title: The Trans-Visible Navigator: A See-Through Neuronavigation System Using Augmented Reality.
abstract: BACKGROUND
  The neuronavigator has become indispensable for brain surgery and works in the manner of point-to-point navigation. Because the positional information is indicated on a personal computer (PC) monitor, surgeons are required to rotate the dimension of the magnetic resonance imaging/computed tomography scans to match the surgical field. In addition, they must frequently alternate their gaze between the surgical field and the PC monitor.
  
  
  OBJECTIVE
  To overcome these difficulties, we developed an augmented reality-based navigation system with whole-operation-room tracking.
  
  
  METHODS
  A tablet PC is used for visualization. The patient's head is captured by the back-face camera of the tablet. Three-dimensional images of intracranial structures are extracted from magnetic resonance imaging/computed tomography and are superimposed on the video image of the head. When viewed from various directions around the head, intracranial structures are displayed with corresponding angles as viewed from the camera direction, thus giving the surgeon the sensation of seeing through the head. Whole-operation-room tracking is realized using a VICON tracking system with 6 cameras.
  
  
  RESULTS
  A phantom study showed a spatial resolution of about 1 mm. The present system was evaluated in 6 patients who underwent tumor resection surgery, and we showed that the system is useful for planning skin incisions as well as craniotomy and the localization of superficial tumors.
  
  
  CONCLUSIONS
  The main advantage of the present system is that it achieves volumetric navigation in contrast to conventional point-to-point navigation. It extends augmented reality images directly onto real surgical images, thus helping the surgeon to integrate these 2 dimensions intuitively.
authors.affiliation: Department of Neurosurgery, Jichi Medical University, Yakushiji, Shimotsuke, Tochigi, Japan. Electronic address: eijuwat@gmail.com.
authors.forename: Eiju
authors.initials: E
authors.lastname: Watanabe
authors.affiliation: Department of Neurosurgery, Jichi Medical University, Yakushiji, Shimotsuke, Tochigi, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Satoh
authors.affiliation: Department of Neurosurgery, Jichi Medical University, Yakushiji, Shimotsuke, Tochigi, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Konno
authors.affiliation: Center for Development of Advanced Medical Technology, Jichi Medical University, Yakushiji, Shimotsuke, Tochigi, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hirai
authors.affiliation: Department of Neurosurgery, Jichi Medical University, Yakushiji, Shimotsuke, Tochigi, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery; D002528:Cerebellar Neoplasms / Q000601:surgery; D003131:Combined Modality Therapy; D003196:Computer Graphics; D005260:Female; D018325:Hemangioblastoma / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008579:Meningioma / Q000601:surgery; D008875:Middle Aged; D038361:Neuronavigation / Q000295:instrumentation / Q000379:methods; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods; D019047:Phantoms, Imaging; D014057:Tomography, X-Ray Computed; D014584:User-Computer Interface
keywords: Augmented reality; Motion capture; Navigator; Tablet PC