Cheap sensors could capture your every move

Video games like Dance Dance Revolution could soon require more than just fancy footwork. Small, cheap sensors for tracking the movement of a person's entire body could lead to "whole-body interfaces" for controlling computers or playing games, researchers say.

Conventionally, motion capture makes use of reflective dots or small LEDs attached at key points on a person's torso, limbs and head. Capturing the movements of these points using an array of cameras allows animators to create a computerized skeleton, which can then guide the movements of an animated character, for example.

Their new motion capture sensors works even while a person is driving or skiing (see video, top right). It could make computer animation or movie effects more lifelike, the researchers say, and perhaps even help doctors analyse movements of patients going through physical therapy.

Several sensors measuring about 2.5 centimetres on each side are attached to a person's legs and arms. The sensors detect movement in two different ways: accelerometers and gyroscopes measure motion, but ultrasonic beeps are also emitted.

The new system does not work when people make very sudden movements, however, because the relatively cheap sensors used are not yet accurate enough to compensate. But they are quickly improving, Adelsberger says.

"This system could record many new activities for sports medicine, behavioral studies [and other fields] that were impossible before," he says.