MIT Motion Tracking System Watches Through Walls

By Wesley Fenlon

The least necessary, but coolest, way to turn off things in other rooms.

MIT's latest stab at Kinect doesn't use a camera to track 3D motion and positioning. Instead, it uses radio waves, which will happily penetrate through walls and track your position down to about four to eight inches. The technology, called WiTrack, bounces weak radio signals off the human body, picks up the reflected signals with a trio of receivers, and uses software to triangulate the close-to-exact position of the human subject. The subject doesn't have to carry any kind of wireless receiver or beacon to make it work.

As MIT researchers explain (PDF), WiTrack's radio signals are about 100 times smaller than Wi-Fi waves and about 1000 times smaller than cellphone waves. Any interfering objects in the way, like furniture, are calculated for using algorithms, leaving the system free to track a human body as it moves around a house.

The "why" isn't immediately obvious. Kinect sits in front of your TV and provides a direct interface between game console and player. What good is tracking from another room? MIT cites fall detection for the elderly as a use case with serious potential, and claims it can detect about 97 percent of falls. WiTrack could also, no doubt, be a powerful addition to any security system.

The coolest use that MIT demonstrates, though, is interacting with appliances from separate rooms. It's an interesting alternative to voice commands, which technology is steering us towards. Hand gestures may end up being less cool, but there's still a touch of magic to them. If you've ever wanted to raise your arm as if using the Force to turn off a lamp in a separate room, the video below will show that dream being within your grasp.