title: Assessing PEP and LVET from heart sounds: algorithms and evaluation.
abstract: This paper addresses the estimation of systolic time intervals, namely the pre-ejection period (PEP) and the left ventricular ejection time (LVET), using heart sound. PEP is estimated with a Bayesian approach resorting to the signal's instantaneous amplitude and typical time intervals between atrio-ventricular valve closure and aortic valve opening. As for LVET, aortic valve closure is determined through the analysis of a high-frequency signature of S2. Additionally, LVET has also been estimated from a PPG signal at a peripheral site, for the sake of comparison over a subset of data. We evaluated our algorithms on a set of 658 heartbeats and achieved 10.32 msec average absolute PEP estimation error with 7.3 msec standard deviation and for LVET, 15.8 msec average estimation error with 13.6 msec standard deviation. Current results support our assumption that heart sounds can be applied to detect the onset of the aortic valve movement processes.
authors: Department of Informatics Engineering, Science and Technology Faculty of the University of Coimbra, Pólo II, Coimbra, Portugal. ruipedro@dei.uc.pt
authors: R P
authors: RP
authors: Paiva
authors: P
authors: P
authors: Carvalho
authors: X
authors: X
authors: Aubert
authors: J
authors: J
authors: Muehlsteff
authors: J
authors: J
authors: Henriques
authors: M
authors: M
authors: Antunes
mesh_terms: D000465:Algorithms; D001021:Aortic Valve; D001499:Bayes Theorem; D001699:Biometry; D015992:Body Mass Index; D004452:Echocardiography / Q000379:methods; D006321:Heart / Q000502:physiology; D006326:Heart Auscultation / Q000295:instrumentation* / Q000379:methods; D006347:Heart Sounds; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors