Manual (DIY) how to create EEG cap for measure EEG for few dollars

This datasheet ( only for test EEG,  to save money who like DIY activities) provides detailed instructions and a list of materials needed to create your Hat, as well as information on how to assemble and use it with your Brain-computer interface. With this DIY approach, you can save costs and have more control over the design of your EEG measurement system. We used available materials without any special skills or tools.

Materials
The electrodes used in this work are Ag-AgCl – Silver chloride electrodes with a hole in the center for installation, Fig.1.

Fig.1. Examples of valid Silver chloride electrodes

To attach the electrode to the hat, a bolt can be used, the diameter of which should be smaller than the hole in the center of the electrode. It is necessary to use bolts with a length of 3-5 centimeters, washer, nut, Fig.2.

Fig.2. Parts for attaching the electrode to the hat

It is recommended to use Copper cables (stranded, 1-3 mm) as wires, the length is set depending on the needs, Fig.3.

Fig.3. Wires for attaching to the electrode

Strap can be used as a hat, for example, a strap for a Camera Mount hat. Electrodes can be located in line international “10-20” electrode placement system, Fig.4.

Fig.4. a – Camera Mount hat, b – arrange the electrodes according to the international “10 20” electrode placement system

Instructions
Prepare cables. Strip the wires of isolation, a few centimeters, as shown in the Fig. 5.

Fig.5. Cable preparation

To connect the electrode to the cap, it is necessary to take the bolt, nuts, washers, cable – 1 and the EEG cap – 2. First clamp the cable between the nut and the bolt, then thread the bolt through the cap and fix it on the other side with the nut, as shown in Fig.6.

Fig.6. Scheme of connecting the electrode with a hat

As a result, the prepared electrode should look like the one shown in Fig.7.

Fig.7. Electrodes prepared for installation in the hat

According to the international “10-20” electrode placement system, make holes for electrodes in the hat, insert the electrode and fix it with a bolt from the other side of the hat, Fig. 8.

Fig.8. An example of installing electrodes in a hat

The pressure of the electrode on the head is adjusted independently as far as is comfortable, the clamping force depends largely on the cap material used, and each electrode must be adjusted manually after the cap has been fitted.

* Not medical, only for test by PiEEG