• 생명과학회지
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• 제34권2호
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• pp.113-121
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• 2024

ER (Endoplasmic reticulume) 스트레스반응은 difenoconazole 등과 같은 다양한 독성물질에 의한 독성반응 동안에 유도되지만, 농업 및 산업에서 전반적으로 사용되는 화학물질로 간독성(Hepatotoxicity)을 유도하는 1,2,3-Trichloropropane (TCP)와의 연관성은 연구된 바 없다. 따라서, 본 연구에서는 TCP처리로 유발된 간독성(Hepatotoxicity) 유발과정 동안에 ER스트레스의 유발기전에 대해 연구하기 위하여, TCP로 처리된 SD(Sprague Dawley)랫드에서 간독성, apoptosis 그리고 ER스트레스에 대한 지표들의 변화를 분석하였다. 그 결과, TCP 처리그룹은 Vehicle 처리그룹에 비하여 체중과 식이 섭취량이 감소하였고, 간 조직에서 괴사(Necrosis)와 공포화(Vaculation) 등이 유의적으로 증가하였다. 또한, apoptosis 관련 인자인 Bax/Bcl-2와 Cleaved Caspase-3(Cas-3)/Cas-3의 발현은 Vehicle 처리그룹보다 TCP 처리그룹에서 유의적으로 증가하였다. ER스트레스 반응지표 분석에서, C/EBP homologous protein (CHOP), p-eukaryotic translation initiation factor 2 alpha subunit (eIF2α), p-iniositor-requiring enzyme 1α (IRE1α)의 발현은 TCP100 처리그룹에서만 증가하였다. 하지만 Growth arrest and DNA damage-34 (GADD34)와 X-box binding protein-1 (XBP1)의 전사는 TCP200 처리그룹에서 유의적으로 변화되었다. 따라서, 이러한 결과는 ER스트레스반응은 TCP 처리에 의해 유도된 간독성과정 동안에 unfolded protein response (UPR) pathway의 조절을 통해 성공적으로 유도됨을 제시하고 있다.

• 한국양식학회지
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• 제2권2호
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• pp.53-90
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• 1989

식욕에 부합되는 적정양의 먹이 섭취는 잉어의 성장을 증가시키고, 동시에 먹이의 허비를 막으며, 그로 인해서 사육수질의 오염을 막는 부수적인 효과도 가지게 된다. 이 목적을 달성하기 위하여 식욕 유발과 그에 따른 빠른 성장의 중요한 요인으로서 용존산소에 관한 정밀한 연구가 필요하다. 수온 $25^{\circ}C$ 하에서 잉어(이스라엘계)의 미성어, 67g, 200g, 400g, 600g 및 800g 되는 실험군으로서, 용존산소를 2.0-6mg/$\iota$ 사이에서 사료를 체중의 $1\%$부터 먹을 수 있는 양까지에 걸쳐서 사육실험연구를 하였다. 어체가 작을수록 동일한 용존산소 조건에서는 보다 높은 식욕과 보다 많은 먹이 섭취량을 나타내었다. 어체가 클수록 낮은 용존산소양에서는 생활 능력이 약해지고, 먹이 섭취량이 증가하면 내성은 더욱 줄어졌다. 