• 제목/요약/키워드: Frame difference method

검색결과 350건 처리시간 0.038초

PET/CT 영상 획득 시 사전설정법 차이에 따른 영상 질 평가 (Evaluation of the Image Quality According to the Pre-set Method in PET/CT Image)

  • 박선명;이혁;홍건철;정은경;최춘기;석재동
    • 핵의학기술
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    • 제15권2호
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    • pp.41-46
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    • 2011
  • 영상장치를 이용한 검사 시 영상의 질은 검사결과와 밀접하게 연관되어 있으며, 이는 영상획득 조건들과 이에 대한 평가방법으로 인해 달라 질 수 있다. 본 연구에서는 영상획득 시 사전설정법(Pre-set method)차이에 따른 영상의 질을 평가하였다. 장비는 PET/CT Discovery STe16(GE Healthcare, Milwaukee, USA)을 사용하였으며, Chest PET Phantom (실험 1)과 94 NEMA Phantom (실험 2)을 이용하였다. 실험 1의 경우 3.5, 6.0, 8.6 kBq/mL, 실험 2의 경우는 3.3, 5.5, 7.7, 9.9, 12.1, 16.5 kBq/mL의 $^{18}F$-FDG를 채웠고, 열소와 배후방사능과의 방사능 농도는 4:1의 비율을 유지하였다. 각 실험은 CT 투과촬영 후 3D로 2분 30초/프레임으로 시간설정법(Time-set method)과 1억 계수의 계수설정법 (Count-set method)을 적용하여 방출촬영 하였다. 영상의 질에 대한 평가는 잡음 등가 계수율 (Noise Equivalent Count Rate, NECR)과 신호 대 잡음비 (Signal to Noise Ratio, SNR)를 이용하였다. 실험 1에서 NECR과 SNR은 방사능 농도의 증가에 따라 시간설정법에서 53.7, 66.9, 91.4 과 7.9, 10.0, 11.7로 평가 모두에서 증가함을 보였으나, 계수설정법은 53.8, 69.1, 97.8과 14.1, 14.7, 14.4로 SNR은 NECR과 다르게 증감현상을 보이지 않았다. 또 다른 모형실험인 실험 2에서도 NECR과 SNR은 방사능 농도가 증가에 따라 시간설정법에서 45.1, 70.6, 95.3 115.6 134.6 162.2 과 7.1, 8.8, 10.6, 11.5, 12.7, 14.0으로 증가함을 보였으나, 계수설정법에서는 42.1 67.3 92.1 112.2 130.7 158.7 과 15.2, 15.9, 15.6, 15.4, 15.5, 14.9로 실험 1에서와 마찬가지로 SNR에서는 증감현상을 보이지 않았다. 사전설정법 변화와 관계없이 단위 질량당 방사능량 증가는 영상의 질도 비례하여 향상된다. 그러나 동일한 단위 질량당 방사능량에서는 영상획득의 시간을 늘려 총계수값을 증가시켜도 NECR에 영향을 주지는 않는다. 이는 NECR을 이용한 영상 질 평가는 영상획득 시 얻은 총 계수 값보다는 단위 시간당의 계수율이 영향을 준다는 것을 의미한다고 할 수 있다. 실험 모두에서 계수설정법으로 얻은 경우에는 단위 질량당 방사능량의 증가에도 불구하고 거의 비슷한 SNR값을 보이게 된다. 따라서 좋은 질의 영상을 얻기 위해서는 총 계수값의 증가보다는 단위질량당 방사능량을 높여야 하며, SNR만을 이용한 영상의 질에 대한 평가는 적절하지 않을 수 있다는 점을 고려하여야 한다.

