scholarly journals Non-Contact Monitoring of Human Vital Signs Using FMCW Millimeter Wave Radar in the 120 GHz Band

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2732
Author(s):  
Wenjie Lv ◽  
Wangdong He ◽  
Xipeng Lin ◽  
Jungang Miao
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Monitoring System ◽  
Millimeter Wave ◽  
Continuous Wave ◽  
Detection Accuracy ◽  
Narrow Beam ◽  
Millimeter Wave Radar ◽  
Fast Independent Component Analysis ◽  
Wave Radar

A non-contact heartbeat/respiratory rate monitoring system was designed using narrow beam millimeter wave radar. Equipped with a special low sidelobe and small-sized antenna lens at the front end of the receiving and transmitting antennas in the 120 GHz band of frequency-modulated continuous-wave (FMCW) system, this sensor system realizes the narrow beam control of radar, reduces the interference caused by the reflection of other objects in the measurement background, improves the signal-to-clutter ratio (SCR) of the intermediate frequency signal (IF), and reduces the complexity of the subsequent signal processing. In order to solve the problem that the accuracy of heart rate is easy to be interfered with by respiratory harmonics, an adaptive notch filter was applied to filter respiratory harmonics. Meanwhile, the heart rate obtained by fast Fourier transform (FFT) was modified by using the ratio of adjacent elements, which helped to improve the accuracy of heart rate detection. The experimental results show that when the monitoring system is 1 m away from the human body, the probability of respiratory rate detection error within ±2 times for eight volunteers can reach 90.48%, and the detection accuracy of the heart rate can reach 90.54%. Finally, short-term heart rate measurement was realized by means of improved empirical mode decomposition and fast independent component analysis algorithm.

scholarly journals Remote Measurement of Short-term Heart Rate with Narrow Beam Millimeter Wave Radar

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Wenjie Lv ◽  
Yan Zhao ◽  
Wei Zhang ◽  
Wenqi Liu ◽  
Anyong Hu ◽  
...  
Keyword(s):  
Heart Rate ◽  
Millimeter Wave ◽  
Remote Measurement ◽  
Narrow Beam ◽  
Short Term ◽  
Millimeter Wave Radar ◽  
Wave Radar

scholarly journals Remote Monitoring of Human Vital Signs Based on 77-GHz mm-Wave FMCW Radar

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2999 ◽  
Author(s):  
Yong Wang ◽  
Wen Wang ◽  
Mu Zhou ◽  
Aihu Ren ◽  
Zengshan Tian
Keyword(s):  
Millimeter Wave ◽  
Human Body ◽  
Continuous Wave ◽  
Intermediate Frequency ◽  
Detection Methods ◽  
Discrete Wavelet ◽  
Phase Information ◽  
Millimeter Wave Radar ◽  
Wave Radar ◽  
Radar Sensing

In recent years, non-contact radar detection technology has been able to achieve long-term and long-range detection for the breathing and heartbeat signals. Compared with contact-based detection methods, it brings a more comfortable and a faster experience to the human body, and it has gradually received attention in the field of radar sensing. Therefore, this paper extends the application of millimeter-wave radar to the field of health care. The millimeter-wave radar first transmits the frequency-modulated continuous wave (FMCW) and collects the echo signals of the human body. Then, the phase information of the intermediate frequency (IF) signals including the breathing and heartbeat signals are extracted, and the Direct Current (DC) offset of the phase information is corrected using the circle center dynamic tracking algorithm. The extended differential and cross-multiply (DACM) is further applied for phase unwrapping. We propose two algorithms, namely the compressive sensing based on orthogonal matching pursuit (CS-OMP) algorithm and rigrsure adaptive soft threshold noise reduction based on discrete wavelet transform (RA-DWT) algorithm, to separate and reconstruct the breathing and heartbeat signals. Then, a frequency-domain fast Fourier transform and a time-domain autocorrelation estimation algorithm are proposed to calculate the respiratory and heartbeat rates. The proposed algorithms are compared with the contact-based detection ones. The results demonstrate that the proposed algorithms effectively suppress the noise and harmonic interference, and the accuracies of the proposed algorithms for both respiratory rate and heartbeat rate reach about 93%.

scholarly journals Time-Frequency Spectral Signature of Limb Movements and Height Estimation Using Micro-Doppler Millimeter-Wave Radar

