Just because it’s come up quite a bit lately on the tDCS subReddit , I thought to re-publish this link to a talk Jamie Tyler gave just prior to the release of their device, where he explains his understanding of what’s going on, as well as their intentions. Jamie’s intro starts at 45:46. He begins his explanation of how Thync’s device works at 52:46.
Thync paper referenced in talk: http://biorxiv.org/content/early/2015/06/03/015032
Thync patent application: https://www.google.com/patents/US20140148872?dq=thync
(My Notes: FDA, ‘limited output’, exempt from pre-market notification, or 510 k process. Below average current of 10mA, current density below 2mA per square centimeter.)