Electronic – Are electrodes mostly homogeneous or are there variations by usage, such as EEG vs EKG/ECG

biopotentialeegelectrode

Are electrodes mostly homogeneous or are there variations by usage? My main usage is EEG. I have some interests in other areas and see similar electrodes sold for less money when marketed for different purposes.

I imagine there are differences in precision? Is that accurate or

Sorry for the basic question.

I've been experimenting with the use of electrodes for EEG and I'm trying to understand if these expensive EEG electrodes ordered from the EEG development board makers are "special" in some way that I'm not aware of – such as if different hardware designs detect different ranges of electrical activity – or if all electrodes styled for use on humans result in essentially the same data and just perhaps vary by accuracy?

Are there common metrics or features used to rate or distinguish electrodes by purpose?

Stated differently, my question is essentially what factors to consider when selecting an electrode for human use, such as EEG, ECG/EKG, EMG, etc.

Best Answer

Biopotential electrodes are often nonpolarizable, meaning that they conduct current well without a blocking capacitance. To do this, there is usually a layer of a metal covered with a salt of that metal, most often silver-silver chloride.

The practice gives you the best frequency response and the least distortion of the signal you're trying to measure.