title: New approach for T-wave peak detection and T-wave end location in 12-lead paced ECG signals based on a mathematical model.
abstract: This paper presents an innovative approach for T-wave peak detection and subsequent T-wave end location in 12-lead paced ECG signals based on a mathematical model of a skewed Gaussian function. Following the stage of QRS segmentation, we establish search windows using a number of the earliest intervals between each QRS offset and subsequent QRS onset. Then, we compute a template based on a Gaussian-function, modified by a mathematical procedure to insert asymmetry, which models the T-wave. Cross-correlation and an approach based on the computation of Trapezium's area are used to locate, respectively, the peak and end point of each T-wave throughout the whole raw ECG signal. For evaluating purposes, we used a database of high resolution 12-lead paced ECG signals, recorded from patients with ischaemic cardiomyopathy (ICM) in the University Hospitals of Leicester NHS Trust, UK, and the well-known QT database. The average T-wave detection rates, sensitivity and positive predictivity, were both equal to 99.12%, for the first database, and, respectively, equal to 99.32% and 99.47%, for QT database. The average time errors computed for T-wave peak and T-wave end locations were, respectively, -0.38±7.12 ms and -3.70±15.46 ms, for the first database, and 1.40±8.99 ms and 2.83±15.27 ms, for QT database. The results demonstrate the accuracy, consistency and robustness of the proposed method for a wide variety of T-wave morphologies studied.
authors.affiliation: Department of Engineering of Teleinformatics, Federal University of Ceará, Fortaleza, Brazil. joaopdvm@yahoo.com.br
authors.forename: João P V
authors.initials: JP
authors.lastname: Madeiro
authors.forename: William B
authors.initials: WB
authors.lastname: Nicolson
authors.forename: Paulo C
authors.initials: PC
authors.lastname: Cortez
authors.forename: João A L
authors.initials: JA
authors.lastname: Marques
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Vázquez-Seisdedos
authors.forename: Narmadha
authors.initials: N
authors.lastname: Elangovan
authors.forename: G Andre
authors.initials: GA
authors.lastname: Ng
authors.forename: Fernando S
authors.initials: FS
authors.lastname: Schlindwein
mesh_terms: D000465:Algorithms; D009202:Cardiomyopathies / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D006339:Heart Rate; D006801:Humans; D017202:Myocardial Ischemia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity