Emergency Medical Holographic program The Emergency Medical Holographic program ( EMH ) was a sophisticated hologram developed in the early 2370s by Starfleet and used on most Federation starship s in the late 24th century . It was designed to provide short - term advanced assistance during emergencies in sickbay to the extent of literally replacing a starship ' s medical officer . ( ) The formal name of the program was " EMH Program AK - 1 Diagnostic and Surgical Subroutine Omega - 323 " . As of 2377 , there had been four versions of the EMH , designated Mark I , II , III , and IV . ( ) History . In 2268 , while testing the ill - fated M - 5 multitronic unit aboard the , Spock lamented to Dr . Leonard McCoy on the misfortune that computer programming had not yet advanced far enough to replace a starship ' s surgeon . McCoy retorted that he ' d rather resign than be replaced . ( ) Starfleet commissioned the brilliant holo - programmer Doctor Lewis Zimmerman at the Jupiter Station Holoprogramming Center as the embodiment of modern medicine . The EMH Mark I was first activated in 2371 , and was programmed with over five million possible treatments from the collective information of two thousand medical references and the experience of 47 individual medical officers . The EMH was also supplemented with contingency programs and adaptive programs to learn while serving as a supplement of a normal medical staff in cases of emergency . It contained fifty million gigaquads of computer memory , which was " considerably more than most highly developed humanoid brains . " ( ) Zimmerman wanted to call his creation the " Holo - Doc " , but Starfleet Command made the request to name the hologram " Emergency Medical Hologram " instead . ( ) Dr . Zimmerman , proud of his achievement , decided to program the EMH with both his physical , and most notably , psychological characteristics . Unfortunately , Dr . Zimmerman did not take into account that his own personality resulted in a poor bedside manner for a medical doctor . The resulting hologram was arrogant and irritable , and as a result was poorly received by many Starfleet doctors . This , in turn , spawned nicknames like " Emergency Medical Hotheads " and " Extremely Marginal Housecalls . " ( ) Some biological Starfleet doctors even went so far as to object to the use of the EMH . Doctor Beverly Crusher swore that she would never use one , although she was forced to do so in order to create a distraction while the Borg tried to assimilate the , allowing her , her medical staff , and her patients , notably Lily Sloane , to escape from sickbay . ( ) Starfleet later requested that Dr . Zimmerman design a holoprogram to operate as a full - time doctor in any posting where life support or living space was at a premium and the primary mission did not require the doctor to leave sickbay . As a result , the research and design for the Long - term Medical Holographic program ( LMH ) was begun in mid - 2373 . ( ) Deep Space 9 did not have an EMH installed initially , as it was incompatible with the station ' s Cardassian technology . An EMH was installed in 2373 as a way to transfer its data into the LMH . ( ) Eventually it was concluded that the EMH Mark I was defective , and they were retired from the medical corps . While an ashamed Dr . Zimmerman tried to have them decommissioned , Starfleet reassigned them to scrub plasma conduits on waste transfer barge s . Later , the Mark Is were also deployed in other menial tasks , like dilithium mining . Of at least 678 Mark Is created , 675 were reassigned , but at least a few escaped by virtue of their ships being lost in the Delta Quadrant ; one aboard the , one aboard the , and the backup copy of " Voyager " s EMH which was in the possession of the Kyrian s – assuming these were not counted among those reconfigured . ( ) Most notably The Doctor , a Mark I serving on the , ran almost continuously for years and was forced to expand his programming extensively to keep up . This EMH originally objected to being the replacement for the entire medical staff , as the EMH program was only meant to function for a maximum of 1 , 500 hour s ( 62 . 5 day s ) ; after this time , memory degradation would occur . Fortunately , with the help of his colleagues , his program was altered to overcome this shortcoming . ( ) To address the flaws in the EMH Mark I , Dr . Zimmerman began work on the Mark II , a prototype of which was finished in time to be included in the sickbay of the in 2374 . While the Mark I ' s outward appearance was a copy of its inventor , a disillusioned Dr . Zimmerman changed the outward appearance of the Mark II . Furthermore , the patterns of behavior of the following versions were designed to be more pleasant and courteous . To achieve this , Zimmerman initially tried to improve on the programming of the Mark I , but eventually decided to create the Mark II from scratch . In addition to that , new ship designs like the enabled full mobility for the EMH , as the whole ship was outfitted with holographic projector s . By 2377 , the Mark II had been replaced by a Mark III , followed by a Mark IV . ( ) By 2378 , the Mark I programs were reconfigured to work at a Federation mining colony in replacement of other forms of labor . These programs , having been reassigned to their new function , were able to obtain bootlegged copies of the holonovel " Photons Be Free " and view them . One of the EMH miners found the holonovel " provocative " . ( ) " Voyager " s EMH Mark I . After