In clinical medicine, electromagnetic tracking (EMT) system, with its safely penetrating property for human tissue,
has been an effective tracking and guiding method for invaded medical devices which are invisible inside a human body.
However, traditional EMT system only implements magnetic methods to solve the complex 6-DOF equations and
demands an ideal magnetic-field distribution model exited by electromagnetic coils or permanent magnet, resulting in
poor anti-interference performance. This paper proposed a new method, combining EMT with the attitude convergence
algorithm using MARG sensors. This fusion method reduces the information reliability on the external field, simplifies
the complexity of magnetic analysis, and improves the robustness. Except for the accuracy testify experiment, we impose
artificial interference to the DC voltage which excites external electromagnetic coils, and the tracking system could still
maintain a high positioning stability.