Paediatric EEG cup electrodes, 6 mm

The 10-20 system is proportional: positions are computed as percentages of the nasion-inion and preauricular distances. On a head of 34 cm circumference, neighbouring positions are barely two centimetres apart.

With 10 mm cups, two neighbouring electrodes almost touch, and the conductive paste of one meets that of the other. The resulting salt bridge gives two identical channels, which does not necessarily show on screen but completely distorts bipolar montages.

The 6 mm cup solves the problem geometrically. The rest is identical to the adult cups: same touchproof DIN 42802 connector, same cable lengths, same care.

Two materials. Ag/AgCl gives the best low-frequency behaviour, which matters for slow potentials and newborn traces. Gold is mechanically tougher and stands repeated cleaning better.

Sold in sets of ten, in 100, 150 or 250 cm. The 100 cm is enough at the bedside in neonatology, longer runs serve when the amplifier is remote.