Design and Development of a Multi-stage High Gain EEG Amplifier for Neonatal Brain Signal Monitoring

The main objective of this paper is to design a high-gain multi-stage EEG amplifier for monitoring the brain signal of neonates. EEG Signals of newborns are in the order of a few microvolts and require amplification and filtering to reduce unwanted noise. The proposed circuit is composed of an instrumentation amplifier, an active filtering network, and a final gain stage with a bandwidth of 0.5–100 Hz. The circuit achieves a total gain of about 90000 V/V without disturbing signal fidelity. The experiment result indicates that clean, stable, and noise-minimized output waveforms are obtained, which can amplify the weak neonatal EEG. The end product is a robust analog front-end for clinical EEG studies, promising potential for further wireless transmission and multi-channel applications.