The Lantean medical scanner was a device that was used by the Lantean civilization.
These devices were small rectangular items that were held in the hand, with one surface used to scan a target and collect data. This information was then sent to a Lantean Life signs detector that displayed whatever data was gathered.
It is possible to attach a wire to the scanner and interface it with Tau'ri laptops, allowing the data to be displayed on those screens instead.
Doctor Carson Beckett from the Atlantis expedition used the scanner on Runner Ronon Dex to locate the Wraith tracker implanted in his body. Using it in conjunction with a portable Ancient computer allowed him to remove the Wraith implant from the Satedan. (SGA: "Runner")
Doctor Jennifer Keller later used this scanner which was attached to her laptop to find a more extensive Wraith tracking device in the Runner Kiryk in order to remove it but determined that the implant was fused to his spine making its removal impossible without killing its Human host. (SGA: "Tracker")