Adaptive Noise Canceller of Single Channel For Heart Sound Enhancement

심음 향상을 위한 단일채널 적응 잡음 제거기

  • 이철현 (경북대학교 대학원 의용생체공학과) ;
  • 김필운 (경북대학교 대학원 의용생체공학과) ;
  • 이윤정 (경북대학교 대학원 의용생체공학과) ;
  • 장용민 (경북대학교 의학전문대학원 분자의학교실) ;
  • 배건성 (경북대학교 IT대학 전자공학부) ;
  • 조진호 (경북대학교 IT대학 전자공학부) ;
  • 김명남 (경북대학교 의대 의공학교실)
  • Received : 2009.12.12
  • Accepted : 2010.03.16
  • Published : 2010.07.31

Abstract

In this paper, we proposed the single-channel adaptive noise canceller for the enhancement of heart sound (HS) in the auscultation signal. In case of either normal or emergency, a HS diagnosis is difficult due to the various signal source in the chest. Therefore, the HS enhancement is necessary. The conventional active noise canceller(ANC) has two channel, main signal and reference signal. For signal channel, the reference signal in ANC was generated by the proposed HS analyser and BS-Gate based on the characteristic of HS. This reference signal is suitable to the ANC condition. Experimental data were acquisited from MP36, SS30L in BIOPAC Inc., By the experiment, we confirmed that the proposed single-channel ANC was efficient for HS enhancement. And by the comparison with active linear enhancement, it was validate that the proposed ANC is not affected by the variation of a heartbeat.

본 논문에서는 심음 향상을 위해 단일 채널 적응 잡음 제거기를 제안한다. 청진음은 일상적이거나 응급 상황 시 다양한 소리가 섞여 심음의 판독이 어려운 특징이 있다. 기존의 두 채널의 입력을 가지는 적응 잡음 제거기에서 단일 채널의 구현을 위해 단일 채널로 입력된 청진음은 심음의 특징을 기반을 둔 HS 분석기와 BS-Gate를 제안하여 기준 신호를 생성하였다. 제안한 단일 채널 적응 잡음 제거기는 BIOPAC Systems, Inc의 SS30L과 MP 36을 이용하여 획득한 청진음을 이용하여 실험하였으며, 그 결과 효과적으로 호흡음이 감쇄하여 심음이 향상되는 것을 확인할 수 있었다. 또한 단일 채널을 사용하는 적응 선 스펙트럼 강조기와의 비교 실험을 통해 심박의 변화에도 효과적으로 잡음을 제거하였음을 확인할 수 있었다.

Keywords

References

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