(foc.us tDCS headset showing “built-on” electrodes and sponges)
Impressive – But…
I continue to be very impressed with the new foc.us tDCS headset. It brings to the table a huge array of features in a package that is relatively user-friendly (and will become more-so when its iOS and Android apps are available.) If your interest is learning enhancement or treatment of depression, the headset alone is probably all you need. So far, I have found it easy to use and reliable.
The accessory kit adds capabilities for placing electrodes in other locations on the head and shoulders for treatment of chronic pain, experimenting with “savant” learning, and other research projects. In this blog post, I want to briefly summarize the basics of electrode use using the “built-on” and accessory electrodes. I have also included a summary of basic operation for those curious about using the headset (or those having trouble understanding the manual.)
The “built-on” electrodes place the anode above the left eye and high on the left forehead (two sponges.) The cathode is in the same positions but on the right side. These positions, while perhaps not “ideal” in the eyes of some are probably close enough to published locations for learning enhancement and depression treatment for many or most users. For depression, some have a preference for moving the cathode off to the right shoulder, but that requires the accessory kit. The headset itself is quite capable and will probably satisfy the needs of most.
Using the External Electrodes
You have to give foc.us some applause. They designed a LOT of capability in to a fairly inexpensive package. This is the first really versatile tDCS device that has a clean, simple design, has high ease-of-use – and doesn’t cost a fortune as many other “commercial” offerings do. tDCS is now within reach of many more who really need it! For those not satisfied with the built-on electrodes, you can do your own thing for special treatments or research with the accessory kit. It includes necessary wires (and other items) along with a small number of “TENS” style stick-on electrodes.
(Cathode wire plugged into the back of the headset)
Important: The Wires
The kit includes a two-wire (anode & cathode) lead with good length, allowing placement pretty much as you see fit. Uniquely, there is a single wire anode and single wire cathode included too. These are very useful when you want to use the built-on anode (or cathode) and have the opposite charge applied at a different location. As mentioned, for depression, users may prefer the built-on anode, but want the cathode placed on the right shoulder. The single cathode wire makes this simple to do.
(Leads plug in to the back of the headset)
CAUTION: Voltage continues to be available via the built-on electrodes even if one of the accessory leads is plugged in. You will need to remove the appropriate sponges (cathode or anode) when using an accessory wire. So for example, a person seeking to treat depression would leave the anode (left) sponges in place, remove the cathode sponges (right side), and then use the cathode wire to place an electrode on the right shoulder.
If you leave sponges out, you need to be VERY CAREFUL that skin cannot come in contact with the copper plate inside the sponge holder (from an odd skin-wrinkle or tag.) If it does, a burn could result. An accessory CAP of some kind would be a nice safety feature – to cover the unused sponge holders. Perhaps the iOS/Android apps will allow disabling unused built-on electrodes – we’ll have to wait and see. Safety caps would still be a good idea.
CAUTION: The plus and minus marking on the anode and cathode leads is BARELY visible and could easily lead to an error. I suggest MARKING the leads in some much more visible manner (I used red and black zip-ties for the purpose.)
(Can you see the minus sign on the back of the electrode clip?)
(You will want to clearly mark lead polarity. Zip ties work.)
Coming in Part 3
In my next blog post I’ll have more information on operation, use, electrode placements, and more. Please feel free to send along any questions or comment. I’ll try to address those in the next post or two. firstname.lastname@example.org
FYI: Summary of Basic Operation
Make sure the headset is charged
- Switch in “W” position
- Green light indicates charging
Turn it ON
- Flick the switch to the “O” position
- Touch the sensor (center back of the headset) for TWO SECONDS to activate it
- If you touch the sensor for three seconds or longer, the headset enters pairing mode (fine if desired, otherwise, switch to “W” then back to “O” and return to 1. above.)
To BEGIN a tDCS Session Already Configured
- Touch the sensor ONCE
- A four second count-down begins (time to put the headset on!) Current then ramps up to the desired level (more below.)
- Current will automatically ramp down at the end of the session
To END a tDCS Session
- Touch the sensor
- Switch to the “W” position to turn off the headset
Changing Session Settings
- Turn the headset on (switch set to “O”)
- Hold the sensor for two seconds to activate the headset
- Tap the sensor TWICE
- The headset will cycle through its four modes
- DC Sine-Wave – Logo brightness will rise and fall over 5 seconds
- Constant DC (DEFAULT) – Logo remains on for 5 seconds
- Pulsed Current (0.5 mA min) – Logo brightens and dim in 5 seconds
- Random Noise (0.5 mA to max random) – Logo brightness changes erratically
- When the logo reaches the state you desire, touch the sensor ONCE
- Next, the Logo will glow for three seconds at each of the below. Press the Logo to select.
- 2.0 (Only settable for use with external electrodes)
- Once current is set, foc.us headset returns to the ready state. You can begin a tDCS session by touching the sensor ONCE or…
To Confirm Settings
- Touch the sensor THREE times and the above Logo displays will appear for confirmation.
- Touch and hold the sensor for 30 seconds.