Monitoring of respiration and cardiorespiratory interactions from multichannel seismocardiography signals
Executive Summary
This study investigates the impact of accelerometer placement on the extraction of respiratory information and cardiorespiratory interactions from seismocardiography (SCG) signals. Using a 4-by-4 matrix of triaxial accelerometers, respiratory signals were derived from chest inclination, amplitude modulation, and morphological changes in SCG signals. A novel continuous morphological similarity index (MSi) was introduced, achieving high accuracy in respiratory act detection (sensitivity >90%) and inter-breath interval estimation (bias ±0.8s). The findings suggest SCG can reliably monitor respiration and cardiorespiratory interactions across multiple chest locations, with implications for wearable health monitoring systems.
Answer Machine Insights
Q: What is the impact of sensor placement on SCG-based respiratory monitoring?
Sensor placement had minimal impact on respiratory signals derived from chest inclination and morphological changes, but amplitude modulation showed higher variability.
Very accurate localization of respiratory acts and measurement of inter-breath intervals were possible in all 16 positions over the chest, thus confirming that sensor placement has no practical impact on respiratory signals based on thoracic movements.
Q: What is the novelty of the morphological similarity index (MSi)?
MSi provides a continuous description of respiratory-induced morphological changes in SCG signals, unlike previous studies that only described discrete changes.
For the first time, a continuous description of morphological changes in SCG signals is presented, as opposed to previous studies that proposed discrete descriptions based only on two SCG morphologies.
Key Results
Sensitivity for respiratory act detection exceeded 90% for chest inclination and MSi signals.
Inter-breath interval estimation showed biases within ±0.8s for chest inclination and MSi signals.
Visual Evidence
Fig. 1 Positioning of the 4-by-4 accelerometer matrix and the respira tion belt on a subject’s chest
Clinical Snapshot
Evidence Rating
Relevance
high Priority