What's around me? Multi-actuator haptic feedback on the wrist

We present the design, implementation and evaluation of a novel wrist-based vibrotactile multi-actuator bracelet, based on a coplanar circular configuration of actuators, for the provision of intuitive and informative haptic feedback for navigation tasks. A two-phase evaluation was conducted in order to assess the perception of the vibrotactile feedback provided by the bracelet and in particular, the ability of users to discriminate a range of vibrotactile patterns. First, a pilot study designed to test perception of different kinds of pattern was conducted with the aim of both refining the pattern design and aiding the choice of a discriminable set of patterns. Second, an identification experiment with the previously chosen set of patterns was conducted with the aim of conveying navigational directions and points of interest to the user. Results highlighted the difficulties in identifying the number of activated actuators as well as their position on the wrist, which subsequently had an impact on the pattern recognition. It was found that one-way horizontal and vertical movements were difficult to perceive correctly, however, less specific movements such as circular or alternating lateral movements and rhythm proved to be suitable parameters for the perception of patterns as long as the patterns were not too similar in design.