Emergency Command Hologram The Emergency Command Hologram ( ECH ) was a holoprogram developed and implemented by the crew of while it was in the Delta Quadrant in the 2370 s . It was an extension of the " Voyager " s Emergency Medical Hologram to include strategic and tactical data in order to function in a command capacity in the event of the current command crew being incapacitated during an emergency . ( ) Design . Essentially , the ECH was designed to be a ' backup captain ' which possessed information from all major Starfleet strategic and tactical database s . The ECH could incorporate the data into its plans for controlling the ship . It also had basic engineering skills in order to assess damage when necessary . The ECH could interact with the computer or use any console manually if desired as the captain would . While the computer can be ordered , when possible , to bypass or reroute systems to get the ship working again , the ECH could replace necessary components or otherwise manually repair any system required . ( ) The ECH was designed to have access to all areas of a ship , especially the bridge , which was only possible if the ship was outfitted with holoemitter s or if the ECH was equipped with a mobile emitter , as The Doctor was . ( ) Once activated by a commanding officer , all command codes were automatically transferred to the ECH . At that point , the ECH became the acting captain of the ship . If available , the ECH was given directives from other crew or Starfleet to follow . If necessary , the ECH could function alone , ordering the computer to take any action necessary , such as maneuvering , sensor scanning , targeting and firing weapons , and opening communications . ( ) The command codes also allowed for the ejection of the warp core through verbal command . ( ) History . The ECH was first envisioned by The Doctor after he added a daydreaming subroutine to his program in 2376 . His initial request to Captain Janeway was denied , but , after The Doctor demonstrated his abilities in practice , Janeway reconsidered and ordered research into the development of the ECH . ( ) Design and testing would occur for the next several months . ( ) Janeway activated The Doctor ' s command subroutines in a real situation in 2377 when tetryon radiation forced everyone to abandon ship . Shortly after the ship was abandoned , " Voyager " was attacked by scavengers . He and the computer disabled one ship and evaded the others by hiding in a nebula . He managed to begin repairs , but when Commander Chakotay , Ensign Harry Kim , and Neelix returned from an away mission , life support was not yet online , because it was not an immediate concern to The Doctor . ( ) After Chakotay and Neelix sought the rest of the crew , who had been abducted by criminal s , Kim and The Doctor disagreed about who was superior to the other ; Kim was a commissioned officer , but The Doctor had information about all of Starfleet ' s great strategists . In one battle with the Quarren , The Doctor called up information about a Romulan battle from his tactical database , leading him to use a photonic shockwave against the ships , before retreating . In the final battle against the Quarren Harry Kim ' s plan to sabotage three escape pod s and detonate them once in the enemies ' tractor beam s saved " Voyager " . This provided a lesson to The Doctor about experience . He realized that he was needed on " Voyager " as a medic more than as a commander , and made peace with Kim before handing back command to a rescued Captain Janeway . ( ) A trial on the rights of The Doctor was initiated when his holonovel was published without his permission in 2378 ; the publisher arguing that The Doctor had no legal rights due to his status as a hologram , prompting the crew to arrange a hearing to determine The Doctor ' s rights as a sentient being . Harry Kim cited the ECH extension in The Doctor ' s favor , regarding it as a Human desire to develop and change . While the publisher argued that this simply showed that The Doctor ' s program could be altered , Harry countered that The Doctor ' s request for the creation of the ECH represented a desire to improve that would not have been expected of a hologram designed to do a specific task . ( ) Later that year , The Doctor disguised himself as Commander Chakotay and used his command code s to transform himself into the ECH . He would later eject the warp core , then escaped from the ship aboard the " Delta Flyer II " with the warp core to exchange it with the Hierarchy for Captain Janeway ' s freedom . Both Janeway and the warp core were recovered and returned to " Voyager " , although The Doctor remained in sickbay for a week out of embarrassment about the " deathbed confessions " he had made while the excess subroutines installed by the Hierarchy were being deleted . ( )