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Ambient Light Contribution as a Reference for Motion Artefacts Reduction in Photoplethysmography

: Measuring the heart rate from a convenient location such as the wrist is commonly achieved using photoplethysmography. As a consequence, this method is widely used on commercial wearable devices. Unfortu-nately, it also highly suffers from motion artefacts superimposed into the cardiac frequency band which gener-ally lead to incorrect heart rate estimation. In this paper we propose a new approach that uses the ambient light contribution as a reference for motion artefacts reduction. Contrarily to accelerometer-based techniques, the proposed method does not require any additional hardware. Moreover, it is especially efﬁcient for reduction of micro-motions that can’t be addressed using conventionally used accelerometry. Using the ambient light signal as a reference in association with adaptive ﬁltering has demonstrated promising results for the reduction of artefacts during both periodic and random motion events.