A Precision Baseline Offset and Drift Corrector for Low-Frequency Applications

An analog technique for correcting baseline offset and drift in low-frequency systems is analyzed. The described method applies to periodic and nearly periodic signals, characterized by a time interval in which they may be considered at rest (electrocardiogram (ECG) signals, for instance), and is limited to linear drifts. Two different circuits have been developed and are discussed here. Signal conditioning performed on suitable input waveforms is presented. Noise effects have been theoretically considered and experimentally evaluated.