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Electronic Portal Imaging Device(EPID)의 유용성 평가 (The evaluation of usefulness of Electronic Portal Imaging Device(EPID))

  • 이양훈;김보겸;정치훈;이제희;박흥득
    • 대한방사선치료학회지
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    • 제17권1호
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    • pp.19-31
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    • 2005
  • 목적 : 방사선치료 시 자세 및 치료부위의 재현성을 유지하기 위해 Port film을 통한 정도관리가 이루어져 왔으며 Mega Voltage Imaging (MVI) System(mvis)이 출현한 이후로 많은 발전을 이루어 현재는 필름과 Electronic portal Image Device(EPID)를 통한 정도관리가 함께 이루어지고 있다. 이에 본 논문에서는 현재 사용하고 있는 EPID 시스템의 소개와 amorphous silicon (aSi) type EPID가 Intersity Modulated Radiation Therapu(IMRT)에서 film dosimetry를 대체할 수 있는지에 대한 가능성을 분석하였다. 대상 및 방법 : Varian 21EX의 aSi type EPID와 Varian 6EX의 LC type EPID를 통해 FDD, Gantry 회전에 따른 재현성 분석과 EPID 출/입시 FDD에 따른 시간분석을 하였으며 Alderson Rando phantom을 이용하여 Couch & Gantry rotation에 따른 영상획득 가능범위를 분석하였다. aSi type EPID를 대상으로 Las Vegas phantom과 물팬텀으로 공간분해능과 대조도 분해능을 비교하였으며 Dynamic Multileaf collimator(DMLC)영상에 대해 저감도 측정용 필름과 EPID로 분석하여 IMRT의 정도관리 적용가능성을 시험하였다. 결과 : aSi type EPID와 LC type EPID 재현성은 출/입시 1mm 이내로 우수하게 나타났으나 Gantry 회전에 따른 재현성은 각각 ${\pm}3\;mm,\;{\pm}2\;mm$였으며 EPID의 출/입시 focus detector distance(FDD)에 따른 시간분석은 14초에서 17초로 측정되었다. Las Vegas phantom을 이용한 공간분해능과 대조도분해능 비교 시 표면과 물 팬텀 10, 20 cm 깊이에서 측정해 보았을 때 EPID가 선량율과 영상획득시간, 영상획득방법, frame수에 따라 달라짐을 확인할 수 있었으며, EPID로 영상획득 가능 범위를 분석해보면 film보다 손쉬운 측정이 가능한 것으로 나타났다. 저감도측정용 필름과 EPID를 통해 DMLC측정을 통한 IMRT 정도관리 결과 필름과 같은 값을 나타내었다. 결론 : EPID에 관한 여러 가지 평가를 통한 적절한 정보제공을 통해 EPID 사용, 관리 시 필요한 정보를 획득 할 수 있었으며 EPID를 통해 얻은 영상이 digital data라는 점에 착안해 적절한 정도관리가 어려운 IMRT의 분야에서 필름을 통한 주기적 점검의 대체수단으로 사용가능성이 있음을 알 수 있었다. 특히 point-dose 측정시 사용하는 diode나 전리조(lonization chamber)를 통해 평가하기 어려운 IMRT의 sliding window영상에 대한 적절한 평가와 MLC에서 leaf사이의 누설선량과 소조사면에서의 DMLC 움직임에 대한 정확한 평가가 기대된다.

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유도 맞잡기 타입과 받기의 신장에 따른 허벅다리걸기의 Kinematic 분석[2] (A Kinematics Analysis of Uchi-mata(inner thigh reaping throw) by Kumi-kata types and Two different Opponent's Height in Judo[II])

