Distinction between Human and Animal in Respiratory Monitoring Based on IR-UWB Radar

Radar as a critical remote sensing tool for non-contact monitoring of vital signals has been widely used in many scenarios, such as sleep monitoring and heart rate measurement in daily homes. In indoor non-contact monitoring by radar, the interference of pets raised in the home is an important issue that has been neglected in the past. Many pet-like animals have similar respiratory frequencies to humans, and they are easily mistaken for human targets in non-contact monitoring, which can lead to a lack of health monitoring data and even trigger an alarm due to the higher heart rate of the animals. In this paper, we proposed a novel method based on respiratory and heart rate energy ratios (RHER) to distinguish humans from animals. The echo signal received by the radar, after background removal and direct-current (DC) component suppression, is decoded by Variational Mode Decomposition (VMD) to obtain the VIMFs determined by human respiratory and heart rate ranges. Then the RHER is calculated using the variational Intrinsic Mode Functions (VIMFs) that obtained in the previous step, and the target category is judged by the RHER index. The experimental results show that the proposed approach can effectively distinguish between human and rabbit, and between human and dog.