Correlation-Based Approach for Heart Rate Extraction Using UWB Impulse Radar

Ultra-wideband (UWB) radar technology has emerged as a significant tool in maritime applications due to its unique capabilities in high-resolution imaging, target detection, obstacle penetration, and vital signs monitoring. Unlike traditional radar systems, UWB radar offers unique advantages, including higher performance in complex environments, making it suitable for various maritime scenarios. These include vessel tracking, search and rescue operations, underwater exploration, and, especially, crew health situation monitoring. UWB impulse radar, in particular, is gaining significant attention for its ability to conduct contactless vital sign monitoring, particularly for measuring respiration and heart rate through thoracic motion. However, heartbeat signals are typically low in intensity and prone to interference from noise and non-stationary signals. This paper proposes a novel correlation-based approach designed to enhance the signal-to-noise ratio (SNR) and improve the accuracy of heart rate extraction. The approach employs the chirp Z-transform for higher frequency resolution, combined with a sliding window-based cross-correlation method to isolate and amplify vital signals in the frequency domain. Experimental results demonstrate that the proposed method significantly improves SNR, achieving a 30 dB increase in respiration and a 10 dB increase in heart rate compared to traditional methods. Furthermore, the approach reduces heart rate error to just 0.003 Hz, showcasing its potential for reliable vital sign monitoring. Future work will focus on exploring larger datasets and expanding this method for behind-wall detection applications.