neuroConn DC-Stimulator, User Manual, Page: 14 / 85

Chapter 2 - Safety
14
Safety aspects of transcranial Direct Current Stimulation (tDCS)
Attention! - In following situations the patient might be injured!
Only place the electrodes on healthy skin. If there are known allergies you should
consult a general practitioner or dermatologist first. Never use it with injured skin
areas. Stimulation of injured skin areas might result in redness of the skin
(erythema) and skin burns. The manufacturer accepts no responsibility for any
injury caused by such use.
Never use tap water to wet the sponges or the skin before or during the
stimulation. This might result in skin burns! Always use 0,9 % NaCl solution!
The manufacturer accepts no responsibility for any injury caused by such use.
If you attach the electrodes with electrode paste only use the electrode paste
supplied by the manufacturer. The use of other electrode pastes and gels might
result in in redness of the skin (erythema) and skin burns. The manufacturer
accepts no responsibility for any injury caused by such use.
Thermal limit for current density
To avoid burning the patient, the German authority (Bundesanstalt für Arzneimittel und
Medizinprodukte) gives a limit of 0.1 mA/cm
² for DC current applications. Observations of
tDCS stimulated patients show, that even current densities as low as 0.028 mA/cm ² can
sometimes be painful.
E.g.: Using electrodes with a surface area of 35 cm ² with a current of 1 mA applies a
current density of 0.02857 mA/cm ² .
Histological limit for current density
To avoid permanent injury of tissue, current density should not be higher than 25 mA/cm ² .
This limit is far above the limit for thermal effects of the current density.