Convenient Electroencephalographic Electrode

Abstract

To make contact with the scalp for electroencephalographic recording the practice has frequently been to cut the hair in small areas and fasten electrodes in place with collodion. The collodion and the electrodes were subsequently removed with ether. The attaching of a dozen or more such electrodes for an electroencephalographic exploration is laborious, the cosmetic effect is not too favorable, and the patient may not be enthusiastic.

A more expeditious procedure for placing of electrodes on hair covered areas is possible with an electrode which makes use of the hair itself to hold the electrode. Two simple electrodes are here described. The first, illustrated in Fig. 1, consists of a ring of metal I/2.” in diameter, 3/16” high, with a wire lead attached, and a slot 3/32” deep in the top into which fits a wire “hairpin” of No. 20 spring wire bent double like a cotter pin or a “bobby pin”. After massage of an area of scalp with electrode paste a wisp of hair from the area is passed through the metal ring and inserted in the slot of the wire hairpin. The wisp of hair is wound up, windlass fashion, on the hairpin until definite tension holds the pin against the top of the electrode ring and pushes the electrode ring against the scalp. The doubled wire pin is then permitted to slip edgewise into the slots in the top of the electrode ring. This prevents the pin from turning or the hair from unwinding, and the electrode ring is held snugly in place. The ring may be filled with electrode paste, insuring contact and providing assurance against drying of the electrode. Corrugations or comblike teeth may be milled on the lower edge of the electrode ring so that stray hairs beneath the ring may not prevent contact with the scalp.