Lena Gourmelon

Contactless EMG sensors embroidered onto textile

To obtain maximum unobtrusiveness with sensors for monitoring health parameters on the human body, two technical solutions are combined. First we propose contactless sensors for capacitive electromyography measurements. Secondly, the sensors are integrated into textile, so complete fusion with a wearable garment is enabled. We are presenting the first successful measurements with such sensors.

Contactless sensors for Surface Electromyography.

Muscle activity can be monitored by measuring the surface electromyography (SEMG) signal at the surface of the body. The SEMG signal is a combination of several activation signals sent through the muscle fibers triggering the contraction of the muscle. SEMG enables to access those signals non-invasively. Usually, metal plate electrodes in combination with electrolytic gel are placed in direct contact with the skin to measure SEMG. For prolonged monitoring of the muscle activity, this type of electrodes is not comfortable and can cause skin irritation. In this paper, we demonstrate capacitive electrodes capable of sensing the SEMG signal. These contactless electrodes do not require direct contact with the skin and thus they can be suitable for prolonged monitoring of the muscle activity

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.