Scalable Multisubject Vital Sign Monitoring With mmWave FMCW Radar and FPGA Prototyping

2025-11-26

AI Summary

Conventional contact-based vital sign monitoring suffers from user discomfort, frequent recalibration requirements, and risks of cross-contamination. This paper proposes a non-contact, multi-subject synchronous monitoring system leveraging millimeter-wave frequency-modulated continuous-wave (FMCW) radar for real-time respiration and heart rate estimation—scalable to arbitrary numbers of subjects in critical clinical settings. Our contributions are threefold: (1) a scalable hardware architecture that overcomes concurrency bottlenecks in multi-user monitoring; (2) FPGA-accelerated edge signal processing, achieving a 2.7× throughput increase, >7400× latency reduction, and 18.4% LUT resource savings compared to pure-software implementations; and (3) a balanced design optimizing accuracy, computational efficiency, and deployment flexibility—thereby advancing non-contact vital sign monitoring toward clinical adoption.

Technology Category

• Machine Learning: Hardware-aware ML
• Computer Vision: Multi-modal Vision
• Planning, Routing, and Scheduling: Plan Execution and Monitoring

Application Category

• Security and Privacy: Large-scale security measurements
• Systems and Infrastructure for Web, Mobile and WoT: Data management and stream processing for Web, mobile and wireless applications
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation

Abstract

In this work, we introduce an innovative approach to estimate the vital signs of multiple human subjects simultaneously in a non-contact way using a Frequency Modulated Continuous Wave (FMCW) radar-based system. Traditional vital sign monitoring methods often face significant limitations, including subject discomfort with wearable devices, challenges in calibration, and the risk of infection transmission through contact measurement devices. To address these issues, this research is motivated by the need for versatile, non-contact vital monitoring solutions applicable in various critical scenarios. This work also explores the challenges of extending this capability to an arbitrary number of subjects, including hardware and theoretical limitations. Supported by rigorous experimental results and discussions, the paper illustrates the system's potential to redefine vital sign monitoring. An FPGA-based implementation is also presented as proof of concept for a hardware-based and portable solution, improving upon previous works by offering 2.7x faster execution and 18.4% less Look-Up Table (LUT) utilization, as well as providing over 7400x acceleration compared to its software counterpart.

Problem

• Estimating vital signs for multiple subjects simultaneously
• Overcoming limitations of contact-based wearable monitoring devices
• Addressing hardware scalability challenges for multisubject monitoring

Innovation

• FMCW radar monitors multiple subjects non-contact
• FPGA implementation enables portable vital sign monitoring
• Hardware acceleration achieves 7400x speed over software