Excentric coils for focused neuromagnetic stimulation and biomagnetic detection

Systems utilizing excentric coils for magnetic stimulation or biomagnetic detection are theoretically and experimentally shown to produce clinically desirable focusing effects not possible with conventional designs. In-plane or orthogonal combinations of excentric coils are employed. Opposing coil currents produce field cancellation near the tissue surface thus eliminating undesirable overstimulation. Subcutaneously peaked fields can electronically be controlled in regard to depth and orientation. Other advantages include improved heat carrying, higher pulse repetition rates and, for the biomagnetic detection, lower noise and higher spatial resolution