Sensing of Life Activities at the Human-Microwave Frontier

Li, Changzhi; Lubecke, Victor M.; Borić–Lubecke, Olga; Lin, Jenshan

doi:10.1109/jmw.2020.3030722

Cited by 38 publications

(21 citation statements)

References 113 publications

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“…Small-size and low-power Doppler radars have also been used in medical and search and rescue applications to provide non-invasive and unobtrusive diagnoses of cardiopulmonary conditions [1,2] . Recent work on physiological Doppler radar further sought to extend continuous radar monitoring beyond controlled settings and into unconstrained environments common to applications such as security, human-machine interface, at-home medical tests, smart buildings and walking aids [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Phase Correlation Single Channel Continuous Wave Doppler Radar Recognition of Multiple Sources

Ishmael¹,

Zheng²,

Borić–Lubecke³

2022

Sensors

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Continuous-wave Doppler radar (CWDR) can be used to remotely detect physiological parameters, such as respiration and heart signals. However, detecting and separating multiple targets remains a challenging task for CWDR. While complex transceiver architectures and advanced signal processing algorithms have been demonstrated as effective for multiple target separations in some scenarios, the separation of equidistant sources within a single antenna beam remains a challenge. This paper presents an alternative phase tuning approach that exploits the diversity among target distances and physiological parameters for multi-target detection. The design utilizes a voltage-controlled analog phase shifter to manipulate the phase correlation of the CWDR and thus create different signal mixtures from the multiple targets, then separates them in the frequency domain by suppressing individual signals sequentially. We implemented the phase correlation system based on a 2.4 GHz single-channel CWDR and evaluated it against multiple mechanical and human targets. The experimental results demonstrated successful separation of nearly equidistant targets within an antenna beam, equivalent to separating physiological signals of two people seated shoulder to shoulder.

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Section: Introductionmentioning

confidence: 99%

Phase Correlation Single Channel Continuous Wave Doppler Radar Recognition of Multiple Sources

Ishmael¹,

Zheng²,

Borić–Lubecke³

2022

Sensors

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“…Contactless remote sensing of vital signs is gaining more attention than contact sensors as it is unobtrusive and users need not intentionally engage themselves with the system ( Molinaro et al, 2022 ). Non-Contact and unobtrusive monitoring of human cardiopulmonary activity is one of the promising solutions for remote respiratory monitoring of COVID patients, sleep apnea diagnosis, post-surgery monitoring, in-home elderly people fall detection, and life signs detection under debris for post-disaster search and rescue applications ( Broic-Lubecke et al, 2012 ; Li et al, 2013 ; Islam et al, 2021 ; Li et al, 2021 ). One of the potential advantages of this technology is that without attaching any sensor to the body it could facilitate the health monitoring of lonely elderly patients in home settings, enable sleep monitoring of patients without any expensive sleep laboratory, and detect the trapped injured person under rubble ( Broic-Lubecke et al, 2012 ; Li et al, 2013 ; Li et al, 2021 ).…”

Section: Introductionmentioning

confidence: 99%

Radar-based remote physiological sensing: Progress, challenges, and opportunities

Islam

2022

Front. Physiol.

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Modern microwave Doppler radar-based physiological sensing is playing an important role in healthcare applications and during the last decade, there has been a significant advancement in this non-contact respiration sensing technology. The advantages of contactless, unobtrusive respiration monitoring have drawn interest in various medical applications such as sleep apnea, sudden infant death syndromes (SIDS), remote respiratory monitoring of burn victims, and COVID patients. This paper provides a perspective on recent advances in biomedical and healthcare applications of Doppler radar that can detect the tiny movement of the chest surfaces to extract heartbeat and respiration and its associated different vital signs parameters (tidal volume, heart rate variability (HRV), and so on) of the human subject. Additionally, it also highlights the challenges, and opportunities of this remote physiological sensing technology and several future research directions will be laid out to deploy this sensor technology in our day-to-day life.

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“…Due to the unique properties such as the simple structure, high sensitivity and ultra-narrow spectrum occupancy, CDRSs are especially suitable for non-contact biosignal detections. So far, there have been many progresses achieved in architectures and algorithms, to linearly demodulate the Doppler phases from signals scattered by moving bio objects [5]- [25].…”

Section: Introductionmentioning

confidence: 99%

Time-Domain Doppler Biomotion Detections Immune to Unavoidable DC Offsets

Min

Cao

et al. 2021

IEEE Trans. Instrum. Meas.

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In the past decades, continuous Doppler radar sensor-based bio-signal detections have attracted many research interests.A typical example is the Doppler heartbeat detection. While significant progresses have been achieved, reliable, accurate demodulation of bio-signals in the presence of unavoidable DC offsets remains a technical challenge. Aiming to overcome this difficulty, we propose in this paper a novel demodulation algorithm that does not need to trace and eliminate dynamic DC offsets based on approximating segmented arcs in a quadrature constellation of sampling data to directional chords.Assisted by the principal component analysis, such chords and their directions can be deterministically determined.Simulations and experimental validations showed fully recovery of micron-level pendulum movements and strongly noised human heartbeats, verifying the effectiveness and accuracy of the proposed approach.

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Sensing of Life Activities at the Human-Microwave Frontier

Cited by 38 publications

References 113 publications

Phase Correlation Single Channel Continuous Wave Doppler Radar Recognition of Multiple Sources

Phase Correlation Single Channel Continuous Wave Doppler Radar Recognition of Multiple Sources

Radar-based remote physiological sensing: Progress, challenges, and opportunities

Time-Domain Doppler Biomotion Detections Immune to Unavoidable DC Offsets

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