Elongated medical devices are disclosed adapted to be inserted through an access pathway into a body vessel, organ or cavity to locate a therapeutic or diagnostic distal segment of the elongated medical device into alignment with an anatomic feature of interest. The first switching element includes a first control terminal, a first electrode terminal, and a first conductor terminal. The tracking coils are disposed in the holder such that virtual center axes for winding coil are set to be substantially perpendicular to the optical axes of the first and second condensing members, and are disposed between the first and second condensing members in a tangential direction. The disclosure describes effective systems for distributed multiclass classification learning on several processors.