Life signs detector

Life signs detectors are small devices that the Atlanteans developed in the Pegasus Galaxy. Hand held devices, they can detect various life signs, but they are incapable of differentiating between species. They require the ATA Gene to use.

Behind the scenes
In Rising, the life signs detectors were clearly able to differentiate between humans (blue) and Wraith (red). In later episodes, they did not have this ability.