title: Robot arm based flat panel CT-guided electromagnetic tracked spine interventions: phantom and animal model experiments.
abstract: OBJECTIVE
  To evaluate accuracy and procedure times of electromagnetic tracking (EMT) in a robotic arm mounted flat panel setting using phantom and animal cadaveric models.
  
  
  METHODS
  A robotic arm mounted flat panel (RMFP) was used in combination with EMT to perform anthropomorphic phantom (n = 90) and ex vivo pig based punctures (n = 120) of lumbar facet joints (FJ, n = 120) and intervertebral discs (IVD, n = 90). Procedure accuracies and times were assessed and evaluated.
  
  
  RESULTS
  FJ punctures were carried out with a spatial accuracy of 0.8 ± 0.9 mm (phantom) and 0.6 ± 0.8 mm (ex vivo) respectively. While IVD punctures showed puncture deviations of 0.6 ± 1.2 mm (phantom) and 0.5 ± 0.6 mm (ex vivo), direct and angulated phantom based punctures had accuracies of 0.8 ± 0.9 mm and 1.0 ± 1.3 mm. Planning took longer for ex vivo IVD punctures compared to phantom model interventions (39.3 ± 17.3 s vs. 20.8 ± 5.0 s, p = 0.001) and for angulated vs. direct phantom FJ punctures (19.7 ± 5.1 s vs. 28.6 ± 7.8 s, p < 0.001). Puncture times were longer for ex vivo procedures when compared to phantom model procedures in both FJ (37.9 ± 9.0 s vs. 23.6 ± 7.2 s, p = 0.001) and IVD punctures (43.9 ± 16.1 s vs. 31.1 ± 6.4 s, p = 0.026).
  
  
  CONCLUSIONS
  The combination of RMFP with EMT provides an accurate method of navigation for spinal interventions such as facet joint punctures and intervertebral disc punctures.
authors.affiliation: Applied Medical Engineering, Helmholtz-Institute Aachen, RWTH Aachen University, Pauwelsstr. 20, 52074 Aachen, Germany. penzkofer@rad.rwth-aachen.de
authors.forename: Tobias
authors.initials: T
authors.lastname: Penzkofer
authors.forename: Peter
authors.initials: P
authors.lastname: Isfort
authors.forename: Philipp
authors.initials: P
authors.lastname: Bruners
authors.forename: Christian
authors.initials: C
authors.lastname: Wiemann
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Kyriakou
authors.forename: Willi A
authors.initials: WA
authors.lastname: Kalender
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Günther
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmitz-Rode
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Mahnken
mesh_terms: D000818:Animals; D004574:Electromagnetic Fields; D066298:In Vitro Techniques; D007403:Intervertebral Disc / Q000601:surgery; D008159:Lumbar Vertebrae / Q000601:surgery; D019047:Phantoms, Imaging; D012371:Robotics / Q000295:instrumentation*; D013129:Spinal Puncture; D025321:Surgery, Computer-Assisted; D034421:Sus scrofa; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods