scholarly journals 24 GHz Flexible Antenna for Doppler Radar-Based Human Vital Signs Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3737
Author(s):  
Nitin Kathuria ◽  
Boon-Chong Seet

Noncontact monitoring of human vital signs has been an emerging research topic in recent years. A key approach to this monitoring is the use of the Doppler radar concept which enables real-time vital signs detection, resulting in a new class of radar system known as bio-radar. The antennas are a key component of any bio-radar module and their designs should meet the common requirements of bio-radar applications such as high radiation directivity and mechanical flexibility. This paper presents the design of a four-element antenna array on a flexible liquid crystal polymer (LCP) substrate of 100 μm thickness and εr of 3.35. The designed antenna array can be used with a 24 GHz bio-radar for vital signs monitoring in a non-contact manner. It features a relatively compact size of 36.5 × 53 mm2 and measured gain of 5.81 dBi. The two vital signs: breathing rate (BR) and heart rate (HR) of two human subjects are detected with relatively good accuracy using the fabricated antenna array and radio frequency (RF) output power of −3 dBm from a distance of approximately 60 cm. The effect of bending on the antenna performance is also analyzed.

2020 ◽  
Vol 12 (14) ◽  
pp. 2279 ◽  
Author(s):  
Shekh Md Mahmudul Islam ◽  
Olga Borić-Lubecke ◽  
Yao Zheng ◽  
Victor M. Lubecke

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.


2019 ◽  
Vol 11 (10) ◽  
pp. 1237 ◽  
Author(s):  
Hyunjae Lee ◽  
Byung-Hyun Kim ◽  
Jin-Kwan Park ◽  
Jong-Gwan Yook

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.


Telecom ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 285-301
Author(s):  
Mariella Särestöniemi ◽  
Marko Sonkki ◽  
Sami Myllymäki ◽  
Carlos Pomalaza-Raez

This paper describes the development and evaluation of an on-body flexible antenna designed for an in-body application, as well as on-body communications at ISM and UWB frequency bands. The evaluation is performed via electromagnetic simulations using the Dassault Simulia CST Studio Suite. A planar tissue layer model, as well as a human voxel model from the human abdominal area, are used to study the antenna characteristics next to human tissues. Power flow analysis is presented to understand the power flow on the body surface as well as within the tissues. Simulation results show that this wearable flexible antenna is suitable for in-body communications in the intestinal area, e.g., for capsule endoscopy, in the industrial, scientific, and medical (ISM) band and at lower ultra-wideband (UWB). At higher frequencies, the antenna is suitable for on-body communications as well as in-body communications with lower propagation depth requirements. Additionally, an antenna prototype has been prepared and the antenna performance is verified with several on-body measurements. The measurement results show a good match with the simulation results. The novelty of the proposed antenna is a compact size and the flexible substrate material, which makes it feasible and practical for several different medical diagnosis and monitoring applications.


2020 ◽  
Vol 14 (11) ◽  
pp. 1778-1787
Author(s):  
Salah H. Abouzaid ◽  
Wael A. Ahmad ◽  
Thomas F. Eibert ◽  
Herman Jalli Ng

2019 ◽  
Vol 67 (4) ◽  
pp. 2390-2404 ◽  
Author(s):  
Mehrdad Nosrati ◽  
Shahram Shahsavari ◽  
Sanghoon Lee ◽  
Hua Wang ◽  
Negar Tavassolian

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