What distance corresponds to the location Pz when measured from the inion?

The location Pz, which is a point on the scalp used in electroencephalogram (EEG) electrode placements, is typically situated at a specific proportion of the head height. When determining this point based on measurements taken from the inion (the bony prominence located at the lower back part of the skull), Pz is located at 30% of the total head height. This is a standardized measurement used in clinical settings to ensure consistency in electrode placements across different individuals.

Using this reference point, the Pz location provides a reliable site for monitoring brain activity related to various sleep stages and other neurological assessments. The 30% measurement allows for a balance in electrode distribution across the scalp, which is essential for accurate readings and analysis.