TDCS: Difference between revisions

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(→‎Other Resources: journalist experience of TDCS)
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*link to that great website with the videos.
*link to that great website with the videos.
*anyone else have spec online?
*anyone else have spec online?
* Journalist becomes a hardened killing machine on [http://www.lastwordonnothing.com/2012/02/09/better-living-through-electrochemistry/ TDCS].


[[Category:Neuro]]
[[Category:Neuro]]

Revision as of 11:45, 22 May 2012

This is a page skeleton for some new projects we're going to document here! Feel free to fill shit in. --Hurtstotouchfire 21:16, 7 May 2012 (UTC)

Transcranial Direct Current Stimulation

Wikipedia, bitches. For the record, the acronyms tDCS and TDCS are both in use in academia, and I think the former is stupid because they're just trying to be cool like iPhones and fMRI. The word transcranial is obviously abbreviated, and when we abbreviate words in an acronym, we capitalize them. So if you move this page to tDCS, I will move it back. --Hurtstotouchfire 01:14, 12 May 2012 (UTC)

Academic publications

The best collection of academic study abstracts is here. (note that we should snatch this and put a copy somewhere, since we have no clue who this dropbox account belongs to or how long access will stay stable. The file has credit within, so I don't think it's evil. I will try to remember to email the creator and make sure he has no issues with same) - JPW

There are quite a few other abstracts from more recent work that aren't included here, including the stuff from the most recent big neuro yearly powwow in DC. (Kelly, do you still have the links to those papers from the military guys at Wright-Patterson?) - JPW

I have no crapping idea. --Hurtstotouchfire 01:14, 12 May 2012 (UTC)

Anecdotes

  • link to reddit thread here.

Spec

The basic circuit for TDCS is ridiculously simple. We are creating a 2ma DC current and running it through 2 inch square or round electrodes that are then connected to the human body. There are various configurations that can be used to place the pads, but the most common is placing the active electrode over the area of the skull corresponding to the brain region to be effected and the other electrode, called the return electrode, is placed on the opposite shoulder. Using the anode, or positive electrode, over the brain will stimulate the target region. The cathode, or negative electrode, will retard the brain region. A standard simulation time in most research is 20 minute sessions. The effect, depending on the type of stimulation and region seems to last up to an hour after the stimulation is removed. Again, depending on the type and location of the stimulation, repeated exposure daily for up to 9 sessions can cause the effects to persist for 30 days or longer in depression studies.

The simplest working circuit for this is a pair of 9v batteries in series, an LM334 current limiter and a fixed resistor across the LM334 reference and output to set the 2ma limit. A better circuit involves replacing the fixed resistor with a 200 ohm pot and adding an ammeter anywhere in series. One of the better designs of this nature is located here. Although the fuse in the circuit is of unlikely utility in reality.

A fairly simple, slightly unsafe and highly voltage limited arduino project that is somewhat clever is located here.

The cadillac of designs here would probably look something like an arduino controlling a SPI variable resistor connected to an LM334 for current control, another LM334 with a fixed resistor to provide failure protection (a fuse is going to blow too slowly and fuses that small are expensive and difficult to source), a shunt ammeter connected back to the Arduino and a display/input to allow the user to set different times, current levels, sham stimulation and so on. Also we would want to put a boost transformer on the battery supply in order to boost the output voltage being used. Discussion of why we want to up the voltage here will happen in the section on electrodes.

(need to add a long discussion about electrodes here, since there is more complexity in the electrodes than the circuit itself)

Other Resources

  • link to that great website with the videos.
  • anyone else have spec online?
  • Journalist becomes a hardened killing machine on TDCS.