhotonic Tactical Officer CandidateVic FontaineThe Warden
notable templates organic templates Julian Bashir (LMH) • LeetaCrell Moset (MCP) • Lewis Zimmerman (EMH • Diagnostic)
synthetic templates ExocompsThe Doctor (25th century EMH Mk I) • Vic Fontaine (Counseling) UFP emblem. Seal of the Federation Starfleet.

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