The Long-term Medical Holographic program (or LMH, for short) was an attempt by Dr. Lewis Zimmerman to extend the usability of his previous work, the Emergency Medical Holographic program, for use as a fully-fledged doctor on isolated bases and outposts where resources may be limited. Zimmerman began this project after receiving a request from Starfleet to enhance the lifespan of the EMH in mid-2373.
In designing the LMH, Zimmerman concluded that it would be necessary for the holo-doctor to interact naturally with patients for weeks at a time. In doing so, he felt it necessary for the holo-doctor to be "expected to share amusing anecdotes, extend sympathy, swap dirty jokes, and even have culinary opinions formed by experience." (DS9: "Doctor Bashir, I Presume")
Fan continuities Edit
The Romulans used the terms EMH and LMH interchangeably, with distinctions made only by the deployment area, starting from their own EMH Mark V. Just like its Federation counterpart, the Romulan LMH was designed so it could interact naturally with patients, as a flesh-and-blood medic would. However, Romulan EMHs/LMHs, from Mark V onward, have the capability of having their outward appearance changed by programming. Rihanna used her father's EMH Mark V so she could use her to learn medicine. (RIS Bouteina: "Days of Wine and D'ohses")