Effects of Scaling and Sequence on Performance of Dynamic Bimanual Path Following Tasks

Bimanual coordination plays a vital role in many haptic and robotic system operations. However, theories in bimanual human motor control are rarely integrated into the control system for human-in-the-loop robots, potentially limiting the usability and collaborative potential between the human and robot, particularly for complex tasks such as robotic surgery. To inform future integration, we investigate unknown manual performance relationships regarding the scaling (the size of one hand’s motions compared to the other) and sequence (the order in which the hands move) of complex bimanual path following tasks. For scaling variations, either the left or right hand desired trajectory amplitude was increased. For sequence, the task was split so that the hands moved sequentially or simultaneously. The experiment is performed by 11 inexperienced, able bodied subjects (all right-handed) in a virtual environment while using haptic devices. Results show significant ([Formula: see text]) decreased manual performance for one hand when the opposite hand is scaled, thus suggesting an increase in the scale of one hand will decrease the performance of the contralateral. Results also show a significant decrease in performance for the left hand when moving simultaneous with the right, but the right hand does not show such a decrease in performance. This might suggest that only the nondominant hand suffers from simultaneous motion conditions. These results may lead to unique opportunities to integrate theories related to human motor control into the control system for haptic and robotic systems used in complex bimanual upper-limb tasks.