VibeWalk: Foot-Based Tactons During Walking and Quiet Stance

Comparatively little research exists on rendering vibrotactile patterns, or tactons, to the sole of the foot. However, it may be a natural placement for vibrotactile stimulation for navigation tasks, posture and gait rehabilitation. Similarly, it may be more appropriate to render general haptic feedback to the foot when such vibrations would be distracting if delivered to other body parts. This motivated our development of a custom instrumented haptic insole, which incorporates four actuators, designed to deliver vibrotactile stimulation to the foot. As an initial test, we conducted a user study measuring recognition rates of tactons rendered during quiet stance and gait. Since actuator coupling and foot sensitivity change during gait, our insole uses a proximity sensor to detect footfall, allowing for consistent triggering at a defined point in the gait cycle when the actuators should be best coupled to the sole of the foot. We found that although overall recognition while standing (>92%) is much better than while walking (>66%), the majority of errors are confined to patterns that begin with the same actuator. Our initial evaluation shows promise for application of the insole, such as for sensorimotor rehabilitation and general human-computer interaction.