Typical CWT coefficients of MMG recorded at the frontalis muscle. The maximum coefficients at 14 scales are shown for different contraction conditions. The dashed lines depict CWT coefficients of the artefact in the MMG signal during rest, eye blinks and head movements. The maximum coefficients across the artefacts are the scale-specific thresholds (x) for contraction-detection. The solid lines depict coefficients for the events to be detected. Contractions are detected when the CWT coefficient of at least one scale is higher than the threshold. After the initial signal transient, sustained contractions could not be detected.