Development of a Digital Auscultation Device for real time Murmur Detection

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Development of a Digital Auscultation Device for
real time Murmur Detection

• Tanvi Kalra1, Abhinav2 and Sneh Anand2
•  
• 1 - Department of Biomedical Engineering, Rayat
  Bahra Institute of Engineering Bio-Technology,
  Punjab
• 2 - Centre for Biomedical Engineering, Indian
  Institute of Technology Delhi

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NEED OF THE SYSTEM

• Training required detection of subtle heart
  sounds
• Ambient noise in the hospital
• Reliable diagnosis
• Portable device

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INTRODUCTION

• development of a digital auscultation device
• second order butterworth filter
• reduce the ambient noise
• integration of
• 1. traditional stethoscope
• 2. an electret microphone
• 3. an amplifier circuit
• software - audacity
• real time plotting
• detection of murmurs
• diagnosing of heart sounds
• battery powered

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features

• Amplification
• Clear audibility
• Volume control
• 4. Noise removal
• 5. Real time plotting

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BLOCK DIAGRAM
Figure 1 block diagram of the digital
auscultation device
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connections
Figure 2 (a) traditional stethoscope, (b)
hardware circuit, (c) compatible earphones, (d)
connecting cable, (e) plotted heart sounds.
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hardware

• Electret microphone frequency response
• (30 Hz - 10 KHz)
• Amplifier circuit linear op-amps
• - gain (20)
• Buffers removing the loading effects.
• Filters 2nd order butterworth band pass filter
• - frequency range (50 Hz 600 Hz)
• - diaphragm mode
• Output potentiometers (volume and gain
  control)
• 1. Jack 1 Audible signal
• 2. Jack 2 Plotted signal

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Features Benefits

• Varying gain
• AUDACITY (compatible)
• Beneficial device for cardiologists
• Easily diagnose HEARTs conditions

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Snapshot of the auscultation
Lubb
Dup
 Figure 3 heart sounds of healthy and unhealthy
subjects
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references
1.Heart Sound Measurement and Analysis System
with Digital Stethoscope Haibin Wang Jian Chen
Yuliang Hu Zhongwei Jiang Choi Samjin
Biomedical Engineering and Informatics, 2009.
BMEI '09. 2nd International Conference on
Digital Object Identifier 10.1109/BMEI.2009.53052
87 Publication Year 2009 , Page(s) 1 - 5 2.
The embedded digital stethoscope uses the
adaptive noise cancellation filter and the type I
Chebyshev IIR bandpass filter to reduce the
noise of the heart sound Ying-Wen Bai Chao-Lin
Lu Enterprise networking and Computing in
Healthcare Industry, 2005. HEALTHCOM 2005.
Proceedings of 7th International Workshop on
Publication Year 2005 , Page(s) 278 - 281 3.
Design and implementation of a remote embedded
DSP stethoscope with a method for judging heart
murmur Ying-Wen Bai Cheng-Hsiang Yeh
Instrumentation and Measurement Technology
Conference, 2009. I2MTC '09. IEEE Digital Object
Identifier 10.1109/IMTC.2009.5168706
Publication Year 2009 , Page(s) 1580 - 1585 4.
Segmentation of heart sound recordings from an
electronic stethoscope by a duration dependent
Hidden-Markov Model Schmidt, S.E. Toft, E.
Holst-Hansen, C. Graff, C. Struijk, J.J.
Computers in Cardiology, 2008 Digital Object
Identifier 10.1109/CIC.2008.4749049
Publication Year 2008 , Page(s) 345 - 348 5.
Analysis and classification of heart sounds and
murmurs based on the instantaneous energy and
frequency estimations Sharif, Z. Zainal, M.S.
Sha'ameri, A.Z. Salleh, S.H.S. TENCON 2000.
Proceedings Volume 2 Digital Object Identifier
10.1109/TENCON.2000.888404 Publication Year
2000 , Page(s) 130 - 134 vol.2 6.Recursive
least squares adaptive noise cancellation
filtering for heart sound reduction in lung
sounds recordings Gnitecki, J. Moussavi, Z.
Pasterkamp, H. Engineering in Medicine and
Biology Society, 2003. Proceedings of the 25th
Annual International Conference of the IEEE
Volume 3 Digital Object Identifier
10.1109/IEMBS.2003.1280403 Publication Year
2003 , Page(s) 2416 - 2419 Vol.3
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Thank youany questions..?