Subject application covers development of automated measurement system with internal microprocessor control for direct measurement of current density within tissue when external electrical currents are applied to the integument. Upon completion of the measurement apparatus and verification of the hypothesis upon which it is based, actual measurements will be made in brain models. Completion of the work with brain models will allow development of a mathematical model for the estimation of current in various brain structures due to such externally applied electrical currents and those used for electroconvulsive therapy, cranial electrical stimulation, etc.