Sweat Ducts May Act As Antenna For Lie Detection

Reservoir Hill writes "Researchers have discovered that human skin may contain millions of tiny "antennas" in the form of microscopic sweat ducts that may reveal a person's physical and emotional state. This discovery might eventually result in lie detectors that operate at a distance. In experiments, the team beamed electromagnetic waves with a frequency range of about 100 gigahertz at the hands of test subjects and measured the frequency of the electromagnetic waves reflecting off the subjects' skin. Initially, the experiments were carried out in contact with the subjects' hands, but even at a distance of 22 cm, researchers found a strong correlation between subjects' blood pressure and pulse rate, and the frequency response of their skin."

This isn't new

[Anonymous Coward]

The most significant result from polygraph tests is and has been the Galvanic Skin Response Test. It works by measuring the voltage change in your skin when your sweat glands dilate due to a response in your sympathetic nervous system. The simplified (and not completely accurate) version is that telling a lie triggers your fight-or-flight reflex which is tied into your sympathetic nervous system.

Sci-Fi Lie-detection at a distance? I think not

[Neuticle]

If they can get this to remotely measure blood pressure and pulse to an accuracy that is acceptable (90%? Pure guessing on my part, the article only mentions a "strong correlation"), using it for lie detection would still be based off of the shaky assumption that increases in blood pressure and pulse indicate lies or deception.

Even a polygraph, which measures blood pressure and pulse directly and accurately, as well as additional things such as respiration, skin conductivity and even muscle movements (fidgeting, ticks etc), is not all that reliable. To borrow from Wikipedia:

The [National Academy of Sciences] found that the majority of polygraph research was of low quality. After culling through the numerous studies of the accuracy of polygraph detection the NAS identified 57 that had "sufficient scientific rigor". These studies concluded that a polygraph test regarding a specific incident can discern the truth at "a level greater than chance, yet short of perfection".
And "A 1997 survey of 421 psychologists estimated the test's average accuracy at about 61%, a little better than chance."

In reality, even if polygraphs could be PROVEN 95% accurate, it wouldn't ever hold up in court: 1 in 20 is reasonable doubt.
This thing would be using the same theory, but with less input. FAIL

The real benefit from this will be in medical monitoring. If blood pressure and can be measured remotely, accurately and in a short amount of time, that would be a big improvement over the current sphygmomanometer (a regular BP cuff that gets pumped up), especially in situations where it is hard to measure BP because of background noise or vibration. Ambulances sometimes have to stop to take a blood pressure (not on critical patients, but still).