Abstract
Monitoring of vital signs, such as respiration, is crucial for assessing a person’s health. Traditionally, contact-based methods have been used for this purpose. Although recent advancements in this field have provided soft, skin-like sensors, and flexible wearable devices have improved comfort, these approaches may still impose certain constraints on continuous monitoring, thereby motivating the development of contactless solutions. To overcome these problems, the recent research focus has been shifted toward contactless monitoring techniques, including camera-based, video-based, and waveform-based methods. In camera and video-based methods, the privacy of the subject is at risk. So, in this study, we propose a radar-based contactless technique named amplitude modulation continuous wave radar for vital estimation (AMCWAVE) for monitoring respiratory signals. This technique involves generating and receiving waveforms using amplitude modulation, which is simpler and less complex compared to alternative approaches. Also, the system model is designed using ADALM-Pluto, MATLAB, and Simulink. The proposed approach is non-contact, remote-operable, cost-effective, less complex, and easily configurable to meet user requirements for respiratory pattern detection. Comprehensive experimental evaluation demonstrates the effectiveness of the proposed method, achieving average root mean square error (RMSE) and mean absolute error (MAE) values of 2.03 and 1.69 breaths per minute (BPM), respectively, along with an average accuracy of 90.00% across all subjects. These results confirm a strong agreement between the estimated and reference respiratory rates under varying conditions.