The ECH was first imagined in one of the USS Voyager's Emergency Medical Hologram's fantasies. The program was eventually implemented by Captain Kathryn Janeway on Voyager. The extension was first envisioned by The Doctor after he had added daydreaming subroutines to his program in 2376. His initial request to Captain Janeway for the subroutine to be added to his program was denied, but after The Doctor demonstrated his abilities in practice, Janeway reconsidered and ordered research into the development of the ECH to begin as soon as possible.