Difference between revisions of "Electroencephalographs"

Revision as of 23:40, 20 August 2008

BeLight

A brief description of EbNeuro BeLight should go here.

Connectors

• 1-21: EEG inputs
• A, B, C, D Bipolar inputs
• NE: EEG reference
• ISOGN: EEG ground (Isolated ground)
• 22-24: Poly channels
• NEP: Poly reference

Booking

Electrodes

There are two types of electrodes: electrodes pre-mounted on caps, and single electrodes. They are very simple, but as they are very important for the quality of the signal and are delicate (and also incredibly expensive, btw), please treat them carefully (avoid rattling them against each other, for example).

Maintenance

The paste or gel used during acquisitions must be thoroughly removed after use. Please follow the following procedure:

1. Rinse the electrodes under running water. This step can remove only a part of the gel/paste. Please avoid washing or wetting the plugs.
2. Put the electrodes in a container half-filled with water (there is a suitable container in the cabinet of the IITLab), so that the electrodes are completely submerged. Leave them there for some minutes, until all the gel/paste become dissolved. Change the water if it becomes too murky. Do not leave the electrodes underwater for too long.
3. Rinse the electrodes under running water (and also rinse the container).
4. Put the electrodes in a dry place, where they can dry up. You can accelerate this phase by first patting them with a towel. Again, make sure that plugs don't come in contact with water; if you hang a cap, make sure that water cannot drip along the cable onto the plug.
5. Put the electrodes away in their bag in their box. Please make sure that they are absolutely dry before you put them away; the coating of electrodes is rather delicate.

Please take into account also the time for electrode cleaning when you plan your EEG acquisitions.

Presets

Description of the presets saved in the Galileo software.

P300

Used for P300 and ErrP recordings. There are 4 EEG channels, 1 EOG, 2 external signals in DC; sampling frequency is 512 Hz.

Channels and connectors

EOG: EOG, input "A"; the "+" input for the electrode above the eye, the "-" input for the one below

Fz: Fz, input 7

Cz: Cz, input 12

Pz: Pz, input 17

Oz: Oz, input 20 (labeled as "O1" on the amplifier)

Sync: phototransistor for stimulus synchronization; positive lead (red) in input 22, negative lead (black) in input NEP

Button: button, used for target signaling; positive lead in input 23, negative lead in input NEP. If it's not used, please short the input 23 with NEP.

Links

• Brain-Computer Interface page on this Wiki
• EEG Montage for instructions on how to mount electrodes