title: New approaches to online estimation of electromagnetic tracking errors for laparoscopic ultrasonography.
abstract: In abdominal surgery, a laparoscopic ultrasound transducer is commonly used to detect lesions such as metastases. The determination and visualization of the position and orientation of its flexible tip in relation to the patient or other surgical instruments can be a great support for surgeons using the transducer intraoperatively. This difficult subject has recently received attention from the scientific community. Electromagnetic tracking systems can be applied to track the flexible tip; however, current limitations of electromagnetic tracking include its accuracy and sensibility, i.e., the magnetic field can be distorted by ferromagnetic material. This paper presents two novel methods for estimation of electromagnetic tracking error. Based on optical tracking of the laparoscope, as well as on magneto-optic and visual tracking of the transducer, these methods automatically detect in 85% of all cases whether tracking is erroneous or not, and reduce tracking errors by up to 2.5 mm.
authors.affiliation: Department of Media Science, Graduate School of Information Science, Nagoya University, Nagoya, Aichi, Japan. fmarco@suenaga.m.is.nagoya-u.ac.jp
authors.forename: Marco
authors.initials: M
authors.lastname: Feuerstein
authors.forename: Tobias
authors.initials: T
authors.lastname: Reichl
authors.forename: Jakob
authors.initials: J
authors.lastname: Vogel
authors.forename: Joerg
authors.initials: J
authors.lastname: Traub
authors.forename: Nassir
authors.initials: N
authors.lastname: Navab
mesh_terms: D002138:Calibration; D055590:Electromagnetic Phenomena; D004868:Equipment Failure; D006801:Humans; D010535:Laparoscopy / Q000379:methods*; D009862:Online Systems; D010865:Pilot Projects; D012372:ROC Curve; D013223:Statistics as Topic; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D018084:Ultrasonography, Interventional / Q000295:instrumentation* / Q000379:methods