the EMH Mark II supplanted the " inferior " Mark I , the only remaining versions to fulfill their original programming were aboard the USS " Voyager " and the USS " Equinox " , which were both stranded in the Delta Quadrant and had to implement the emergency holograms for extended periods of time . However , a notable caveat was that the crew of the " Equinox " deleted their EMH ' s ethical subroutine s in order to allow him to act contrary to the Hippocratic Oath . In 2376 , the " Equinox " EMH was deleted while in " Voyager " s database , leaving " Voyager " s program , " The Doctor " , as the only Mark I still operating as an EMH . ( ) " Voyager " s EMH ( The Doctor ) developed a distinct personality over the ship ' s seven - year - long journey to the Alpha Quadrant . Despite this , The Doctor was not granted the rights of a living person by a Federation Arbiter , although he did determine that The Doctor fulfilled the requirements of an artist under the law . The Arbiter did , however , encourage The Doctor to pursue recognition as a sentient being at a later point in time . ( ) An ability unique to The Doctor , " Voyager " s EMH was able to leave sickbay or the holodeck and to roam freely with the help of a mobile emitter ( originating from 29th century technology ) . ( ) " Voyager " s EMH was even given the responsibility of commanding the ship as the Emergency Command Hologram ( ECH ) if the ship ' s commanding officers were not present , incapacitated , or dead . ( ) When The Doctor was sent in a holographic data stream to contact the USS " Prometheus " , he found the starship in the hands of Romulan s , who had killed the Starfleet crew and captured the ship . The Doctor activated the ship ' s EMH , a Mark II , to help him recapture the ship , although the Mark II initially preferred to just deactivate and wait for rescue , and then treated The Doctor as inferior despite the latter ' s vastly superior life experiences . The Doctor ultimately persuaded the Mark II to take action and help him . They planned to disable the Romulans by venting an anesthetic gas , but The Doctor was captured by the Romulans when he attempted to reach the environmental controls on the bridge . During The Doctor ' s interrogation , the Mark II simulated a bio - hazard , opening the vents which released the gas , knocking out the Romulans . The Doctor and the Mark II successfully fought off Romulan warbird s using the ship ' s experimental weapons systems , returned the ship into Starfleet ' s hands , and informed Starfleet that " Voyager " was in the Delta Quadrant . ( ) Mechanics . The EMH was a holographic simulation of a Human , but with no internal organs beneath the apparent surface to conserve computer power . EMHs were not equipped with reproductive organs . The Doctor , however , wrote additional routines into his holomatrix to facilitate romantic endeavors and has also had several relationships , one of which inexplicably resulted in a son . ( ) Holodeck s used omnidirectional holographic diode s ( OHD ) . A sickbay was fitted with a system of OHDs that projected an image of the EMH . Each projected a complete image . Visible portions changed as the hologram moved , creating an illusion of fluid motion . Magnetic containment field s allowed the EMH to interact with physical objects . These force field s moved as the EMH moved to create the appearance of solid matter . The containment fields could be shut off , allowing objects and people to pass through them – an EMH ' s cohesion could range from solid to intangible . ( ) When OHDs and magnetic field generators were added to other parts of a ship , they allowed the hologram to leave sickbay ( as in more advanced Starfleet ships or modified configurations ) . Without these additional projectors , the EMH could only function in sickbay and the holodeck . The USS " Voyager " also discovered the 29th century mobile emitter technology which , when attached to the EMH and its program transferred to emitter , allowed the EMH to roam freely on board ship , shuttles , or even planetary surfaces . This allowed the EMH to act as a medical aid during away mission s . However , damage to the emitter posed a risk of damage or even deletion of the EMH . The universal translator algorithm was written into the EMH ' s matrix . ( ) When he was first activated , the " Voyager " EMH apparently did not have the ability to deactivate himself after he finished his duties . However , he was later given that ability by issuing computer command " Override Command 1 - EMH - Alpha ; End Program " . ( ) The Mark II apparently had this ability as part of his programming . ( ) While not designed to act as ship ' s counselor , the EMH had been programed with some psychological knowledge . ( ) Appendices . Apocrypha . In " Star Trek Online " s Federation tutorial , players encounter a new version of the Emergency Medical Hologram ( EMH Mark VI ) serving aboard the USS " Khitomer " . Resembling a Vulcan with silver hair , this EMH , in dialogue released on YouTube but not included in game , claims to have a " personality matrix [ that ] combines qualities of more than twenty physicians , scientists , and counselor s - including Admiral Beverly Crusher of Starfleet Medical , Ambassador Spock , and Ghee P ' Trell of Andoria . " He is voiced by Zachary Quinto . Also in " Star Trek Online " , Emergency Medical Holograms , alongside the new Emergency Engineering Holograms and Emergency Security Holograms , can be acquired as Duty Officers .