Artifact Noise Removal Techniques on Seismocardiogram Using Two Tri-Axial Accelerometers
1Department of Electrical and Computer Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada. loc.luu@usask.ca.
Sensors (Basel, Switzerland)
|April 5, 2018
Summary
This study enhances motion noise removal for seismocardiography (SCG) signals using a two-accelerometer system. Horizontal sensor placement and digital processing significantly improve signal quality during walking and gentle movements.
Area of Science:
- Biomedical Engineering
- Signal Processing
- Wearable Technology
Background:
- Seismocardiography (SCG) signals are susceptible to motion artifacts.
- Effective noise removal is crucial for accurate SCG analysis.
- Traditional methods using a single accelerometer have limitations in mitigating motion noise.
Purpose of the Study:
- To investigate motion noise removal techniques for SCG signals.
- To evaluate the effectiveness of a two-accelerometer system with various sensor placements.
- To compare analog and digital processing methods for motion artifact reduction.
Main Methods:
- Developed a Wi-Fi based data acquisition system and Matlab framework.
- Utilized two-accelerometer sensor systems with horizontal, vertical, and diagonal placements.
- Implemented and compared analog (signal addition/subtraction, bandpass filtering) and digital (total acceleration, z-axis acceleration) processing techniques.
- Analyzed data from eight healthy volunteers during gentle motion and walking.
Main Results:
- Digital processing using total acceleration and z-axis acceleration improved systolic signal-noise-ratio (SNR) by ~2x and diastolic SNR by ~3x for gentle motion.
- For walking, ADDER and z-axis acceleration techniques enhanced average systolic SNR by ~7x and diastolic SNR by ~11x compared to single-accelerometer methods.
- Horizontal sensor placement demonstrated superior performance across all motion types and processing techniques.
Conclusions:
- A two-accelerometer system with appropriate processing significantly reduces motion artifacts in SCG.
- Digital processing, particularly using z-axis acceleration, offers substantial improvements in SCG signal quality.
- Optimal sensor placement (horizontal) is critical for maximizing noise reduction and enhancing SCG analysis.
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