Multi-channel pulse oximetry for wearable physiological monitoring

Pulse oximetry is a widely accepted clinical method for noninvasive monitoring of arterial oxygen saturation and pulse rate. Significant improvements aimed at curbing motion artifacts and improving reliability in detecting sufficiently strong photoplethysmographic signals are required to reduce errant measurements before the pulse oximeter can be considered for wider mobile applications. The present work describes the development of a wearable multi-channel reflectance pulse oximeter to investigate if a motion artifact-free signal can be obtained in at least one of the multi-channels at any given time. Pilot findings provided a proof of concept to support the hypothesis that photoplethysmograms acquired concurrently from independent channels in a multi-channel pulse oximeter sensor respond differently to motion artifacts, thus laying the foundation for future development of robust active noise cancellation and data fusion based algorithms to mitigate the effects of motion artifacts.