How to track movement without a wearable device
New wireless technology out of MIT can measure movements as slight as heart rate and breathing through a wall. They call their system Wi-Vi -- seeing with Wi-Fi signals -- and it could be useful for health tracking apps, baby monitoring (pictured below), and search-and-rescue operations.
Developed by a team from the Computer Science and Artificial intelligence Laboratory (CSAIL), the system can detect gestures as subtle as the rise and fall of your chest, from as far as another room away -- no device on the other side of the wall is necessary. From those measurements, the system can determine heart rate with 99 percent accuracy.
- Wi-Vi transmits a low-power wireless signal and uses its reflections to track the movement of up to four people in a closed room.
- As the signal is transmitted, a portion penetrates through the wall and reflects off the people on the other side.
- As the person moves (however slightly), that tiny change in distance leads to a difference in timing of the reflected signal.
- The technology cancels out irrelevant reflections to limit signal interference from stationary objects.
Wi-Vi was presented at the ACM Sigcomm conference in Hong Kong last year. Here's their latest report [pdf] and you can watch videos of the technology in action: monitoring baby breathing and heart rate and multiple adults in a room.
Image: Christine Daniloff/MIT (top) & MIT (middle)
This post was originally published on Smartplanet.com