Reducing Motion Artefacts of Capacitive Sensors

Summary form only given. For unobtrusive continuous monitoring of body electrical signals (ECG, EMG) the capacitive sensors are very promising. Due to the loose mechanical coupling to the body however, they exhibit higher levels of motion artefacts. One important motion induced artefact in capacitive sensing is the variation of the sensor to skin distance, effectively causing a varying capacitance in the circuit. In this presentation we will focus on two ways of dealing with motion artefacts: choosing suitable sensor materials and combining with a small optical device which uses the laser self-mixing interferometry effect.