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4660
Author(s):  
Yael Balal ◽  
Nezah Balal ◽  
Yair Richter ◽  
Yosef Pinhasi
Keyword(s):  
Millimeter Wave ◽  
Continuous Wave ◽  
Animal Movement ◽  
Doppler Frequency ◽  
Spectral Signature ◽  
Millimeter Wave Radar ◽  
Time Frequency ◽  
Structure And Motion ◽  
W Band ◽  
Wave Radar

We present a technique for the identification of human and animal movement and height using a low power millimeter-wave radar. The detection was based on the transmission of a continuous wave and heterodyning the received signal reflected from the target to obtain micro-Doppler shifts associated with the target structure and motion. The algorithm enabled the extraction of target signatures from typical gestures and differentiated between humans, animals, and other ‘still’ objects. Analytical expressions were derived using a pendulum model to characterize the micro-Doppler frequency shifts due to the periodic motion of the human and animal limbs. The algorithm was demonstrated using millimeter-wave radar operating in the W-band. We employed a time–frequency distribution to analyze the detected signal and classify the type of targets.

Research on Millimeter-Wave Radar Based Automotive Lateral Anti-Collision Warning System

2013 ◽  
Vol 278-280 ◽  
pp. 804-808 ◽  
Author(s):  
Xing Tian ◽  
Xin Bi ◽  
Yi Yang Liu ◽  
Jin Song Du
Keyword(s):  
Millimeter Wave ◽  
Frequency Modulation ◽  
Continuous Wave ◽  
Warning System ◽  
Difficult Problem ◽  
False Alarms ◽  
Collision Warning ◽  
Millimeter Wave Radar ◽  
Wave Radar ◽  
Frequency Modulation Continuous Wave

According to the reasons and features of car accidents happening in vehicles’ side areas, this paper designed and developed a kind of automotive lateral anti-collision warning system by frequency modulation continuous wave, based on the research on 24GHz linear frequency modulation continuous wave radar-probing system. The system designed in this paper will forecast the potential danger to drivers and avoid the accidents. The hardware structures, algorithm, program flows and working patterns of the warning system were introduced. Furthermore, pointing to the problem of false alarms, a kind of filtering method was presented creatively. This method improved the reliability of the warning system and the accuracy of the forecast. It filtered the disturbance coming from the side of the vehicles, and solved the difficult problem that prevented the millimeter-wave radar from being applied in automotive lateral anti-collision warning system. Finally, the experiment was designed and carried out. The result verified the rationality of the solution and the practicality of the system’s function.

scholarly journals Design of a Millimeter-Wave Radar Remote Monitoring System for the Elderly Living Alone Using WIFI Communication

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7893
Author(s):  
Kai Guo ◽  
Chang Liu ◽  
Shasha Zhao ◽  
Jingxin Lu ◽  
Senhao Zhang ◽  
...  
Keyword(s):  
Older People ◽  
Monitoring System ◽  
Millimeter Wave ◽  
Remote Monitoring ◽  
Detection System ◽  
Vital Signs ◽  
Living Alone ◽  
Millimeter Wave Radar ◽  
Vital Signs Monitoring ◽  
Wave Radar

In response to the current demand for the remote monitoring of older people living alone, a non-contact human vital signs monitoring system based on millimeter wave radar has gradually become the object of research. This paper mainly carried out research regarding the detection method to obtain human breathing and heartbeat signals using a frequency modulated continuous wave system. We completed a portable millimeter-wave radar module for wireless communication. The radar module was a small size and had a WIFI communication interface, so we only needed to provide a power cord for the radar module. The breathing and heartbeat signals were detected and separated by FIR digital filter and the wavelet transform method. By building a cloud computing framework, we realized remote and senseless monitoring of the vital signs for older people living alone. Experiments were also carried out to compare the performance difference between the system and the common contact detection system. The experimental results showed that the life parameter detection system based on the millimeter wave sensor has strong real-time performance and accuracy.

The Large Millimeter Wave Radar Phased Antenna Array

2000 ◽  
Vol 54 (10) ◽  
pp. 101-111
Author(s):  
Aleksey Alekseevich Tolkachev ◽  
Vasiliy Andreevich Makota ◽  
Mariya Petrovna Pavlova ◽  
Anatoliy Moiseevich Nikolaev ◽  
Vladimir Victorovich Denisenko ◽  
...  
Keyword(s):  
Antenna Array ◽  
Millimeter Wave ◽  
Millimeter Wave Radar ◽  
Wave Radar ◽  
Phased Antenna Array
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