# Non-Contact Measurement of Human Vital Signs in Dynamic Conditions Using Microwave Techniques: A Review

## TL;DR

This paper reviews microwave and radar technologies for measuring vital signs without contact, even when people are moving or doing daily activities.

## Contribution

The paper introduces flexible antenna designs and advanced signal processing for reliable vital sign monitoring in dynamic environments.

## Key findings

- Microwave techniques like UWB radar and Doppler sensors can accurately measure respiration and heart rate during movement.
- Deep learning algorithms improve the robustness of vital sign estimation in the presence of body motion.
- Applications include telemedicine, home monitoring, and search and rescue operations.

## Abstract

This article reviews recent advances in microwave and radar techniques for non-contact measurement of human vital signs in dynamic conditions. The focus is on solutions that work when the subject is moving or performing everyday activities, rather than lying motionless in clinical settings. This review covers innovative biodegradable and flexible antenna designs for wearable devices operating in multiple frequency bands and supporting efficient 5G/IoT connectivity. Particular attention is paid to ultra-wideband (UWB) radar, Doppler sensors, and microwave reflectometry combined with advanced signal-processing and deep learning algorithms for robust estimation of respiration, heart rate, and other cardiopulmonary parameters in the presence of body motion. Applications in telemedicine, home monitoring, sports, and search and rescue are discussed, including localization of people trapped under rubble by detecting their vital sign signatures at a distance. This paper also highlights key challenges such as inter-subject anatomical variability, motion artifacts, hardware miniaturization, and energy efficiency, which still limit widespread deployment. Finally, related developments in microwave imaging and early detection of pathological tissue changes are briefly outlined, highlighting the shared components and processing methods. In general, microwave techniques show strong potential for unobtrusive, continuous, and environmentally sustainable monitoring of human physiological activity, supporting future healthcare and safety systems.