한국정보기술학회논문지 (The Journal of Korean Institute of Information Technology)

  • 제15권12호
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  • Pages.157-164
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  • 2017
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  • 1598-8619(pISSN)
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  • 2093-7571(eISSN)
한국정보기술학회 (Korean Institute of Information Technology)
권호 표지

심전도 기저선 흔들림 잡음 제거를 위한 적응형 필터 설계

Adaptive Filter Design for Eliminating Baseline Wandering Noise of Electrocardiogram

  • 최철형 (공주대학교 전기전자제어공학과) ;
  • 세이푸르 (공주대학교 전기전자제어공학과) ;
  • 김시경 (공주대학교 전기전자제어공학과) ;
  • 박인덕 (대덕대학교 전기과) ;
  • 김영필 (공주대학교 전기전자제어공학과)
  • 투고 : 2017.11.09
  • 심사 : 2017.12.02
  • 발행 : 2017.12.31

⟨ 이전 논문 다음 논문 ⟩

초록

모바일 심전도(ECG) 신호 측정은 수 mV의 작은 소 신호를 측정하는 기술로서 동적 잡음을 제거하기 위한 많은 연구가 진행 되어 왔다. 특히 심전도 전극 케이블의 흔들림이나 피부의 움직임으로 인하여 유발 되는 등 전위선 잡음의 제거는 심전도 측정을 위한 핵심 연구 내용 중 하나이다. 본 연구에서는 심전도 신호의 등전위선 동적 잡음을 제거하기 위해 정규화 최소 자승법(NLMS)와 지연 최소 자승법(DLMS) 방식을 결합한 적응 필터의 스텝 사이즈를 결정하여 적용하는 기법을 제안 하였다. 제안한 기법은 필터의 초기 스텝 사이즈를 조정하여 기본 노이즈를 차감 한 후, 해당 과정에서 발생할 수 있는 심전도 신호 특성의 왜곡을 줄이는 방법이다. 본 논문에서의 제안한 기법에서, 필터 계수의 값은 필터 순서 사이즈 및 왜곡 최소화 인자에 의해 직접적으로 스케일링 설정 된다. 그리고 제안된 필터는 실시간 필터링에 필수적인 계산의 복잡성을 줄이도록 하여, 연산시간을 줄일 수 있을 것으로 기대되므로 소형 프로세서 및 저전력 소비가 요구되는 모바일 심전도 측정기기에 적합한 장점을 가진다. 또한 종래의 NLMS 적응 필터와 신호대잡음비(SNR)를 비교하여 우수함을 확인하였다.

Mobile ECG signal measurement is a technique to measure small signals of several mV, and many studies have been conducted to remove noise including wandering scheme. Removal of the equipotential line noise caused by shaking or movement of the electrode cable is one of the core research contents for the electrocardiogram measurement. In this study, we proposed a modified step-size of combined NLMS(normalized least squares) and DLMS(delayed least squares) adaptive filter to eliminate baseline noise from ECG signals. The proposed method mainly adjusts initial filter step-size to reduce distortion of original ECG signals characteristic after eliminating baseline noise. The modified filter step-size is scaled by filter order size and distortion minimization factor. This method is suitable for portable ECG device with a small processor and less power consumption. This technique also decreases computation time which is essential for real-time filtering. The proposed filter also increase the signal to noise ratio (SNR) compared to conventional NLMS filter.

키워드

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