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스펙트럼 이동을 이용한 청진음 강화

Reinforcing Stethoscope Sound using Spectral Shift

  • 정동근 (동아대학교 의과대학 의공학교실)
  • Jung, Dong Keun (Department of Medical Engineering, College of Medicine, Dong-A University)
  • 투고 : 2021.01.11
  • 심사 : 2021.01.26
  • 발행 : 2021.01.31

초록

Human hearing sensitivity is frequency-dependent. The sensitivity is low at both ends of the audible frequency, and the sensitivity is the highest in the middle band at 3000 Hz. The heart sound of a healthy person is concentrated at a low frequency of 200 Hz or less, and despite using a stethoscope, the hearing sensitivity of the human body is low, and the stethoscope sound is low. Amplifying the sound of the stethoscope is not effective in distinguishing heart sounds in noisy environments because it maintains the same signal-to-noise ratio. In this study, a method of enhancing auditory stimulation was developed by applying a method of moving the spectrum of auscultation sounds into a high-frequency region where the human body is highly sensitive to hearing. The spectrum of the auscultation sound was moved up by 500 Hz in the frequency domain, and an inverse fast Fourier transform (FFT) was performed to reconstruct the auscultation sound. The heart sounds reconstructed by moving the spectra were divided into the first heart and second heart sound components, as in the original heart sound, and it was confirmed that the intensity was large in the cochleagram representing auditory stimulation. Therefore, this study suggested that spectral shift is a method to enhance auditory stimulation during auscultation without increasing the intensity of the auscultation sound.

키워드

참고문헌

  1. L. A. Geddes, "Birth of the stethoscope", IEEE Eng Med Biol Mag, Vol. 24, No. 1, pp.84-86, 2005. https://doi.org/10.1109/MEMB.2005.1384105
  2. V. A. McKusick, Cardiovascular Sound, Baltimore, Williams Wilkins, 1958.
  3. M. L. Rice and D. J. Doyle, "Comparison of phonocardiographic monitoring location," in Proc. 17th , Annu Int Conf IEEE Eng Med Biol Soc, Montreal, Canada, pp. 685-686, 1995.
  4. K. lee, Y. Ji, Y. J, and Y. C. Park, "Development and Implementation of Noise-Canceling Technology for Digital Stethoscope", J Biomed Eng Res, Vol. 34, pp.204-211, 2013. https://doi.org/10.9718/JBER.2013.34.4.204
  5. C. McMechan, S. Poman, "Design and implementation of a low cost electronic stethoscope", in Proc. IEEE Pacific Rim Conf Commun Comput Sig Process, pp.714-718, 2011.
  6. A. W. Hahn, "On stethoscope design: A challenge for biomedical circuit designers", Biomed Sci Instrum, Vol. 37, pp. 499-503, 2001.
  7. H. K. Kim, J. I. Jung, and J. S. Cho, "Design and Implementation of tele auscultation medicine smart-healthcare system based on digital stethoscope", J Korean Inst Electron Eng CI, Vol. 48, No. 6, pp.62-70, 2011.
  8. V. A. McKusick, Cardiovascular Sound in Health and Disease, Baltimore: Williams & Wilkins, 1958.
  9. E. E. Rappaport and H. B. Sprague, "Physiologic and physical laws that govern auscultation and their clinical application", Am Heart J, Vol. 21, pp.257-318, 1941. https://doi.org/10.1016/S0002-8703(41)90904-3
  10. J. D. Richard, C. Gables, "Frequency spectra of some normal heart sounds", Am Heart J, Vol. 53, pp.183-192, 1957. https://doi.org/10.1016/0002-8703(57)90206-5
  11. J. Keith, Acoustic and Auditory Phonetics, (3rd ed.), Wiley-Blackwell, 2015.
  12. T. G. Dolan, S. R. Oliver, and J. F. Maurer, "Stethoscopes: Real-ear measurements and digital frequency transposition", Hearing J, Vol. 54, No. 1, pp.36-44, 2001. https://doi.org/10.1097/01.HJ.0000294495.25034.29
  13. H. M. Aumann, N. W. Emanetoglu, "Stethoscope with digital frequency translation for improved audibility", Healthc Technol Lett, Vol. 6, No. 5, pp143-146, 2019. https://doi.org/10.1049/htl.2019.0011
  14. www.fon.hum.uva.nl/praat/manual/Excitation.html (retrieved on Dec. 15, 2020).
  15. www.fon.hum.uva.nl/praat/manual/Cochleagram.html (retrieved on Dec. 15, 2020).