Respiration and Heart Rate Monitoring in Smart Homes: An Angular-Free Approach with an FMCW Radar.

Area of Science:

• Biomedical Engineering
• Signal Processing
• Smart Home Technology

Background:

• Continuous monitoring of vital signs is crucial for smart home healthcare applications.
• Existing methods for vital sign monitoring may have limitations in range and angle coverage.
• Radar technology offers a non-contact method for physiological monitoring.

Purpose of the Study:

• To develop and validate a wide-angle vital sign monitoring system using indoor radar.
• To enable real-time extraction of breathing and heart rates from reflected radar signals.
• To assess the system's performance in a smart home environment.

Main Methods:

• Utilizing a multi-input multi-output (MIMO) millimeter-wave FMCW radar for person tracking.
• Implementing an automatic beam-focusing mechanism on static subjects.
• Applying continuous wavelet transform (CWT) analysis to extract vital signs from radar signals.
• Employing Bland-Altman plots for performance evaluation against a reference.

Main Results:

• The system successfully monitored vital signs within a range of 1.15 to 2.3 m and an angular span of -44.8 to +44.8 degrees.
• Average differences of -1.5 BPM for heart rate and 0.06 BPM for breathing rate were observed compared to the reference.
• Real-time vital sign extraction was achieved by leveraging the radar's on-chip processor.

Conclusions:

• The proposed radar-based approach provides effective wide-angle vital sign monitoring for smart home applications.
• The system demonstrates high accuracy and real-time capabilities for non-contact physiological measurements.
• This technology holds potential for enhanced remote patient monitoring and elderly care within smart homes.