Friday, June 13, 2014

Introducing The Cognitive Kit


We are excited to offer a new cognitive enhancement device based on tDCS, The Cognitive Kit. The Cognitive Kit is a simple, safe, easy to use kit that provides everything needed for a safe cognitive enhancement session. Included in the $200 is the hand held device, 2 x 9V devices, headband, and 2 x Amrex sponge electrodes. That's right, we believe in safety and comfort so much we have included the best electrodes in the kit.


The Cognitive Kit will be commercially available in mid July, we are not taking pre-orders (don't believe in them), but if you are interested, after you check out the website, email Keith at support@cognitivekit.com and I will keep you informed of the release.

Sales will be North America and internationally. Shipping charges are still being figured out.


Thursday, May 8, 2014

The Electrical Nature of tDCS


When there is a description of a circuit or circuit elements, you see even some of the smartest people become all glazed over, as if the words current or Ohm's Law inexplicably creates a block in understanding (I must admit, the same thing happens to me with probability math, I just can't get my head around it). The concepts of basic circuit theory are indeed simple, and luckily the circuit theory of basic tDCS is indeed straightforward. I will do my best to dispel some confusion about current flow, brain currents, and anode and cathode.

Consider the drawing below, a simple tDCS setup using current regulating diodes. Firstly, this is a DC circuit, none of the values are changing with time. After it is powered up and reached a steady state, it keeps that value. A current can only occur if there is a closed loop, and since there is only one loop, there can only be one current (I).



In most tDCS circuits a current regulating device is used. That means even with varying input voltage (i.e. as the battery changes) and with varying load (i.e. if the head resistance changes due to drying of the sponges or movement changing the electrode position) the current will still remain the same. Now you see why simple current regulating devices (in this case a Current Regulating Diode (CRD)) are perfectly suited for tDCS. What this means that as long as you have a bias voltage, and an appropriate load, the current will be 1mA, and the current will only flow in one direction.

There is confusion about current direction. We electrical engineers like to use current (because algebraic equations can be used to calculate current and voltage), and in the DC situation, current always flows from positive (+) to negative (-). Not to confuse anybody, but charge (and electrons) flow in the opposite direction but that is not relevant here because all circuit elements are best described using current.

All the math you need for this discussion is Ohms law,  V = I x R or I = V/R. What that means is if there is a smaller resistance, the current will be greater and also if there is a resistance and there is a current, there is a voltage drop over that resistance. OK back to tDCS.

Looking at the tDCS schematic above, the 2k Ohm resistor is there to limit the current; if the CRD fails, and there is 18V at the head. The head resistance will vary due to numerous things, but a good range is 2kOhm to 6kOhm. For worst case, use 2 kOhm. So if there is 18V at the head, and the current regulator is not working, then the maximum current can be 4.5mA (18V/4kOhm).  The 2kOhm will also limit the current in fail mode or normal mode if the electrodes are shorted together. During normal functioning, you can short them together and the CRD is still happy to produce 1mA into a 2kOhm load. This also protects the electronics. Obviously shorting together is not something that happens at the head but when the electrodes are taken off or fall off the head when still on and come together on the table or desk.

With tDCS nomenclature, the current flows through the Anode, the positive electrode, through the head to the Cathode, negative electrode (forget electrochemistry, diodes etc.). I, like many people, have wondered how much current really goes through the brain. Since the dura mater, connective tissue, and the skull will be more resistive than the fluid just under the skin you would think that most of the current travels tangentially under the scalp but obviously some current goes in to the brain. What I have read is that the closer together the electrodes, the more current travels under the scalp (which makes sense).

From a physiological view, it is more complicated. The head is not a true resistor (but for the circuit design, it works to make this assumption), as the skin, connective tissue, skull and then brain have a non uniform electrical characteristic. For the effect on the brain, research scientists are more concerned with current density and achieving the best current density. Hence another reason why the nice uniform current density of the sponge electrode is the best choice. The drawing below shows an imaging of current density with a 2mA DC stimulation. The red is the section where current is flowing into the brain and blue is the section where current is flowing out of the brain.



