EEG to tDCS

[SJK]

Hey all,
this is my first post and i'm seeking aid on a project of mine,
any thoughts / comments would be greatly appreciated!

I'm looking to connect an EEG device to a tDCS for purpose of brainwave stimulation,
In theory when the EEG outputs a reading of a specific Hz category (depending on the brain state), it would then trigger the tDCS to emit a specific Hz for short period of time.

This EEG schematic is the one I am confident in building, although I have only had experience in circuitry at a school based level :- see attachments

The questions I really wanted to ask are:-
What materials would be needed to
a) connect the EEG to the tDCS in such a way that when the EEG gave a specific reading it would trigger the tDCS to work its magic for, say half a minute, 30s.

&

The specific circuitry required for such an operation,

Any thoughts/feedback greatly appreciated!
Thank you

Also may I add, i'm looking to bypass any computer connections, such as EEG software etcetera. Having it localized to a single automated device

[pebe]

I am not familiar with this subject, but if your specific requirements are known, then it should be possible to provide an answer.

You mention getting an output from the tDCS to provide something for half a minute, but Wiki describes a tDCS as a source of stimulating current for the brain, rather than a device that can be triggered. Can you be more specific?