title: The PreOp flexible sigmoidoscopy trainer. Validation and early evaluation of a virtual reality based system.
abstract: OBJECTIVE
  To demonstrate face and construct validity of a computer based flexible sigmoidoscopy trainer.
  
  
  METHODS
  The PreOp (Immersion Medical, USA) system is a virtual reality based flexible sigmoidoscopy simulator. The system records several performance parameters, such as percentage of colonic mucosa visualized, time taken, and pathlength of endoscope travel. Forty-five subjects were divided into three groups: novice (never performed a lower GI endoscopy), intermediate (5-50 examinations), and trained (greater than 200 examinations). After initial familiarization subjects were assessed three times on a case module. Results showed a nonparametric distribution.
  
  
  RESULTS
  There was a significant difference between all three groups with respect to percentage of mucosa visualized (novice 71.0 +/- 3.7%, intermediate 77.3 +/- 5.6%, expert 84.8 +/- 4.6%, Kruskal-Wallis p <0.001) and efficiency ratio (%mucosa/time, novice 0.163 +/- 0.055, intermediate 0.259 +/- 0.07, expert 0.306 +/- 0.058, p <0.001). The novice group was also slower and had a lower pathlength of instrument travel compared to the others.
  
  
  CONCLUSIONS
  PreOp virtual reality simulator is a valid discriminator of flexible sigmoidoscopic experience. Its effect on training needs to be explored.
authors.affiliation: Department of Surgical Oncology and Technology, Imperial College School of Medicine at St. Mary's, London, United Kingdom. v.datta@ic.ac.uk
authors.forename: V
authors.initials: V
authors.lastname: Datta
authors.forename: M
authors.initials: M
authors.lastname: Mandalia
authors.forename: S
authors.initials: S
authors.lastname: Mackay
authors.forename: A
authors.initials: A
authors.lastname: Darzi
mesh_terms: D002983:Clinical Competence; D004501:Education, Medical / Q000379:methods*; D013502:General Surgery / Q000193:education*; D006801:Humans; D010820:Physicians; D020694:Sigmoidoscopes; D012812:Sigmoidoscopy; D006113:United Kingdom; D014584:User-Computer Interface