Lastly you can calculate the current density by dividing the current of stimulation by the area of the electrode, but just knowing that there is a sufficient size electrode, the correct connection between electrode and scalp, and limiting the stimulation level to 2 mA, then the current density is not a concern.








Tuesday, April 15, 2014

TDCS and Cognitive enhancement success, anybody want to do a video for $50?


We are preparing a video and application to run an Indiegogo campaign. The campaign will be based on Cognitive Enhancement, TDCS, and its ability to successfully improve mental performance. The funding will go towards development of Plato, a Cognitive Enhancement device based on TDCS. As part of the development of Plato, we will later be doing a feasibility study on its safety and side effects.But now we concentrate on cognitive enhancement.

Cognitive enhancement is an exciting, and somewhat controversial, method of altering ones mental capacities and changing behavior. Possibilities include improving attention and memory which would benefit the test taker; increased alertness and focus which would benefit those striving for an edge in productivity, and learn a skill faster for example learning a new language for a job. The cognitive enhancement dialogue has resided mostly in the pharmaceutical realm. With TDCS the momentum is shifting and we want to be there.

So for our campaign, in our video, we will be describing the usefulness of TDCS, describing Plato, and we would like to include the videos of people that have had benefit and success in using TDCS in a cognitive enhancement or mood altering method.  And if the video is chosen (3 - 4 will be chosen) we will be giving $50 to the lucky participant.

Please send a video:

  • 20s - 30s long
  • Describing your success in using TDCS in enhancing mental performance, improving insight, memory, altering mood etc.
  • We are more interested in the description of benefits, the story, and less interested in the montage, treatment protocol, etc.
  • The better quality videos as well as better content will be chosen. 3 - 4 videos will be chosen and each will given $50.00.
  • Decision will be made in early May.
So tell us your story, take a video, and make some money!

Email me with questions, and instructions how to send the video, to keith@humanbioelectric.com

Sunday, March 23, 2014

The Safety of TDCS



About 15 years ago, when I was deep in my studies to become a Doctor of Naturopathic Medicine (I have a medical background, but now I am an EE, and hope to be a successful businessman in a few years time…) my daily experience was immersed in my studies and my colleagues. The subculture would deceive where we truly were: common health problems were low cholesterol and fatigue, there was little obesity, pharmaceuticals as intervention were only the very last resort. This is the perception I have to be aware of when thinking of the safety of TDCS.

I have been an active participant in DIY TDCS for about two years, initially just practicing, then becoming a little more vocal. And in that community the safety of TDCS is so wholeheartedly believed, known, that there is definitely a risk of accusation if speaking otherwise. But then I step out into the “real world”, with scary descriptions and still the “don’t do this at home” mentality. It is important for someone to have this perspective, it is a new technology and there are still questions, but using scare tactics to disregard the technology, or to mock it, or to attempt to slow its dissemination into the general public is foolish, and maybe immoral.
 
In the research community, the message is similar to the DIY (and much more complicated to read) but definitely more tempered. The work is there: a systematic review on the adverse effects of TDCS found pretty much the same as all the others (39% itching, 22% tingling, 15% headache, 9% burning) (Brunoni 2009). Other papers have similar adverse effects, I have also seen fatigue, the percentages are different, but the adverse effects are similar (a list of some papers below). To be straight, the research is on commercial devices (but not those designed for TDCS), with experienced research personnel running the studies. Not just putting a 9V battery on the head.

But that is the crazy thing about TDCS. People, most likely in the thousands, are putting 9V batteries on their head (hopefully at least through a couple resistors and good electrodes), as well as designing and building simple current regulating circuits to produce real, effective TDCS devices. And the consequences? I have certainly read examples of people saying it is greatly helping with their medical condition, helping them pass exams, learn languages. Is this scientifically proving TDCS, hell no, it is more exciting. It is the beginning of TDCS as it is disseminated through the greater population; psychonauts performing the long term experiments of TDCS that is lacking in the research. These are people experimenting with poor equipment, perhaps making mistakes in their designs or builds, with varied medical conditions, varied personalities (and maybe personality disorders) and the disasters have not occurred (fingers crossed). But despite the scare tactics they are taking the chance and striving nonetheless to better themselves. This is the exciting part.

