Table 4.

Results of categorization of false detections. FD false detection. Numbers represent numbers of false detections for each category. Percentages in columns 2–8 represent percentage of overall false detections for each category. Where no artefact was identified on the EEG at the time of the false detection (column 8), a description of the background is given in column 9 (FD No artefact: comment). The percentages and numbers in column 9 therefore represent a breakdown of the totals in column 8.

SDA threshold	FD respiration artefact	FD ECG/Pulse artefact	FD bad electrode artefact	FD head movement /Handling artefact	FD sweat artefact	FD unclassified artefact	FD No artefact identified	FD No artefact: comment
0.4	278 (34.7%)	34 (4.2%)	21 (2.6%)	57 (7.1%)	160 (19.9%)	29 (3.6%)	221 (27.6%)	132 (59.73%) Highly rhythmic EEG, 67 (30.32%) normal background, 20 (9.05%) sharp waves, 2 (0.9%) low amplitude EEG
0.5	249 (47.9%)	42 (8.1%)	11 (2.1%)	16 (3.1%)	97 (18.7%)	19 (3.7%)	96 (18.5%)	55 (57.29%) Highly rhythmic EEG, 25 (26.04%) normal background, 15 (15.63%) sharp waves, 1 (1%) low amplitude EEG
0.6	221 (64.6%)	43 (12.5%)	4 (1.2%)	4 (1.2%)	14 (4.1%)	10 (2.9%)	46 (13.5%)	30 (65.22%) Highly rhythmic EEG, 11 (23.91%) normal background, 5 (10.87%) sharp waves