title: Optimizing the positional relationships between instruments used in laparoscopic simulation using a simple trigonometric method.
abstract: BACKGROUND
  Various methods for evaluating laparoscopic skill have been reported, but without detailed information on the configuration used they are difficult to reproduce. Here we present a method based on the trigonometric relationships between the instruments used in a laparoscopic training platform in order to provide a tool to aid in the reproducible assessment of surgical laparoscopic technique.
  
  
  METHODS
  The positions of the instruments were represented using triangles. Basic trigonometry was used to objectively establish the distances among the working ports RL, the placement of the optical port h', and the placement of the surgical target OT.
  
  
  RESULTS
  The optimal configuration of a training platform depends on the selected working angles, the intracorporeal/extracorporeal lengths of the instrument, and the depth of the surgical target. We demonstrate that some distances, angles, and positions of the instruments are inappropriate for satisfactory laparoscopy.
  
  
  CONCLUSIONS
  By applying basic trigonometric principles we can determine the ideal placement of the working ports and the optics in a simple, precise, and objective way. In addition, because the method is based on parameters known to be important in both the performance and quantitative quality of laparoscopy, the results are generalizable to different training platforms and types of laparoscopic surgery.
authors.affiliation: 1 Bioelectronics Section, Electrical Department, Research and Advanced Studies Center of the National Polytechnic Institute of Mexico , Mexico City, Mexico .
authors.forename: Daniel
authors.initials: D
authors.lastname: Lorias Espinoza
authors.forename: Ricardo
authors.initials: R
authors.lastname: Ordorica Flores
authors.forename: Arturo
authors.initials: A
authors.lastname: Minor Martínez
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Gutiérrez Gnecchi
mesh_terms: D002983:Clinical Competence; D003198:Computer Simulation; D010535:Laparoscopy / Q000295:instrumentation* / Q000592:standards