Arul-Anandam AP, Loo C, Sachdev. Transcranial direct current stimulation - what is the evidence for its efficacy and safety? Medicine Reports 2009, 1:58
 Bikson M, Datta A, lwassif M. Establishing safety limits for transcranial direct current stimulation. Clin Neurophysiol 2009;120(6):1161
 Brunoni AR, Amadera J, Berbel B, Volz MS, Rizzerio BG, Fregni F. A Systematic review on reporting and assessment of adverse effects associated with transcranial direct current stimulation. Int J Neuropsypharm 2011;14:1133-1145
 Iyer MB, Mattu U, Grafman J, Lomarev M, Sato S, Wasserman EM. Safety and cognitive effect of frontal DC brain polarization in healthy individuals. Neurology 2005;64:872-875.
 Nitsche MA, Liebetanz K, Lang N, Antal A, Tergan F, Paulus W. Safety criteria for transcranial direct current stimulation in humans. Clin Neurophysiol 2003; 114(11):2220-2. 
 Poreisz C, Boros K, Antal A, Paulus W. Safety aspects of tDCS concerning healthy subjects and patients. Brain Res Bull 2007;72:208-214.

Sunday, March 9, 2014

The Plato PTSD TDCS Study


Human Bioelectric is excited to announce that we have been developing a hand-held, cognitive enhancement device based on the TDCS technology. TDCS is slowly moving out of its early research stage, and brave early adopter stage where the psychonauts of today do a little research, build a device and become DIY TDCS experimenters. There is a sophisticated, complicated commercial device (somehow legally available) but we thought that it is important to make the TDCS device simpler, easier-to-use, have the important safety features, yet supply flexible TDCS requirements. Meet Plato (ok, this is just the PCB but the cover is cool too). 


Plato provides three levels of regulated current (Low (1.0mA), Med (1.5mA), and High (2.0mA) through 2” x 2” sponge electrodes to minimize tingling and the slight burning that can occur with TDCS. Plato also has an over-current protection and a timeout that turns the current off 20min after you start a treatment.
But TDCS devices are not regulated in the US for commercial or even clinical use. Brain centers, researchers, and some DIY enthusiasts are using iontophoresis devices in an “off label” circumstance. But these devices are not made for TDCS use, the allowable levels of current and voltage are higher than a TDCS device, hence development of a simple TDCS device is important.

To develop a medical device, the first step is often a feasibility study. Hence we are very excited to announce that we will be undertaking a study:

The Safety of Anodal DLPFC direct current stimulation on the PTSD population, a feasibility study for the Plato TDCS device.

Surprisingly there has been little research into using TDCS for the clinical condition of Post Traumatic Stress Disorder. In the research you can find TDCS benefitting depression, chronic pain, improving concentration, and even the down regulation of negative emotional conditions, all of these crucial symptoms in the battle of PTSD. For these conditions, many of the studies use Anodal Dorsolateral Prefrontal Cortex (DLPFC). Hence we will be performing a small study, about 20 people, in the Portland ME area, receiving Anodal DLPFC over a four week period using Plato to provide the TDCS. The study outcomes will be questioning the safety and side effects of the TDCS treatments showing similar results to other TDCS safety studies. But any benefit to the study participants will occur. More details of the study to follow.

And lastly to fund the study we will be starting an Indiegogo campaign in April. More information about Plato and the Plato PTSD Safety study can be found at the website:


And you can stay in touch by following our Facebook or Google+ page.




Everybody’s help will allow us to open an important new tool in the treatment of PTSD and inch forward the regulation of TDCS through an inexpensive easy-to-use device.

Thursday, October 24, 2013

The Uses of TDCS


The dramatic potential benefits of tdcs is just beginning to trickle through our society. Imagine having a tool that has such widespread uses as alleviating depression to helping people learn a language faster, or helping with pain to improving math skills; and this tool is easy to build and still shows little side effects after substantial research. This is transcranial direct current stimulation (tdcs).

