Portable Micro-Doppler Radar with Quadrature Radar Architecture for Non-Contact Human Breath Detection

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Signal Processing

Background:

• Micro-Doppler radar technology has advanced significantly, finding applications in disaster victim detection, drone monitoring, and animal/human classification.
• Its potential extends to medical fields for non-contact remote patient monitoring and health examinations.
• Accurate and non-invasive monitoring of vital signs like respiration rate is crucial for healthcare.

Purpose of the Study:

• To propose and validate a human respiration rate detection system using micro-Doppler radar.
• To investigate the feasibility of using a 5.8 GHz Industrial, Scientific, and Medical (ISM) band radar for this application.
• To develop a portable and flexible radar system for remote respiratory monitoring.

Main Methods:

• A micro-Doppler radar system with quadrature architecture operating at 5.8 GHz was designed.
• The system employed a USRP B200 mini-module and Vivaldi antennas.
• GNU Radio Companion software was used for real-time signal processing, incorporating a mathematical model of human breathing.

Main Results:

• The proposed system successfully detected human respiration rates at distances up to 2 meters with acceptable error.
• The radar system demonstrated high sensitivity by differentiating varying frequency rates corresponding to different targets.
• The system's performance was validated using a 5.8 GHz frequency and a low USRP output power of 0.33 mW.

Conclusions:

• The developed micro-Doppler radar system is effective for detecting human respiration rates.
• The system's portability and flexibility allow for versatile application in various environments.
• This technology offers a promising non-contact solution for remote respiratory monitoring in medical and other fields.