RingSense: Exploring User-defined Gestures for Phone Ring Holders

We present RingSense, a phone ring-holder-style device equipped with eight pressure sensors for back-of-device (BoD) interaction on smartphones. The phone ring holder is a ring-type smartphone accessory attached to the back of the smartphone, and RingSense can be easily affixed to the smartphone, similar to a standard smartphone accessory. RingSense serves as both a smartphone input device and a safety accessory for fall prevention. To develop RingSense, we first conducted a gesture elicitation study and created a user-defined gesture set for the phone ring holder. Next, we prototyped RingSense using 8 pressure sensors and a machine-learning-based gesture classification system. We then evaluated our system using the gesture data from 10 participants. Consequently, our system achieved 92.7% accuracy for within-user validation and showed the feasibility of gesture classification by our approach. Finally, we demonstrated some potential applications of RingSense.