tDCS Device Comparison

What is Important in a tDCS Device

When choosing a tDCS device it is important to check for these essential features.
• Build Quality - The highest quality consumer devices are professional grade.
• Accurate Current Delivery - Does the device have enough power (minimum 20 volts max output) to provide an accurate current delivery with varying skin resistances?
• Automatic Current Ramp Up / Down - Does the device gradually increase and decrease the current automatically to allow your skin to accommodate to the sensation of stimulation?
• Built-in Timer - Does the device automatically ramp down and shut off after your pre-set amount of time?
• Low Battery Indicator - Does the device let you know when the battery is too low to complete a session?

What is consumer tDCS? Consumer tDCS devices are marketed directly towards users. They can be marketed simply as “tDCS” or for cognitive enhancement or for performance enhancement. They cannot be marketed for medical use, such as the treatment of a disease, since then they would be classified as medical devices. Once a consumer obtains a device, they can use their device for for any application. Consumer devices are cheaper then research grade devices. The FDA has provided letters to companies like Thync and Halo; allowing them to market tDCS for consumer purposes without making claims on medical therapy. The highest quality consumer devices are professional grade.

What is research grade tDCS? Research devices are those marketed for use in clinical trials. Research devices used in clinical trials must see the same design and manufacturing standards as professional devices. This means, according to regulations in the US, Europe and other countries, devices tested on people need to be built to professional devices standards, even when they are not yet approved for use. For this reason, professional and research grade devices are the same thing as far the devices themselves. The difference is simply how they are marketed. For example, the Soterix Medical 1x1 tDCS is marketed in the US for research but is approved and marketed in Europe for the treatment of depression, pain (migraine, fibromyalgia) and stroke rehabilitation.

What is HD-tDCS? HD-tDCS stands for High Definition transcranial Direct Current Stimulation. Regular tDCS uses relatively large electrodes (about 5x5 cm) while HD-tDCS uses relatively small electrodes (about 1x1 cm) which are gel filled. HD-tDCS is found only on Research / Professional grade devices. HD-tDCS can be used with EEG to record brain activity.

References

Limited output transcranial electrical stimulation (LOTES-2017): Engineering principles, regulatory statutes, and industry standards for wellness, over-the-counter, or prescription devices with low risk. Bikson M, Paneri B, Mourdoukoutas A, Esmaeilpour Z, Badran BW, Azzam R, Adair D, Datta A, Fang XH, Wingeier B, Chao D, Alonso-Alonso M, Lee K, Knotkova H, Woods AJ, Hagedorn D, Jeffery D, Giordano J, Tyler WJ. Brain Stimul. 2018 Jan - Feb;11(1):134-157. doi: 10.1016/j.brs.2017.10.012. Epub 2017 Oct 17.

A pragmatic analysis of the regulation of consumer transcranial direct current stimulation(TDCS) devices in the United States. Wexler A. J Law Biosci. 2015 Oct 12;2(3):669-696. eCollection 2015 Nov. PMID: 27774217

The off-label use, utility and potential value of tDCS in the clinical care of particular neuropsychiatric conditions. Bikson M, Paneri B, Giordano J. J Law Biosci. 2016 Sep 10;3(3):642-646. doi: 10.1093/jlb/lsw044. eCollection 2016 Dec. No abstract available. PMID: 28852542

Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines. Antal A, Alekseichuk I, Bikson M, Brockmöller J, Brunoni AR, Chen R, Cohen LG, Dowthwaite G, Ellrich J, Flöel A, Fregni F, George MS, Hamilton R, Haueisen J, Herrmann CS, Hummel FC, Lefaucheur JP, Liebetanz D, Loo CK, McCaig CD, Miniussi C, Miranda PC, Moliadze V, Nitsche MA, Nowak R, Padberg F, Pascual-Leone A, Poppendieck W, Priori A, Rossi S, Rossini PM, Rothwell J, Rueger MA, Ruffini G, Schellhorn K, Siebner HR, Ugawa Y, Wexler A, Ziemann U, Hallett M, Paulus W. Clin Neurophysiol. 2017 Sep;128(9):1774-1809. doi: 10.1016/j.clinph.2017.06.001. Epub 2017 Jun 19. Review. PMID: 28709880

Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016. Bikson M, Grossman P, Thomas C, Zannou AL, Jiang J, Adnan T, Mourdoukoutas AP, Kronberg G, Truong D, Boggio P, Brunoni AR, Charvet L, Fregni F, Fritsch B, Gillick B, Hamilton RH, Hampstead BM, Jankord R, Kirton A, Knotkova H, Liebetanz D, Liu A, Loo C, Nitsche MA, Reis J, Richardson JD, Rotenberg A, Turkeltaub PE, Woods AJ. Brain Stimul. 2016 Sep-Oct;9(5):641-61. doi: 10.1016/j.brs.2016.06.004. Epub 2016 Jun 15. Review. PMID: 27372845

Outstanding questions concerning the regulation of cognitive enhancement devices. De Ridder D, Vanneste S, Focquaert F. J Law Biosci. 2014 Sep 19;1(3):316-321. eCollection 2014 Sep. PMID: 27774170

Early adopters of the magical thinking cap: a study on do-it-yourself (DIY) transcranial direct current stimulation (tDCS) user community. Jwa A. J Law Biosci. 2015 Jun 2;2(2):292-335. eCollection 2015 Jul. PMID: 2777419

A technical guide to tDCS, and related non-invasive brain stimulation tools. Woods AJ, Antal A, Bikson M, Boggio PS, Brunoni AR, Celnik P, Cohen LG, Fregni F, Herrmann CS, Kappenman ES, Knotkova H, Liebetanz D, Miniussi C, Miranda PC, Paulus W, Priori A, Reato D, Stagg C, Wenderoth N, Nitsche MA. Clin Neurophysiol. 2016 Feb;127(2):1031-1048. doi: 10.1016/j.clinph.2015.11.012. Epub 2015 Nov 22. Review. PMID: 26652115

Noninvasive techniques for probing neurocircuitry and treating illness: vagus nerve stimulation(VNS), transcranial magnetic stimulation (TMS) and transcranial direct current stimulation(tDCS). George MS, Aston-Jones G. Neuropsychopharmacology. 2010 Jan;35(1):301-16. doi: 10.1038/npp.2009.87. Review. PMID: 19693003

Regulatory Considerations for the Clinical and Research Use of Transcranial Direct Current Stimulation (tDCS): review and recommendations from an expert panel. Fregni F, Nitsche MA, Loo CK, Brunoni AR, Marangolo P, Leite J, Carvalho S, Bolognini N, Caumo W, Paik NJ, Simis M, Ueda K, Ekhitari H, Luu P, Tucker DM, Tyler WJ, Brunelin J, Datta A, Juan CH, Venkatasubramanian G, Boggio PS, Bikson M. Clin Res Regul Aff. 2015 Mar 1;32(1):22-35. PMID: 25983531