Electro-mechanical stability of surface EMG sensors

Abstract

This study compared the performance of surface electromyographic (sEMG) sensors for different detection conditions affecting the electro-mechanical stability between the sensor and its contact with the skin. These comparisons were made to gain a better understanding of how specific characteristics of sensor design and use may alter the ability of sEMG sensors to detect signals with high fidelity under conditions of vigorous activity. The first part of the study investigated the effect of different detection surface contours and adhesive tapes on the ability of the sensor to remain in electrical contact with the skin. The second part of the study investigated the effects of different skin preparations and hydrophilic gels on the production of movement artifact resulting from sinusoidal and impact mechanical perturbations. Both parts of the study evaluated sensor performance under dry skin and wet skin (from perspiration) conditions. We found that contouring the detection surface and adding a more adhesive double-sided tape were effective in increasing the forces needed to disrupt the electrical contact between the electrodes and the skin for both dry skin and wet skin conditions. The mechanical perturbation tests demonstrated that hydrophilic gel applied to the detection surface of the sensor produced greater movement artifacts compared to sensors without gel, particularly when the sensors were tested under conditions in which perspiration was present on the skin. The use of a surfactant skin preparation did not influence the amount of movement artifacts that resulted from either the sinusoidal or impact perturbations. The importance of these findings is discussed in terms of their implications for improving sEMG signal fidelity through sensor design modifications and procedures for interfacing them with the skin.

Electrical Concepts in the Surface Electromyographic Signal

“…Those practitioners involved in muscle re-education have an additional challenge due to the fact that sweat accumulation can alter the dielectric properties of passive as well as active electrodes (DeLuca, 2006). Roy et al (2007) found that conductive gel does not improve the signal quality in situations where perspiration or mechanical perturbations are encountered (as in dynamic SEMG activities). The most challenging scenario would be gait work with an adolescent because one would have to deal with movement artifact and excess skin oils due to adolescence.…”

Electromyographic assessment of forearm muscle function in tennis players with and without Lateral Epicondylitis

“…racquet making contact with the ball or a foot making contact with the floor) can cause a movement at the electrode-skin interface and impair 22 the consistency of the signal by generating motion artefact (De Luca et al, 2010;Roy et al, 2007;Whitting et al, 2009). While it is expected that excessive motion artefact in the EMG signal caused 535 by mechanical perturbation at impact to have affected the consistency and reliability of data during some of the measurements, only one study reported the effect of impact from tennis strokes on EMG recordings (Groppel and Nirschl, 1986).…”

Hands-Free Maneuvers of Robotic Vehicles via Human Intentions Understanding Using Wearable Sensing

“…The sensory system that we choose is Myo [21], which can be worn at the driver's forearm and integrates with an inertial measurement unit (IMU) [22][23][24] and eight EMG sensors [25][26][27]. The IMU chip contains an onboard digital motion processor (DMP) and MPU-9150 module which consists of a 3-axis accelerometer, a 3-axis gyroscope, and a 3-axis magnetometer.…”