DOI QR코드

DOI QR Code

Wireless RF Sensor Structure for Non-Contact Vital Sign Monitoring

  • Kim, Sang-Gyu (Degree in Electrical and Electronic Engineering, Yonsei University) ;
  • Yun, Gi-Ho (School of Information and Communication Engineering, Sungkyul University) ;
  • Yook, Jong-Gwan (Degree in Electrical and Electronic Engineering, Yonsei University)
  • Received : 2011.12.21
  • Accepted : 2012.02.10
  • Published : 2012.03.31

Abstract

This paper describes a compact and novel wireless vital sign sensor at 2.4 GHz that can detect heartbeat and respiration signals. The oscillator circuit incorporates a planar resonator, which functions as a series feedback element as well as a near-field radiator. The periodic movement of a human body during aerobic exercise could cause an input impedance variation of the radiator within near-field range. This variation results in a corresponding change in the oscillation frequency and this change has been utilized for the sensing of human vital signs. In addition, a surface acoustic wave (SAW) filter and power detector have been used to increase the system sensitivity and to transform the frequency variation into a voltage waveform. The experimental results show that the proposed sensor placed 20 mm away from a human body can detect the vital signs very accurately.

Acknowledgement

Supported by : NIPA(National IT Industry Promotion Agency)

References

  1. V. M. Lubecke, Boric-Lubecke, A. Host-Madsen, and A. E. Fathy, "Through-the-wall radar life detection and monitoring," IEEE MTT-S Int. Microwave Symposium Digest, pp. 769-772, May 2007.
  2. S. G. Kim, H. Kim, Y. Lee, I. S. Kho, and J. G. Yook, "5.8 GHz vital signal sensing Doppler radar using isolation-improved branch-line coupler," Radar Conference 3rd, EuMW, Sep. 2006.
  3. Y. Yan, C. Li, and J. Lin, "Effect of I/Q mismatch on measurement of periodic movement using a Doppler radar sensor," Proc. IEEE Radio and Wireless Symp., pp. 196-199, Jan. 2010.
  4. Y. Xiao, J. Lin, O. Boric-Lubecke, and V. M. Lubecke, "Frequency tuning technique for remote detection of heartbeat and respiration using low-power double-sideband transmission in a-band," IEEE Trans. Microw. Theory Tech., vol. 54, no. 5, pp. 2023-2032, May 2006. https://doi.org/10.1109/TMTT.2006.873625
  5. A. D. Droitcour, O. Boric-Lubecke, V. M. Lubecke, J. Lin, and G. T. A. Kovac, "0.25 um CMOS and BiCMOS single chip direct conversion Doppler radars for remote sensing of vital signs," IEEE Int. Solid State Circuits Conf. Dig., pp. 348-349, Feb. 2002.
  6. T. J. Sullivan, S. R. Deiss, T. P. Jung, and G. Cauwenberghs, "A brain machine interface using drycontact, low noise EEG sensors," IEEE International Symp., pp. 1986-1989, 2008.
  7. Alfredo Lopez, P. C. Richardson, "Capacitive electrocardiographic and bioelectrodes," IEEE Trans. on Biomedical Engineering., vol. 1, pp. 96-99, Jan. 1969.
  8. T. J. Sullivan, S. R. Deiss, and G. Cauwenberghs, "A low-noise, non-contact EEG/ECG sensor," in Biomedical Circuit and Systems Conf., pp. 154-157, 2007.
  9. C. Park, P. H. Chou, Y. Bai, R. Matthews, and A. Hibbs, "An ultra-wearable, wireless, low power ECG monitoring system," in Biomedical Circuits and Systems Conf., pp. 241-244, Nov. 2006.
  10. A. Ueno, Y. Akabanem, T. Kato, H. Hoshino, S. Kataoka, and Y. Ishiyama, "Capacitive sensing of electrocardiographic potential through cloth from the dorsal surface of the body in a supine position: A preliminary study," IEEE Trans. on Biomedical Engineering, vol. 54, pp. 759-766, Apr. 2007. https://doi.org/10.1109/TBME.2006.889201
  11. Jeremy Everard, Fundamentals of RF Circuit Design with Low Noise Oscillators, John Wiley & Sons, Ltd., 2001.
  12. Randall W. Rhea, Oscillator Design and Computer Simulation, 2nd edition, Novel Publishing Corporation, 1995.
  13. Jeremy Everard, Fundamentals of RF Circuit Design with Low Noise Oscillators, John Wiley & Sons, Ltd., 2001.
  14. F. Giannini, G. Leuzzi, Nonlinear Microwave Circuit Design, John Wiley & Sons, Ltd., 2004.
  15. A. A. Behagi, S. D. Turner, "A non-linear CAD model for the regenerative dielectric resonator oscillator," IEEE International Frequency Control Symposium, 1995.
  16. A. Takaoka, K. Ura, "Noise analysis of nonlinear feedback oscillator with AM-PM conversion coefficient," IEEE Trans. Microwave Theory and Tech., vol. 28, no. 6. Jun. 1980.
  17. M. Regis, O. Llopis, and J. Graffeuil, "Nonlinear modeling and design of bipolar transistors ultra low phase-noise dielectric-resonator oscillators," IEEE Trans. Microwave Theory and Tech., vol. 46, no. 10, Oct. 1998.
  18. C. Gabriel, S. Gabriel, and E. Corthout, "The dielectric properties of biological tissues: I. Literature survey," Phy. Med. Biol., 41, 2231, 1996. https://doi.org/10.1088/0031-9155/41/11/001
  19. M. Jaeger, M. Mueller, D. Wettach, T. Oezkan, J. Motsch, T. Schauer, R. Jaeger, and A. Bolz, "Firstaid sensor system : New methods for single-point detection and analysis of vital parameters such as pulse and respiration," IEEE Engineering in Medicine and Biology Society, Aug. 2007.

Cited by

  1. Wrist Pulse Detection System Based on Changes in the Near-Field Reflection Coefficient of a Resonator vol.24, pp.10, 2014, https://doi.org/10.1109/LMWC.2014.2340584
  2. Flexible Non-Constrained RF Wrist Pulse Detection Sensor Based on Array Resonators vol.10, pp.2, 2016, https://doi.org/10.1109/TBCAS.2015.2406776
  3. Sensitivity Enhanced Vital Sign Detection Based on Antenna Reflection Coefficient Variation vol.10, pp.2, 2016, https://doi.org/10.1109/TBCAS.2014.2380435
  4. A Proximity Coupling RF Sensor for Wrist Pulse Detection Based on Injection-Locked PLL vol.64, pp.5, 2016, https://doi.org/10.1109/TMTT.2016.2549531