Modern wireless tech isn’t just for communications. It can also sense a person’s breathing and heart rate, even gauge emotions. When I was a boy, I secretly hoped I would discover latent within me some amazing superpower—say, X-ray vision or the ability to read people’s minds. Lots of kids have such dreams. But even my fertile young brain couldn’t imagine that one day I would help transform such superpowers into reality. Nor could I conceive of the possibility that I would demonstrate these abilities to the president of the United States. And yet two decades later, that’s exactly what happened.
There was, of course, no magic or science fiction involved, just new algorithms and clever engineering, using wireless technology that senses the reflections of radio waves emanating from a nearby transmitter. The approach my MIT colleagues and I are pursuing relies on inexpensive equipment that is easy to install—no more difficult than setting up a Wi-Fi router.
These results are now being applied in the real world, helping medical researchers and clinicians to better gauge the progression of diseases that affect gait and mobility. And devices based on this technology will soon become commercially available. In the future, they could be used for monitoring elderly people at home, sending an alert if someone has fallen. Unlike users of today’s medical alert systems, the people being monitored won’t have to wear a radio-equipped bracelet or pendant. The technology could also be used to monitor the breathing and heartbeat of newborns, without having to put sensors in contact with the infants’ fragile skin.
You’re probably wondering how this radio-based sensing technology works. If so, read on, and I will explain by telling the story of how we managed to push our system to increasing levels of sensitivity and sophistication.
Popular media article:
Original research article: Emotion Recognition using Wireless Signals
ABSTRACT
This paper demonstrates a new technology that can infer a person’s emotions from RF signals reflected off his body. EQ-Radio transmits an RF signal and analyzes its reflections off a person’s body to recognize his emotional state (happy, sad, etc.). The key enabler underlying EQ-Radio is a new algorithm for extracting the individual heartbeats from the wireless signal at an accuracy comparable to on-body ECG monitors. The resulting beats are then used to compute emotion-dependent features which feed a machine-learning emotion classifier. We describe the design and implementation of EQ-Radio, and demonstrate through a user study that its emotion recognition accuracy is on par with stateof-the-art emotion recognition systems that require a person to be hooked to an ECG monitor.
