Synamps rt 64 channel amplifier

The international 10–20 system was used for an electroencephalographic study. The subjects wore Quik cap. After an electrode alignment, Quik gel was loaded to each designated electrode and the impedance was adjusted to be lower than 5 kΩ using Compumedics Neuroscan, SynAmps RT 64-channel amplifier (Compumedics Neuroscan, Victoria, Australia). Thirty-two electrodes were chosen and were divided into four categories consisting of regions frontal (Fp1, Fp2, AF3, AF4, F7, F3, FZ, F4, FC5, FC1, FC2, and FC6), centro-temporal region (T7, C3, CZ, C4, T8, CP5, CP1, CP2, and CP6), parietal region (CP5, CP1, CP2, CP6, P7, P3, PZ, P4, and P8) and occipital region (PO7, PO3, OZ, PO4, and PO8). The sampling rate was adjusted to 1 kHz. The raw data was filtered and removed eye-blink artifacts using Curry7 analysis software (Compumedics Neuroscan, Victoria, Australia). Three 10-s epochs were analyzed using fast-Fourier transform method. Power spectral analysis was then used to show the differences. For sleep staging study, 8-channel electrodes (F3, F4, C3, C4, O1, O2, A1, and A2), electromyography, and electrooculography were recorded. Sleep onset latency was analyzed by the duration from switch off the light to the presentation of sleep spindles or K-complexes.