SPATIAL PERCEPTION IN MACROSCOPIC AND MICROSCOPIC SURGICAL MANIPULATIONS - DIFFERENCES BETWEEN EXPERIENCED AND INEXPERIENCED SURGEONS

The spatial perceptions of the phantom surgical field with the naked e ye and under the surgical microscope were analyzed in a group of exper ienced and a group of inexperienced neurosurgeons. The phantom surgica l field contained a start point, a virtual gate, and a target point. T he Virtual gate was an invisible zone arbitrarily set in the phantom s urgical field. The examinees were first instructed regarding the posit ion of the invisible virtual gate. Then they were asked to point conse cutively to the three points with a suction tube under three different circumstances: with the naked eye, under the microscope, and by watch ing a navigation monitor. A surgical navigator was used to record the three-dimensional position of the suction tip. The pointing deviation from the suction tip to the center of the virtual gate was evaluated. The pointing accuracy with the naked eye did not differ between the tw o groups, but that under the microscope was significantly better in th e experienced group than in the inexperienced group. Fluctuations in p ointing deviation were significantly greater in the inexperienced neur osurgeons, especially with the microscope. Further analysis demonstrat ed that these differences were attributable to poorer depth perception of the phantom surgical space among the inexperienced neurosurgeons.