Motion assistance and resistance using pseudo-haptic feedback for upper-limb rehabilitation

Diseases such as stroke and proprioception loss may cause inability to control the arm in the activities of daily living. Studies show that intensive motor training with virtual reality games can help patients to restore arm functions. This paper proposes a pseudo-haptic feedback method to add motion assistance or resistance to virtual reality-mediated upper-limb rehabilitation. The alterations to the cursor speed produced by the proposed technique create the illusion of virtual forces providing motion assistance or resistance to the arm movement during rehabilitation training. The proposed method is experimentally evaluated involving human subjects to demonstrate the feasibility. The experimental results reveal that the motion assistance mode is more time-efficient and is claimed to be easier than the motion resistance mode by human subjects. The difficulty of the path following task of virtual reality-mediated upper-limb rehabilitation training can be modulated by the proposed pseudo-haptic feedback method without using any haptic feedback devices.