A System for Seismocardiography-Based Identification of Quiescent Heart Phases: Implications for Cardiac Imaging

Abstract

Seismocardiography (SCG), a representation of mechanical heart motion, may more accurately determine periods of cardiac quiescence within a cardiac cycle than the electrically derived electrocardiogram (EKG) and, thus, may have implications for gating in cardiac computed tomography. We designed and implemented a system to synchronously acquire echocardiography, EKG, and SCG data. The device was used to study the variability between EKG and SCG and characterize the relationship between the mechanical and electrical activity of the heart. For each cardiac cycle, the feature of the SCG indicating Aortic Valve Closure was identified and its time position with respect to the EKG was observed. This position was found to vary for different heart rates and between two human subjects. A color map showing the magnitude of the SCG acceleration and computed velocity was derived, allowing for direct visualization of quiescent phases of the cardiac cycle with respect to heart rate.

Sternal vibrations during head-out immersion: A preliminary demonstration of underwater wearable ballistocardiography

“…The upper cutoff frequency of 50 Hz was chosen after the FFT revealed that most of the energy was below this frequency, consistent with the existing literature. 9 Next, ensemble averages (EA) of each recording were computed. Ensemble averaging is employed to improve the signal-to-noise ratio (SNR) of a repeating event-in this case, the heartbeats in the UW BCG signal-by computing the sampleby-sample average over multiple instances.…”

Seismocardiography-based detection of cardiac quiescence for cardiac computed tomography angiography

“…SCG and ECG data were synchronously acquired for nine healthy human subjects at a rate of 1.2 kHz using a custom SCG acquisition device described in [5]. The SCG sensor was placed at the end of sternum superior to the xiphoid process and acceleration was measured in the dorso-ventral direction.…”

“…As a direct representation of chest wall motion due to cardiac activity, seismocardiography (SCG) can be used as a marker of cardiac quiescence and may prove more reliable than the ECG for the prediction of cardiac quiescent periods [2]- [5].…”

BCG Artifact Removal Using Improved Independent Component Analysis Approach

“…Process of information extraction from biomedical signal is called as biomedical signal processing. In order to perform the analysis and information extraction different signals are present which are used for activity analysis such as Seismocardiography (SCG) [1], Electrocardiography (ECG) [2] and Ballistocardiography (BCG) [3] etc. Following section briefs about these biomedical signal processing techniques and their advantages.…”