title: Validation of a new basic virtual reality simulator for training of basic endoscopic skills: the SIMENDO.
abstract: BACKGROUND
  The aim of this study was to establish content, face, concurrent, and the first step of construct validity of a new simulator, the SIMENDO, in order to determine its usefulness for training basic endoscopic skills.
  
  
  METHODS
  The validation started with an explanation of the goals, content, and features of the simulator (content validity). Then, participants from eight different medical centers consisting of experts (> or =100 laparoscopic procedures performed) and surgical trainees (<100) were informed of the goals and received a "hands-on tour" of the virtual reality (VR) trainer. Subsequently, they were asked to answer 28 structured questions about the simulator (face validity). Ratings were scored on a scale from 1 (very bad/useless) to 5 (excellent/very useful). Additional comments could be given as well. Furthermore, two experiments were conducted. In experiment 1, aimed at establishing concurrent validity, the training effect of a single-handed hand-eye coordination task in the simulator was compared with a similar task in a conventional box trainer and with the performance of a control group that received no training. In experiment 2 (first step of construct validity), the total score of task time, collisions, and path length of three consecutive runs in the simulator was compared between experts (>100 endoscopic procedures) and novices (no experience).
  
  
  RESULTS
  A total of 75 participants (36 expert surgeons and 39 surgical trainees) filled out the questionnaire. Usefulness of tasks, features, and movement realism were scored between a mean value of 3.3 for depth perception and 4.3 for appreciation of training with the instrument. There were no significant differences between the mean values of the scores given by the experts and surgical trainees. In response to statements, 81% considered this VR trainer generally useful for training endoscopic techniques to residents, and 83% agreed that the simulator was useful to train hand-eye coordination. In experiment 1, the training effect for the single-handed task showed no significant difference between the conventional trainer and the VR simulator (concurrent validity). In experiment 2, experts scored significantly better than novices on all parameters used (construct validity).
  
  
  CONCLUSIONS
  Content, face, and concurrent validity of the SIMENDO is established. The simulator is considered useful for training eye-hand coordination for endoscopic surgery. The evaluated task could discriminate between the skills of experienced surgeons and novices, giving the first indication of construct validity.
authors.affiliation: Man Machine Systems Group, Faculty of Mechanical, Maritime & Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands. e.g.g.verdaasdonk@wbmt.tudelft.nl
authors.forename: E G G
authors.initials: EG
authors.lastname: Verdaasdonk
authors.forename: L P S
authors.initials: LP
authors.lastname: Stassen
authors.forename: L J
authors.initials: LJ
authors.lastname: Monteny
authors.forename: J
authors.initials: J
authors.lastname: Dankelman
mesh_terms: D000328:Adult; D002983:Clinical Competence; D004724:Endoscopy / Q000193:education*; D004867:Equipment Design; D005260:Female; D013502:General Surgery / Q000193:education; D006176:Gynecology / Q000193:education; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D013647:Task Performance and Analysis; D014584:User-Computer Interface