title: Orientation strategies in natural orifice translumenal endoscopic surgery.
abstract: OBJECTIVE
  The aims of this study were to (1) describe the visual attention strategies employed by surgeons that are associated with high performance in reorientation and (2) identify key structures guiding attention deployment of the surgeon in the process of self-orientation in common clinical natural orifice translumenal endoscopic surgery (NOTES) scenarios.
  
  
  BACKGROUND
  Disorientation has been identified as one of the major barriers to be overcome before widespread clinical NOTES uptake. Understanding disorientation requires description of key perceptual-motor factors leading to disorientation, assessment of their relative impact, and quantification of navigation performance.
  
  
  METHODS
  Twenty-one surgeons were shown a series of 8 images acquired during human NOTES operations from the flexible endoscope from different perspectives to induce disorientation. Gaze behavior was recorded using an eye tracker as the subjects were asked to establish the image orientation. Main outcome measures were times taken to establish orientation, eye-tracking parameters, and fixation sequences on organs and structures/regions of interest (ROI).
  
  
  RESULTS
  High-performance subjects had a lower number of fixations and normalized dwell time per ROI compared with others, suggesting a more structured and focused approach to orientation. Orientation strategies associated with high performance were described using a validated algorithm for comparing visual reorientation behavior and amount of visual attention on individual ROIs in each scenario were quantified. Key areas of organs and structures during reorientation were illustrated using dwell time normalized visual maps.
  
  
  CONCLUSIONS
  Targeted orientation strategies revealed in this study are expected to aid in decreasing the learning curve associated with NOTES and increase performance even for experienced surgeons and gastroenterologists. Crucially, these data can provide guidance for designing orientation friendly NOTES platforms.
authors.affiliation: Department of Biosurgery and Surgical Technology, Imperial College London, London, United Kingdom. m.sodergren@imperial.ac.uk
authors.forename: Mikael H
authors.initials: MH
authors.lastname: Sodergren
authors.forename: Felipe
authors.initials: F
authors.lastname: Orihuela-Espina
authors.forename: Peter
authors.initials: P
authors.lastname: Mountney
authors.forename: James
authors.initials: J
authors.lastname: Clark
authors.forename: Julian
authors.initials: J
authors.lastname: Teare
authors.forename: Ara
authors.initials: A
authors.lastname: Darzi
authors.forename: Guang-Zhong
authors.initials: GZ
authors.lastname: Yang
mesh_terms: D000465:Algorithms; D001288:Attention; D004867:Equipment Design; D005260:Female; D006801:Humans; D007396:Internship and Residency; D008297:Male; D008875:Middle Aged; D057605:Natural Orifice Endoscopic Surgery / Q000193:education / Q000295:instrumentation / Q000379:methods*; D009949:Orientation; D010529:Peritoneal Cavity / Q000033:anatomy & histology* / Q000601:surgery*; D013028:Space Perception; D018709:Statistics, Nonparametric; D014796:Visual Perception