Single channel surface electromyogram deconvolution to explore motor unit discharges

Single channel surface electromyogram deconvolution is a useful pre-processing for myoelectric control

Myoelectric control requires fast and stable identification of a movement from data recorded from a comfortable and straightforward system. Here we consider a new real-time pre-processing method applied to a single differential surface electromyogram (EMG): deconvolution, providing an estimation of the cumulative firings of motor units. A 2 channel-10 class finger movement problem has been investigated on 10 healthy subjects. We have compared raw EMG and deconvolution signals, as sources of information for two specific classifiers (based on either Support Vector Machines or k-Nearest Neighbours), with classical time-domain input features selected using Mutual Component Analysis. The overall results show that, using the proposed pre-processing technique, classification performances statistically improve. For example, the true positive rates of the best-tested configurations were 80.9% and 86.3% when using the EMG and its deconvoluted signal, respectively. Even considering the limited dataset and range of classification approaches investigated, these preliminary results indicate the potential usefulness of the deconvolution pre-processing, which could be easily embedded in different myoelectric control applications.