EEG Signal Quality of a Subcutaneous Recording System Compared to Standard Surface Electrodes

Table 1

EEG scoring sheet for subjective analysis by neurophysiologists. Each 30 s epoch was given a score for the signal quality as well as the noise level.

Score	Signal quality	Noise level
5	EEG signal clear, evaluation straight forward	No or very little noise present
4	EEG signal clear, evaluation possible and close to optimal	Some noise present but does not hamper EEG analysis significantly
3	EEG signal recognized, evaluation possible however not optimal	Moderate amount of noise present, EEG analysis challenging but still possible
2	EEG signal recognized, evaluation difficult	Larger amount of noise present, EEG analysis challenging and less reliable
1	EEG signal is not readily recognized	EEG severely noisy, EEG analysis unreliable