Vital-Signs Detector Based on Frequency-Shift Keying Radar

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Signal Processing

Background:

• Vital signs monitoring is crucial for healthcare.
• Existing radar systems face challenges in accuracy and signal-to-noise ratio.
• Frequency-shift keying (FSK) radar offers potential for improved detection.

Purpose of the Study:

• To propose and evaluate a 2.45-GHz FSK radar system for highly accurate vital signs detection.
• To enhance heartbeat measurement accuracy using cross-correlation of phase differences between two frequencies.
• To improve signal discrimination and data processing for reliable vital signs extraction.

Main Methods:

• Utilized an FSK radar system operating at two frequencies (2.45 GHz and 2.5 GHz).
• Employed envelope detection with frequency control signals for frequency discrimination.
• Applied data-based imbalance compensation algorithms (Gram-Schmidt, Pratt method) for phase difference calibration.
• Performed cross-correlation analysis on phase differences for heartbeat detection.

Main Results:

• Demonstrated effective discrimination between the two operating frequencies.
• Achieved accurate vital signs detection with cross-correlation of phase differences.
• Showcased improved heartbeat detection accuracy, reduced error rates, and increased signal-to-noise ratio at distances under 2.4 m.
• Validated the performance against single-frequency radar systems.

Conclusions:

• The proposed dual-frequency FSK radar system significantly enhances vital signs detection accuracy.
• Cross-correlation of phase differences is an effective method for improving heartbeat detection.
• This technology offers a promising non-contact solution for remote vital signs monitoring.