Visual Wrench Reference and Feedback for Robot-Assisted Minimally Invasive Surgery

Wrench feedback for guided Minimally Invasive Surgery (MIS) is described in the paper. A visual wrench diagram scheme is constructed to provide objective, high resolution and accurate feedback for MIS. The six-component wrench vector is characterized entirely through force-moment components on a two-dimensional display. The wrench diagrams are obtained with respect to multiple frames of reference, including target points in the Region of Interest defined on the patient body. Simulated experiments are conducted to display the wrench state in perspective of the target point on the patient body. The capability of wrench diagrams in preserving the historical instants shows the course of the wrench trajectory for supervision and correction. The paper shows that the simultaneity of position and wrench trajectory provides a comprehensive surgical state. Wrench diagrams help to effectively convey the deviation of the actual wrench trajectory from the commanded wrench trajectory.