Multichannel seismocardiography: an imaging modality for investigating heart vibrations
Executive Summary
This study introduces a multichannel seismocardiography (mchSCG) system with 16 three-axis accelerometers to investigate chest wall vibrations caused by cardiac activity. The system demonstrated high synchronization accuracy, linear frequency response, and signal quality, enabling the identification of fiducial points associated with aortic valve events. Analysis of vibration propagation patterns across 13 subjects revealed spatial and temporal trends linked to cardiac mechanics, suggesting potential applications in cardiac resynchronization therapy and physiological parameter estimation.
Answer Machine Insights
Q: What fiducial points were identified in the SCG signals?
Four fiducial points were identified: AOvalley, AOhill, ACvalley, and AChill, corresponding to aortic valve opening and closing events.
Fiducial point was defined as the negative and positive peaks that align with aorta valve opening, for the systolic points, and with aorta valve closing for the diastolic points.
Q: How does the system handle spatial propagation of chest vibrations?
The system uses a 4x4 grid of sensors to map vibration propagation, calculating centers of mass for fiducial points to analyze spatial trends.
To qualify spatial movement of acceleration waves on the chest surface, the center of mass of each colormap was calculated and illustrated as a magenta point on the colormaps.
Key Results
The system achieved a synchronization latency of 0 ms between sensors and 4 samples between ECG and SCG channels.
Average signal-to-noise ratio (SNR) of 25.8 dB across 208 signals from 13 subjects.
Visual Evidence
Figure 9. Mean colormaps from the 13 subjects from the SCG markers, illustrates how the center of mass propagates across the chest over time. The colormaps are normalized to the absolute maximum acceleration for each subject.
Clinical Snapshot
Evidence Rating
Relevance
high Priority