Vol. 5

Front:[PDF file] Back:[PDF file]
Latest Volume
All Volumes
All Issues
2008-12-03

Wireless Bio-Radar Sensor for Heartbeat and Respiration Detection

By Byung-Jun Jang, Sang-Hyuk Wi, Jong-Gwan Yook, Moon-Que Lee, and Kyoung-Joung Lee
Progress In Electromagnetics Research C, Vol. 5, 149-168, 2008

Abstract

In this study, a wireless bio-radar sensor was designed to detect a human heartbeat and respiration signals without direct skin contact. In order to design a wireless bio-radar sensor quantitatively, the signal-to-noise ratio (SNR) in the baseband output of a sensor should be calculated. Therefore, we analyzed the SNR of the wireless bio-radar sensor, considering the signal power attenuation in a human body and all kinds of noise sources. Especially, we measured a residual phase noise of a typical free-running oscillator and used its value for the SNR analysis. Based on these analysis and the measurement results, a compact, low-cost 2.4 GHz direct conversion bio-radar sensor was designed and implemented in a printed circuit board. The demonstrated sensor consists of two printed antennas, a voltage-controlled oscillator, an I/Q demodulator, and analog circuits. The heartbeat and respiration signals acquired from the I/Q channel of the sensor are applied to the digital signal processing circuit using MATLAB. ECG (electrocardiogram), and reference respiration signals are measured simultaneously to evaluate the performance of the sensor. With an output power of 0dBm and a free running oscillator without a phase locked loop circuits, a detection range of 50 cm was measured. Measurement results show that the heart rate and respiration accuracy was very high. Therefore, we verified that a wireless bio-radar sensor could detect heartbeat and respiration well without contact and our SNR analysis could be an effective tool to design a wireless bio-radar sensor.

Citation


Byung-Jun Jang, Sang-Hyuk Wi, Jong-Gwan Yook, Moon-Que Lee, and Kyoung-Joung Lee, "Wireless Bio-Radar Sensor for Heartbeat and Respiration Detection," Progress In Electromagnetics Research C, Vol. 5, 149-168, 2008.
http://jpier.org/PIERC/pier.php?paper=08110603

References


    1. Lubecke, V. M., O. Boric-Lubecke, A. Host-Madsen, and A. E. Fathy, "Through-the-Wall radar life detection and monitoring," IEEE MTT-S Int. Microwave Symposium Digest, 769-772, May 2007.

    2. Lin, J. C., "Non-invasive microwave measurement of respiration ," Proceedings of the IEEE, Vol. 63, No. 10, 1530, 1975.
    doi:10.1109/PROC.1975.9992

    3. Droitcour, A. D., O. Boric-Lubecke, V. M. Lubecke, and J. Lin, "A microwave radio for Doppler radar sensing of vital signs," IEEE MTT-S Int. Microwave Symposium Digest, 175-178, 2001.

    4. Droitcour, A. D., O. Boric-Lubecke, V. M. Lubecke, J. Lin, and G. T. A. Kovac, "Range correlation and I/Q performance benefits in single-chip silicon doppler radars for non-contact cardiopulmonary monitoring ," IEEE Transactions on Microwave Theory Technique, Vol. 52, 838-848, March 2004.
    doi:10.1109/TMTT.2004.823552

    5. Park, B.-K., O. Boric-Lubecke, and V. M. Lubecke, "Arctanget demodulation with dc offset compensation in quadrature Doppler radar receiver systems," IEEE Transactions on Microwave Theory Technique, Vol. 55, 1073-1079, May 2007.
    doi:10.1109/TMTT.2007.895653

    6. Nguyen, D., S. Yamada, B.-K. Park, V. M. Lubecke, O. Boris-Lubecke, and A. H. Madsen, "Noise considerations for remote detection of life signs with microwave Doppler radar," Proceedings of the 29th Annual International Conference of the IEEE EMBS , 1667-1670, August 2007.

    7. Droitcour, A., Non-contact measurement of heart and respiration rates with a single-chip microwave doppler radar , Ph.D. Thesis, Stanford University, June 2006.

    8. Lohman, B., O. Boric-Lubecke, V. M. Lubecke, P. W. Ong, and M. M. Sondhi, "A digital signal processor for Doppler radar sensing of vital signs," Proceedings of IEEE 23rd Annual Engineering in Medicine and Biology Society Conference, Vol. 4, 3359-3362, 2001.
    doi:10.1109/IEMBS.2001.1019547

    9. Henry, G., Anatomy of the Human Body, Lee & Febiger, Philadelphia, 1918.

    10. Chang, K., RF and Microwave Wireless Systems, Wiley Science, 2000.

    11. Staderini, E. M., "UWB radar in medicine," IEEE AESS Systems Magazine, Vol. 17, 13-18, January 2002.
    doi:10.1109/62.978359

    12. Gabriel, C., "Compilation of the dielectric properties of body tissues at RF and microwave frequencies," http://niremf.ifac.cnr.it/..

    13. Fan, Z., S. Qiao, H.-F. Jiang Tao, and L.-X. Ran, "Signal descriptions and formulations for long range UHF RFID readers," Progress In Electromagnetics Research, Vol. 71, 109-127, 2007.
    doi:10.2528/PIER07021501