Spatially distributed tactile feedback for kinesthetic motion guidance

Apraxic stroke patients need to perform repetitive arm movements to regain motor functionality, but they struggle to process the visual feedback provided by typical virtual rehabilitation systems. Instead, we imagine a low cost sleeve that can measure the movement of the upper limb and provide tactile feedback at key locations. The feedback provided by the tactors should guide the patient through a series of desired movements by allowing him or her to feel limb configuration errors at each instant in time. After discussing the relevant motion capture and actuator options, this paper describes the design and programming of our current prototype, a wearable tactile interface that uses magnetic motion tracking and shaftless eccentric mass motors. The sensors and actuators are attached to the sleeve of an athletic shirt with novel plastic caps, which also help focus the vibration on the user's skin. We connect the motors in current drive for improved performance, and we present a full parametric model for their in situ dynamic response (acceleration output given current input).