The scaling of the gripper affects the action and perception in teleoperated grasping via a robot-assisted minimally invasive surgery system

摘要

We use psychophysics to investigate human-centered transparency of graspingin unilateral robot-assisted minimally invasive surgery (RAMIS) without forcefeedback. Instead of the classical definition of transparency, we define here ahuman-centered transparency, focusing on natural action and perception inRAMIS. Demonstrating this approach, we assess the effect of gripper scaling onhuman-centered transparency in teleoperated grasping of rigid objects.Thirty-one participants were divided into three groups, with different scalingbetween the opening of the gripper of the surgeon-side manipulator and thegripper of the surgical instrument. Each participant performed two experiments:(1) action experiment: reaching and grasping of different cylinders; and (2)perception experiment: reporting the size of the cylinders. In two out of threegripper scaling, teleoperated grasping was similar to natural grasping. In theaction experiment, the maximal grip aperture of the surgical instrument wasproportional to the size of the grasped object, and its variability did notdepend on object size, whereas in the perception experiment, consistently withWeber's law, variability of perceived size increased with size. In the finegripper scaling, action and perception variabilities decreased with size,suggesting reduced transparency. These results suggest that in our RAMISsystem, if the gripper scaling is not too fine, grasping kinematics and the gapbetween action and perception are similar to natural grasping. This means thatin the context of grasping, our system induces natural grasping behavior and ishuman-centered transparent. We anticipate that using psychophysics foroptimizing human-centered teleoperation control will eventually improve theusability of RAMIS.