전자공학회논문지SC (Journal of the Institute of Electronics Engineers of Korea SC)

대한전자공학회 (The Institute of Electronics and Information Engineers)
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전기 임피던스 단층촬영법에서 수정된 반복 Landweber 방법을 이용한 영상 복원

Image Reconstruction using Modified Iterative Landweber Method in Electrical Impedance Tomography

  • 김봉석 (제주대학교 원자력과학기술연구소) ;
  • 김지훈 (경북대학교 전자전기컴퓨터학부) ;
  • 김신 (제주대학교 에너지공학과) ;
  • 김경연 (제주대학교 전자공학과)
  • Kim, Bong-Seok (Institute for Nuclear Science and Technology, Jeju National University) ;
  • Kim, Ji-Hoon (Dept. of Electronic Engineering, Kyungpook National University) ;
  • Kim, Sin (Dept. of Nuclear and Energy Engineering, Jeju National University) ;
  • Kim, Kyung-Youn (Dept. of Electronic Engineering, Jeju National University)
  • 투고 : 2012.02.14
  • 심사 : 2012.06.27
  • 발행 : 2012.07.25
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초록

전기 임피던스 단층촬영법은 대상물의 경계면에 부착된 여러 개의 전극들을 통해 전류를 주입하고 이에 유기되는 전압을 측정한 후, 이를 바탕으로 대상물 내부의 도전율(또는 저항률) 분포를 영상으로 복원하는 비교적 새로운 영상복원 기법이다. 본 논문에서는, 대상물 내부의 저항률 분포를 추정하기 위해서 전극사이의 전기저항과 저항률 분포와의 관계를 선형으로 가정하고, 이 선형 관계로부터 가중행렬을 계산한 후, 수정된 반복 Landweber 알고리즘을 적용하였다. 그리고 제안한 방법의 수렴시간을 줄이고 영상 복원의 정확도를 향상시키고자 목적 함수를 최소화하는 최적의 step length를 찾아 제안한 방법에 적용하였다. 몇 가지 시나리오를 설정하고 모의실험을 통해 제안된 방법의 영상 복원 성능을 평가한 결과, 비교적 양호한 복원 성능을 나타내었다.

Electrical impedance tomography is a relatively new imaging modality in which the internal conductivity (or resistivity) distribution of a object is reconstructed based on the injected currents and measured voltages through the electrodes placed on the surface of the object. In this paper, it is assumed that the relationship between the resistivity distribution and the resistance of electrodes is linear. From this linear relation, the weighting matrix can be obtained and modified iterative Landweber method is applied to estimate the internal resistivity distribution. Additionally, to accelerate the convergence rate and improve the spatial resolution of the reconstructed image, optimal step lengths for the iterative Landweber method are computed from the objective function in the least-square sense. The numerical experiments have been performed to illustrate the superior reconstruction performance of the proposed scheme.

키워드

참고문헌

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