Medical & Biological Engineering & Computing

, Volume 45, Issue 11, pp 1113–1119 | Cite as

A study on a non-contacting respiration signal monitoring system using Doppler ultrasound

  • Se Dong Min
  • Dae Joong Yoon
  • Sung Won Yoon
  • Yong Hyeon Yun
  • Myoungho LeeEmail author
Special Issue


We proposed non-contacting respiration signal monitoring system for sleep apnea syndrome. Experiments were conducted by emitting 40 kHz ultrasound beam, which is set tone burst mode by 1 ms period to a subject chest. Normal respiration condition and a simulated sleep apnea syndrome condition were measured while subjects were holding breath. To obtain the actual respiration signal from the raw signal, ultrasound attenuation characteristics were considered. The Doppler ultrasound signal was detectable once the received signal obtained by demodulation circuits passed through a low pass filter (LPF). The signal’s ripples were eliminated by moving average method and the signal’s peaks were detected by phase portrait reconstruction method to measure the respiration rate.


Non-contacting Respiration signal monitoring Sleep apnea Ultrasound attenuation characteristic Phase portrait reconstruction method 


  1. 1.
    Fei J, Pavlidis I (2006) Analysis of breathing air flow patterns in thermal imaging. In: Proceedings of the 28th IEEE EMBS annual international conference, New York City, USAGoogle Scholar
  2. 2.
    Gammell PM (1981) Improved ultrasonic detection using the analytic signal magnitude, Ultrasonics, March, pp 73–76Google Scholar
  3. 3.
    Kim DS (2003) Clinical physiology, vol 540. Korea Medical Book Publisher, pp 549–551Google Scholar
  4. 4.
    Lee J-W, Kim K-S, Lee B, Lee B, Lee M (2002) A real time QRS detection using delay-coordinate mapping for the microcontroller implementation. Ann Biomed Eng 30:1–12CrossRefGoogle Scholar
  5. 5.
    Nakai H, Ishihara K, Miyake Y, Watannabe M (2000) Non-restrictive visual respiration monitoring. In: Proceedings of 15th international conference on pattern recognitionGoogle Scholar
  6. 6.
    Niizeki K, Nishidate I, Uchida K, Kuwahara M (2005) Unconstrained cardiorespiratory and body movement monitoring system for home care. Med Biol Eng Comput 43:716–724CrossRefGoogle Scholar
  7. 7.
    Tanaka S, Matsumoto Y, Wakimoto K (2002) Unconstrained and non-invasive measurement of heart-beat and respiration periods using a phonocardiographic sensor. Med Biol Eng Comput 40:246–252CrossRefGoogle Scholar
  8. 8.
    Takens F (1980) Lectures Notes in Mathematics, vol 898, Spinger, Heidelberg, p 230Google Scholar
  9. 9.
    Uenoyama M, Matsui T, Yamada K, Suzuki S, Takase B, Suzuki S, Ishihara M, Kawakami M (2006) Non-contact respiratory monitoring system using a ceiling-attached microwave antenna. Med Biol Eng Comput 44:835–840CrossRefGoogle Scholar
  10. 10.
    Várady P, Micsik T, Benedek S (2002) A novel method for the detection of apnea and hypopnea events in respiration signals. IEEE Trans Biomed Eng 49(9):936CrossRefGoogle Scholar

Copyright information

© International Federation for Medical and Biological Engineering 2007

Authors and Affiliations

  • Se Dong Min
    • 1
  • Dae Joong Yoon
    • 1
  • Sung Won Yoon
    • 1
  • Yong Hyeon Yun
    • 1
  • Myoungho Lee
    • 1
    Email author
  1. 1.Department of Electrical and Electronic EngineeringYonsei UniversitySeoulSouth Korea

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