Reduced field distortion in medical tools

摘要

A medical tool for operating in a working volume of a magnetic position tracking system includes a first plurality of layers including an electrically conductive material and a second plurality of layers including an electrically insulating material and interleaved with the first plurality. The layers are arranged to reduce eddy current distortion in a magnetic field generated by the magnetic position tracking system. Another medical tool includes a core including a ferromagnetic material and an outer coating layer on the core. The coating layer includes a conductive material configured to produce eddy current distortion so as to cancel at least part of a distortion caused by the core in a magnetic field of the magnetic position tracking system. Yet another medical tool includes an electrically conducting loop-shaped element having an electrical discontinuity introduced therein, so as to reduce eddy current distortion caused by the loop-shaped element.