The Electric Field Induced by a Microcoil During Magnetic Stimulation

Objective:
The purpose of this study is to calculate the electric field produced by an implanted microcoil during magnetic stimulation of the brain.
Methods:
The electric field of a microcoil was calculated numerically.
Results:
The maximum value of the induced electric field is approximately 0.000026 V/m for a 1 mA, 3 kHz current passed through the coil.
Conclusion:
This electric field value is too small to cause neural stimulation.
Significance:
Previous studies reporting magnetic stimulation using a microcoil must have been exciting neurons by some other mechanism.