title: Development and testing of an endoscopic pseudo-viewpoint alternating system.
abstract: OBJECTIVE
  An endoscopic system is needed that presents informative images irrespective of the surgical situation and the number of degrees of freedom in endoscopic manipulation. This goal may be achieved with a virtual reality view for a region of interest from an arbitrary viewpoint. An endoscopic pseudo-viewpoint alternation system for this purpose was developed and tested.
  
  
  METHODS
  Surgical experts and trainees from an endoscopic surgery training course at the minimally invasive surgery training center of Kyushu University were enrolled in a trial of a virtual reality system. The initial viewpoint was positioned to approximate the horizontal view often seen in laparoscopic surgery, with [Formula: see text] between the optical axis of the endoscope and the task surface. A right-to-left suturing task with right hand, based on a task from the endoscopic surgery training course, was selected for testing. We compared task outcomes with and without use of a new virtual reality-viewing system.
  
  
  RESULTS
  There was a 0.37 mm reduction in total error ([Formula: see text]) with use of the proposed system. Error reduction was composed of 0.1 mm reduction on the y-axis and 0.27 mm reduction on the x-axis. Experts benefited more than novices from use of the proposed system. Most subjects worked at a pseudo-viewpoint of around 34[Formula: see text].
  
  
  CONCLUSIONS
  Suturing performance improved with the new virtual reality endoscopic display system. Viewpoint alternation resulted in an overview that improved depth perception and allowed subjects to better aim the marker. This suggests the proposed method offers users better visualization and control in endoscopic surgery.
authors.affiliation: Graduate School of Science and Engineering, Waseda University, 59-309, 3-4-1, Okubo, Shinjuku Ward, Tokyo, Japan, yuta-is-here@ruri.waseda.jp.
authors.forename: Y
authors.initials: Y
authors.lastname: Koreeda
authors.forename: S
authors.initials: S
authors.lastname: Obata
authors.forename: Y
authors.initials: Y
authors.lastname: Nishio
authors.forename: S
authors.initials: S
authors.lastname: Miura
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: K
authors.initials: K
authors.lastname: Kawamura
authors.forename: R
authors.initials: R
authors.lastname: Souzaki
authors.forename: S
authors.initials: S
authors.lastname: Ieiri
authors.forename: M
authors.initials: M
authors.lastname: Hashizume
authors.forename: M G
authors.initials: MG
authors.lastname: Fujie
mesh_terms: D003198:Computer Simulation; D004724:Endoscopy / Q000193:education / Q000379:methods*; D006801:Humans; D019060:Minimally Invasive Surgical Procedures / Q000193:education / Q000379:methods*; D014584:User-Computer Interface