Abstract des Autors

We determined the quiet eye (QE) duration, hand movement times (MT) and performance of expert surgeons and novices while they tied one-handed surgical knots. Knot tying is a skill that all surgeons must master, but little is known about the perceptual and cognitive skills needed to perform this critical skill. A long duration QE has been shown to reliably distinguish elite athletes from non-elite and novices, as well as successful from unsuccessful performance. Elite athletes have longer duration of QE on a critical task location prior to performing a final movement. Seven surgeons and five novices tied one-handed square knots while wearing a light mobile eye tracker that simultaneously recorded their gaze and hand movements. Dependent variables were knot tying performance, knot tying duration, hand MT, fixation location, and QE duration. The experts were rated higher than novices in performance, and had faster MTs. Experts allocated 77.9% of their fixations within three degrees (foveal vision) of the knot location and had a significantly longer QE duration placement location on the first throw. In contrast, Novices allocated 49.2% of their fixations within three degrees of the knot location, had a lower QE duration on the first throw, and allocated 50.8% of their fixations to their hands, sutures and surrounding tissue, thus increasing the likelihood of a weaker foundation for the complete knot. Novices first learning to tie knots should be made aware of the importance of a long duration QE on the placement location of the first throw, and be encouraged to reduce the number of fixations on the movement of their hands and the sutures.