Amirkabir University
of Technology
A Review on Differences Found
Poster Code: 487
between Conventional and High-Definition tDCS
Golnaz Baghdadi, Farzad Towhidkhah
Amirkabir University of Technology, Department of Biomedical Engineering
Method
Introduction
Transcranial direct current stimulation (tDCS) is one of
therapeutic methods that has been recently taken into
consideration by researchers. In this method, the cerebral
Anode
Cathode
C-tDCS
Two electrodes: Anode and cathode
25 or 35 cm2
Sponge-based electrodes
Size of electrodes: 25 or 35 cm2
cortex is stimulated using a very low electrical current
Saline
(about 1 to 2 mA). Considering the number of electrodes,
tDCS devices can be categorized into conventional tDCS
HD-tDCS
More than two electrodes: Anode(s) and return(s)
(C-tDCS) and high-definition tDCS (HD-tDCS).
Anode
Gel-based electrodes
The aim of this paper is to provide a
Size of electrodes: 1 to 2 cm2
1 or 2 cm2
brief review on differences have been
found between C-tDCS and HD-tDCS.
HD-tDCS vs. C-tDCS
Return
Conductive
gel
Results
HD-tDCS can increase the focus of the current flow. Designing, manufacturing,
and using the HD-tDCS have some considerable challenges: 1) Controlling the
constant current, impedance level and synchronization of multi-channels (more
than two) is harder. 2) Finding the appropriate place, fixation of several small gelbased electrodes, and keeping their contact with the head skin is a time
consuming procedure in comparison with C-tDCS electrodes. Hence, the usage
of HD-tDCS is less welcomed in clinical centers for therapeutic goals. However,
1) the higher tolerability of subjects, 2) more focused stimulation of region of
interest, 3) lower and safer intensity of stimulation current, and 4) long lasting
intervention effect of HD-tDCS have been reported in comparison with C-tDCS.
Conclusion
To study the role of a specific part of the cerebral cortex or to target one region of interest for therapeutic goals, using
HD-tDCS is suggested to have focal brain stimulation. However, several consideration such as finding the appropriate
place of each electrodes, checking the impedance of all electrodes, and keeping the total current of all channels
bellow the 2 mA should be taken into account. Despite the problems of using the HD-tDCS and the higher cost of its
devices, due to its benefits as well as the reported long-lasting effects, the arrival of HD-tDCS in healthcare and
therapeutic centers is highly expected.
Acknowledgment
This research has been supported by the cognitive sciences and technologies council grant (#3175).