성장률(일간 성장률)은 낮은 용존산소에 의해서 영향을 받지 않는 한, 먹이의 섭취량이 많을수록 증가하였다. 최고성장률은 67 g 어에서는 D.O. 5.0 mg/$\iota$에서 1일 먹이 량이 체중의 $7\%$ 일때 일간성장률 $\5.05%$였고, 200g 어에서는 D.O. 5.5/$\iota$ 에서 먹이량 $6\%$일때 1일 성장률이 $3.75\%$였다. 400g 어에서는 D.O. 6.0 mg/$\iota$에서 먹이량이 $5\%$ 일때 1일 성장률 $3.37\%$ 였으며, 600g 어에서는 D.O. 5.5 mg/$\iota$에서 먹이량이 1일 $4\%$였을 때 1일 성장률 $2.82\%$였다. 800g 어에서는 D.O. 5.0mg/$\iota$에서 먹이량이 1일 $3\%$었을 때 1일 성장율이 $1.95\%$였다. 정상적인 생활 및 성장 기능발휘 가능 D.O. 농도로부터 최고 먹이 섭취가능양에 부합되는 D.O. 농도까지 사이에서 먹이 전환효율(사료가 어체로 바뀌는 효율)은 처음 D.O.가 증가함에 따라 높아지고, 최고치에 이른 뒤, D.O.가 더욱 더 높아짐 에 따라 먹이 전환효율은 다시 감소하기 시작한다. 이 최고 사료효율은 작은 어체에서는 큰 어체 보다 높은 먹이 섭취량에서 나타난다 (물론 먹이 섭취량에 부응하는 D.O.량이 갖춰졌을때). 즉 최고 먹이 전환효율은 67g 어에서 D.O. 3.0-4.0 mg/$\iota$에서 먹이 섭취량 $4\%$때 였으며, 200g 어에서는 D.O. 3.0-4.5mg/$\iota$에서 먹이 섭취량 $3\%$때였고, 400 g 어에서는 D.O. 4.0-4.5mg/$\iota$에서 먹이 섭취량 $2\%$때였다. 600g 및 800 g 어에서는 가장 낮은 D.O.에서 먹이 섭취량 $1\%$ 때였다. 적절하지 못한 낮은 D.O. 함량에서는 정상적인 조건하의 개체보다 먹이 섭취량이 감소하며, 또 먹이가 소화관을 빨리 통과하고, 똥의 양이 증가하는 것을 관찰할 수 있었다. 그리고, 견디지 못할 만큼 낮은 D.O.하에서는 먹이를 토하고, 체색이 옅은 황색으로 변하거나, 또는 회색의 얼국진 반점으로 변하기도 했다. 이 모든 현상들이 먹이 전환효율의 감소로 이어졌다. 반면에 아주 높은 D.O.하에서는 강한 활동을 하였으며, 어체 크기가 같고 먹이의 양도 같았지만 D.O.가 약간 낮은 상에 비교하여 먹이 전환효율이 떨어지는 경향이 나타났다. 모든 크기에서 먹이량을 체중의 $1\%$만 주었을 때는 D.O. 량이 2.0-2.5mg/$\iota$ 이면 적절하였다. 먹이량을 증가시키면 어체의 정상활동을 유지시키기 위하여 보다 높은 D.O.가 필요하였다. 67g 어에서는 D.O. 2.0-2.5mg/$\iota$이면 체중의 $2\%$이상 먹이량을 충분히 지탱할 수 있었으나, 먹이를 $5\%$로 증가시키면 D.O. 3.0-4.0 mg/$\iota$일 때 식욕이 보다 왕성하고 높은 성장을 가져 왔다. 먹이량이 $5-7\%$에서는 4.0 mg/$\iota$ 이상의 D.O.라야 식욕을 유지시킬수 있다. 200g 어에서는 먹이량이 체중의 $2-3\%$ 일때는 D.O. 3.5-4.5mg/$\iota$에서 가장 높은 성장률을 보였으나 먹이량이 체중의 $3-6\%$로 올라가면 D.O. 함량이 4.5mg/$\iota$을 넘어서야만 어류의 생활기능 발휘에 부응될 수 있었다. 400 g, 600 g 및 800 g 어에서는 먹이량이 체중의 $2\%$를 넘을 때는 ($4\%$ 및 $5\%$까지 실험) 모두 D.O. 함량이 4.5 mg/$\iota$를 넘어야 했다.

