Effect of haptic and visual information on asymmetric hand motion in a robot-assisted task

In a robot-assisted tele-operation, the operator uses a hand controller to maneuver a tool attached to the robot´s end-effector. The performance in such tele-operation may depend on perceptual information about the operating site as well as the design of the hand-controller. A hand-controller that provides haptic information as force feedback during the interaction in tele-operation may be beneficial in robot-assisted tasks such as robot-assisted surgery. To evaluate the effect of such perceptual information such as visual and haptic information, it is important to analyze their effect on human hand motion and performance in a robot-assisted task. This study examines the effect of visual and haptic information on hand motion and the performance in a robot-assisted tracing task in each of three degrees of freedom (DOF). Our findings reveal that there is a significant asymmetry in performance in each DOF. The effect of force conditions as haptic information is more evident under inadequate visual information during the tracing task. A force condition opposite to the motion direction of the tracing yields best performance in compared to no force or other force conditions. These findings can be useful in designing a hand controller interface that yields optimal performance in robot-assisted tasks.