Accuracy scan
An accuracy scan was a means used during the 23rd century to use a computer to determine whether or not someone was lying based on physiological changes of their body. 

During the formal s conducted aboard the  in 2266, against transport  Leo Walsh, Captain James T. Kirk activated the ship's computer to record Walsh's responses. As Kirk questioned Walsh, and Walsh responded (with a lie), the library computer reported that his response was "incorrect". Walsh, whose real identity was Harcourt Fenton Mudd, argued that "surely you're not going to take the word of a soulless mechanical device over that of a real flesh and blood man." Once Walsh's true identity was revealed, Ruth Bonaventure, one of "Mudd's women" who was also present at the hearing, feared that it might be able to read their minds, too. Mudd, however, assured her that "it can't, darling. It can't. Just what's on the record." 

Also during the hearing, Kirk requested the computer to "go to sensor probe", to take further readings of the room's occupants. Among the computer's detection abilities were the detection of respiration patterns, perspiration rates, heart rate, and blood pressure. ()

When Montgomery Scott gave his testimony, after being accused of murdering the Argelian dancer  in 2268, Captain Kirk inquired whether Scott was lying about his memory loss. After Scott responded that he was not lying, and specifically that "I don't remember a thing about the first two murders," Kirk requested an accuracy scan from the ship's computer, which concurred that the "subject relaying accurate account. No physiological changes." 

Kirk further inquired if Scott killed Lieutenant Karen Tracy, which Scott said he could again not recall, and which the computer still concurred was an accurate statement. Argelian Prefect Jaris, however, was not convinced by the testimony, pointing out that "all [the accuracy scan] proves is that he's telling the truth when he says he doesn't remember." As the testimony continued, and against the protest of Mr. Hengist, Jaris agreed that "for the time being, we will accept Captain Kirk's explanation of the machine's accuracy as factual. I do, however, reserve to myself the right to make the final determination." ()

See also 
Autonomic response analysis
Encephalographic polygraph scan

Analyses
Medical procedures