Friction force evaluation for grasping in minimally invasive surgery

This study investigates direct and indirect measurement techniques for a typical laparoscopic operation in an ex vivo experiment. The direct measurement technique involves obtaining contact forces at the tissue-tool level. The indirect measurement technique involves acquiring contact forces without compromising the contact surface. The two techniques are compared in terms of the friction force. This estimation is important to ensure that grasping is stable so that tissue sliding is avoided. The results demonstrate that direct measurement is better at measuring the pinch force and estimating the friction force because of the alteration of the force center. However, integration of the tactile sensor into the tool tip increases the pull-off force by approximately 44%.