Abstract
Through-the-wall human subject localization and respiration rate detection using a multi-channel Doppler radar is proposed. The proposed methodology is used to detect respiration signal of the subject when the environment between the radar and the subject is wood, glass or any other material which resembles real-life situations. The noise level is reduced using cross-correlation between received signals from different channels. The system is compact enough to be carried on a micro-drone. This work finds application in real-life situations such as earthquake, medical-care, building collapse and patient monitoring.
Introduction
- The non-invasive detection of respiration rate of subject uses the Doppler Effect.
- The RF wave is transmitted towards the human subject and wave reflected back from the human body is used for detection of vital signs.
- Vital signs of human are:
i. Heartbeat- 0.8-2 Hz and chest movement ~ 1 mm
ii. Respiration rate- 0-0.8 Hz and chest movement due to respiration ~ 5 mm.
- Received signal contains the information about the vital signs.
- The information of respiration signal is present in the phase of the received signal
- Respiration signal is used to detect the presence of human subject behind the wall or under the debris.
- Easily mounted on the UAV to scan the area under surveillance or natural calamity like earthquake, tsunami etc.
- UAV scan the effected area to find the alive person buried under the debris
- UAV can be controlled and monitored from the control room
- The system is able to detect and localize the living person behind the wall or in the natural calamity situation
- Multichannel system improve the detection and localization of alive human
References
- Harikesh, A. Basu, M. P. Abegaonkar, and S. K. Koul, “Through the wall respiration rate detection using Hilbert vibrational decomposition,” IEEE MTT-S Int. Microw. Symp. Dig., Philadelphia, PA, USA, Jun. 2018, pp. 961–963.
- F.-K. Wang, C.-H. Fang, T.-S. Horng, K.-C. Peng, J.-Y. Li, and C.-C. Chen, “Concurrent vital sign and position sensing of multiple individuals using self-injection-locked tags and injection-locked I/Q receivers with arctangent demodulation,” IEEE Trans. Microw. Theory Techn., vol. 61, no. 12, pp. 4689–4699, Dec. 2013.
- Y. Xiong, S. Chen, X. Dong, Z. Peng and W. Zhang, "Accurate Measurement in Doppler Radar Vital Sign Detection Based on Parameterized Demodulation," IEEE Trans. Microw. Theory Techn., Vol. 65, No. 11, 4483-4492, Nov. 2017.
- . Xiong, S. Chen, X. Dong, Z. Peng and W. Zhang, "Accurate Measurement in Doppler Radar Vital Sign Detection Based on Parameterized Demodulation," IEEE Trans. Microw. Theory Techn., Vol. 65, No. 11, 4483-4492, Nov. 2017.
Conclusions
- In complex environment between the radar and human subject, respiration signal is detected from the noisy signal.
- The results are repeatable under different scenario of measurement. So a compact, low cost and portable system is made for respiration rate detection of human subject which is used in real-life scenario or complex environments.
- The presence of human subject is detected behind the wall
Center for Applied Research in Electronics(CARE) IIT Delhi
Industrial Significance
- Continuous patient Monitoring in Hospitals.
- Non-Invasive Health Tracking Hand-held/ fixed Devices.
- Early detection of people under debris due to building collapse in a scenario of natural calamities.
- Human search and rescue operations in a remote location.
- Military Applications.
Through the Wall Human Subject Respiration Detection and Localization using Doppler Radar
Harikesh, Ananjan Basu* and Mahesh P. Abegaonkar*
Result
- The radar and human subject are present 0.5 m away from the wall.
- Frequency of operation 2.4 GHz.
- Brick wall Thickness is 15 cm.
- The respiration rate is estimated in complex environment.
- For different medium between the radar and human subject the DOA is estimated.
- Respiration rate is estimated in complex real-life environment
- Localization of target can be done by finding the range and angular position.
Table1:Measured results for different medium
Industry Day Theme {Communication Technologies}
Fig 2. Block diagram and measurement setup
Fig 3. Measurement setup for different medium
Fig 4. System Mounted on Drones for buried people detection in the debris
Fig 1. Natural calamities: Earthquake, Tsunami