Yea pretty similar idea to a polygraph test which for years was called a "lie detector."

In reality, they measure a bunch of things that may indicate lying, but they are just as likely to indicate that a person is nervous or reacting to the fact they're being tested at all.

They're typically inadmissible in court these days, however, there is still a pretty solid amount of blind trust in their results.

That part of the article gives a similar "lie detecting" hypothesis, just without the machine.