Tdcs
Disclaimer
Copying what crazy people do to mess with their brains on the internet is not a good idea. Understand the risks and that there are unknown risks involved with the project, especially if you use it long term. If you just want to give it a try and see what the future might hold, then proceed at your own risk and learn what is involved. This is not a complete guide and don't copy it slavishly, read the latest research and try to improve upon it.
What is this page
This will mainly be my a log of my experiments and a guide if you want to use the equipment in the space --Eb4890 23:03, 7 March 2012 (UTC) Note: Do not contact me if you are the media.
If people are interested in trying it out, you will be expected to read this guide to a sufficient level to be able to assess the risks involved and test the equipment to make sure it is safe to your satisfaction. No proof of safety is given and I'm just experimenting now. Not for people with epilepsy.
Introduction to transcranial direct current stimulation
Neurons are electric devices, they can be stimulated by electricity or electricity can make it easier or harder for them to fire. TDCS is the latter. So it works by having two electrodes and passing a very small current between them. The neurons near the anode (positive) have enhanced firing rates and those near the cathode are depressed (some experiments run this electrode in the shoulder to avoid depressing the brain).
It seems to have effects lasting 5 or so hours and seems to switch on protein production and help with long term memory formation and improving skills. Some people have tried to use it for treating depression. http://www.sciencecodex.com/new_depression_treatment_safe_and_effective-87382
Tests to run through before use/in construction
Make sure you don't suffer from epilepsy or other neural stimulation problems.
Check resistance of the pads soaked with saline (should be below 2K ohms)
Use an ammeter to check the maximum current
To use an ammeter to check current it must be placed in series with the circuit,
Place on an arm or leg, check for tingling, check current flow.
It shouldn't produce phosphenes.
Placing the anodes and cathodes - This will depend on what part of the brain you want to stimulate.
I need to find out about how to prepare the scalp. Ask redd`
How to Make
Making the electrodes Calculating current density - You want fairly low current density between 0.06 and 0.14 mA/cm^2. So with a 2mA source you need an electrode between 14cm and 30cm squared. X is found to be dangerous in rats. You cannot use EEG electrodes so you need to make your own Making the circuit boards Dead man switch? Making saline solution. Water can dissolve 35g per 100ml. You probably want it as high as possible. I ended up with 150g in about 450ml of water.
Todo
- Get more sponge. Sew in the sponge, rather than glueing.
- Test resistance
- Get some lm337z current regulator.
- Make a circuit board in eagle for the dual regulator/pot thing
Recommended reading
http://en.wikipedia.org/wiki/Transcranial_direct-current_stimulation
