Is skin preparation necessary when using BioSemi active electrodes ?

The ActiveTwo system is the only commercially available system with active electrodes (first amplifier stage on the electrode), the use of active electrodes eliminates 50 Hz interference pickup by the electrode wires, even when the electrode impedance is high (in the 100 kOhm range), for background theory see http://www.biosemi.com/publications/artikel3.htm. Because high electrode impedances are tolerated, the
system can be used without the usual skin preparation (scrubbing) to lower the impedance. This makes the application of the electrodes very fast, minimizes discomfort of the subject, and eliminates the risk for infection.

The preparations for an EEG measurement are very simple. Put on the headcap, fill the electrode holders with Signa gel and push the Active electrodes in the electrode holders. Excellent quality signals are immediately available. The whole procedure takes less then 20 minutes for a 128 channel headcap. The electrode contact can be continuously checked by the offset values in the BioSemi acquisition software.

Step 1
 
Step 2
 
Step 3
 
 
Place headcap over the head.
 
Apply electrode gel in holes. No further scrubbing of the skin necessary !
 
Click Active electrodes into holders. (electrodes & holders are color labeled)