Update: Spent a lot of time tracking down the Eldith device today and wherever I found it there was no mention of price. Dave Siever does mention the price and features in comparison to the device his company makes and I thought you might find it interesting. Not sure how much has changed since this was written.
There are presently only two stand-alone devices that produce tDCS. They are: the Eldith DC Stimulator by Neuro Conn, of Germany, which sells for €3000 (about $4,000US) and the CESta, by Mind Alive Inc., of Canada, which sells for $350US. [now $450. + accessories] Both units are current controlled and programmable. The CESta has the added benefits of providing cranio-electro stimulation and micro-electro therapy for muscle work. It also features randomization of the frequency stimulation and usage tracking for patient compliance. The CESta has been “tuned” with the electrodes provided so that at 1 ma stimulation, the active electrode delivers 50 µa/cm2, while the reference electrode produces 18 µa/cm2. This table shows the current density using various sizes at 1 and 2 ma currents.
25 cm2 5 x 5 @ 1 ma = 40 µa/cm2
25 cm2 5 x 5 @ 2 ma = 80 µa/cm2
36 cm2 6 x 6 @ 1 ma = 27 µa/cm2
49 cm2 10 x 10 @ 1 ma = 20.4 µa/cm2
You have to wonder about a tDCS device that doubles as a colloidal silver maker, but in the interest of ‘covering the field’ I wanted to post this video of Mind Alive’s Dave Siever discussing tDCS.
The photos and diagrams used in the talk can be found here. Mind Alive has a large collection of tDCS related papers and articles available to download (zip file of pdfs).
Mind Alive sells a variety of devices including what I believe are called ‘Mind Machines’-devices intended to alter your brainwaves using light and sound. One of their devices, the Oasis Pro can also be used for tDCS.
The system is based on the relationship between the location of an electrode and the underlying area of cerebral cortex. The numbers ‘10’ and ‘20’ refer to the fact that the distances between adjacent electrodes are either 10% or 20% of the total front- back or right-left distance of the skull. Each site has a letter to identify the lobe and a number to identify the hemisphere location.
This is the single example of the frequently sited Eldith device matched to a photo of the device. I’m not sure if perhaps neuroConn changed the name of the device, or…?
Transcranial direct current stimulation (tDCS)
_ Mechanism of action
Contemporary tDCS protocols typically involve the application of a 1 mA or 2 mA direct current (DC) for up to 20 minutes between two surface electrodes. These may vary in size, but are commonly _35cm2 (5×7 cm). The electrodes are placed on the scalp, one serving as the anode and the other as the cathode. Current flows from the anode to the cathode, some being diverted through the scalp and some moving through the brain.15
Figure 2. Eldith transcranial direct current stimulation (tDCS)
stimulator with electrodes. Photo by the author.
Worth reading the whole thread. For this person with Complex regional pain syndrome (CRPS is a chronic pain condition that can affect any area of the body, but often affects an arm or a leg) tDCS seems to be very effective. She mentions it having a positive effect on her Tinnitus as well. Can you imagine the impact if tDCS turned out to be beneficial in treating Tinnitus? I’d like to point out that anyone can say anything on a forum and this post feels a little ‘too good to be true’ to me.
In only one week of treating myself for twenty minutes twice a day my tinnitus has vanished, my teeth clenching due to pain is reduced, my posture is improving, my right hand is no longer clenched. I am no longer sleeping with a bungee cord attached to my wrist and the bottom of my bed to keep my arm from curling up for eight hours at a time. I am able to wear a top for up to an hour and a half. That’s right-I can’t wear anything on my upper body for any extended period of time- which means I am confined to one room of the house with a space heater, only half clothed My range of motion is improving. Yesterday I unloaded the dishwasher for the first time in three years! Typically my body is covered in bruises because of falls. Although I have bruises on my abdomen and legs from a fall prior to beginning treatment about a week ago I have not fallen since I began treatment. By evening I am usually wiped and feeling irritable so I excuse myself and take an epson salts bath. For the past three evenings my husband has enjoyed my company so much that he insists I still take the bath but he comes in the room with me.Two days ago was a most dreary raining and gray day. I looked out the kitchen door and noticed the poison ivy vine curling its way up the downspout. It had been a constant source of aggravation because I could not pull or dig it up. Suddenly is was a gorgeous orange and gold work of art. When I looked past it down the street I noticed the red and gold trees against the gray sky. The were absolutely beautiful. I had not noticed one single color of fall.
Later in the thread she gives more details about the device.
The equipment used for my original treatment at Beth Israel in NYC was an Ionto Phoresis unit by Iomed. By the time I decided to treat myself this particular unit had been discontinued. The unit I use now is advertised as the replacement unit for the Iomed model. The device is a Trivarion Activa Dose Phoresor. The wires needed are standard TENS unit wires. The electrodes are square sponge electrodes, which must be soaked in Saline solution. They are held in place with ace bandages.
Which I believe can be found here. Note that this device is not made specifically for tDCS but is, I believe, an Iontophoresis device. It has a Maximum Voltage of 80V DC! Not something to be fooling around with.
Iontophoresis (a.k.a. Electromotive Drug Administration (EMDA)) is a technique using a small electric charge to deliver a medicine or other chemical through the skin. It is basically an injection without the needle. The technical description of this process is a non-invasive method of propelling high concentrations of a charged substance, normally a medication or bioactive agent, transdermally by repulsive electromotive force using a small electrical charge applied to an iontophoretic chamber containing a similarly charged active agent and its vehicle.
via t.D.C.S. Update Could remission be within my reach and your’s too? – NeuroTalk Support Groups.
This is a paper from Drs. Nitsche and Paulus at the University of Goettingen in 2000. I gather that this paper was responsible for the resurgence of interest in tDCS.
In this paper we demonstrate in the intact human the possibility of a non-invasive modulation of motor cortex excitability by the application of weak direct current through the scalp.
Excitability changes of up to 40 %, revealed by transcranial magnetic stimulation, were accomplished and lasted for several minutes after the end of current stimulation.
Excitation could be achieved selectively by anodal stimulation, and inhibition by cathodal stimulation.
By varying the current intensity and duration, the strength and duration of the after-effects could be controlled.
The effects were probably induced by modification of membrane polarisation. Functional alterations related to post-tetanic potentiation, short-term potentiation and processes similar to postexcitatory central inhibition are the likely candidates for the excitability changes after the end of stimulation. Transcranial electrical stimulation using weak current may thus be a promising tool to modulate cerebral excitability in a non-invasive, painless, reversible, selective and focal way.
We’ll have to wait until June 2013 to read the dissertation however.
…Results from Study 1 using model-free analysis showed that a specific fronto-parietal network at rest was modulated up to a period of 30 minutes outlasting the duration of the stimulation. Further model-based analysis of this fronto-parietal network showed that these differences were driven by network activity primarily involving high frequency gamma band connectivity to and from the supplementary motor area to associated regions left primary motor cortex stimulated region, left prefrontal and parietal cortices. Results from Study 2 showed that the tDCS exerts highly polarity-specific effects on the impact of oscillatory network connectivity, within the functionally relevant fronto-parietal network, on behavioral changes associated with motor learning. These results advance our understanding of neuroplasticity mediated by tDCS and thus, have implications in the clinical use of tDCS for enhancing efficacy of neurorehabilitation in patients with stroke and traumatic brain injury.