BACKGROUND: Complex laparoscopic tasks are nearly impossible to complete when the telescope is pointed toward the operator (i.e., paradoxic image). Attempts at image manipulation have been reported, but altered monitor displays may introduce even more confusion. The availability of high-quality, lightweight, head-mounted displays (HMDs) now allows individualization of the laparoscopic image. We studied the effect of manipulation of the paradoxic image on task performance. STUDY DESIGN: Fifteen surgical residents (PGY levels 1-5) were timed while performing the standard "bead pass" skill from the Fundamentals of Laparoscopic Surgery (FLS) course. Conventional diamond-shaped configuration, with telescope and camera in line with the operator and overhead image projection at the opposite end, served as control. A paradoxic image was created by placing the telescope at the opposite side of the box trainer (180 degrees from operator), and the task was repeated with different image corrections: (1) paradoxic image as-is; (2) left-right reversed image (mirror); and (3) left-right reversed and upside-down image (i.e., inverted mirror). Times were recorded and analyzed for intra- and interoperator variance and compared with control. RESULTS: Time-per-bead was 7.5 +/- 1.5 seconds (standard error of the mean) in controls. With the as-is paradoxic image, time-per-bead was 164.1 +/- 80.8 seconds/bead. All but 2 residents failed to complete the task. Times were 120.0 +/- 55.9 seconds/bead for the mirror image and 46.7 +/- 26.0 seconds/bead for the inverted mirror image (P < 0.01; ANOVA and Kruskal-Wallis). CONCLUSIONS: The difficulty of performing a relatively simple laparoscopic task with paradoxic image display was almost insurmountable. Left-right image inversion was not sufficient to correct the handicap. Inverted mirror-image projection significantly improved performance, which almost reached control levels. The availability of personal image-display devices may, in the future, allow image customization for task performance in suboptimal conditions during endoscopic surgery.
BACKGROUND: Complex laparoscopic tasks are nearly impossible to complete when the telescope is pointed toward the operator (i.e., paradoxic image). Attempts at image manipulation have been reported, but altered monitor displays may introduce even more confusion. The availability of high-quality, lightweight, head-mounted displays (HMDs) now allows individualization of the laparoscopic image. We studied the effect of manipulation of the paradoxic image on task performance. STUDY DESIGN: Fifteen surgical residents (PGY levels 1-5) were timed while performing the standard "bead pass" skill from the Fundamentals of Laparoscopic Surgery (FLS) course. Conventional diamond-shaped configuration, with telescope and camera in line with the operator and overhead image projection at the opposite end, served as control. A paradoxic image was created by placing the telescope at the opposite side of the box trainer (180 degrees from operator), and the task was repeated with different image corrections: (1) paradoxic image as-is; (2) left-right reversed image (mirror); and (3) left-right reversed and upside-down image (i.e., inverted mirror). Times were recorded and analyzed for intra- and interoperator variance and compared with control. RESULTS: Time-per-bead was 7.5 +/- 1.5 seconds (standard error of the mean) in controls. With the as-is paradoxic image, time-per-bead was 164.1 +/- 80.8 seconds/bead. All but 2 residents failed to complete the task. Times were 120.0 +/- 55.9 seconds/bead for the mirror image and 46.7 +/- 26.0 seconds/bead for the inverted mirror image (P < 0.01; ANOVA and Kruskal-Wallis). CONCLUSIONS: The difficulty of performing a relatively simple laparoscopic task with paradoxic image display was almost insurmountable. Left-right image inversion was not sufficient to correct the handicap. Inverted mirror-image projection significantly improved performance, which almost reached control levels. The availability of personal image-display devices may, in the future, allow image customization for task performance in suboptimal conditions during endoscopic surgery.