Methods and systems for controlling magnetic fields and magnetic field induced current

A system for controlling magnetic fields and induced currents in a target volume inside a brain of a human or animal, the system comprising:

• (a). an array of magnetic coils disposed on an external housing, the array comprising:
• a first set of coils configured to generate a DC magnetic field in the brain;
• and
• a second set of coils configured to generate transient magnetic fields inducing a plurality of currents in brain matter of a patient, wherein the DC magnetic field generated by the first set of coils generates a Lorentz force capable of confining the transient magnetic fields generated by the second set of coils to the target volume within the brain;
• (b). a power source;
• and
• (c). a control system;
• wherein the target volume is smaller than 20% of a full volume of the brain and is disposed at least 2 cm deep under a surface of the brain;
• wherein the currents induced in the target volume are large enough so as to trigger neuronal firing in more than 75% of the target volume;
• wherein the currents induced outside the target volume are small enough so as not to trigger neuronal firing in more than 5% of the brain matter outside the target volume.