Frequently Asked Questions (FAQ)
What is tDCS/tACS?
Transcranial current stimulation is a non-invasive type of brain stimulation where small electric currents are applied to the scalp. Stimulation with a constant current is referred to as transcranial direct current stimulation (tDCS). When a sine-wave stimulation waveform is applied, the term transcranial alternating current stimulation (tACS) is used.
What safety features does XCSITE 100 have?
XCSITE 100 has multiple safety features to ensure safe delivery of electric current. Both output current and voltage are limited by dedicated hardware (think "special fuse") that ensures that high current or voltage are not applied as long as the device is used as intended. The microprocessor at the heart of XCSITE 100 also monitors current and voltage and interrupts stimulation as soon as an abnormally high value is detected. These two features together provide the reassurance you can expect from a high-quality tDCS/tACS device.
What types of double-blind study designs can I do with XCSITE 100?
You have absolute flexibility and can even design studies in which every participant receives a different stimulation paradigm. At the heart of the stimulator is a stimulation configuration file which lists all the stimulation parameters for as many participant codes as you need.
I want to record EEG during tACS!
Unfortunately, recovering the EEG signal during stimulation is very hard and the field has not yet agreed on if this is possible at all. If you want to try to do that, we recommend you use XCSITE 100 since we are soon releasing an extra module to get real-time access to current and voltage (these signals will help your artifact removal algorithm). In addition, you need a superb EEG system with a very high sampling rate (at least 10kHz), additional analog input ports to collect the current and voltage signal from XCSITE 100 (this will help your post-hoc algorithm), and a fantastic input range such that the EEG system does not introduce non-linearities by means of built-in electronics to protect the amplifiers. Contact us if you would like more information on this. But remember, if somebody promises to you that you can routinely and precisely record the EEG during tACS, we advise you ask more probing questions...
How many 9V batteries will I need?
Not to worry. XCSITE 100 is powered by a single rechargeable 9V battery and we provide 10 of them together with a charger for our customers in the early access program. Battery charge indicators can break the blind to the type of stimulation used, therefore interchangeable and replaceable batteries are critical when performing double blind studies.
I am outside the USA - can I still buy your device?
With our CE certification (EN 61010-1:2010) we are able to sell the XCSITE 100 as an investigational device to customers in the EU as well as the USA. We are currently working on our ability to sell the XCSITE 100 to other geographies -- keep in touch with us to receive updates.
Where can I learn more about non-invasive brain stimulation and the study of brain networks in general?
Of course we are biased and recommend the textbook Network Neuroscience written by our very own CSO Dr. Flavio Frohlich.
My question has not been answered!
Sorry! Please contact us by email or on twitter.