Design and in vivo validation of a force-measuring manipulator for MIS providing synchronized video, motion and force data

This paper describes a force-measuring manipulator for minimally invasive surgery. It employs an extracorporeal force measurement system combined with a passive trocar support to deal with the restrictions of a single insertion point in the body. The first contribution is the detailed description of the design and the involved kinematics of the device and the force measurement system, while the second contribution is an extensive performance evaluation including an in vivo animal experiment. During the latter, endoscopic video images were recorded simultaneously with motion and force information of the instrument tip. Breathing effects, contact with other instruments and nonlinear soft tissue stiffness could be detected by the system, indicating its potential as a MIS manipulator and as an in vivo tissue property measurement tool.