Development and performance evaluation of an electromagnetic tracking system for surgery navigation

In Image Guided Surgery (IGS), an electromagnetic tracking system is used nowadays to locate surgical instruments in the patient's anatomical 3D model. In this work we illustrate the development and the evaluation of a new Electromagnetic Tracking system (EMTS) able to provide a large tracking volume. The innovation of this proposed EMTS consists in the development of the Field Generator (FG), which includes five properly designed coils. Attention has been paid to the magnetic field generated by each coil in order to comply with the safety limits imposed by IEEE Stds C95.1 and C95.6. The simultaneous transmission of the five coils is possible thanks to a suitable frequency division multiplexing. To validate the proposed design, a detailed noise analysis was performed with several experimental tests in different working conditions with the aim of evaluating measurement errors. Actual performance of the system in reconstructing sensor position has been quantified by using a suitable interpolation technique. In particular, mean position error and standard deviation were evaluated for different distances of magnetic sensor from field generator