Heart Sound Localization and Reduction in Tracheal Sounds by Gabor Time-Frequency Masking

Yıl 2017, Cilt: 17 Sayı: 1, 3275 - 3282, 27.03.2017

Esra Saatcı Aydın Akan

Öz

Background and aim: Respiratory
sounds, i.e. tracheal and lung sounds, have been of great interest due to their
diagnostic values as well as the potential of their use in the estimation of
the respiratory dynamics (mainly airflow). Thus the aim of the study is to
present a new method to filter the heart sound interference from the tracheal
sounds.

Materials and methods: Tracheal
sounds and airflow signals were collected by using an accelerometer from 10 healthy
subjects. Tracheal sounds were then pre-processed by Recursive Least Square -
Adaptive Noise Cancellation (RLS-ANC) filter to remove background noise. Gabor
time-frequency expansion was used for both heart sound localization and
reduction problem.

Results: In
the first step of filtering, RLS-ANC successfully filtered out the broad - band
ambient noise. Reconstruction of tracheal sound was achieved from modified
Gabor coefficients without heart sound noise.

Conclusion: Visual inspection and quantitative analysis
demonstrated that Gabor time-frequency masking with RLS-ANC filters provides successful
tracheal sound signal separation.

Anahtar Kelimeler

tracheal sound filtering, Gabor expansion, time frequency filtering

Kaynakça

• [1] Pasterkamp H, Kraman SS, Wodicka GR. Respiratory sounds advances beyond the stethoscope. Am J Respir Crit Care Med 1997; 156: 974-987.
• Moussavi Z, Leopando MT, Pasterkamp H, Rempel G. Computerized acoustical respiratory phase detection without airflow measurement. Med Biol Eng Comput 2000; 38(2): 198-203.
• Yadollahi A, Zaussavi Z. A robust method for estimating respiratory flow using tracheal sounds entropy. IEEE Trans Biomed Eng 2006; 53(4):662-668