title: Optical performance comparison of deflectable laparoscopes for laparoendoscopic single-site surgery.
abstract: OBJECTIVE
  Flexible working angles and fine optical visualization are major requisite factors in performing laparoendoscopic single-site (LESS) urologic procedures. Multiple mechanical design approaches have been used to develop deflectable laparoscopes for LESS procedures. We compared the optical characteristics of three such devices using a bench top approach to simulate LESS in straight and deflected positions.
  
  
  METHODS
  A 10-mm fixed-rod rotating lens device (Storz EndoCameleon) and two 5-mm articulating devices (Olympus EndoEye and Stryker IdealEye) were compared using standard industry testing protocols for image resolution (United States Air Force-1951 test target), distortion (multifrequency grid distortion target), and color reproducibility (Gretag Macbeth color checker).
  
  
  RESULTS
  The 10-mm fixed-rod rotating lens system demonstrated the highest image resolution (5.04 line pairs/mm), but also the highest distortion (22.8%). Among the 5-mm flexible articulating laparoscopes, resolution was superior with the Olympus EndoEye (4.00 line pairs/mm) compared with the Stryker IdealEye (3.17 line pairs/mm). Distortion (7.0%) and color reproduction (1.18) were superior with the IdealEye vs the EndoEye (18.8 %, 1.27). Laparoscope deflection resulted in attenuation of resolution by 11% with both articulating models, but not with the fixed rod system.
  
  
  CONCLUSIONS
  Definition of these optical characteristics may inform further development and selection of laparoscopic systems optimized for LESS surgery. A narrow but flexible camera can be crucial in the limited working space available during these procedures. Further investigation is warranted to determine if these objective findings translate into improved surgeon performance.
authors.affiliation: Department of Urology, Pratt School of Engineering, Duke University Medical Center, Durham, NC 27713, USA.
authors.forename: Zachariah G
authors.initials: ZG
authors.lastname: Goldsmith
authors.forename: Gastón M
authors.initials: GM
authors.lastname: Astroza
authors.forename: Agnes J
authors.initials: AJ
authors.lastname: Wang
authors.forename: W Neal
authors.initials: WN
authors.lastname: Simmons
authors.forename: Muhammad W
authors.initials: MW
authors.lastname: Iqbal
authors.forename: Michael E
authors.initials: ME
authors.lastname: Lipkin
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Preminger
authors.forename: Michael N
authors.initials: MN
authors.lastname: Ferrandino
mesh_terms: D004867:Equipment Design; D006801:Humans; D020706:Laparoscopes / Q000592:standards*; D010535:Laparoscopy / Q000592:standards*; D055620:Optical Phenomena; D015203:Reproducibility of Results