A novel spatial-temporal encoding strategy for presenting time on the wrist using vibrotactile cues

Presenting time accurately with a high resolution using haptic modality on the wrist is a challenging task. In this paper, we present a novel spatial-temporal vibrotactile encoding strategy using 4 motors for presenting time. The hours and minutes were presented using vibrotactile stimuli with a resolution of 5 minutes. The hours were presented by long duration vibrations while the minutes were presented by short duration vibrations. To validate the design we conducted two experiments and measure the reaction time and the correct rate of 12 participants for perceiving the time in the presence of audio-visual distraction. In the first experiment, the hours and the minutes were presented in the focused state. The average reaction time and the correct rate of the users were 9.60sec and 95.22% respectively. In the second experiment, the hours and the minutes were presented in the distracted state. The average reaction time and the correct rate of the users were 11.09sec and 90.55% respectively. This performance was achieved after ten minutes training. These results indicate the potential of using wrist-based haptic sensation to present time.