  • 권문석;김의환;조동희
    • 한국운동역학회지
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    • 제12권2호
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    • pp.143-157
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    • 2002
  • 본 연구는 6년 이상의 유도경력 소유자인 Y.대학교 유도전공자를 대상으로 맞잡기 타입과 받기신장에 따른 허벅다리걸기 동작시 3차원 영상분석법을 이용하여 운동학적 변인의 특성을 분석하는데 그 목적이 있다. 유도 맞잡기 타입과 받기신장에 따른 허벅다리걸기 동작은 비디오카메라 2대를 사용하여 촬영(30frame/sec.)하였으며, 분석을 위한 운동학적 변인들은 시간, 자세, 중심변인이며, 실험 결과에 대한 분석과 논의를 통하여 다음과 같은 결론 및 제언을 얻을 수 있었다. 허벅다리걸기 동작의 맞잡기 타입에 따른 유의한 차이는 3국면 소요시간, 걸기1단계 공격둔부각, 걸기1단계 공격무릎각, 걸기2단계 공격무릎각, 걸기2단계 지지무릎각, 걸기1단계 공격발목각, 걸기2단계 공격발목각, 걸기2단계 지지발목각에서 유의한 차이(p<.05)를 보였으며, 타입에 따른 걸기2단계 지지둔부각에서만 신장이 큰 받기에 대해서 A, B타입 모두 유의한 차이(p<.05)를 보였다. 종합해보면, 허벅다리걸기를 수행할 때 맞잡기와 상대신장이 허벅다리걸기 기술에 영향을 미친다는 것을 알 수 있었으며, 상대의 신장이 작을 경우 목 뒤를 잡는 타입 A가 시간이 단축(<.05)되었다. 따라서 경기 중 상대의 신장이 작다면 목 뒤를 잡는 것이 유리하다. 이러한 사실들을 종합해 볼 때, 유도 경기 중 허벅다리걸기를 수행할 대 맞잡기가 많은 영향을 주었다. 또한 기술의 핵심단계인 3(걸기)국면에서도 받기신장에 의한 차가 더 크게 나타나 받기신장 역시 많은 영향을 주었다. 단계별 변인들의 변화량에 있어서는 전체적으로 모든 변인들이 변화량에서 큰 차이를 나타내지는 않았다고 할 수 있다. 따라서 맞잡기와 받기신장은 상당한 관계가 있음을 알 수 있었으며 유도 경기 중 상대에 따른 다양한 잡기와 신장을 고려한 기술이 요구된다.

해석수준과 메시지 프레이밍에 따른 자율주행택시의 사용의도에 관한 연구 (A Study on the Construal Level and Intention of Autonomous Driving Taxi According to Message Framing)

  • 윤승정;김민용
    • 지능정보연구
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    • 제24권3호
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    • pp.135-155
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    • 2018
  • 본 연구는 최근 4차산업 혁명의 산물로 대두되고 있는 자율주행차가 대중교통 수단인 택시로 이용될 때 해석수준과 메시지 프레이밍에 따른 사용 의도의 차이를 분석하는 것이다. 해석수준이란 가까운 미래에 발생한 일과 먼 미래에 발생할 일을 가정하여 어떤 제품이나 서비스를 해석하는 것이 다르다는 것을 말한다. 메시지 프레이밍이란 긍정 혹은 부정의 표현 또는 혜택, 손실의 양극단의 메시지를 구성한 것을 말한다. 즉, 기존연구에서는 이 두 개념에 따라 제품이나 서비스의 가치를 다르게 해석한다고 한다. 본 연구는 자율주행차가 택시로 출시될 때 두 개념을 적용할 경우 사용 의도의 차이를 보이는지 살펴보고자 한다. 결과를 요약하면 우선, 메시지 프레이밍 구성에서 자율주행 택시를 이용할 경우 혜택(Gain)과 왜(Why) 사용해야 하는지를 설명한 메시지 형식과 자율주행 택시를 이용하지 않았을 경우 손실(Loss)와 어떻게(How)를 강조한 메시지를 구성하여 비교해 보았다. 두 메시지 프레이밍은 차이를 보였으며(t= 3.063) 혜택(Gain)과 왜(Why)를 설명한 메시지 형태가 더 높은 사용 의도를 보였다. 또한, 해석수준에 따른 결과를 요약하면 다음과 같다. 혜택(Gain) 및 손실(Loss)에 대한 먼 미래와 가까운 미래에 발생할 것을 가정한 경우 사용 의도에 차이가 있었으며, 구체적으로 혜택(Gain)을 설명한 메시지와 먼 미래에 발생할 것을 가정한 경우가 사용 의도가 높았다. 요약하면 자율주행 택시의 사용 의도를 높이기 위해서는 긍정의 메시지(Gain)와 먼 미래에 일어날 수 있는 것을 가정하여 사람들에게 메시지를 전달해야 한다는 결론이다. 또한, 본 연구를 통하여 향후 신기술의 출현에 대한 사용 의도 연구 시 연구방법을 활용할 수 있을 것이다.

