The Emergency Medical Hologram was a medical tool developed by Dr. Lewis Zimmerman, one of the foremost experts on holographic technology at the time. The EMH contained the combined medical knowledge of the entire Federation, as well as various other Alpha Quadrant doctors, and could perform any and all known medical procedures available at the time of its creation.
The original EMH was intended only for limited use as supplement to the ship's regular staff, and was rated for a maximum of 1500 hours. However, Voyager's EMH was forced to operate continuously for almost 7 years, after the ship's entire medical complement was killed. Due to this extended use, the matrix began breaking down, but quick action on Voyager's part allowed them to combine an included diagnostic program and stabilize the matrix.
The success of the EMH program has also given rise to the Emergency Engineering Hologram and Emergency Security Hologram. An Emergency Command Hologram has also been created, but controversy surrounding a fully-artificial crew has prevented its deployment thus far. Instead, all EMH programs have been given the equivalent authority to a Medical Officer. Should the entire medical staff be incapacitated or killed, the EMH program is automatically instated as the acting Chief Medical Officer.
Variants[]
As of 2377, there were four versions of the EMH, called Mark I, II, III, and IV. As of 2428, there are a total of ten versions, three of which are still in use today.
Mark I[]
Physically and psychologically based on Dr. Zimmerman himself, the Mark I was considered to be rude and hard to work with. By 2374, almost all Mark I EMH had been reassigned to other uses.
Mark II[]
The Mark II was a complete redesign of the EMH, with a new appearance and personality. However, the Mark II proved to be rather skittish when faced with dangerous situations, and was eventually replaced.
Mark III[]
By 2376, the Mark III had been introduced to active service. Unfortunately, the Mark III's matrix proved to be inadequate, and was replaced by 2377.
Mark IV[]
Zimmerman appears to have perfected the EMH in the Mark IV, which features completely new physical parameters and personality subroutines.
Mark V[]
Introduced in 2384, the Mark V consisted mostly of updates to the Medical database, as well as increased dexterity and movement. Additionally, the Mark V included many of the upgrades that the Doctor made to himself, with his permission.
Mark VI[]
Introduced in 2406, the Mark VI contained still more upgrades to the EMH, as well as the capacity to transfer itself to a mobile emitter as needed. The Mark VI also included combat capability (limited to self-defense), to better perform on tactical ships.
Mark VII[]
The Mark VII is currently the most widely-used version, but is expected to be phased out within the next ten years as ships undergo refits. This version allows for significantly reduced response time and processing requirements, double the previous limit. The increased processing capacity allows for simultaneous deployment of two separate EMH instances. Additionally, the MKVII is fully customizable by the CO, XO, and CMO, and can be given individual appearances or orders as needed.
Mark VIII[]
The Mark VIII was deployed during the late 2410's and early 2420's. This version uses a shared database among all iterations, allowing for a more modular design that can utilize multiple avatars at once. The limitations on iterations depends on the processing capacity of the ship using it, but current versions can deploy at least three simultaneous units, and larger ships like the Jupiter can use up to ten units simultaneously.
Mark IX[]
The Mark IX is the version currently being installed on new starships. As with the Mark VIII, the Mark IX further optimizes the shared resources. The current configuration allows for up to five iterations on smaller ships, and up to twenty on larger ships. This version began active testing beginning in 2422, and entered full production in 2425.
Mark X[]
The Mark IX is currently in the experimental stage, and further optimizes the shared resources. The current configuration allows for up to eight iterations on smaller ships, and up to thirty on larger ships. This version began active testing beginning in 2426, and was fully deployed by 2428.
Long-Term Medical Hologram[]
The Long-Term Medical Hologram is a modification of the EMH matrix to ensure stability when running for longer than standard. An EMH is not designed for more than short term use measured in hours or days. The LMH is designed for periods of activity measured in weeks to months.
Legality[]
As of 2428, The EMH was not considered sentient at deployment, although it was assumed to have the capability to become sentient with extended use. As such, Starship Captains with these versions deployed were authorized to determine the EMH's sentience using the guidelines laid out by the Federation Council, and award citizenship as it became necessary. Additionally, all EMH programs were evaluated at each starship's refit cycle, to determine their status.
As per the Federation Council's ruling in 2398, Emergency Medical Holograms who had demonstrated their sentience were afforded the same rights and privileges as all Federation citizens and Starfleet officers. Since they are programmed with the necessary knowledge, EMH programs are not required to enter the academy, and are granted privileges appropriate for a Chief Medical Officer where necessary.