Control of a mechatronics-assisted system for surgeries using flexible tools

Flexible and lightweight surgical tools have the potential to significantly increase the dexterity of mechatronics-assisted surgical systems for minimally invasive surgeries. However, the control of a mechatronics-assisted system with the link and joint flexibility is quite challenging and needs to be studied. In this paper, a bilateral impedance-controlled master-slave teleoperation system is considered, where the slave (surgical) robot is flexible. Two reference impedance models are designed for the master and slave robots to control the mechatronics-assisted system. Also, depending on different feedback and feedforward signals, four cases are distinguished. To obtain better transparency of the system, the tuning rules for the impedance parameters for each case are presented and the corresponding transparency measures are analyzed and compared. As a result, by appropriately adjusting the impedance model parameters, ideal position and force tracking can be attained for a teleoperation system with a flexible surgical robot. The theoretical findings are validated in simulations.