Force controlled and teleoperated endoscopic grasper for minimally invasive surgery - Experimental performance evaluation

Minimally invasive surgery generates new user interfaces which create visua l and haptic distortion when compared to traditional surgery. In order to r egain the tactile and kinesthetic information that is lost, a computerized force feedback endoscopic surgical grasper (FREG) was developed with comput er control and a haptic user interface, The system uses standard unmodified grasper shafts and tips. The FREG can control grasping forces either by su rgeon teleoperation control, or under software control. The FREG performanc e was evaluated using an automated palpation function (programmed series of compressions) in which the grasper measures mechanical properties of the g rasped materials. The material parameters obtained from measurements showed the ability of the FREG to discriminate between different types of normal soft tissues (small bowel, lung, spleen, liver, colon, and stomach) and dif ferent kinds of artificial soft tissue replication materials (latex-silicon e) for simulation purposes. In addition, subjective tests of ranking stiffn ess of silicone materials using the FREG teleoperation mode showed signific ant improvement in the performance compared to the standard endoscopic gras per. Moreover, the FREG performance was closer to the performance of the hu man hand than the standard endoscopic grasper, The FREG as a tool incorpora ting the force feedback teleoperation technology may provide the basis for application in telesurgery, clinical endoscopic surgery, surgical training, and research.