title: Development and testing of a tethered, independent camera for NOTES and single-site laparoscopic procedures.
abstract: BACKGROUND
  "Tunnel vision" associated with endoscopes used in NOTES and laparoscopes used in laparoendoscopic single-site surgery (LESS) procedures present the surgeon with a disorienting view of familiar surroundings. Given the in-line arrangement of the devices, it is difficult to achieve adequate triangulation, a critical component of successful surgical technique. A potentially more useful vantage point would be from above, looking down at the surgical field, i.e., "stadium view." The purpose of this study was to develop stadium-view camera prototypes for evaluation.
  
  
  METHODS
  Cylindrical (15 mm diameter, 30 mm length) imagers were built using white light LEDs for illumination and a near-VGA resolution CMOS camera. These prototypes were delivered to the abdominal cavity through an overtube (Steerable Flex Trocar (SFT)); the electronic tether for power and video signal was pulled through the abdominal wall using a 2-mm rigid grasper. The prototypes were attracted to the abdominal wall magnetically. Clinicians performed the procedures in IACUC/Home Office-approved porcine labs.
  
  
  RESULTS
  Introduction of the device into the peritoneal cavity and magnetic coupling to the abdominal wall were straightforward. Illumination was adequate to provide reasonable imagery of nearby abdominal organs. Bowel was successfully sutured laparoscopically under visualization provided by the prototype. All points on the abdominal wall could be reached via the magnetic control, and the camera could be successfully aimed through abdominal palpation. Retrieval was uncomplicated.
  
  
  CONCLUSIONS
  The prototypes provide the clinician a point of view similar to that of a traditional laparoscope, although the image quality needs improvement. The stadium view helps to overcome limitations associated with in-line visualization and working tools. Use of such a camera in NOTES or LESS could enable reduction of the number/size of ancillary trocars, reduce the size of the LESS port, and/or increase the number of working devices that can be deployed.
authors.affiliation: Department of Surgical Oncology and Technology, Imperial College, London, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Swain
authors.forename: Ralph
authors.initials: R
authors.lastname: Austin
authors.forename: Kurt
authors.initials: K
authors.lastname: Bally
authors.forename: Robert
authors.initials: R
authors.lastname: Trusty
mesh_terms: D000818:Animals; D004867:Equipment Design; D007089:Image Enhancement / Q000295:instrumentation*; D020706:Laparoscopes; D010535:Laparoscopy / Q000379:methods*; D013552:Swine