title: Real time QRS complex detection using DFA and regular grammar.
abstract: BACKGROUND
  The sequence of Q, R, and S peaks (QRS) complex detection is a crucial procedure in electrocardiogram (ECG) processing and analysis. We propose a novel approach for QRS complex detection based on the deterministic finite automata with the addition of some constraints. This paper confirms that regular grammar is useful for extracting QRS complexes and interpreting normalized ECG signals. A QRS is assimilated to a pair of adjacent peaks which meet certain criteria of standard deviation and duration.
  
  
  RESULTS
  The proposed method was applied on several kinds of ECG signals issued from the standard MIT-BIH arrhythmia database. A total of 48 signals were used. For an input signal, several parameters were determined, such as QRS durations, RR distances, and the peaks' amplitudes. σRR and σQRS parameters were added to quantify the regularity of RR distances and QRS durations, respectively. The sensitivity rate of the suggested method was 99.74% and the specificity rate was 99.86%. Moreover, the sensitivity and the specificity rates variations according to the Signal-to-Noise Ratio were performed.
  
  
  CONCLUSIONS
  Regular grammar with the addition of some constraints and deterministic automata proved functional for ECG signals diagnosis. Compared to statistical methods, the use of grammar provides satisfactory and competitive results and indices that are comparable to or even better than those cited in the literature.
authors.affiliation: Laboratory of Technology and Medical Imaging (LTIM), Faculty of Medicine of Monastir (FMM), University of Monastir, Monastir, Tunisia. salahxhamdi@gmail.com.
authors.forename: Salah
authors.identifier: http://orcid.org/0000-0001-7870-9536
authors.initials: S
authors.lastname: Hamdi
authors.affiliation: Laboratory of Technology and Medical Imaging (LTIM), Faculty of Medicine of Monastir (FMM), University of Monastir, Monastir, Tunisia.
authors.forename: Asma
authors.initials: A
authors.lastname: Ben Abdallah
authors.affiliation: Laboratory of Technology and Medical Imaging (LTIM), Faculty of Medicine of Monastir (FMM), University of Monastir, Monastir, Tunisia.
authors.forename: Mohamed Hedi
authors.initials: MH
authors.lastname: Bedoui
mesh_terms: D000465:Algorithms; D001145:Arrhythmias, Cardiac / Q000175:diagnosis; D004562:Electrocardiography; D006801:Humans; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D013997:Time Factors
keywords: DFA; ECG signal; QRS complex; RR distance; Regular grammar