• Tuberculosis and Respiratory Diseases
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• 제44권4호
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• pp.822-835
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• 1997

연구배경 : 기관지천식의 병태생리중 IgE의 합성 및 조절에 IL-4가 중요한 역할을 하며, IFN-$\gamma$는 이러한 IL-4의 작용을 길항하는 것으로 알려져 있다. 이를 근거로 최근에 IFN-$\gamma$를 아토피 피부염등 IgE가 높은 알레르기성 질환의 치료에 이용하고자 하는 임상적 시도가 있는데, 아직 기관지천식에 대한 임상적 시도는 별로 보고되어 있지 않다. 그러나 IFN-$\gamma$는 in vitro에서 말초혈액 다형핵구나 단핵세포에 의한 독성산화물 생성을 증가시킨다는 보고도 있어, 실제 임상에서 IFN-$\gamma$ 치료의 임상적 효과는 확실하지 않다. 이에 저자들 IL-4 매개성 IgE 생성에 대한 IFN-$\gamma$의 길항작용에 기초하여, IgE가 정상범위보다 높은 기관지천식 환지들에서 in vitro 에서와 같이 in vivo 에서도 IFN-$\gamma$가 IgE 생성을 억제하는지 여부와, 그 결과로 임상적 치료효과를 나타내는지에 대해 관찰하는 한편, 다형핵구의 독성산화물 생성능에 미치는 영향은 in vitro의 경우와 어떻게 다른지에 대해서 관찰하였다. 대상 및 방법 : IgE가 200IU/ml 이상이고 정규적인 부신피질호르몬 치료에 반응을 보이지 않는 기관지천식 환자 50명과 정상인 17명을 대상으로, 혈중 CD23+ B-상층액 발현도, sCD23 농도, T-상층액의 IL-4 activity, 다형핵구에 의한 과산화 음이온 생성능등을 측정한 후, 환자군과 정상군간의 차이를 비교하고, 환자군에 대해서는 상기 검사외에 혈중 IgE 농도 및 histamine $PC_{20}$등을 함께 측정하여 IFN-$\gamma$ 치료전후의 변화를 관찰하였다. IFN-$\gamma$ 치료는 체중당 30,000IU를 매일 4주간 피하주사하였다. 결 과 : 다형핵구의 ${O_2}^-$ 생성능 환자군의 다형핵구는 정상군의 다형핵구에 비해 ${O_2}^-$생성능이 높았다(P<0.05). IFN-$\gamma$ 치료후 추적이 가능했던 환자들에서는 IFN-$\gamma$ 치료후에 다형핵구의 ${O_2}^-$ 생성능이 현저하게 감소하였다(P<0.05). 다형핵구 배양시간에 따라 자연적인 ${O_2}^-$ 생성능 및 PMA 혹은 fMLP 자극에 의한 ${O_2}^-$ 생성능을 관찰하였을 때에도, 배양시간 및 자극제의 종류와 무관하게 IFN-$\gamma$ 치료후가 치료전에 비해 ${O_2}^-$ 생성능이 감소하는 경향을 보였다. IFN-$\gamma$ 치료전의 환자군의 말초혈액내 CD23+ B-상층액의 발현도는 정상군에 비해 현저히 높았으나(P<0.05), 치료후 추적검사가 가능하였던 15명의 환자들에서 치료전후에 의미있는 변화를 나타내지는 않았다. IFN-$\gamma$ 치료전의 환자군의 혈청내 sCD23 농도는 정상군에 비해 다소 높은 경향을 보였으며, 이중 치료 후 추적검사가 가능하였던 17명의 환자들중 11명(64.7%)에서 치료후에 혈청 sCD23 농도가 감소되었다. T-상층액의 IL-4 activity는 정상군에 비해 환자군에서 다소 높은 경향을 보였는데, IFN-$\gamma$ 치료후에는 큰 변화를 보이지 않았다. IFN-$\gamma$ 치료후 혈청 IgE 농도의 추적검사가 시행되었던 환자 15명 중 9명(60%)에서 치료후 혈청 IgE 농도가 유의하게 감소되었다(P<0.05). IFN-$\gamma$ 치료에 따른 기관지과민반웅의 변화는 모두 12명의 환자에서 관찰되었는데, 이중 10명(83.3%)에서 IFN-$\gamma$ 치료후 histamine $PC_{20}$가 유의하게 호전되는 소견을 보여주었다(P<0.05). 결 론 : 이상의 연구결과 IFN-$\gamma$는 IgE가 높은 기관지천식 환자의 치료에 유용할 것으로 추측되며, in vivo에서의 IgE 합성 및 조절기전과 이에 대한 IFN-$\gamma$의 역할을 보다 명확하게 규명하기 위한 노력이 필요할 것으로 생각된다.

