COMPARATIVE ANALYSIS OF DIGITAL FILTERS FOR ELECTROGASTROGRAPHY (EGG) SIGNAL PREPROCESSING

This paper presents a comparative analysis of three digital bandpass filters—Butterworth, Chebyshev Type I, and FIR Hamming window—for enhancing electrogastrography (EGG) signal preprocessing. EGG signals are severely compromised by physiological interference (~0.25 Hz respiration, ~1 Hz cardiac activity) and motion artifacts in the ultra-low-frequency band (0.015–0.15 Hz). Using synthetic EGG signals, filter performance is quantified using signal-to-noise ratio (SNR) improvement. Results demonstrate that FIR Hamming achieves the highest SNR improvement (+16.88 dB), while Butterworth produces the smoothest temporal output suitable for clinical interpretation, and Chebyshev Type I offers optimal computational efficiency. These findings provide practical guidance for filter selection based on clinical diagnostic and machine learning requirements.