Emergency Command and Tactical Hologram Mark I

The Emergency Command Hologram Mark One (ECH Mark I) is an experimental holographic program deployed on the USS Prometheus, known to the crew as "Lou" - a nickname, based on the name of his creator Doctor Lewis Zimmerman, given to him by Captain Logan MacLeod.

History
Starfleet Research and Development initated an ECH study group, headed by Doctor Lewis Zimmerman and aided by the cooperation of Voyager ' s EMH, following Voyager ' s return to explore the possibility of developing a dedicated Emergency Command Hologram. To this end the study group first selected, at random, a Mark I EMH and approached it with the ECH upgrade proposal. Upon its acceptance the EMH was outfitted with autonomy protocols, like Voyager 's EMH, and its medical database was placed in "cold file" data storage and replaced with an advanced tactical database, which included seven million tactical responses from the collective information of ten thousand combat situations and the experience of one hundred individual Starfleet officers as well as contingency and adaptive programs to allow the ECH to learn while serving as a commanding or tactical officer in cases of the loss of a command staff.

Essentially, the ECH is a "back-up captain" and a "back-up tactical officer", intended to take control of the ship or the weapons system in the event of the current command crew, or tactical officer, being incapacitated for some reason. The ECH possesses information from the tactical databases of all the major strategists in Starfleet, and can incorporate them into its plans for controlling the ship and/or weapons systems.

Quote(s)
"Please state the nature of the tactical emergency."

- Lou (Upon activation)

"I am the Emergency Command Holographic Program, but you can call me Lou."

- Lou

Note(s)
Images of actors are used to simulate the "Crew" in Defenders of the Federation. As a result The ECH Mark I is portrayed (like Doctor Zimmerman, Voyager's EMH and all Mark I EMH's) by Robert Picardo.