An effective solution to reduce motion artefact in new generation reflectance pulse oximeter

This paper presents a non-invasive and wearable optical technique to monitor physiological assessment by means of photoplethysmography (PPG). The study aims to research into an effective way to capture human critical physiological parameters, i.e. oxygen saturation (SaO2%), heart rate, respiration rate through a well contracted and wearable patch probe together with a real-time and secure wireless communication functionalities. The work presents the first step of this research; an automatic noise cancellation method using a 3-axes MEMS accelerometer to recover signals corrupted by body movement as one of the biggest sources of motion artefacts. These kinds of motion artefacts could be reduced by an appropriate electronic design and development for self-cancellation noise and stability of the sensor. The signals from the acceleration and the PPG sensor are highly correlated thus the desire PPG signals retrieved with reduced motion artefacts. The preliminary results from the bench tests and the laboratory setup demonstrate that the goal of the high performance wearable PPG is viable and feasible.