As tdcs spreads into the mainstream, people will come up with weird and wonderful uses. I decided to outline some major categories how people may use the technology of tdcs for clinical as well as cognitive enhancement purposes.

1.       From the medical establishment, clinical uses are the most prevalent of course: depression, bipolar (especially with depression), pain, speech disorders, stroke etc. Although some montage prescriptions may be frequent treatments (two or more times per week), the particular montage prescription with a particular condition will most likely have been researched in a small clinical study, so you would think risk is low. On the other hand as people begin to experiment themselves and they may be mixing tdcs treatments with other medications, chance an adverse reaction is greater.
2.     Some people will use tdcs to receive a mental boost on a frequent basis, nearly daily to keep sharp, and keep motivation and mood up. Obviously the chances of side effect are great here. Long term steady use has not been thoroughly studied, and it begs the question, if you use it all the time to maintain some level of personality and performance, what happens when you stop?
3.     Some people are using only for a particular grand task or project: learning a new skill, learning a new language, working on an important project at work. For this situation the person would receive a treatment more frequently (couple times a week or more) when doing the skill or work, and it should improve this skill during the other times. For example someone receiving treatments while studying for the SATs a couple times per week for a few months while studying, could see a better score when they take the SAT without receiving treatment, of course. Personally, this is what I do. Particularly if I have a large writing project to do, I will give myself treatments at early in the day, or the night before, while writing and/or studying about the topic. I feel my writing is more focused and more productive. Since this is generally a shorter period of time, the risk is lower.

I discuss adverse reaction. As more people do tdcs, adverse reactions will happen. someone that is unstable who probably shouldn’t have done it, might hurt somebody, hurt themselves, end up in an ER, and then tdcs will be the culprit. It happens when certain vitamins become popular, and think of the adverse reactions with drug trials…

And lastly, of course, if ever in doubt about a medical condition, consult your doctor before receiving treatments. Also to minimize risk and any side effects, you can start with lower levels of stimulation (1mA or less), and stimulate less frequently (once a week or less). If no side effects or adverse effects are noticed, then you can increase frequency or current amplitude. 

Wednesday, August 14, 2013

A little less Simple DIY TDCS circuit using CRDs

There has been some important points brought up about the benefits (easy to build, robustness) and drawbacks (turn on transients and lack of accuracy) of the Simple DIY TDCS circuit using CRDs. Considering the lack of accuracy, this is a characteristic of the diode not the circuit.

For the E-102, the the datasheet only gives a range of 0.88mA - 1.32mA. But I have seen that there is a higher probability of finding them near 1mA (for example if you test 100 of them most will be between 0.9mA - 1.1mA), with some outliers at the full range. And physiologically, it is still not clear whether 0.9mA will be much different than 1.0mA will be much different than 1.1mA.

Regarding the transients at turn on, that is a circuit issue. So to remedy, it is easy to add an LC filter at the output (see picture below for new schematic). The LC filter acts to dampen any transients. Bench testing shows the ramp up to be 500ms, which is plenty to dampen any turn on pulses, but unfortunately not enough to prevent any flash that occurs with certain montages. At mouser.com, the L can be 22R105C and the C can be UKL1E100KDDANA.







The above explanation is for informational purposes only, and I take no responsibility for the use or intended use of this information. TDCS is currently not FDA regulated, and there is no intention here in providing a TDCS device. Also I suggest you read, read, and read more about TDCS, particularly any safety considerations before undertaking any project like DIY TDCS and contact your health provider if you have any particular questions about your particular condition.

UPDATE

I always attach the electrodes and attach all connections before I turn on at the Battery. Make a switch at the battery and the switch at the battery should be turned on last after the electrodes are attached. If you turn the battery on first, not only will you be putting on hot electrodes but there will be a transient probably higher than 1mA.

For a simple, more foolproof circuit see the Simple DIY TDCS Circuit using CRD's below.