title: Three-dimensional (3-D) video systems: bi-channel or single-channel optics?
abstract: OBJECTIVE
  This paper presents the results of a comparison between two different three-dimensional (3-D) video systems, one with single-channel optics, the other with bi-channel optics. The latter integrates two lens systems, each transferring one half of the stereoscopic image; the former uses only one lens system, similar to a two-dimensional (2-D) endoscope, which transfers the complete stereoscopic picture.
  
  
  METHODS
  In our training centre for minimally invasive surgery, surgeons were involved in basic and advanced laparoscopic courses using both a 2-D system and the two 3-D video systems. They completed analog scale questionnaires in order to record a subjective impression of the relative convenience of operating in 2-D and 3-D vision, and to identify perceived deficiencies in the 3-D system. As an objective test, different experimental tasks were developed, in order to measure performance times and to count pre-defined errors made while using the two 3-D video systems and the 2-D system.
  
  
  CONCLUSIONS
  Using the bi-channel optical system, the surgeon has a heightened spatial perception, and can work faster and more safely than with a single-channel system. However, single-channel optics allow the use of an angulated endoscope, and the free rotation of the optics relative to the camera, which is necessary for some operative applications.
authors.affiliation: Section for Minimally Invasive Surgery, Eberhard-Karls-University Tübingen, Germany. patrick@van-bergen.de
authors.forename: P
authors.initials: P
authors.lastname: van Bergen
authors.forename: W
authors.initials: W
authors.lastname: Kunert
authors.forename: G F
authors.initials: GF
authors.lastname: Buess
mesh_terms: D017081:Cholecystectomy, Laparoscopic / Q000295:instrumentation; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D020706:Laparoscopes; D007909:Lenses; D019060:Minimally Invasive Surgical Procedures; D055095:Optics and Photonics; D019047:Phantoms, Imaging; D013525:Surgical Instruments; D014741:Video Recording / Q000295:instrumentation*