Star Trek Expanded Universe

The Emergency Medical Holographic program (EMH) was a sophisticated hologram used on most Federation starships in the late 24th century that was designed to provide assistance to medical staff in times of emergency. It was developed by Dr. Lewis Zimmerman on Jupiter Station and was formally known as EMH Program AK-1 Diagnostic and Surgical Subroutine Omega-323. (DS9: "Doctor Bashir, I Presume"; VOY: "Projections", "Lifesigns")

Mark I[]

The original EMH, the Mark I (2373).

The Mark I was based on their designer, Dr. Zimmerman, both physically and psychologically. This produced an arrogant and irritable hologram that became notorious for its less than gracious bedside manner, which saw some doctors try to avoid activating the program. (Star Trek: First Contact)

The first vessel equipped with the Mark I was the USS Voyager. (VOY: "Relativity") The Doctor, as it was known on Voyager would also become the most notable Mark I due to its continuous operation over several years and it evolving from a purely short-term emergency protocol to a critical and important contributor to the crew of the USS Voyager during its years stranded in the Delta Quadrant. (Star Trek: Voyager)

The Mark I would eventually be declared "defective" and replaced by newer models. The Mark Is were transferred to undertake menial tasks such as dilithium mining and scrubbing plasma ducts. (VOY: "Message in a Bottle", "Life Line")

Mark II[]

The EMH Mark II (2374).

The EMH Mark II was the designation for the second installment of the Emergency Medical Holographic program, which became standard equipment aboard Federation starships starting in 2374. The Mark II prided itself as superior to its predecessor, the Mark I, whose appearance and personality were modeled after project designer Lewis Zimmerman. (VOY: "Message in Bottle")

Although the EMH Mark II was programmed with a better bedside manner than the Mark I, USS Lambda Paz chief medical officer Aurellan Markalis found that ship's Mark II to be just as rude as its predecessor. Its standard greeting to individuals with whom it was unfamiliar was "What the hell are you doing in my sickbay? I am programmed to identify every member of this crew. You are not one of them." As of the launching of the Lambda Paz, the program had not been updated to identify Limis Vircona and the other Maquis aboard as members of the crew, and so regarded the captain as an intruder when the two first met. (Star Trek: Lambda Paz: "Revenge a Dish Best Served Cold")

Mark III[]

The EMH Mark III (2375).

In early-2375, Federation starships were equipped with the Mark III. He was designed to be more personable than its two predecessors. Because of an error in the projectors of the Mark III equipped onboard the USS Lambda Paz, it walked with a limp in its right leg. (Star Trek: Lambda Paz)

The EMH Mark III had stringent security protocols in place due to it being in use during the Dominion War, although by 2376, the security protocols were seen as a hindrance to effective caregiving. (TNG novel: Losing the Peace)

Mark IV[]

Emmie, the EMH Mark IV from the USS Prometheus

By 2376, the Mark IV of the EMH program had been developed. (VOY: "Life Line")

Three years later, the Mark IV of the USS Prometheus had personalized her appearance, expanded her personality subroutines, and named herself Emmie. (Star Trek: Prometheus)

Mark XII[]

Charlotte, the EMH Mark XII installed on the USS Antechrist

Due to Starfleet Intelligence requests, and reverse-engineering of the Romulan EMH Mark V-VI, the Mark XII EMH was developed in the 2390s. The primary improvement of the Federation EMH Mark XII over the Romulan EMH Mark V-VIs (which were seen to be roughly as advanced as Federation EMH Mark X and XI respectively) was that the outward appearance of the footwear could be altered without the need to modify the physical configuration of the mobile emitter. For this reason, the Mark XII saw extensive service in Starfleet Intelligence. The Antechrist-class was equipped with a Mark XII EMH. (Star Trek: False Vacuum)

Other races[]

Romulans designed an EMH based on a design of holo-emitter that was extensively used by the Tal Shiar to execute missions that required shapeshifting. As such, the EMH could change its appearance according to the patients it served. (RIS Bouteina: "No Child Left Untested")

Sometimes, faulty EMHs could be frightening to behold by Romulans. Depending on the nature of the EMH's failure, they can frighten patients rather than help them heal. Also, their holoprojector was located into their footwear, thus limiting their capabilities for shapeshifting. This could be a liability for the Tal Shiar if they chose to use EMHs on espionage missions among the Hydrans or other species that had abnormal feet, like Bowsers. (RIS Bouteina: "Monster-in-a-Box")

The Rakelli were also fond of using EMHs as fashion objects, but as a fashion object, it was more the shoe in which the holoprojector was placed that served as such, rather than the EMH itself, although EMHs were used on occasion by Rakelli fashion designers as models for clothing. Their EMHs had a changeable holoprojector. (RIS Bouteina: "Yesterday's Lyrans")

Romulan regulations demanded that there be one EMH in medical facilities (like field hospitals) for every 30 patients a medical facility could hold. (RIS Bouteina: "Hospital Blues")

Rakelli-made EMHs were among the merchandise sold on Lakeshore Avenue. (RIS Bouteina: "Redshirt Computer")

The Lyrans were assumed to have acquired EMH technology at some point between the late 2380s and 2401. The Stoneship-class was one of the first Lyran starship classes equipped with an EMH. (Star Trek: The Stoneship Files: "Ancient Horrors")

The USS Phoenix-X, half the crew being Exchange officers from the IKS B'Cnah, also employed a KMH (Klingon Medical Hologram), who was more aggressive than the EMH. (Star Trek: Phoenix-X: "Fantastic Method", "Triple Tribble Sunday")

Notable EMHs[]


RIS Bouteina[]

Since the crewmen on the Bouteina have changed the appearance of their EMHs several times, and they even had more than one, the personalities of these EMHs are listed in chronological order by their owners.

Star Trek: The Stoneship Files[]

Ships with unnamed EMHs[]

Background Information[]

External links[]