title: A hybrid classifier for characterizing motor unit action potentials in diagnosing neuromuscular disorders.
abstract: BACKGROUND
  The time and frequency features of motor unit action potentials (MUAPs) extracted from electromyographic (EMG) signal provide discriminative information for diagnosis and treatment of neuromuscular disorders. However, the results of conventional automatic diagnosis methods using MUAP features is not convincing yet.
  
  
  OBJECTIVE
  The main goal in designing a MUAP characterization system is obtaining high classification accuracy to be used in clinical decision system. For this aim, in this study, a robust classifier is proposed to improve MUAP classification performance in estimating the class label (myopathic, neuropathic and normal) of a given MUAP.
  
  
  METHODS
  The proposed scheme employs both time and time-frequency features of a MUAP along with an ensemble of support vector machines (SVMs) classifiers in hybrid serial/parallel architecture. Time domain features includes phase, turn, peak to peak amplitude, area, and duration of the MUAP. Time-frequency features are discrete wavelet transform coefficients of the MUAP.
  
  
  RESULTS
  Evaluation results of the developed system using EMG signals of 23 subjects (7 with myopathic, 8 with neuropathic and 8 with no diseases)  showed that the system estimated the class label of MUAPs extracted from these signals with average of accuracy of 91% which is at least 5% higher than the accuracy of two previously presented methods.
  
  
  CONCLUSIONS
  Using different optimized subsets of features along with the presented hybrid classifier results in a classification accuracy that is encouraging to be used in clinical applications for MUAP characterization.
authors.affiliation: Biomedical Engineering Group, CSE & IT Department, ECE Faculty, Shiraz University, Shiraz, Iran.
authors.forename: T
authors.initials: T
authors.lastname: Kamali
authors.affiliation: Biomedical Engineering Group, CSE & IT Department, ECE Faculty, Shiraz University, Shiraz, Iran.
authors.forename: R
authors.initials: R
authors.lastname: Boostani
authors.affiliation: Department of Medical Physics and Biomedical Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: H
authors.initials: H
authors.lastname: Parsaei
keywords: EMG; Hybrid classifier design; MUAP characterization; Mutual information; Wavelet