Eye gaze of endoscopists during simulated colonoscopy

Regaining orientation during an endoscopic procedure is critical. We investigated how endoscopists maintain orientation based on video and eye gaze analysis. Novices and experts performed a simulated colonoscopy procedure. Task performance was assessed by completion time, total distance traveled, maximum depth of insertion, percentage of mucosa viewed, and air insufflation volume. Procedure videos were analyzed by transfers among three viewing areas: center of bowel lumen, edge of bowel lumen, and other structure without bowel lumen in sight. Performers' gaze features were also examined over these viewing areas. Experts required less time to complete the procedure (P < 0.001). Novices' scope traveled a greater distance (P < 0.001) and more scope was inserted compared to an expert (P < 0.001). Novices also insufflated more air than experts (P < 0.001). Experts maintained the view of bowel lumen in the middle of the screen, while novices often left it on the edge (P = 0.032). When disorientation happened, novices brought the view to the edge more frequently than the center. However, experts were able to bring it back to the center directly. Eye tracking showed that the rate of saccades in experts increased when the bowel lumen moved away from the central view, such a behavior was not observed in novices. Maintaining a centered view of the bowel lumen is a strategy used by expert endoscopists. Video and eye tracking analysis revealed a key difference in eye gaze behavior when regaining orientation between novice and experienced endoscopists.