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A Method for Remotely Sensing Vital Signs of Human Subjects Outdoors.

Li C, Chen F, Jin J, Lv H, Li S, Lu G, Wang J - Sensors (Basel) (2015)

Bottom Line: Although human bodies can be found by smart vehicles and drones equipped with cameras, it is difficult to verify if the person is alive or dead this way.Finally, the detection capabilities of the radar system and the signal processing method are verified through experiments which show that human respiration signals can be extracted when the subject is 7 m away outdoors.The method provided in this paper will be a promising way to search for human subjects outdoors.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an 710032, China. lichuantao614@126.com.

ABSTRACT
After chemical or nuclear leakage or explosions, finding survivors is a huge challenge. Although human bodies can be found by smart vehicles and drones equipped with cameras, it is difficult to verify if the person is alive or dead this way. This paper describes a continuous wave radar sensor for remotely sensing the vital signs of human subjects. Firstly, a compact and portable 24 GHz Doppler radar system is designed to conduct non-contact detection of respiration signal. Secondly, in order to improve the quality of the respiration signals, the self-correlation and adaptive line enhancer (ALE) methods are proposed to minimize the interferences of any moving objects around the human subject. Finally, the detection capabilities of the radar system and the signal processing method are verified through experiments which show that human respiration signals can be extracted when the subject is 7 m away outdoors. The method provided in this paper will be a promising way to search for human subjects outdoors.

No MeSH data available.


Related in: MedlinePlus

Signals collected in a strong interference environment when the radar is 3 m away from the human body. (a) Original signal waveform and frequency spectrum; (b) Signal after FIR filter processing and its frequency spectrum.
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sensors-15-14830-f009: Signals collected in a strong interference environment when the radar is 3 m away from the human body. (a) Original signal waveform and frequency spectrum; (b) Signal after FIR filter processing and its frequency spectrum.

Mentions: Figure 9 shows the signals collected in a strong interference environment when the radar is 3 m away from human body. Figure 9 refers to the original signal waveform and its frequency spectrum, and for the frequency spectrum, the improved Welch method is adopted, with overlap of 1024 points, rectangular window and 2048 Fast Fourier Transform points. Figure 9b refers to the signal after applying the low pass FIR filter to Figure 9a and its frequency spectrum. FIR adopts a Hamming window, with filter order of 100, and 1 Hz cut-off frequency. After only FIR filtering, it is still difficult to see s stable and regular respiration waveform in the waveform as shown in Figure 9b.


A Method for Remotely Sensing Vital Signs of Human Subjects Outdoors.

Li C, Chen F, Jin J, Lv H, Li S, Lu G, Wang J - Sensors (Basel) (2015)

Signals collected in a strong interference environment when the radar is 3 m away from the human body. (a) Original signal waveform and frequency spectrum; (b) Signal after FIR filter processing and its frequency spectrum.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541809&req=5

sensors-15-14830-f009: Signals collected in a strong interference environment when the radar is 3 m away from the human body. (a) Original signal waveform and frequency spectrum; (b) Signal after FIR filter processing and its frequency spectrum.
Mentions: Figure 9 shows the signals collected in a strong interference environment when the radar is 3 m away from human body. Figure 9 refers to the original signal waveform and its frequency spectrum, and for the frequency spectrum, the improved Welch method is adopted, with overlap of 1024 points, rectangular window and 2048 Fast Fourier Transform points. Figure 9b refers to the signal after applying the low pass FIR filter to Figure 9a and its frequency spectrum. FIR adopts a Hamming window, with filter order of 100, and 1 Hz cut-off frequency. After only FIR filtering, it is still difficult to see s stable and regular respiration waveform in the waveform as shown in Figure 9b.

Bottom Line: Although human bodies can be found by smart vehicles and drones equipped with cameras, it is difficult to verify if the person is alive or dead this way.Finally, the detection capabilities of the radar system and the signal processing method are verified through experiments which show that human respiration signals can be extracted when the subject is 7 m away outdoors.The method provided in this paper will be a promising way to search for human subjects outdoors.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an 710032, China. lichuantao614@126.com.

ABSTRACT
After chemical or nuclear leakage or explosions, finding survivors is a huge challenge. Although human bodies can be found by smart vehicles and drones equipped with cameras, it is difficult to verify if the person is alive or dead this way. This paper describes a continuous wave radar sensor for remotely sensing the vital signs of human subjects. Firstly, a compact and portable 24 GHz Doppler radar system is designed to conduct non-contact detection of respiration signal. Secondly, in order to improve the quality of the respiration signals, the self-correlation and adaptive line enhancer (ALE) methods are proposed to minimize the interferences of any moving objects around the human subject. Finally, the detection capabilities of the radar system and the signal processing method are verified through experiments which show that human respiration signals can be extracted when the subject is 7 m away outdoors. The method provided in this paper will be a promising way to search for human subjects outdoors.

No MeSH data available.


Related in: MedlinePlus