Life sign A life sign , bio - sign , biosignature , or bio - electrical signature was a signal or collection of signals given off by a lifeform that indicates that it is currently alive , or functional . They are unique to a species . Upon approaching another starship or a planet for which they had limited intelligence , starship s usually performed a scan for life signs . This information became part of the bridge crew ' s determination as to whether to board the ship , send a landing party , or carry out any other action . By the 24th century , Starfleet sensor s were sensitive enough to discern an individual ' s identity based on their biosignature . ( ) In 2152 , the crew of the managed to isolate Captain Archer ' s biosignature , confirming that he had not become a casualty of a conflict between Andorian s and Vulcan s on the surface of a contested planet . ( ) In 2154 , Shran ' s crew was able to locate Ambassador Soval aboard " Enterprise " by isolating Soval ' s biosignature for the purpose of abducting and torturing him for information on Vulcan fleet deployments . ( ) Later that year , the biosignature of a prisoner in " Enterprise " s sickbay revealed him to be Klingon , a fact which surprised the crew , as the augment virus had altered his outward appearance to resemble a Human . ( ) The was designed to track its crew member ' s life signs . " When Captain Richard Robau was murder ed in 2233 of an alternate reality , the computer signaled his termination . " ( ) " The also monitored life signs of crew in environmental suit s undergoing space dives . " ( ; ) Dr . Juliana Tainer was a Soong - type android that was designed to give off Human life signs . ( ) In 2371 , Neelix detected a bio - electrical signature while surveying the caves inside an asteroid leading to the conclusion there was another lifeform . ( ) In 2372 , a subspace divergence field perfectly duplicated every particle of matter aboard the , a fact which was revealed to the crew when they realized that all of their sensor readings had doubled the moment they encountered the field , including mass , energy output , and biosignatures . ( ) Later that year , Ensign Harry Kim , " Voyager " s chief of operations , was able to detect three extremely faint biosignatures 2 . 3 kilometer s beneath the surface of a Kohl settlement , revealing the presence of a group of aliens in suspended animation . ( ) In 2375 , Lieutenant Daniels , the " Enterprise " - E ' s tactical officer , detected Captain Picard ' s biosignature aboard the Son ' a collector . This allowed the " Enterprise " to beam Picard off of the collector moments before it exploded . ( ) In 2376 , while attempting to salvage an ion distributor from the recently discovered " Ares IV " , Seven of Nine instructed Lieutenant Torres to obtain a transporter lock on both her biosignature and combadge , which she had placed on the corpse of Lieutenant John Kelly , allowing Torres to retrieve both Seven and Kelly at the same time . ( ) Later that year , Seven was able to alter her own biosignature in a successful attempt to prevent the " Voyager " crew from obtaining a transporter lock on her , after she stole a shuttlecraft while experiencing paranoid delusions , believing that the crew had been conspiring against her . ( ) Later in 2376 , after crewman William Telfer was abducted by a dark matter lifeform , Crewman Tal Celes frantically attempted to locate Telfer ' s biosignature , with no success . ( ) The next year , Ensign Kim managed to isolate the biosignatures of an away team which had successfully infiltrated a Borg tactical cube , but was unable to beam them out until the cube ' s shields were deactivated . ( ) Later that year , General Geral , an Annari , informed Captain Janeway that he had recently detected two Human biosignatures aboard a warship , belonging to the Kraylor , a species with which the Annari were at war , and subsequently escorted " Voyager " out of Annari space . ( )