Description
Onset and offset detection of the muscle contraction is an important part of the electromyography (EMG) signal processing. It is used to find important parts of the EMG signal that are further analysed. Many methods for onset and offset detection of the muscle contraction in the EMG signal were proposed in the past. However, all these methods have limitations and/or must be used manually. Our aim was to develop a new method for onset and offset detection in the EMG signal that can be used automatically without a user interaction. We used EMG signals from the human trunk while performing quick arm rise test and postural reactions on sudden loading test. We proposed a new method for onset and offset detection of muscle contraction based on local changes in amplitude of the EMG signal. The proposed method uses two adjacent sliding windows to calculate a ratio of standard deviations between the two windows. The ratio of standard deviations represents local changes in the EMG signal. Additional processing steps on the ratio of standard deviations are used to precisely locate the onset and offset of the muscle contraction in the EMG signal. The proposed method was evaluated for detection of presence of muscle contraction in the EMG signal and was compared with the existing methods for the accuracy of the onset detection. Proposed method proved to be reliable for the detection of muscle contraction in the EMG signal and it was more accurate in the onset detection compared to existing methods.
Primary author
Mr
Andrej Panjan
(S2P, Science to Practice, Ltd., Laboratory for Motor Control and Motor Behaviour)
