Most gesture control systems we come across work by either physically measuring the movement of the hand (like with sensors in a glove), or by tracking that movement with cameras and computer vision. Both have fairly obvious drawbacks: wearing sensors on your hand is uncomfortable and conspicuous, and computer vision tracking requires that a camera be mounted somewhere. But, a new proposed technology called EchoFlex might make all of that unnecessary.
New research has shown future wearable devices, such as smartwatches, could use ultrasound imaging to sense hand gestures. (📷: Bristol Interaction Group)
EchoFlex, which is mostly just a concept at this point, would use ultrasound imaging to detect the movement of muscles and tendons in your arm. This would, theoretically, allow gestures to be registered with just a band worn on your arm (like a smartwatch). As the research team from the University of Bristol's Bristol Interaction Group demonstrates, muscle and tendon movement can clearly be seen with ultrasound imaging.