• 한국식품위생안전성학회지
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• 제27권1호
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• pp.42-49
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• 2012

우리나라에서 식품위생법이 처음 공표된 1962년에는 허용된 식용색소가 19종이었으나 독성 또는 안전성의 이유로 약 40년이 경과된 현재에는 9종이 허용 되고 있다. 또한 각국의 합성 착색료의 관리실태를 알아보면 미국은 착색료를 CFR (code of federal regulation)에서 별도 관리하고 있고, 유럽연합은 지침(european parliament and council directive 94/36/EC)으로 관리하고 있으며, 각 지침에는 사용가능한 첨가물의 목록과 번호 및 사용기준 등이 목록화되어 있다. 일본은 착색료로 사용을 허용하고 있는 품목의 경우 후생성 고시를 통해 관리하고 있다. 우리나라는 별도로 식품 첨가물 공전(2007)에서 9종의 산성 수용성이고 유기용매에는 거의 녹지 않는 타르색소 (녹색 제3호, 청색 제1호, 청색 제2호, 적색 제2호, 적색 제3호, 적색 제40호, 적색 제 102호, 황색 제4호 황색 제5호) 및 물에 잘 녹지 않도록 만든 알루미늄 레이크 (적색 제3호, 적색 제102호 제외) 7 종의 사용을 허용하고 있다. 현재 논란이 되고 있는 식용 타르색소의 동물실험에서 발암성이 발견된 이유로 미국 및 여러 국가들에서 사용이 금지된 식용색소 적색 제3호, 적색 제40호, 황색 제4호 및 청색 제1호가 있다. 뿐만 아니라 타르색소에 노출에 의해 황색 4호 +청색1호의 병용 조합 경우 해마 신경세포의 흥분 독성에 대한 감수성에 영향을 준다는 보고가 있다. 국내외에서 금지하는 타르색소와 그 이유는 적색1호는 간 장애, 간 종양 적색4호는 부신 위축, 방광염 적색5호는 간, 비장 장애 등색1호는 신장의 출혈, 비장 비대 등색2호는 간장, 심장 장애 황색2호는 빈혈, 복수증, 간장장애, 발암성 녹색1호는 장기간 섭취시 만성 독성유발 녹색2호는 종양 유발 자색1호는 종양유발 황색1호는 장관 궤양 신장 장애를 일으키는 이유로 금지하고 있다. 1950년 미국에서 발생한 인공색소 오렌지1호(FD&C orange NO.1)의 과용에 의한 어린이 집단 중독 사건을 계기로 타르색소의 독성에 대한 재 검토가 시작되어 우리나라를 비롯한 여러 나라에서 계속적으로 연구되고 있다. 그 결과 식용색소 적색2호는 1976년 미국에서 발암성이 있다는 이유로 식품에의 사용이 금지되었고 적색3호의 경우도 미국식품의약품안전청(FDA)에서 발암성 판정을 받은 바 있으며 FAO/WHO에서 권장하는 일일허용섭취량도 각 색소마다 차이가 있다. 우리나라에서의 식용색소 적색2호의 일일허용섭취량은 0~0.5 mg/kg/day로 적용하며 미국에서 사용 금지된 적색2호는 우리나라의 경우 어린이들이 좋아하는 식품 등에 빈번하게 사용되고 있음은 물론 타르색소를 다량 첨가하고도 명칭과 용도를 제대로 표시하지 않은 제품이 많아 소비자에게 식품 선택 시 정확한 정보를 제공하지 못하고 있었다. 따라서 어린이 선호 식품뿐만 아니라 항상 섭취하는 식품은 타르색소의 안전성을 파악하고 사용색소와 더불어 사용량을 규제하는 것이 바람직하며 홍보, 교육, 감시, 표시기준 관리 등으로 다각적인 관리가 이루어져야 할 것으로 사료 된다. 천연색소는 양도 적고 가격도 비싼데 비해 석유의 타르에서 합성된 타르색소는 안전성도 높다고 알려졌고, 가격이 저렴하기 때문에 구매 효과나 섭취의욕을 높이기 위해 타르색소가 사용된다. 식용색소 적색2호는 식품의 색상을 아름답게하여 제품의 가치를 높이기 위한 수단으로 가공 단계에서 다양하게 사용되고 있다. 