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Design of Filter to Remove Motionartifacts of Photoplethysmography Based on Indepenent Components Analysis and Filter Banks

독립성분 분석법과 필터뱅크를 기반한 PPG 신호의 동잡음제거 필터 설계

  • Lee, Ju-won (Department of Medical Engineering, Andong science college) ;
  • Lee, Byeong-ro (Department of Electronics Engineering, Gyeongnam Nat. Univ. of Science and Technology)
  • Received : 2016.06.09
  • Accepted : 2016.06.29
  • Published : 2016.08.31

Abstract

In mobile healthcare device, when to measure the heart rate by using the PPG signal, its performance is reduced according to the motion artifacts that is the movement of user. This is because the frequency range of motion (0.01-10 Hz) and that of PPG signals overlap. Also, the motion artifacts cannot be rectified by general filters. To solve the problem, this paper proposes a method using filter banks and independent component analysis (ICA). To evaluate the performance of the proposed method, we were artificially applied various movements and compared heart rate errors of the moving average filter and ICA. In the experimental results, heart rate error of the proposed method showed very low than moving average filter and ICA. In this way, it is possible to measure stable heart rate if the proposed method is applied to the healthcare terminal design.

모바일 헬스 장치에서 PPG 신호를 이용하여 심박수를 측정함에 있어 사용자의 움직임인 동잡음에 따라 그 성능이 현저하게 떨어진다. 이의 원인은 PPG 신호의 주파수 대역과 동잡음의 주파수 대역이 겹쳐있기 때문이고, 일반적인 대역필터로는 동잡음을 제거하기가 어렵다. 이러한 문제점 해결하기 위해 본 연구에서는 필터뱅크와 ICA를 이용하여 PPG 신호에 포함되어 있는 동잡음 제거 방법을 제안한다. 제안된 방법을 검증하기 위해 인위적으로 다양한 동잡음을 가하여 기존의 이동평균필터법과 ICA법의 심박수 변화를 비교 평가를 하였다. 이 실험의 결과에서 제안된 기법은 동잡음 환경에서도 기존의 이동평균필터와 ICA 보다 심박수 오차가 매우 낮게 나타났다. 이와 같이 제안된 방법을 헬스케어 단말기 설계에 적용한다면, 보다 안정적인 심박수 측정이 가능할 것으로 사료된다.

Keywords

References

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