December 11, 2013
New 3D Tracking Device Could Revolutionize Gaming, Help The Elderly
Lee Rannals for redOrbit.com - Your Universe Online
A new technology could not only be useful in the gaming industry, but it could also provide a better fall detection system for the elderly.
The new system, developed by Dina Katabi’s research group at the MIT Computer Science and Artificial Intelligence Lab (CSAIL), allows for highly accurate, 3D motion tracking. The WiTrack system uses radio signals to track a person through walls and obstructions, helping to pinpoint their location to within just a few inches.
The scientists believe their new system could help revolutionize the gaming industry.
“Today, if you are playing a game with the Xbox Kinect or Nintendo Wii, you have to stand right in front of your gaming console, which limits the types of games you can play,” Katabi, a professor of computer science and engineering and co-director of the MIT Center for Wireless Networks and Mobile Computing, said in a statement. “Imagine playing an interactive video game that transforms your entire home into a virtual world. The game console tracks you as you run down real hallways away from video game enemies, or as you hide from other players behind couches and walls. This is what WiTrack can bring to video gaming.”
WiTrack works by tracking specialized radio signals reflected off a person’s body to pinpoint location and movement. The system uses multiple antennas, including one for transmitting signals and another for receiving. WiTrack builds a geometric model of the user’s location by transmitting signals between the antennas and using the reflections off a person’s body to estimate the distance between the antennas and the user. The system is able to track movement more accurately than other technologies that rely on wireless signals.
“Because of the limited bandwidth, you cannot get very high location accuracy using WiFi signals,” graduate student Fadel Adib said in a statement. “WiTrack transmits a very low-power radio signal, 100 times smaller than WiFi and 1,000 times smaller than what your cell phone can transmit. But the signal is structured in a particular way to measure the time from when the signal was transmitted until the reflections come back. WiTrack has a geometric model that maps reflection delays to the exact location of the person. The model can also eliminate reflections off walls and furniture to allow us to focus on tracking human motion.”
Other systems require a user to carry a wireless device or stand directly in front of the sensing device in order for it to pick up on someone’s movement. However, with WiTrack, users are freed from these devices, allowing them to roam space freely while still providing high-accuracy location.
“Motion tracking has generally been accomplished by analyzing images captured from strategically placed cameras inside the room. A limitation of such systems is that they only work when the moving object is directly in the camera’s line of sight,” Victor Bahl, a principal researcher and director of mobility and networking research at Microsoft Research, said in a statement. “Another problem is [that] image analysis is a computationally heavyweight operation.”
He said this new technology does not have these same limitations. WiTrack detects movement without requiring a huge amount of computational power, and without having to be placed inside the room.
“The surprising thing is that it is very accurate. There is still more research to be done, but the approach is promising,” Bahl said.
The researchers also envision WiTrack being used in tracking elderly patients who are at high risk of falling. Current systems require individuals to continuously wear sensors or install cameras in the person’s home. With WiTrack, individuals will not need these other accessories, while also being able to track movement very accurately.
The team said they are working on advancing WiTrack so it can track more than one person in motion at a time. They believe the system should be easily adaptable to commercial settings.
“The system is not expensive or time-consuming to produce and it could be miniaturized for easier production and use,” graduate student Zach Kabelac said in a statement.