Noncontact Multi-Point Vital Sign Monitoring with mmWave MIMO Radar

TL;DR

This paper presents MultiVital, a noncontact mmWave MIMO radar system for multi-point vital sign monitoring, demonstrating high accuracy and consistency with reference sensors, addressing limitations of contact-based and optical methods.

Contribution

The paper introduces MultiVital, a novel noncontact multi-point vital sign monitoring system using mmWave MIMO radar with a multi-modal signal processing framework for accurate physiological measurement.

Findings

Achieves high-precision multi-point vital sign monitoring

Demonstrates consistency with reference SCG and ECG sensors

Validates effectiveness through simulations and experiments

Abstract

Multi-point vital sign monitoring is essential for providing detailed insights into physiological changes. Traditional single-sensor approaches are inadequate for capturing multi-point vibrations. Existing contact-based solutions, while addressing this need, can cause discomfort and skin allergies, whereas noncontact optical and acoustic methods are highly susceptible to light interference and environmental noise. In this paper, we aim to develop a non-contact, multi-point vital sign monitoring technique using MIMO radar, focused on physically differentiating and precisely measuring chest-wall surface vibrations at multiple points induced by cardiopulmonary mechanical activity. The primary challenges in developing such a technique involve developing algorithms to extract and separate entangled signals, as well as establishing a reliable method for validating detection accuracy. To address these limitations, we introduce MultiVital, a wireless system that leverages mmWave Multiple-input Multiple-output (MIMO) radar for synchronous multi-point vital sign monitoring. It integrates two reference modalities: five-channel seismocardiography (SCG) sensors and a one-channel electrocardiogram (ECG) electrode, enabling comprehensive radar-based research and performance validation across multiple physiological metrics. Additionally, we have developed a multi-modal signal processing framework, consisting of a radar signal processing module, an SCG calibration module, and a spatial alignment scheme. To evaluate the radar signal processing module, we conducted mathematical derivation and simulation. The experimental results indicate that the noncontact MultiVital system achieves multi-point synchronous monitoring with high precision, highly consistent with the results from reference modalities.