title: Image guidance for all--TilePro display of 3-dimensionally reconstructed images in robotic partial nephrectomy.
abstract: OBJECTIVE
  To determine the feasibility of a novel low-barrier-to-entry image guidance system.
  
  
  METHODS
  Initially a randomized crossover study was performed to establish the interface (iPad or 3-dimensional mouse) that minimized both the amount of time required to perform a manual image registration and the error of that registration. A subsequent clinical feasibility study was undertaken on 5 patients undergoing robot-assisted partial nephrectomy. Randomized crossover study primary outcomes were time to task completion, NASA-Task Load Index score, and alignment error (translational and rotational). The Mann-Whitney U test was used to compare groups. Surgeon feedback was sought when assessing the system in a clinical setting.
  
  
  RESULTS
  In the initial randomized crossover study, the iPad-based system was able to achieve adequate alignment accuracy (Frobenius norm of 0.3; total error of 20.8 mm) in significantly less time (33 seconds; P<.01) than the 3-dimensional mouse interface. The platform received good feedback from the operating surgeon in all instances with the surgeon commenting particularly on the improved appreciation of hilar vascular anatomy.
  
  
  CONCLUSIONS
  In this study, we have demonstrated the feasibility of a "low-barrier-to-entry" image guidance system in a clinical setting. The system was able to achieve swift and sufficiently accurate alignment, with little impact on the surgical workflow.
authors.affiliation: Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
authors.forename: Archie
authors.initials: A
authors.lastname: Hughes-Hallett
authors.affiliation: Hamlyn Centre for Robotic Surgery, Imperial College London, London, United Kingdom.
authors.forename: Philip
authors.initials: P
authors.lastname: Pratt
authors.affiliation: Department of Surgery and Cancer, Imperial College London, London, United Kingdom. Electronic address: e.mayer@imperial.ac.uk.
authors.forename: Erik
authors.initials: E
authors.lastname: Mayer
authors.affiliation: Imperial College Healthcare NHS Trust, London, United Kingdom.
authors.forename: Shirley
authors.initials: S
authors.lastname: Martin
authors.affiliation: Department of Surgery and Cancer, Imperial College London, London, United Kingdom; Hamlyn Centre for Robotic Surgery, Imperial College London, London, United Kingdom.
authors.forename: Ara
authors.initials: A
authors.lastname: Darzi
authors.affiliation: Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
authors.forename: Justin
authors.initials: J
authors.lastname: Vale
mesh_terms: D018592:Cross-Over Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D009392:Nephrectomy / Q000379:methods*; D012371:Robotics; D012984:Software; D025321:Surgery, Computer-Assisted