• Title/Summary/Keyword: 극좌표 분해

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A Study on Biomechanical Noise Reduction Technique Using Length Information (길이 정보를 이용한 생체 잡음 제거 기술에 관한 연구)

  • Gang, Sin-Gil;Yun, Yong-San;Park, Jae-Hui
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.7 s.178
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    • pp.1643-1649
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    • 2000
  • When markers attached to body segment are captured by camera, they generally have many noises due to intrinsic biomechanical characteristics. In this study, one technique to reduce these noises is suggested, which constructs a local coordinates of the markers using time-mean lengths of the measured markers and calculates a linear transformation matrix of the interesting body using least square error technique. This matrix is decomposed into two matrices of rotation and flexibility. Suggested method does well for 3 markers or more, and shows consistent results without regard to choice of reference axis.

Automatic Identification of the Lumen Border in Intravascular Ultrasound Images (혈관 내 초음파 영상에서 내강 경계면 자동 분할)

  • Park, Jun-Oh;Ko, Byoung-Chul;Park, Hee-Jun;Nam, Jae-Yeal
    • The KIPS Transactions:PartB
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    • v.19B no.3
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    • pp.201-208
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    • 2012
  • Accurately segmenting lumen border in intravascular ultrasound images (IVUS) is very important to study vascular wall architecture for diagnosis of the cardiovascular diseases. After each of IVUS image is transformed to a polar coordinated image, initial points are detected using wavelet transform. Then, lumen border is initialized as the set of important points using non parametric probability density function and smoothing function by removing outlier initial points occurred by noises and artifacts. Finally, polynomial curve fitting is applied to obtain real lumen border using filtered important points. The evaluation of proposed method was performed with related method and the proposed method produced accurate lumen contour detection when compared to another method in most types of IVUS images.