따라서 식품 중에 첨가된 식용색소 적색2호에 대한 정확한 안전성과 독성을 알아보기 위하여 이 실험을 연구하게 되었으며 이에 본 연구에서는 시중에서 유통되는 사탕, 청량음료, 빙과, 껌 등에 주로 첨가된 식용 색소 적색2호를 SD 랫드를 이용해서 식용색소 적색2호를 지속적으로 다량 섭취하였을 때 SD 랫드에 미치는 영향을 연구함으로써 우리 몸에 미치는 영향을 알아보고자 하였다. 가공식품을 많이 먹는 우리 어린이와 비슷한 4 주령의 랫드를 임상 적용 용량의 최대 67배를 4주간 꾸준히 경구 투여 하였다. 그 결과 4주간 대조군과 시험군 간의 체중차이는 나타나지 않았으며, 사료섭취량도 별다른 점이 없었다. 투여 후 1일부터 변 증상이 관찰되었는데 이는 시험물질의 영향으로 점액성이 있는 적색변을 배설 하였으며 물이나 뇨가 묻게 되면 적색변과 반응하여 색이 변하게 되는 것을 알 수 있었다. 뇨검사 결과는 별다른 이상소견이 발견되지 않았으며 뇨에서는 시험물질이 흡수, 배설되지 않는다는 것을 알 수 있었다. 혈액학적 검사에서도 별다른 소견이 나타나지 않았으며 혈액생화학적 검사에서는 간 수치를 나타내는 ALT가 22.0 U/L, 21.3 U/L, 18.9 U/L, 17.6 U/L으로 대조군에서 저용량군, 중간용량군, 고용량군으로 갈수록 수치가 낮아지는 것을 알 수 있었으며 AST도 167.9 U/L, 141.4 U/L, 106.9 U/L, 90.4 U/L으로 대조군에서 저용량군, 중간용량군, 고용량군으로 갈수록 수치가 낮아지는 것을 볼 수 있었다. ALP도 383.6 U/L, 374.7 U/L, 350.9 U/L, 348.2 U/L으로 대조군에서 저용량군, 중간용량군, 고용량군으로 갈수록 수치가 낮아지는 것을 볼 수 있었다. 이 결과로 미루어 볼 때 4주간 반복투여를 통해서는 육안적으로나 수치상으로 별다른 소견이 나타나지 않았지만 아직 면역력이 약한 우리 어린이들이 주로 생활하는 학교나 학원주변에서 무분별하게 판매되고 있는 껌, 빙과류, 청량음료, 캔디류, 초콜릿류 등의 기호식품들을 다량 오래 섭취하게 된다면 큰 문제를 일으킬 수도 있을 것으로 사료되며 성인들도 장기간 다량 복용 시에는 식용색소 적색2호가 간에 손상을 입힐 것으로 사료된다. 장기 중량 및 병리 검사를 통해서는 4주간 사육된 랫드를 해부하여 얻은 각각의 장기 무게를 측정하고 육안적 검사와 병리검사를 실시한 결과 먼저 육안적으로 위와 장에서 시험물질로 인해 내부가 착색이 된 것을 알 수 있었다. 하지만 각각의 장기 중량을 측정한 결과도 대조군과 시험군간의 무게 차이는 별다른 차이를 발견하지 못하였다. 모든 결과를 종합해 볼 때 4주간 임상 적용 용량의 67배를 투여한 결과는 별다른 이상을 발견하지 못하였고 ALT, AST 수치가 점점 낮아지는 이러한 변화는 독성학적으로 의미 있다고 판단하기는 어렵다. 그러나 이러한 일부 변화에 대한 정확한 독성 규명과 식용색소 적색 2호의 안전성에 대한 확립을 위하여 향후 보완적인 장기독성 실험이나 발암성 시험이 진행되어야 할 것이며 정부 차원에서는 기호식품에 잠재적 독성을 가지고 있는 타르색소를 무분별하게 사용하는 기업에 대해 강력한 단속 및 규제를 해야 할 것이다. 기업들도 이러한 타르색소 대신 천연색소를 쓰도록 노력해야 할 것이며 또한 식품색소는 한 가지 타르색소의 사용보다는 한 가지 이상의 색소가 복합적으로 사용되고 있으므로, 현재 우리나라의 타르색소 기준을 개선하여 최대 사용 허용량에 대한 기준을 설정하는 것이 보다 적합한 것으로 판단되어진다.

• 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.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
• /
• pp.17-17
• /
• 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.