Evaluation of noise performance of an electromagnetic image-guided surgery system

In Image Guided Surgery, an electromagnetic tracking system is used 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 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 Std C95.1 and C95.6. The simultaneous transmission of the five coils is possible thanks to frequency division multiplexing. To validate the proposed design, a detailed noise analysis was performed to identify the main contributions to measurement error. Several experimental tests were carried out in different working conditions to identify a suitable model of measurement error and identify main error contributions.