Magnetic Tracking Inside Conducting Bores for Radiotherapy Tumor Localization Systems

Magnetic tracking is sensitive to the eddy currents induced on the conducting gantry during radiotherapy tumor localization. We propose a unique magnetic tracking method that can resist the eddy current distortion. Our method uses a specific sensor array to estimate the secondary magnetic field generated from the eddy currents. An optimization procedure is adopted to reduce the distortion effects. A technique of providing the initial guess is also presented to accelerate the convergence of the algorithm. Numerical results demonstrate the effectiveness of our method for tumor localization inside radiotherapy gantry bores.