Vital Sign Monitoring Based on Wireless Sensing

With the acceleration of aging societies and the growing demand for health monitoring, wireless perception-based vital sign monitoring has become a research hotspot in various fields.Traditional contact devices have problems such as poor comfort and privacy leakage risks, while wireless sensing technology based on WiFi and millimeter-wave radar can achieve real-time monitoring of vital signs such as non-contact breathing and heart rate by analyzing the physical characteristics of wireless signals, such as channel state information CSI and the Doppler effect.CSI captures human micro-movements by using changes in subcarrier phase and amplitude.It has the characteristics of low cost and strong universality but is vulnerable to environmental interference; Millimeter-wave radar, on the other hand, detects micron-level body movements through highresolution signals, with high precision but high hardware costs.This article reviews the technical principles, application scenarios and challenges of CSI and millimeter-wave radar, providing a reference for the promotion of wireless sensing vital sign monitoring.The research focuses on multimodal data fusion, privacy protection mechanisms, and hardware cost optimization to drive the technology from the laboratory to large-scale commercial scenarios, providing reliable non-contact monitoring solutions for areas such as smart healthcare, security monitoring, and smart home.