Emphasis added:

"Researchers at the MIT Computer Science and Artificial Intelligence Laboratory have developed a device that uses radio waves to detect whether someone is happy, sad, angry or excited.

The breakthrough makes it easier to accomplish what scientists have tried to do for years with machines: sense human emotions. The researchers believe tracking a person's feelings is a step toward improving their overall emotional well-being.

The technology isn't invasive [?]; it works in the background without a person having to do anything, like wearing a device. The device called EQ-Radio, which was detailed in a paper published online Tuesday, resembles a shoebox, as of now. In the future, it may shrink down and integrate with an existing computing gadget in your home.

It works by bouncing wireless signals off a person. These signals are impacted by motion, such as breathing and heartbeats. When the heart pumps blood, a force is exerted onto our bodies, and the skin vibrates ever so slightly.

After the radio waves are impacted by these vibrations, they return to the device. A computer then analyzes the signals to identify changes in heartbeat and breathing.

The researchers demonstrated their system detects emotions on par with an electrocardiogram (EKG), a common wearable device medical professionals use to monitor the human heart.

Source: http://money.cnn.com/2016/09/20/technology...