A W-Band MMIC Radar System for Remote Detection of Vital Signs

Diebold, S.; Ayhan, Serdal; Scherr, Steffen; Maßler, H.; Tessmann, A.; Leuther, A.; Ambacher, O.; Zwick, Thomas; Kallfass, Ingmar

doi:10.1007/s10762-012-9941-7

Cited by 17 publications

(16 citation statements)

References 15 publications

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“…The respiratory and cardiac rates obtained exhibited mean errors less than 0.5 beat/min and 1 beat/min, respectively. A W-band millimeter-wave radar was successfully designed and tested on a human subject in [123]. In [124], a Doppler radar was designed at 60 GHz for short-range detection of human presence as well as vital signs detection.…”

Section: Biomedical Practicementioning

confidence: 99%

Human Vital Signs Detection Methods and Potential Using Radars: A Review

Kebe

Gadhafi

Mohammad

et al. 2020

Sensors

127

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Continuous monitoring of vital signs, such as respiration and heartbeat, plays a crucial role in early detection and even prediction of conditions that may affect the wellbeing of the patient. Sensing vital signs can be categorized into: contact-based techniques and contactless based techniques. Conventional clinical methods of detecting these vital signs require the use of contact sensors, which may not be practical for long duration monitoring and less convenient for repeatable measurements. On the other hand, wireless vital signs detection using radars has the distinct advantage of not requiring the attachment of electrodes to the subject’s body and hence not constraining the movement of the person and eliminating the possibility of skin irritation. In addition, it removes the need for wires and limitation of access to patients, especially for children and the elderly. This paper presents a thorough review on the traditional methods of monitoring cardio-pulmonary rates as well as the potential of replacing these systems with radar-based techniques. The paper also highlights the challenges that radar-based vital signs monitoring methods need to overcome to gain acceptance in the healthcare field. A proof-of-concept of a radar-based vital sign detection system is presented together with promising measurement results.

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Section: Biomedical Practicementioning

confidence: 99%

Human Vital Signs Detection Methods and Potential Using Radars: A Review

Kebe

Gadhafi

Mohammad

et al. 2020

Sensors

127

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“…Figure 3 shows the implemented W-band Doppler radar using waveguide modules [ 9 ]. W-band CW signal is produced by the signal generator (8341A by Agilent) followed by the frequency multiplier-by-6 (AMC-10-RFHB0 by Millitech).…”

Section: Measurementmentioning

confidence: 99%

“…In this paper, we applied the W-band frequency (94 GHz) for non-contact detection of human respiration and heartbeat. For this purpose, the W-band CW radar sensor was implemented in waveguide-based modules using horn antenna, quadrature mixer module, low noise amplifier (LNA) module, waveguide components, and frequency multiplier [ 9 ]. The reflected signals from the human chest containing the displacement information were down-converted into the baseband and digitized for the digital signal processing, such as low-pass filtering, arctangent demodulation, trend and peak removal, and band-pass filtering, to accurately extract the respiration and heartbeat signals.…”

Section: Introductionmentioning

confidence: 99%

Non-Contact Measurement of Human Respiration and Heartbeat Using W-band Doppler Radar Sensor

Kim

Jeong

2020

Sensors

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This paper presents a W-band continuous-wave (CW) Doppler radar sensor for non-contact measurement of human respiration and heartbeat. The very short wavelength of the W-band signal allows a high-precision detection of the displacement of the chest surface by the heartbeat as well as respiration. The CW signal at 94 GHz is transmitted through a high-gain horn antenna to the human chest at a distance of 1 m. The phase-modulated reflection signal is down-converted to the baseband by the quadrature mixer with an excellent amplitude and phase matches between I and Q channels, which makes the IQ mismatch correction in the digital domain unnecessary. The baseband I and Q data are digitized using data acquisition (DAQ) board. The arctangent demodulation with automatic phase unwrapping is applied to the low-pass filtered I and Q data to effectively solve the null point problem. A slow-varying DC component is rejected in the demodulated signal by the trend removal algorithm. Then, the respiration signal with a frequency of 0.27 Hz and a displacement of ~6.1 mm is retrieved by applying a low-pass filter. Finally, the respiration signal is removed by the band-pass filter and the heartbeat signal is extracted, showing a frequency of 1.35 Hz and a displacement of ~0.26 mm. The extracted respiration and heartbeat rates are very close to the manual measurement results. The demonstrated W-band CW radar sensors can be easily applied to find the angular location of the human body by using a phased array under a compact size.

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“…It can detect the movement of an object by measuring the change in the phase between the object and the radar. On the basis of the Doppler principle, biological radar can detect body movement at a remote distance to identify vital signs [ 4 ]. Besides monitoring physiological signals in a noncontact and noninvasive manner, biological radar is also capable of penetrating a nonmetallic substance with a certain thickness.…”

Section: Introductionmentioning

confidence: 99%

Searching for Survivors through Random Human-Body Movement Outdoors by Continuous-Wave Radar Array

Chen

et al. 2016

PLoS ONE

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It is a major challenge to search for survivors after chemical or nuclear leakage or explosions. At present, biological radar can be used to achieve this goal by detecting the survivor’s respiration signal. However, owing to the random posture of an injured person at a rescue site, the radar wave may directly irradiate the person’s head or feet, in which it is difficult to detect the respiration signal. This paper describes a multichannel-based antenna array technology, which forms an omnidirectional detection system via 24-GHz Doppler biological radar, to address the random positioning relative to the antenna of an object to be detected. Furthermore, since the survivors often have random body movement such as struggling and twitching, the slight movements of the body caused by breathing are obscured by these movements. Therefore, a method is proposed to identify random human-body movement by utilizing multichannel information to calculate the background variance of the environment in combination with a constant-false-alarm-rate detector. The conducted outdoor experiments indicate that the system can realize the omnidirectional detection of random human-body movement and distinguish body movement from environmental interference such as movement of leaves and grass. The methods proposed in this paper will be a promising way to search for survivors outdoors.

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A W-Band MMIC Radar System for Remote Detection of Vital Signs

Cited by 17 publications

References 15 publications

Human Vital Signs Detection Methods and Potential Using Radars: A Review

Human Vital Signs Detection Methods and Potential Using Radars: A Review

Non-Contact Measurement of Human Respiration and Heartbeat Using W-band Doppler Radar Sensor

Searching for Survivors through Random Human-Body Movement Outdoors by Continuous-Wave Radar Array

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