Using Operator Gaze Tracking to Design Wrist Mechanism for Surgical Robots

This article assessed how surgical robot parameters influenced operator viewpoint during a simulated surgical procedure. Surgical robots are useful tools in minimally invasive surgery. However, even with robots, suturing is difficult because the needle is sometimes obscured by tissue or manipulators and is thus not always visible during the procedure. This is especially true in pediatric surgery, where the surgical environment is smaller than in adult surgery. Hence, surgeons must carefully track the instruments and tissues to understand and predict their current and expected situations. In this article, we used gaze-tracking techniques to analyze the location and timing of the gaze of participants while they manipulated a virtual robotic surgical simulation system. To differentiate between the ideal and actual viewpoint trajectories, we conducted experiments with and without obstacles (i.e., simulated tissue and the manipulator arm). In the obstacle condition, we modulated the wrist length of the manipulator to bring it into view. In the no-obstacle condition, the participants mostly watched the suture needle tip. In the with-obstacle condition, the participants spent less time watching the instruments and more time watching the target point. The amount of time spent watching the target point increased as wrist length increased. Given this tradeoff relationship, we examined the proportion of time the participants spent looking at the instruments or target points by wrist length. We calculated the Pareto solutions and clarified the relationship between wrist length and the watching parts.