Bio-scanner
From Memory Alpha, the free Star Trek reference
A bio-scanner was technology used to detect and scan biological entities. Bio-scanners were found in devices such as tricorders as well as starships themselves.
Earth Starfleet ships were equipped with bio-scanners since at least the mid-22nd century, though the technology was not perfect. In 2152, the bio-scanners aboard the Enterprise NX-01 failed to detect a lymphatic virus brought onboard along with canisters of deuterium. (ENT: "The Seventh")
24th century Starfleet tricorders were equipped with bio-scanners. In 2371, Neelix's tricorder picked up a single class 3 humanoid organism on a rogue planetoid that was thought to be uninhabited. (VOY: "Phage") Later that same year, the USS Voyager used its own bio-scanners to investigate new space-dwelling lifeforms discovered in the Delta Quadrant. (VOY: "Elogium")
The Nechani race had bio-scanners, and used them to detect a subdermal bioprobe implanted in Captain Kathryn Janeway during her visit to their homeworld. (VOY: "Sacred Ground")
The Nyrian biosphere vessel was equipped with bio-scanners, which Captain Janeway and Tuvok used to help locate other Voyager crewmembers that were being held captive. (VOY: "Displaced")
[edit] Background
According to the script for TNG: "A Matter of Time", a "bioscanner" was one of the devices that time traveler Berlinghoff Rasmussen had stolen while on board the USS Enterprise-D, indicating that Federation bio-scanners may have existed as stand-alone devices, and not necessarily only as a function found in tricorders and starships.
