Delineation and Analysis of Seismocardiographic Systole and Diastole Profiles

Precise estimation of fiducial points of a seismocardiogram (SCG) signal is a challenging problem for its clinical usage. Delineation techniques proposed in the existing literature do not estimate all the clinically significant points of an SCG signal simultaneously. The aim of this research work is to propose a delineation framework to identify various systole and diastole fiducial points with the help of a photoplethysmogram (PPG) signal. The proposed delineation method processes a wavelet-based scalographic PPG, and an envelope construction scheme is proposed to estimate the prominent peaks of the PPG signal. A set of amplitude-histogram-based decision rules is developed for estimation of three fiducial points of SCG diastole. Subsequently, three systolic phases are detected by applying diastole masking on SCG and decision rules. Experimental results on real-time SCG signals acquired from our designed data acquisition circuitry and their analysis shows the effectiveness of the proposed scheme. In addition, these estimated parameters are analyzed to show the discrimination between normal breathing and breathlessness conditions.