Design and experimental evaluation of a skin-stretch haptic device for improved control of brain-computer interfaces

Robotic systems, such as prosthetics and exoskeletons, offer people suffering from motor impairments a chance to regain lost physical functionality. However, the neural control that individuals are able to exert over these robots is currently limited. This is due to both lack of control authority in many degrees of freedom and insufficient sensory feedback through the human-robot interface. We propose that haptic feedback is paramount for accurate and efficient control of robots via brain-computer interfaces (BCIs). Skin stretch at the fingertip is a novel form of haptic feedback for improving BCI-based robot control. In this paper, we describe the design of a BCI-driven skin-stretch device, assess several control paradigms for this device, and evaluate its effectiveness in a small user study. We show that BCI-based movement-intent classification improved in the presence of skin-stretch feedback for 3 of 4 healthy individuals controlling a computer cursor via an inexpensive, commercial electroencephalography-based (EEG) BCI.