Enabling Robust Radar-Based Localization and Vital Signs Monitoring in Multipath Propagation Environments.

Area of Science:

• * Biomedical engineering
• * Signal processing
• * Radar technology

Background:

• * Radar-based contactless monitoring of vital signs (heartbeat and respiration rate) has gained interest for healthcare applications.
• * Indoor multipath propagation, caused by signal reflections, has been a significant obstacle to the reliable adoption of this technology.
• * Multipath interference corrupts individual vital sign extraction and localization by combining direct signals with reflections from people and objects.

Purpose of the Study:

• * To develop a methodology for separating desired radar signals from undesired multipath reflections in indoor environments.
• * To enable accurate, individual vital signs monitoring and localization in complex indoor settings.
• * To overcome a key hurdle for the real-world implementation of contactless health monitoring.

Main Methods:

• * Developed accurate models for indoor multipath propagation and radar signals.
• * Implemented a signal processing technique to distinguish individual signals from multipath interference.
• * Validated the approach using a frequency-modulated continuous wave (FMCW) radar system.

Main Results:

• * Successfully separated desired signals from multipath reflections in a challenging office environment.
• * Accurately measured individual heart rates and respiration rates of paired volunteers.
• * Obtained precise absolute distance (range) information for each individual.

Conclusions:

• * The proposed methodology effectively mitigates the impact of indoor multipath reflections on radar-based vital signs monitoring.
• * The validated FMCW radar approach demonstrates robustness in environments with severe signal interference.
• * This advancement paves the way for practical applications in healthcare, assisted living, and security.