Micro coils suitable for magnetic neural stimulation

A system, comprising:

• an implantable magnetic neurostimulation probe comprising:
• at least one substrate;
• at least one electrical conductor disposed on the at least one substrate and arranged as at least one planar loop, the at least one electrical conductor configured to produce an electric field sufficient to activate neurons;
• at least one planar magnetic core comprising a magnetic material disposed on the at least one substrate and within the at least one planar loop;
• and
• a biocompatible coating disposed over the at least one substrate, the at least one electrical conductor, and the at least one planar magnetic core;
• and
• an energizer configured to apply an electrical current through the at least one electrical conductor, wherein:
• the at least one electrical conductor is arranged such that the at least one planar loop comprises multiple sections within the at least one planar loop;
• and
• the at least one planar magnetic core comprises multiple magnetic cores, each magnetic core disposed within a respective one of the multiple sections.

An implantable magnetic neurostimulation probe, comprising:

• at least one substrate;
• at least one electrical conductor disposed on the at least one substrate and arranged in at least one planar loop, the at least one electrical conductor configured to produce an electric field sufficient to activate neurons;
• at least one planar magnetic core comprising a magnetic material disposed on the at least one substrate and within the at least one planar loop;
• and
• a biocompatible coating disposed over the at least one substrate, the at least one electrical conductor, and the at least one planar magnetic core, wherein:
• the at least one planar loop comprises multiple planar loops;
• the multiple planar loops are concentric;
• and
• the at least one planar magnetic core comprises multiple magnetic cores, each of the multiple magnetic cores disposed within a respective one of the multiple concentric planar loops.

An implantable magnetic neurostimulation probe, comprising:

• at least one substrate;
• at least one electrical conductor disposed on the at least one substrate and arranged in at least one planar loop, the at least one electrical conductor configured to produce an electric field sufficient to activate neurons;
• at least one planar magnetic core comprising a magnetic material disposed on the at least one substrate and within the at least one planar loop;
• and
• a biocompatible coating disposed over the at least one substrate, the at least one electrical conductor, and the at least one planar magnetic core;
• wherein, when energized by an electric current of about 50 mA through the at least one loop, the probe is configured to produce an excitation volume having a boundary with a radius of about 50 μm such that at an electric field gradient generated by the probe is greater than 11000 V/m2 within the boundary and is less than 11000 V/m2 at and beyond the boundary.

An implantable magnetic neurostimulation probe, comprising:

• at least one substrate;
• at least one electrical conductor disposed on the at least one substrate and arranged in at least one planar loop, the at least one electrical conductor configured to produce an electric field sufficient to activate neurons;
• at least one planar magnetic core comprising a magnetic material disposed on the at least one substrate and within the at least one planar loop;
• and
• a biocompatible coating disposed over the at least one substrate, the at least one electrical conductor, and the at least one planar magnetic core;
• wherein, when energized by an electric current having a predetermined value through the at least one planar loop, the probe has an activation volume with a radius that is up to about 60% less than a radius of an activation volume of an otherwise identical probe without the at least one planar magnetic core that is energized by the predetermined value of the electric current.