Non-Invasive Contactless Tracking of Respiratory Rate and Heart Rate During Sleep

Area of Science:

• Biomedical Engineering
• Sleep Medicine
• Wearable Technology

Background:

• Traditional sleep monitoring (polysomnography) is accurate but costly and uncomfortable.
• Contactless physiological monitoring offers a more patient-friendly alternative.
• Smart Bedding integrates a sensor network into a flexible bedsheet for unobtrusive data collection.

Purpose of the Study:

• To evaluate the accuracy of Smart Bedding's Inertial Measurement Unit (IMU) for estimating cardiorespiratory parameters during sleep.
• To develop and validate a low-cost preprocessing pipeline for cardiorespiratory signal analysis from Smart Bedding data.

Main Methods:

• Simultaneous data collection from 30 participants using Smart Bedding and polysomnography.
• Development of a preprocessing pipeline for sensor data.
• Estimation of respiratory and heart rates using zero-crossing, peak detection, and Burg's method.
• Validation against polysomnography as the gold standard.

Main Results:

• Respiratory rate estimation achieved 93.9% accuracy (zero-crossing).
• Heart rate estimation achieved 88.7% accuracy (peak detection).
• Respiratory rate estimation was consistent across frequencies and sleep positions.
• Heart rate accuracy decreased below 55 BPM and in lateral sleep positions.

Conclusions:

• Smart Bedding accurately tracks respiratory and cardiac patterns during sleep.
• The developed methodology provides a low-cost, effective approach for contactless sleep monitoring.
• Smart Bedding shows potential for future applications in sleep tracking and physiological monitoring.