title: On-patient see-through augmented reality based on visual SLAM.
abstract: OBJECTIVE
  An augmented reality system to visualize a 3D preoperative anatomical model on intra-operative patient is proposed. The hardware requirement is commercial tablet-PC equipped with a camera. Thus, no external tracking device nor artificial landmarks on the patient are required.
  
  
  METHODS
  We resort to visual SLAM to provide markerless real-time tablet-PC camera location with respect to the patient. The preoperative model is registered with respect to the patient through 4-6 anchor points. The anchors correspond to anatomical references selected on the tablet-PC screen at the beginning of the procedure.
  
  
  RESULTS
  Accurate and real-time preoperative model alignment (approximately 5-mm mean FRE and TRE) was achieved, even when anchors were not visible in the current field of view. The system has been experimentally validated on human volunteers, in vivo pigs and a phantom.
  
  
  CONCLUSIONS
  The proposed system can be smoothly integrated into the surgical workflow because it: (1) operates in real time, (2) requires minimal additional hardware only a tablet-PC with camera, (3) is robust to occlusion, (4) requires minimal interaction from the medical staff.
authors.affiliation: IRCAD (Institut de Recherche contre les Cancers de l'Appareil Digestif), Strasbourg, France. nader-mahmoud.ali@etu.unistra.fr.|ICube (UMR 7357 CNRS), Université de Strasbourg, Strasbourg, France. nader-mahmoud.ali@etu.unistra.fr.
authors.forename: Nader
authors.initials: N
authors.lastname: Mahmoud
authors.affiliation: IRCAD (Institut de Recherche contre les Cancers de l'Appareil Digestif), Strasbourg, France.
authors.forename: Óscar G
authors.initials: ÓG
authors.lastname: Grasa
authors.affiliation: IRCAD (Institut de Recherche contre les Cancers de l'Appareil Digestif), Strasbourg, France.
authors.forename: Stéphane A
authors.initials: SA
authors.lastname: Nicolau
authors.affiliation: ICube (UMR 7357 CNRS), Université de Strasbourg, Strasbourg, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Doignon
authors.affiliation: IRCAD (Institut de Recherche contre les Cancers de l'Appareil Digestif), Strasbourg, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Soler
authors.affiliation: IRCAD (Institut de Recherche contre les Cancers de l'Appareil Digestif), Strasbourg, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Marescaux
authors.affiliation: Instituto de Investigación en Ingeniería de Aragón (I3A), Universidad de Zaragoza, Saragossa, Spain.
authors.forename: J M M
authors.initials: JM
authors.lastname: Montiel
mesh_terms: D059925:Anatomic Landmarks; D000818:Animals; D034201:Computers, Handheld; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008953:Models, Anatomic; D019047:Phantoms, Imaging; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013552:Swine
keywords: Augmented reality; Operating room; Registration; Surface meshes; Visual SLAM