Teleoperation with sensor/actuator asymmetry: task performance with partial force feedback

For practical application of force feedback in robot-assisted surgical systems, it may not be possible to match the number of degrees of freedom of position sensing and control with the degrees of freedom of force sensing and feedback. The goal of this experimental study is to determine the effect of such sensor/actuator asymmetry during bilateral telemanipulation. We examined the performance of two tool-based teleoperated tasks: (1) a task to push a cup through a series of poses and (2) a blunt dissection task using phantom tissues. Three different force feedback conditions were applied to a 3D teleoperation system: (1) 3D force feedback, (2) force feedback without the axial forces measured on the slave tool, and (3) no force feedback. The tasks were also performed manually using a hand-held stylus. Results show that the absence of measured axial forces does not create a statistically significant difference in the level of applied forces, in comparison with complete 3D force feedback. In addition, this partial force feedback is a significant improvement over teleoperation with no force feedback.