SonarWatch: appropriating the forearm as a slider bar

Human bodies become an emerging type of human-computer interfaces recently. Not only because our skin is a surface that is always available and highly accessible, but also the sense of how our body is configured in space allows us to accurately interact with our bodies in an eye-free manner. Hence, this input method is suitable to be applied on extending the interaction space of mobile devices [Harrison et al. 2010] or providing more degrees-of-freedom for enhancing gaming experiences such as Kinect1. Nevertheless, since the additional gesture detector may be obtrusive or not so portable for users, this approach can hardly be applied in everyday life.