Embodiments provide an electrical machine bearing first and second pluralities of permanent magnets having different number of pole pairs, a plurality of pole-pieces that enable the magnetic interaction between the pluralities of permanent magnets, and winding that couples with the firstfundamental harmonic of the first plurality of permanent magnets to enable electromechanical energy conversion. The coarse particles are counted and sized in an optical particle counter. As the drive members continue to rotate in the same direction, the plow is carried along the upper runs of the drive members back to its starting location for another slag-removal cycle. In some embodiments, one or more sensed conditions are used to adjust stimulation parameters. A method includes receiving EEG signals from the subject using a plurality of EEG electrodes positioned extracranially; and recording EEG signals using a recording circuit coupled to said EEG electrodes and contained in an enclosure implanted beneath the subject’s scalp and above the subject’s caldarium.