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

2019 ◽  
Vol 11 (10) ◽  
pp. 1237 ◽  
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.

Multi-target Vital Signs Detection Using SIMO Continuous-wave Radar with DBF Technique

2020 ◽  
Author(s):  
Junjun Xiong ◽  
Hongqiang Zhang ◽  
Hong Hong ◽  
Heng Zhao ◽  
Xiaohua Zhu ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Vital Signs ◽  
Wave Radar

scholarly journals Correction: Park, J.-H. et al. 915-MHz Continuous-Wave Doppler Radar Sensor for Detection of Vital Signs. Electronics 2019, 8, 561

Electronics ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 855 ◽  
Author(s):  
Park ◽  
Jeong ◽  
Lee ◽  
Oh ◽  
Yang
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Vital Signs ◽  
Radar Sensor ◽  
Continuous Wave Doppler ◽  
Published Paper

The authors wish to make the following corrections to the published paper [...]

scholarly journals Speed Calibration and Traceability for Train-Borne 24 GHz Continuous-Wave Doppler Radar Sensor

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1230
Author(s):  
Lei Du ◽  
Qiao Sun ◽  
Jie Bai ◽  
Xiaolei Wang ◽  
Tianqi Xu
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Single Channel ◽  
Full Range ◽  
Calibration Method ◽  
Simulation System ◽  
Radar Sensor ◽  
Dual Channel ◽  
Calibration Methods ◽  
24 Ghz

The 24 GHz continuous-wave (CW) Doppler radar sensor (DRS) is widely used for measuring the instantaneous speed of moving objects by using a non-contact approach, and has begun to be used in train-borne movable speed measurements in recent years in China because of its advanced performance. The architecture and working principle of train-borne DRSs with different structures including single-channel DRSs used for freight train speed measurements in railway freight dedicated lines and dual-channel DRSs used for speed measurements of high-speed and urban rail trains in railway passenger dedicated lines, are first introduced. Then, the disadvantages of two traditional speed calibration methods for train-borne DRS are described, and a new speed calibration method based on the Doppler shift signal simulation by imposing a signal modulation on the incident CW microwave signal is proposed. A 24 GHz CW radar target simulation system for a train-borne DRS was specifically realized to verify the proposed speed calibration method for a train-borne DRS, and traceability and performance evaluation on simulated speed were taken into account. The simulated speed range of the simulation system was up to (5~500) km/h when the simulated incident angle range was within the range of (45 ± 8)°, and the maximum permissible error (MPE) of the simulated speed was ±0.05 km/h. Finally, the calibration and uncertainty evaluation results of two typical train-borne dual-channel DRS samples validated the effectiveness and feasibility of the proposed speed calibration approach for a train-borne DRS with full range in the laboratory as well as in the field.

scholarly journals A dataset of clinically recorded radar vital signs with synchronised reference sensor signals

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Sven Schellenberger ◽  
Kilin Shi ◽  
Tobias Steigleder ◽  
Anke Malessa ◽  
Fabian Michler ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
Continuous Wave ◽  
Vital Signs ◽  
Radar System ◽  
Tilt Table ◽  
Non Invasive ◽  
Impedance Cardiogram ◽  
Wave Radar ◽  
Reference Device ◽  
Sensor Signals

Abstract Using Radar it is possible to measure vital signs through clothing or a mattress from the distance. This allows for a very comfortable way of continuous monitoring in hospitals or home environments. The dataset presented in this article consists of 24 h of synchronised data from a radar and a reference device. The implemented continuous wave radar system is based on the Six-Port technology and operates at 24 GHz in the ISM band. The reference device simultaneously measures electrocardiogram, impedance cardiogram and non-invasive continuous blood pressure. 30 healthy subjects were measured by physicians according to a predefined protocol. The radar was focused on the chest while the subjects were lying on a tilt table wired to the reference monitoring device. In this manner five scenarios were conducted, the majority of them aimed to trigger hemodynamics and the autonomic nervous system of the subjects. Using the database, algorithms for respiratory or cardiovascular analysis can be developed and a better understanding of the characteristics of the radar-recorded vital signs can be gained.

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%.

Target Range and Velocity Measurement to Reduce False Targets in FMCW Automotive Anti-Collision Radar

2012 ◽  
Vol 253-255 ◽  
pp. 1410-1417 ◽  
Author(s):  
Zhi Gang Li ◽  
Qiong Chan Gu
Keyword(s):  
Computer Simulation ◽  
Theoretical Analysis ◽  
Continuous Wave ◽  
Target Range ◽  
Multiple Targets ◽  
Fmcw Radar ◽  
Wave Radar ◽  
Frequency Modulate ◽  
Inherent Problem ◽  
Simulation Results

For frequency modulate continuous wave radar, it is necessary and difficult to search the pairs of beat frequencies in an up-chirp mode and a down-chirp mode t o measure range and velocity of multiple targets. However, the inherent problem of FMCW radar is multiple targets detection. False targets can appearance because of mistaking the combination of these beat frequencies. A novel waveform named double-slope symmetrical saw-tooth wave is proposed and its corresponding algorithm is also introduced to resolve the problem of multiple targets detection for automotive anti-collision radar. Computer simulation results and theoretical analysis prove that the method is effective and practical for multiple targets detection in intelligence transportation system.

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