완성품 돋보기와 조제가공된 돋보기가 광학적 요소에 미치는 영향 (The Effect of the Optical Points Difference between Finished-Reading Glasses and Dispensing Reading Glasses)

  • 심영철;유근창;김인숙
    • 한국안광학회지
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    • 제13권3호
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    • pp.65-71
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    • 2008
  • 목적: 본 연구는 시중에서 유통되고 있는 완성품 돋보기와 안경원에서 조제가공된 돋보기의 광학적 중심점간의 문제점을 비교하여 눈에 미치는 영향을 연구하였다. 방법: 연구대상은 +1.00D에서 +4.00D까지 11개의 범주로 나누어 측정하였으며, 광주시 광산구에 사는 안질환이 없는 40세 이상의 남녀로 안경테 사이즈를 세 그룹으로 나누어 광학적 중심점과 광학적 높이를 측정하였다. 결과: 광학적 중심점은 57 mm에서 80 mm 범위 사이에 있었으며 대부분 61 mm에서 65 mm(64.6%) 사이였다. 광학적 중심높이 오차는 1 mm에서 8 mm 범주에 있었으며 4 mm가 공통범주(23%)에 속하였다. 완성품 돋보기는 불규칙한 사이즈를 가지고 있었다. 조사대상들은 거의 대부분 75.5%(151명)가 시중에 유통되는 완성품 돋보기를 사용하고 있었다. 대상자 151명을 조사한 결과, 완성품 돋보기의 광학적 중심점과 장용자의 P.D 사이에는 4 mm의 공통된 오차가 있었다. 더구나 광학적 중심 높이와 착용자의 O.H 사이에는 3 mm에서 4 mm의 오차가 있었다. 151명의 완성품 돋보기를 사용하는 사람들은 모두 피곤함을 느끼고 있었으며, 53명(35%)은 돋보기 착용 후 10분에서 20분 후부터 피곤함을 호소하였다. 이러한 조사를 바탕으로, 우리는 돋보기에 있어서 광학적 중심점 오차시 발생되는 프리즘 값을 발견할 수 있었으며 이는 완성품 돋보기가 착용하기에 충분하지 않다는 것을 나타낸다. 완성품 돋보기는 렌즈 굴절력과 상관관계가 있다는 것을 알 수 있었으며 또한 독일 RAL-915 규정을 따르지 않는다는 것도 알 수 있었다. 결론: 우리가 조사한 바를 기초로 할 때 완성품 돋보기는 우리의 시생활에 많은 위험적인 요소를 품고 있으며 안경사는 광학적 중심점을 토대로 정확하게 조제가공된 돋보기를 소비자에게 반드시 권하여야 할 것이다.

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큰 병변에 대한 다단계 감마나이프 방사선수술의 전략 (Strategy of Multistage Gamma Knife Radiosurgery for Large Lesions)

