Evaluating remote centers of motion for minimally invasive surgical robots by computer vision

This paper addresses the measurement of the location and precision of stationary points in the three dimensional space, commonly termed remote center of motion (RCM), of minimally invasive surgical robotic manipulators. Two-view computer vision is used for its versatility, portability, remote sensing, and cost effectiveness. Geometrical models of cylindrical tools are constructed from camera images. The RCM is computed from the vectors of the cylindrical tool center lines at multiple poses. To verify the approach, a gold standard spherical bearing is first used to measure the RCM location and precision. The same computer vision system and RCM method is then applied to evaluate the RCM of a commercially available laparoscopy surgical robot.