Respiration Analysis of SCG
Respiration affects the cardiovascular system significantly and this is observed in hemodynamic parameters such as stroke volume and heart rate. The morphology of signals relevant to the heart also changes with respiration. Such changes have been used to extract respiration signal from the electrocardiogram (ECG). It is also shown that accelerometers placed on the body can be used to extract respiration signals. Apart from measuring the respiration rate or estimating the respiration signal morphology, what is also important is to detect the phases of respiration using the same accelerometers. This project mainly focuses on detection of the start and end timings of respiration phases and also discriminating heart beats related to inhaling from those related to exhale phases rather than detecting them alone or computing respiration rates only. Thus, the idea behind this study is to compare the efficacy of accelerometer-derived respiration (ADR) to Electrocardiogram derived respiratory (EDR) in detecting the respiration phases and investigate the feasibility of detecting inhale and exhale from the same accelerometer recording the seismocardiography. In addition, investigate the possibility of estimating the timings of inhaling and exhale phases in both methods. Figure 1 shows respiration, ECG, SCG signals and estimated signals.
 Nasim Alamdari, Kouhyar Tavakolian, Vahid Zakeri, Reza Fazel-Rezai, Mikko Paukkunen, Raimo Sepponen, and Alireza Akhbardeh. “Using Electromechanical Signals Recorded from the Body for Respiratory Phase Detection and Respiratory Time Estimation: A Comparative Study.” Computing in Cardiology Conference (CinC), 2015. IEEE, 2015.
 Tavakolian K, Vaseghi A, Kaminska B. Improvement of ballistocardiogram processing by inclusion of respiration information. Physiol Meas. 2008 Jul;29(7):771–81.