  • 허병익
    • 한국방사선학회논문지
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    • 제13권5호
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    • pp.801-809
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    • 2019
  • 큰 병변에 대한 기존 감마나이프 방사선수술은 종종 체적 또는 선량 분할 단계들로 수행된다. 체적 분할의 경우, 병변은 처방된 선량 하에서 하루 또는 이틀, 3 ~ 6개월로 분할된 다중 세션에서 조사되는 하위 체적들로 분할되곤 한다. 치료의 전체 과정 동안, 이전 단계의 치료 정보는 세션 사이의 좌표 변환을 통해 새로 장착된 정위 프레임 상의 후속 세션에 반영될 필요가 있다. 그러나 동일한 정위 공간을 제외하고 기존 감마나이프 시스템으로는 이전 선량 분포를 구현하는 것은 실제로 어렵다. 최신 감마나이프 플랫폼을 사용하여 다단계 치료를 수행할 수 있기 때문에 치료 영역이 확장되고 있다. 이 연구의 목적은 정위적 공간에 기초한 영상 정합과 새로운 감마나이프 플랫폼을 사용하여 각 단계에서 처방 선량 결정과 같은 다단계 감마나이프 방사선수술 전략을 소개하는 것이다. 일반적으로 영상 정합에서 수술적으로 내장된 기준점 또는 내부 해부학적 랜드마크들이 변환 관계를 결정하는데 사용된다. 저자는 내부 해부학적 랜드마크들을 사용하는 예로서 4개 또는 6개의 해부학적 랜드마크를 사용하는 다중 세션 간의 좌표 변환 정확도를 비교하였다. 측정된 좌표들과 계산된 좌표들 사이의 불일치를 최소화하기 위해서 PseudoInverse 또는 Singular Value Decomposition을 사용하여 두 정위 공간 사이의 변환 행렬이 결정되었다. 변환 정확도를 평가하기 위해 측정된 좌표와 변환된 좌표들 사이의 차이, 즉 ${\Delta}r$이 10개의 랜드마크들을 사용하여 계산되었다. 10개의 랜드마크들 중 4개 또는 6개의 점들을 사용하여 좌표 변환을 결정하고 나머지는 접근 방법을 평가하는데 사용되었다. 두 가지 접근 방법에서 각각의 ${\Delta}r$ 값은 0.6 ~ 2.4 mm, 0.17 ~ 0.57 mm 범위이었다. 게다가 병변 분할의 경우 한 번에 전체 병변의 치료와 동일한 효과를 제공하는 처방 선량을 결정하는 방법이 제안되었다. 동일한 정위 공간에서의 다단계 치료 전략은 전체 병변에 대한 치료를 먼저 디자인하는 것이며, 전체 치료 디자인 샷들은 각 단계 치료의 샷들로 나누어 각 단계별 샷들을 구성하고 각 단계에서 적절한 처방 선량을 결정한다. 결론적으로 저자는 다단계 치료 전략으로서 처방 선량 결정의 정확성을 확인하였고, 다중 세션 간의 좌표 변환을 결정하기 위해 적은 랜드마크들을 사용하는 것보다 가능한 많은 내부 랜드마크들을 사용하는 것이 더 나은 결과를 산출함을 보았다. 향후 제안된 다단계 치료 전략은 여러 감마나이프 센터들의 틀 없는 분할 치료에 크게 기여할 것이라 사료된다.

자유탐구 수업이 초등학생의 과학적 태도 및 과학탐구능력에 미치는 영향과 지도교사들의 자유탐구에 대한 인식 조사 (The Effect of the Specific Open-inquiry Lesson on the Elementary Student's Science-related Attitude, Science Process Skill and the Instructing Teachers' Cognition about Open-inquiry)

  • 이형철;이정화
    • 과학교육연구지
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    • 제34권2호
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    • pp.405-420
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    • 2010
  • 본 연구의 목적은, 2007년 개정 과학과 교육과정에서 강조되고 있는 자유탐구를 현장에 원활하게 적용하기 위한 구체적인 지도방안을 구안하여 그것에 따른 자유탐구 수업이 초등학생들의 과학적 태도와 과학탐구능력에 어떠한 영양을 미치는지 알아보고 또한 자유탐구를 지도한 교사들이 자유탐구에 대해 어떠한 인식을 가지고 있는지를 알아보는것이다. 연구대상은 부산광역시 소재의 동일한 급지에 속한 J 및 S 초등학교의 5학년 각각 1개 반이었다. 실험집단이 속한 J초등학교는 자유탐구 수업을, 비교집단이 속한 S초등학교는 전통적 방식으로 제7차 교육과정에 의한 수업을 실시하였다. 연구의 결과는 다음과 같다. 자유탐구 수업을 한 학생들은 전통적 방식의 수업을 학생들에 비해 과학적 태도에서의 평균 점수가 더 높게 나왔으나 유의미한 차이는 아니었다. 하지만 하위 요소별로 보았을 때 정직성과 비판성의 요소에서 유의미한 차이가 나타났다. 자유탐구 수업을 한 학생들은 전통적 방식의 수업을 학생들에 비해서 과학탐구능력의 평균 점수도 높아졌을 뿐만이 아니라 그 차이는 p<.05의 수준에서 유의미한 것으로 나타났다. 특히 하위 영역에서 보았을 때 기초탐구능력에서 그러한 효과를 확인할 수 있었다. 자유탐구를 지도한 교사들은 자유탐구에 대해 '학생들의 흥미를 높이고 과학탐구능력 향상을 위한 자기 주도적 문제 해결학습'이라 생각하였다. 교사들의 자유탐구에 대한 부정적 인식척도는 환경 요인에 다소 높게 치우쳐 있어 환경 요인에 대한 요구가 많이 남아 있음을 보여준다. 그리고 교사들은 자유탐구의 장애요인으로서 주로 학생들의 경험이나 지식의 부족, 학급당 인원수 과다 등을 지적하였으며 자유탐구 정착을 위한 선행 조건으로는 자유탐구 지도를 위한 교육과정과 교재의 개발을 꼽았다.

