title: Image inversion and digital mirror-image technology aid laparoscopic surgery task performance in the paradoxical view: a randomized controlled trial.
abstract: BACKGROUND
  As laparoscopic surgical procedures increase in complexity, surgeons may find themselves with the laparoscope opposite to their laparoscopic instruments, thus creating the paradoxical viewpoint. We assessed whether surgical task performance in the paradoxical viewpoint would be improved by digitally altering the image or by changing the camera orientation.
  
  
  METHODS
  Sixty-one laparoscopically naïve operators performed a Peg Transfer task using a trainer box. In the first "round," naïve operators were block-randomized to perform the Peg-Transfer task either in the standard view or the paradoxical view. In the second "round," naïve operators were positioned in the paradoxical view and block-randomized to having the monitor image as paradoxical (n = 19) or altered by being digitally flipped (mirror-image) (n = 22) or inverted (n = 20). The task consisted of transferring six plastic objects in 5 min (300 s). Scoring was based on the formula of total time = time to completion (max = 300 s) + penalty time (50 s/peg not transferred).
  
  
  RESULTS
  In the first round, average total time to perform the Peg Transfer task using the standard view was 215 ± 20 s, which was significantly less (P < 0.001) than the 563 ± 13 s for the paradoxical view. In the second round (with all naïve operators in the paradoxical viewpoint), the total time for the paradoxical image, digitally flipped image (mirror-image), and inverted image were 561 ± 12, 449 ± 25, and 259 ± 37 s, respectively. The total time for the inverted image was significantly less than both the paradoxical image and digitally flipped image (P < 0.001). The total time for the digitally flipped image was also less than paradoxical image (P < 0.05). The group with the paradoxical image completed 0.8 ± 0.2 peg transfers, which was less than both the digitally flipped and inverted-view groups (P < 0.05).
  
  
  CONCLUSIONS
  This is the first study to demonstrate that when in the paradoxical viewpoint, altering the image on the video monitor, either by digitally flipping or inverting the image, can improve surgical task performance.
authors.affiliation: Department of Surgery, University of Alberta, 9-50 Medical Sciences Building, University of Alberta, 114 Street - 89 Avenue, Edmonton, AB, Canada. richdeep@ualberta.ca
authors.forename: Richdeep S
authors.initials: RS
authors.lastname: Gill
authors.forename: David P
authors.initials: DP
authors.lastname: Al-Adra
authors.forename: Harshdeep
authors.initials: H
authors.lastname: Mangat
authors.forename: Haili
authors.initials: H
authors.lastname: Wang
authors.forename: Xinzhe
authors.initials: X
authors.lastname: Shi
authors.forename: Cliff
authors.initials: C
authors.lastname: Sample
mesh_terms: D002983:Clinical Competence; D006801:Humans; D010535:Laparoscopy / Q000193:education / Q000379:methods; D020535:Video-Assisted Surgery; D014796:Visual Perception