Journal of Biomedical Engineering Research (대한의용생체공학회:의공학회지)

The Korean Society of Medical and Biological Engineering (대한의용생체공학회)
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Design of ECG/PPG Gating System in MRI Environment

MRI용 심전도/혈류 게이팅 시스템 설계

  • Jang, Bong-Ryeol (Department of Biomedical Engineering, College of Health Science, Yonsei University) ;
  • Park, Ho-Dong (Department of Biomedical Engineering, College of Health Science, Yonsei University) ;
  • Lee, Kyoung-Joung (Department of Biomedical Engineering, College of Health Science, Yonsei University)
  • 장봉렬 (연세대학교 보건과학대학 의공학과) ;
  • 박호동 (연세대학교 보건과학대학 의공학과) ;
  • 이경중 (연세대학교 보건과학대학 의공학과)
  • Published : 2007.02.28
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Abstract

MR(magnetic resonance) image of moving organ such as heart shows serious distortion of MR image due to motion itself. To eliminate motion artifacts, MRI(magnetic resonance imaging) scan sequences requires a trigger pulse like ECG(electro-cardiography) R-wave. ECG-gating using cardiac cycle synchronizes the MRI sequence acquisition to the R-wave in order to eliminate image motion artifacts. In this paper, we designed ECG/PPG(photo-plethysmography) gating system which is for eliminating motion artifacts due to moving organ. This system uses nonmagnetic carbon electrodes, lead wire and shield case for minimizing RF(radio-frequency) pulse and gradient effect. Also, we developed a ECG circuit for preventing saturation by magnetic field and a finger plethysmography sensor using optic fiber. And then, gating pulse is generated by adaptive filtering based on NLMS(normalized least mean square) algorithm. To evaluate the developed system, we measured and compared MR imaging of heart and neck with and without ECG/PPG gating system. As a result, we could get a clean image to be used in clinically. In conclusion, the designed ECG/PPG gating system could be useful method when we get MR imaging of moving organ like a heart.

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References

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