gms | German Medical Science

76th Annual Meeting of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery

German Society of Oto-Rhino-Laryngology, Head and Neck Surgery

04.05. - 08.05.2005, Erfurt

Image-guided surgical microscope with integrated minitracker

Meeting Abstract

  • corresponding author Marco Caversaccio - ENT-Department, University Bern, Schweiz
  • Jaime Garcia - MEMcenter, Bern, Schweiz
  • Charles Baur - VRAI-Group, Lausanne, Schweiz
  • Gaetan Marti - VRAI-Group, Lausanne, Schweiz
  • Miguel Gonzalez - MEMcenter, Bern, Schweiz
  • Rudolf Häusler - ENT-Department, University Bern, Schweiz

Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie. 76. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e.V.. Erfurt, 04.-08.05.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05hno414

The electronic version of this article is the complete one and can be found online at:

Published: September 22, 2005

© 2005 Caversaccio et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Surgical microscopy is used in many complex procedures in the area of otorhinolaryngology. Here we present a new imag-guided microscope system using augmented reality image overlays directly added onto one of the views of the operating microscope (Leica M500). With this system, segmented objects, outlines of risk regions or access pathways, previously extracted from preoperative tomographic images can be directly displayed as augmented reality overlays on the microscope image. Unlike other systems that uses an external tracking device, or based on the image information, the novelty of this design consists in mounting a precise mini-tracker (Actracsys, Lausanne) directly on the microscope, in parallel to the optical axis, to track the movements of the surgical tools and the patient. The rigid connection of the tracker with the microscope (Patent Ref. Nr: 0299-001.B.CH-P) eliminates the need to externally track the position of the microscope, thereby bypassing the greatest source of error. Besides the gain in accuracy (theoretical: 0,8 mm; cadaver heads: 1,3mm),

this setup offers an improved ergonomy since the new location of the tracker makes it much easier for the surgeon to keep the line of sight to the tracked objects unobstructed.