Bio-scanner

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 failed to detect a lymphatic virus brought on board along with canisters of deuterium. 

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. Later that same year, the USS Voyager used its own bio-scanners to investigate new space-dwelling lifeforms discovered in the Delta Quadrant. 

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. 

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.