ThumbRing: private interactions using one-handed thumb motion input on finger segments

We propose an input device, ThumbRing, for items selection on head-mounted displays (HMDs) or smart glasses. ThumbRing is a ring with an inertial measurement unit (IMU) worn on the thumb to track the motion. By arranging an item to a finger segment, users touch and slide finger segments to select the items. To resist shake in mobile conditions such as walking, another IMU is attached to the back of the hand to compute relative angles between the hand and the thumb. Sliding and touching the segments with the thumb in the hand provide privacy, subtlety, natural haptic feedback and similar input area to smartphones. A pilot study is performed to obtain users' preference finger segments. We evaluate the performance of ThumbRing in different conditions and commitment approaches in a user study. The results show that accuracy are 92.3% and 89.7% in the sitting and walking conditions, respectively.