Annals of Biomedical Engineering

, Volume 33, Issue 7, pp 937–942 | Cite as

Computer-Based Detection and Analysis of Heart Sound and Murmur

  • M. El-SegaierEmail author
  • O. Lilja
  • S. Lukkarinen
  • L. Sörnmo
  • R. Sepponen
  • E. Pesonen


To develop a digital algorithm that detects first and second heart sounds, defines the systole and diastole, and characterises the systolic murmur. Heart sounds were recorded in 300 children with a cardiac murmur, using an electronic stethoscope. A Digital algorithm was developed for detection of first and second heart sounds. R-waves and T-waves in the electrocardiography were used as references for detection. The sound signal analysis was carried out using the short-time Fourier transform. The first heart sound detection rate, with reference to the R-wave, was 100% within 0.05–0.2R-R interval. The second heart sound detection rate between the end of the T-wave and the 0.6R-R interval was 97%. The systolic and diastolic phases of the cardiac cycle could be identified. Because of the overlap between heart sounds and murmur a systolic segment between the first and second heart sounds (20–70%) was selected for murmur analysis. The maximum intensity of the systolic murmur, its average frequency, and the mean spectral power were quantified. The frequency at the point with the highest sound intensity in the spectrum and its time from the first heart sound, the highest frequency, and frequency range were also determined. This method will serve as the foundation for computer-based detection of heart sounds and the characterisation of cardiac murmurs.


Detection algorithm Signal analysis Short-time Fourier transform Systolic murmur 


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Copyright information

© Biomedical Engineering Society 2005

Authors and Affiliations

  • M. El-Segaier
    • 1
    • 4
    Email author
  • O. Lilja
    • 2
  • S. Lukkarinen
    • 3
  • L. Sörnmo
    • 2
  • R. Sepponen
    • 3
  • E. Pesonen
    • 1
  1. 1.Department of Paediatrics, Division of Paediatric CardiologyLund University HospitalSweden
  2. 2.Department of ElectroscienceLund UniversitySweden
  3. 3.Department of Applied ElectronicsHelsinki University of TechnologyHelsinkiFinland
  4. 4.Department of Paediatrics, Division of Paediatric Cardiology, Children’s HospitalLund University HospitalLundSweden

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