Microstrip patch and Sierpinski fractal antennas: simulations and experimental characterization for vital signs detection with Doppler radar technique

Non-contact vital signs monitoring using microwave Doppler radar has shown great promise in healthcare applications. Recently, this unobtrusive form of physiological sensing has also been gaining attention for its potential for continuous identity authentication, which can reduce the vulnerability of traditional one-pass validation authentication systems. Physiological Doppler radar is an attractive approach for continuous identity authentication as it requires neither contact nor line-of-sight and does not give rise to privacy concerns associated with video imaging. This paper presents a review of recent advances in radar-based identity authentication systems. It includes an evaluation of the applicability of different research efforts in authentication using respiratory patterns and heart-based dynamics. It also identifies aspects of future research required to address remaining challenges in applying unobtrusive respiration-based or heart-based identity authentication to practical systems. With the advancement of machine learning and artificial intelligence, radar-based continuous authentication can grow to serve a wide range of valuable functions in society.

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Software-Defined Doppler Radar Sensor for Human Breathing Detection

Sensors ◽

10.3390/s19143085 ◽

2019 ◽

Vol 19 (14) ◽

pp. 3085 ◽

Cited By ~ 7

Author(s):

Sandra Costanzo

Keyword(s):

Software Defined Radio ◽

Doppler Radar ◽

Low Cost ◽

Vital Signs ◽

Phase Correlation ◽

Wireless Sensing ◽

Radar Sensor ◽

Human Respiration ◽

Critical Issues ◽

Radio Transceiver

Non-contact wireless sensing approaches have emerged in recent years, in order to enable novel enhanced developments in the framework of healthcare and biomedical scenarios. One of these technologically advanced solutions is given by software-defined radar platforms, a low-cost radar implementation, where all operations are implemented and easily changed via software. In the present paper, a software-defined radar implementation with Doppler elaboration features is presented, to be applied for the non-contact monitoring of human respiration signals. A quadrature receiver I/Q (In-phase/Quadrature) architecture is adopted in order to overcome the critical issues related to the occurrences of null detection points, while the phase-locked loop components included in the software defined radio transceiver are successfully exploited to guarantee the phase correlation between I/Q signal components. The proposed approach leads to a compact, low-cost, and flexible radar solution, whose application abilities may be simply changed via software, with no need for hardware modifications. Experimental results on a human target are discussed so as to demonstrate the feasibility of the proposed approach for vital signs detection.

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A Novel Vital-Sign Sensing Algorithm for Multiple Subjects Based on 24-GHz FMCW Doppler Radar

Remote Sensing ◽

10.3390/rs11101237 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1237 ◽

Cited By ~ 15

Author(s):

Hyunjae Lee ◽

Byung-Hyun Kim ◽

Jin-Kwan Park ◽

Jong-Gwan Yook

Keyword(s):

Vital Sign ◽

Continuous Wave ◽

Doppler Radar ◽

Spectral Estimation ◽

Estimation Method ◽

Vital Signs ◽

Phase Information ◽

Multiple Targets ◽

Wave Radar ◽

24 Ghz

A novel non-contact vital-sign sensing algorithm for use in cases of multiple subjects is proposed. The approach uses a 24 GHz frequency-modulated continuous-wave Doppler radar with the parametric spectral estimation method. Doppler processing and spectral estimation are concurrently implemented to detect vital signs from more than one subject, revealing excellent results. The parametric spectral estimation method is utilized to clearly identify multiple targets, making it possible to distinguish multiple targets located less than 40 cm apart, which is beyond the limit of the theoretical range resolution. Fourier transformation is used to extract phase information, and the result is combined with the spectral estimation result. To eliminate mutual interference, the range integration is performed when combining the range and phase information. By considering breathing and heartbeat periodicity, the proposed algorithm can accurately extract vital signs in real time by applying an auto-regressive algorithm. The capability of a contactless and unobtrusive vital sign measurement with a millimeter wave radar system has innumerable applications, such as remote patient monitoring, emergency surveillance, and personal health care.

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Review-Microwave Radar Sensing Systems for Search and Rescue Purposes

Sensors ◽

10.3390/s19132879 ◽

2019 ◽

Vol 19 (13) ◽

pp. 2879 ◽

Cited By ~ 9

Author(s):

Nguyen Thi Phuoc Van ◽

Liqiong Tang ◽

Veysel Demir ◽

Syed Faraz Hasan ◽

Nguyen Duc Minh ◽

...

Keyword(s):

Doppler Radar ◽

Vital Signs ◽

Invasive Technique ◽

System Architectures ◽

Radar Sensors ◽

Sensing Systems ◽

Microwave Radar ◽

Recent Developments ◽

Location Detection ◽

Radar Sensing

This paper presents a survey of recent developments using Doppler radar sensor in searching and locating an alive person under debris or behind a wall. Locating a human and detecting the vital signs such as breathing rate and heartbeat using a microwave sensor is a non-invasive technique. Recently, many hardware structures, signal processing approaches, and integrated systems have been introduced by researchers in this field. The purpose is to enhance the accuracy of vital signs’ detection and location detection and reduce energy consumption. This work concentrates on the representative research on sensing systems that can find alive people under rubble when an earthquake or other disasters occur. In this paper, various operating principles and system architectures for finding survivors using the microwave radar sensors are reviewed. A comparison between these systems is also discussed.

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