No more fumbling in your pocket to silence your ringing phone in the cinema 鈥� a quick wave of your hand could now suffice. That鈥檚 thanks to researchers at Deutsche Telekom (DT) in Berlin, Germany, who have developed software that makes it possible to control a cellphone by moving a magnet around near it. It works on devices with a compass sensor, now a standard feature of smartphones such as the Apple iPhone or Google鈥檚 Nexus One.
The DT team鈥檚 software, dubbed MagiTact, tracks changes to the magnetic field around a cellphone to identify different gestures by a hand holding or wearing a magnet. The software scans several times a second for rapid changes in local magnetic fields to ensure that it is picking up on a user鈥檚 moves, not other magnetic fields.
Using MagiTact a user can turn the pages of an on-screen document by moving their hand right to left. A sharp patting motion 10 to 20 centimetres above a device鈥檚 screen is enough to terminate a call. They can also move their hand behind the device to control the zoom on a map without obscuring the screen.
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In early testing, the software recognised volunteers鈥� gestures with 90 per cent accuracy.
Space constraints
鈥淐urrent methods of interaction are usually restricted by the physical boundaries of the device,鈥� says DT researcher . Given the modest proportions of today鈥檚 smartphones, interactions can be fiddly. 鈥淭he idea is to develop a way to interact with mobile devices through more natural human gestures.鈥�
Elsewhere, researchers are attempting to improve touchscreen interaction by, for example, adding a touch-sensitive pad on the back of gadgets, or attempting to make virtual buttons smaller by identifying the angle at which users鈥� fingers typically touch the screen.
鈥淒evices are getting smaller and so eventually it may be impossible to interact with them through touch,鈥� says at the Hasso Plattner Institute in Potsdam, Germany. 鈥淭o take the interaction space off the actual device seems very reasonable because that gives you so much more space and you don鈥檛 occlude the screen anymore.
Ready to go
In October 2009 a team from the Human-Computer Interaction Institute at Carnegie Mellon University in Pittsburgh, Pennsylvania, unveiled a prototype magnet-controlled gadget of their own.
But although it allows similar interaction to MagiTact, it was a one-off research device and not a finished product. The DT team鈥檚 approach works with devices already on the market. In theory, a software application could be released to allow MagiTact interaction with phones already in people鈥檚 pockets.
Ketabdar and his colleagues presented the new technique at this month鈥檚 in Hong Kong, China.