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두경부환자 고정기구제작을 통한치료기 가동범위에 관한 고찰 (Consideration about LINAC movable range by H&N patient immobilization device manufacture)

  • 정도형;심진섭;염두석;최계숙
    • 대한방사선치료학회지
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    • 제16권2호
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    • pp.63-67
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    • 2004
  • 목적 : 방사선치료가 발전함에 따라 3D-CRT나 IMRT 등의 새로운 치료기법이 등장하게되었다. 이러한 치료법은 여러 방향의 방사선조사를 필요로 한다. 그러나 지금의 선형가속기만으로는 사실상 여러 방향의 방사선조사에 많은 제약이 따른다. 본원에서는 이러한 장치적제한을 극복하고 궁극적으로 다양한 방향의 선속을 이용함으로서 선량분포를 개선하고자 두경부고정장치를 제작하였다. 이에 기존의 고정장치에 비해 치료기의 가동범위가 얼만큼 효율적으로 개선되었는지를 정량적으로 측정하여 조사하였다. 대상 및 방법 : 선형가속기 Couch에 기존의 고정장치를 놓고 Gantry를 각각 $45^{\circ},\;90^{\circ},\;135^{\circ}$에서 고정시키고 Couch를 돌려 장비의 clearance를 확인한다. 또한 Couch를 $0^{\circ},\;45^{\circ},\;90^{\circ}$에서 고정시키고 Gantry의 clearance를 확인한 후 제작된 Extended Head Holder(EHH)를 Couch에 부착하고 다시 앞에서 시행한 방법과 동일한 과정을 반복함으로서 EHH부착 후의 Gantry와 Couch사이의 clearance의 개선여부를 확인한다. 결과 : Gantry를 고정하고 Couch를 회전시켜본 결과 $45^{\circ}$에서는 큰 차이가 없었으나 $90^{\circ},\;135^{\circ}$로 각도가 커질수록 EHH를 사용한 경우 Couch의 가동범위가 커지는 것으로 나타났으며, Couch를 고정시키고 Gantry를 회전시킨 경우는 $45^{\circ}$에서 EHH를 사용한 경우가 사용하지 않을 경우보다 가동범위가 크게 나타나는 것을 볼 수 있었고 $0^{\circ}$$90^{\circ}$에서는 모두다 양호한 가동상태를 보여주었다. 또한 방사선의 후방조사시 EHH의 사용으로 Couch의 frame에 의한 방사선 감쇄를 막을 수 있었다. 결과 : 두경부환자의 치료 시 환자고정기구(EHH)를 제작하여 사용함으로서 보다 많은 방향에서 방사선조사가 가능해지고 이로 인해 보다나은 치료계획을 세울 수 있게 되었으며, 치료장비의 회전에 따른 장비와 환자사이 또는 장비와 장비사이의 안전공간이 보다 많이 확보될 수 있었다. 그리고 외국의 제품에 비해 저렴한 가격으로 제작이 가능하였고 또한 치료소모품의 절약을 가져올 수가 있게 되었다.

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Sensory Information Processing

  • Yoshimoto, Chiyoshi
    • 대한의용생체공학회:의공학회지
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    • 제6권2호
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    • pp.1-8
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    • 1985
  • The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70$\pm$1.32mmHg/min)compared to CF dialyzers(4.32$\pm$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500, 550, 570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500, 550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100, 300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3, 000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.SpO2 with Plethysmograph.

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High Resolution HC$_3$N Observations toward the Central Region of Sagittarius B2

  • H.S-Ching;Oh, M.ishi;M.Morimoto
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
    • /
    • 한국우주과학회 1993년도 한국우주과학회보 제2권2호
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    • pp.17-17
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    • 1993
  • The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70${\pm}$1.32mmHg/min)compared to CF dialyzers(4.32${\pm}$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500,550,570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500,550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100,300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.

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