[Influence of the electrical properties of electrodes (platinum wire) on the myoelectric signal].

The use, in electromyography, of platinum wire electrodes required a knowledge of the electrical characteristics of these electrodes in the frequency range of the myoelectric signal. For this purpose the impedance of these electrodes was measured by the "cercle pointe" method (Gougerot 1951) in conditions similar to those in use. These electrodes behave like the majority of metal electrodes. Their impedance in particular can be represented by a polarization capacity shunted by an ohmic resistance, in series with a resistance representing the electrolyte resistance. It is shown that, depending on the electrode area and the way they are used, these electrodes can detect the myoelectric signals more or less selectively.