Author's School

School of Engineering & Applied Science

Author's Department/Program

Electrical and Systems Engineering


English (en)

Date of Award

January 2010

Degree Type


Degree Name

Master of Arts (MA)

Chair and Committee

Joseph O'Sullivan


This thesis explores the novel use of a wireless electromagnetic: EM) tracking device in a Computed Tomography: CT) environment. The sources of electromagnetic interference inside a Philips Brilliant Big Bore CT scanner are analyzed. A research version of the Calypso wireless tracking system was set up inside the CT suite, and a set of three Beacon transponders was bonded to a plastic fixture. The tracking system was tested under different working parameters including orientation of tracking beacons, the gain level of the frontend amplifier, the distance between the transponders and the sensor array, the rotation speed of the CT gantry, and the presence/absence of the CT X-ray source. The performance of the tracking system reveals two obvious factors which bring in electromagnetic interference: 1) metal like effect brought in by carbon fiber patient couch and 2) electromagnetic disturbance due to spinning metal inside the CT gantry. The accuracy requirements for electromagnetic tracking in the CT environment are a Root Mean Square: RMS) error of <2 mm in stationary position tracking. Within a working volume of 120×120×120 mm3 centered 200 mm below the sensor array, the tracking system achieves the desired clinical goal.


Permanent URL: