Video shows computer simulation of current distribution using ‘4 X 1 Ring Configuration (HD-tDCS)

Compared with conventional pads.

Source and more details: http://neuralengr.com/projects/tar
More from CUNY Neural Engineering Group (home of Marom Bikson)
Bio-heat Transfer model of tDCS
High Density Electrodes/Adapters
High-Density Transcranial Electrical Stimulation (HD-TES) Targeting Software Development
And this is interesting. Looks like CUNY is about to spin off another company.
Neuromatters Perhaps the brainchild of Paul Sajda.