Embroidered Electromyography: A Systematic Design Guide

TY - JOUR

T1 - Embroidered Electromyography

T2 - A Systematic Design Guide

AU - Shafti, Ali

AU - Manero, Roger B. Ribas

AU - Borg, Amanda M.

AU - Althoefer, Kaspar

AU - Howard, Matthew J.

PY - 2017/9/2

Y1 - 2017/9/2

N2 - Muscle activity monitoring or Electromyography (EMG) is a useful tool. However, EMG is typically invasive, expensive and difficult to use for untrained users. A possible solution is textile-based surface EMG (sEMG) integrated into clothing as a wearable device. This is, however, challenging due to (i) uncertainties in the electrical properties of conductive threads used for electrodes, (ii) imprecise fabrication technologies (e.g., embroidery, sewing), and (iii) lack of standardization in design variable selection. This paper, for the first time, provides a design guide for such sensors by performing a thorough examination of the effect of design variables on sEMG signal quality. Results show that imprecisions in digital embroidery lead to a trade-off between low electrode impedance and high manufacturing consistency. An optimum set of variables for this trade-off is identified and tested with sEMG during a variable force isometric grip exercise with n=12 participants, compared with conventional gel-based electrodes. Results show that thread-based electrodes provide a similar level of sensitivity to force variation as gel-based electrodes with about 90% correlation to expected linear behavior. As proof of concept, jogging leggings with integrated embroidered sEMG are made and successfully tested for detection of muscle fatigue while running on different surfaces.

AB - Muscle activity monitoring or Electromyography (EMG) is a useful tool. However, EMG is typically invasive, expensive and difficult to use for untrained users. A possible solution is textile-based surface EMG (sEMG) integrated into clothing as a wearable device. This is, however, challenging due to (i) uncertainties in the electrical properties of conductive threads used for electrodes, (ii) imprecise fabrication technologies (e.g., embroidery, sewing), and (iii) lack of standardization in design variable selection. This paper, for the first time, provides a design guide for such sensors by performing a thorough examination of the effect of design variables on sEMG signal quality. Results show that imprecisions in digital embroidery lead to a trade-off between low electrode impedance and high manufacturing consistency. An optimum set of variables for this trade-off is identified and tested with sEMG during a variable force isometric grip exercise with n=12 participants, compared with conventional gel-based electrodes. Results show that thread-based electrodes provide a similar level of sensitivity to force variation as gel-based electrodes with about 90% correlation to expected linear behavior. As proof of concept, jogging leggings with integrated embroidered sEMG are made and successfully tested for detection of muscle fatigue while running on different surfaces.

KW - Electromyography

KW - Wearable sensors

KW - Biomedical Engineering

UR - http://www.scopus.com/inward/record.url?scp=85029572904&partnerID=8YFLogxK

U2 - 10.1109/TNSRE.2016.2633506

DO - 10.1109/TNSRE.2016.2633506

M3 - Article

SN - 1534-4320

VL - 25

SP - 1472

EP - 1480

JO - IEEE transactions on neural systems and rehabilitation engineering

JF - IEEE transactions on neural systems and rehabilitation engineering

IS - 9

ER -