Automated Identification of Persistent Time-Domain Features in Seismocardiogram Signals

Abstract

In the field of cardiac monitoring, the seismocardiogram (SCG) measures the movement of the chest wall using accelerometers and gyroscopes. A key limitation of SCG signals is their sensitivity to transient signal disruptions primarily due to motion artifacts. This work describes a method for automated extraction of time-domain features in SCG signals in the presence of such artifacts, using an iterative method of clustering and re-sampling features to optimize consistency. The accelerometer (axl) and gyroscope (gyr) features extracted with this method are shown to correlate more strongly (median R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> =0.88 (axl), 0.88 (gyr)) with the reference standard for pre-ejection period (PEP), impedance cardiography (ICG), than both peak-counting (R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> =0.29 (axl), 0.48 (gyr)) and manual labeling (R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> =0.44 (axl), 0.38 (gyr)) in the post-exercise period. This result has implications for the feasibility of at-home SCG monitoring.