Signal Drift

Signal drift is the gradual, unintended change in the baseline level of a measured signal over time, caused by factors unrelated to the intended measurement. In bio-electrical sensing for assistive technology, drift is a major challenge — for example, in electrooculography (EOG), the baseline potential changes due to electrode contact variations, temperature fluctuations, and physiological processes, making it difficult to distinguish genuine eye movements from drift artifacts. Compensating for drift is critical in any biosignal-based assistive interface, and techniques include derivative-based filtering, adaptive algorithms, fuzzy logic classification, and periodic recalibration using secondary signals.