Compliant force-feedback actuation for accurate robot-mediated sensorimotor interaction protocols during fMRI

We propose and describe two novel force-feedback actuation systems to support accurate robot-mediated wrist motor protocols during fMRI: a co-located actuation approach and a remote actuation system based on a plastic cable-conduit transmission. To decouple the load from the non-linearities of the actuators/transmission and to enable force feedback, in both systems we include physical compliance and additional position and force sensing capabilities. Through a detailed description of the actuators design, we show how the choice between co-located and non co-located actuation influences the design of a wrist exoskeleton, to be used for robot-mediated protocols during fMRI, resulting in a parallel robot design and in a serial robot design respectively.