Accuracy of electromagnetic tracking with a prototype field generator in an interventional OR setting.
OBJECTIVE
The authors have studied the accuracy and robustness of a prototype electromagnetic window field generator (WFG) in an interventional radiology suite with a robotic C-arm. The overall purpose is the development of guidance systems combining real-time imaging with tracking of flexible instruments for bronchoscopy, laparoscopic ultrasound, endoluminal surgery, endovascular therapy, and spinal surgery.


METHODS
The WFG has a torus shape, which facilitates x-ray imaging through its centre. The authors compared the performance of the WFG to that of a standard field generator (SFG) under the influence of the C-arm. Both accuracy and robustness measurements were performed with the C-arm in different positions and poses.


RESULTS
The system was deemed robust for both field generators, but the accuracy was notably influenced as the C-arm was moved into the electromagnetic field. The SFG provided a smaller root-mean-square position error but was more influenced by the C-arm than the WFG. The WFG also produced smaller maximum and variance of the error.


CONCLUSIONS
Electromagnetic (EM) tracking with the new WFG during C-arm based fluoroscopy guidance seems to be a step forward, and with a correction scheme implemented it should be feasible.
Department of Medical Technology, SINTEF Technology and Society, Trondheim, Norway. lars.eirik.bo@sintef.no
Lars Eirik
LE
Bø
Håkon Olav
HO
Leira
Geir Arne
GA
Tangen
Erlend Fagertun
EF
Hofstad
Tore
T
Amundsen
Thomas
T
Langø
D004867:Equipment Design; D019544:Equipment Failure Analysis; D008280:Magnetics / Q000295:instrumentation*; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D013525:Surgical Instruments