I’ll put it down very straightforwardly: the tricorder is a medical device that can diagnostic a tumor\cancer within minutes with an accuracy far beyond the classical diagnostic systems.
it’s called BioScanner - Trimprob:
Trimprob is the acronym of TRIcorder Medical PROBe
Watch this TEDx TALK video, with English subtitles (15’:03’’):
La Tecnologia di Star Trek alla portata di tutti: Clarbruno Vedruccio at TEDxBologna
P.S.: this is not ‘fiction’.