electrode impedance
Electrical resistance between electrodes and scalp that must be minimized for optimal EEG recording quality.
Full Definition
Electrode impedance refers to the electrical resistance that occurs at the interface between recording electrodes and the patient's scalp. High impedance can significantly degrade signal quality by reducing amplitude, increasing noise, and creating artifacts. Standard practice requires impedances below 5-10 kilohms for most EEG recordings, though some systems tolerate higher values. Impedance is measured before recording begins and monitored throughout longer studies. Factors affecting impedance include skin preparation, electrode paste application, hair interference, and electrode condition. Proper impedance management is fundamental to obtaining interpretable neurophysiological recordings.
Usage
Usage note: Always measured in kilohms or ohms; essential for technical quality control documentation.
In Context
- "All electrode impedances were below 5 kilohms before recording commenced." — EEG technical report
- "Poor electrode impedance at T4 required reapplication of the electrode." — Technical quality assessment