This machine was invented years ago, it's intention recently has been to read lies, and if someone is lying, it gives a signal for the reader of the polygraph to let them know. The lie detector, also known as the polygraph was invented in 1921 by John Augustus Larson.
Th Polygraph was used to measure and record blood pressure, pulses, respiration, and skin conductivity while the person is asked to answer a specific amount of questions. Even though a lot people know this to be a device used to be able to tell if someone is lying accurately, it actually has little evidence to support its use. The National Research Council has found no evidence of its effectiveness of 90 percent validity. In a 1988 Supreme Court case, United States v. Scheffer, the majority stated that there was simply no consensus that polygraph evidence is reliable. Some people in the United States had begun to find ways to defeat or maneuver around polygraphs so they would not get caught lying. People began to get paid to teach their ways of defeating the polygraphs, such as a man named Doug Williams. Who taught to people who would molest or commit other crimes. Some would get caught, and other's would not, but it only proved the case that polygraphs are inaccurate even more.