Notes : The Emergency Medical Hologram was developed by - and styled after - Doctor Lewis Zimmerman in order to provide limited medical coverage for situations in which a real Doctor was not available. The EMH was capable of performing an incredibly wide range of medical procedures - over five million possible medical treatments in all taken from over 2,000 medical references spanning 3,000 cultures, and the experiences of 47 physicians. These were governed by adaptive programmes which offered a wide range of contingency options and even allowed the EMH to create new medical procedures if needed.

The limitations of the system were largely hardware related. The primary limitation was the EMH's inability to operate outside of a holographic projection system. In the Intrepid class this limited the Doctor to the sickbay and holodecks, while the later Prometheus class allowed the EMH to operate throughout the ship. However, even with this advance the EMH was unable to operate outside the ship itself.

When the USS Voyager was snatched to the Delta Quadrant, the entire medical staff was killed in the crossing. The EMH was forced to provide full time medical care for the entire crew for a prolonged period. Initially the crew found the EMH's personality to be abrasive, and some consideration was given to reprogramming him to be more amenable. However, Kes befriended the Doctor and fought successfully to keep his personality intact. Over the first few months of his service the EMH was frequently left active for hours or days at a time, allowing his adaptive programming to alter his basic personality routines. He took up singing, and even began to contemplate giving himself a name - although to date he has hesitated over the final choice.

The EMH went on his first 'away mission' shortly after Voyager arrived in the Delta Quadrant, when a photonic being trapped in one of Voyagers holodecks kidnapped three members of the crew. He was able to convince the creature of the crews peaceful intentions and it returned them unharmed; the action earned him a special commendation from Captain Janeway.

In 2372 Voyager rescued Danara Pel, a Vidiian woman suffering from the Phage. The Doctor was able to create a holographic body for Pel which was free of the Phage, and the two became very close. The Doctor apparently added genitalia to his physical matrix, and the two became lovers until Pel returned to her people.

The EMH considers himself bound by the Hippocratic Oath, and this has led to problems on at least two occasions. When Tuvok and Neelix were combined into one person - Tuvix - later in 2372 he refused Janeways order to reverse the situation on the grounds that he could not harm Tuvix. More seriously, in late 2373 he developed a problem when he was confronted by two severely injured crewmen - Ensigns Harry Kim and Jetal. The Doctor only had the time to save one, and chose Harry Kim. Unfortunately, this led to a conflict between his ethical and cognitive subroutines which led to outbursts of uncontrolled rage and threatened total failure of the program. Captain Janeway ordered the Doctors memory of the events deleted in order to preserve his sanity.

Unfortunately, the Doctors developing personality added many 'unnecessary' files to his system, leading to a level 4 memory fragmentation within his program. The condition almost caused catastrophic failure, but Kes was able to use a diagnostic program to repair him. Although there was some memory loss the problem has not reoccurred. In 2373 the Doctor underwent his most significant development when Voyager was able to obtain a piece of 29th Century Federation technology, the Mobile Emitter. This small device allowed the Doctors program to function completely independently of Voyager, allowing him to participate in away missions as easily as any other member of the crew. He continued his improvements later in the year by adding various new personality traits to his program; unfortunately, the negative aspects of these traits combined to form an alternate personality which killed at least one person and harmed several others before being deleted. undaunted, the Doctor next began to create a more realistic lifestyle for himself by creating a holographic family for himself. B'Elanna Torres was unimpressed with this effort, declaring his choice of personalities for the family unrealistic. She introduced various new features into the program, ultimately leading to a serious injury to his daughter. The Doctor shied away from the program, unwilling to experience the emotional intensity of the situation, but was convinced by Tom Paris to return and experience his daughters death in order to become fully aware of the joy and pain of family life.

In 2374 Voyager encountered an alien communications array which spanned much of the galaxy, and was able to use it to transmit the Doctor to the Federation Starship Prometheus. He found the Starfleet crew dead and the ship in Romulan hands; with the help of the newer, more advanced - but less experienced - EMH mark 2, the Doctor was able to defeat the Romulans and deliver the ship back to Starfleet. This marked Voyagers first communication with home; the EMH gave Starfleet a detailed account of the ships journey before he returned with the message 'Voyager is no longer alone'.

The Doctor continued to expand his capabilities in order to make himself more effective for the crew, but later in 2374 a recently installed Psychotherapy subroutine led him to unwittingly encourage Seven of Nine to develop false memories of an assault. Although he was eventually able to realize his mistake and discover the truth, the error led to the death of the accused man.

In 2375 the Doctor began to make medical holoimages of the crew, and discovered the medical procedure he had performed on Harry Kim in 2373. Janeway attempted to delete the knowledge, but he was able to catch her and stumbled upon the entire plot. Initially the Captain decided to delete his knowledge of the entire incident, but Seven of Nine was able to convince her to allow the Doctor to work through his guilt in order to allow him to grow further as a person.

The Doctor struck up a close relationship with Seven of Nine shortly after she came aboard, and by 2375 he realized he was beginning to fall in love with her. As of the present, the two remain nothing more than close friends.