Accurate Haptic Teleoperation on Soft Tissues through Slave Friction Compensation by Impedance Reflection

Although touch clues are very important during manual surgical procedures, none of the commercial robotic tele-operation systems for soft tissue surgery offer force feedback from the slave robot to the master controller. The search for ideal telemanipulation, whereby the operator feels as if he is manipulating the remote environment directly, is often hampered by the disturbing friction forces in the slave manipulator. These mask and distort the minute interaction forces occurring during manipulation of soft tissues during surgery. In this paper, impedance reflection is put forward as a powerful means to neutralise the negative influence of disturbance forces in the slave manipulator in robotised laparoscopic surgery. Experimental evidence obtained with a Storz endoscopic robot prototype shows that almost ideal force reflection can be achieved, even in the presence of high levels of friction