• Tuberculosis and Respiratory Diseases
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• 제42권3호
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• pp.302-313
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• 1995

연구배경: 종양괴사인자(Tumor necrosis factor; TNF)는 다양한 생물학적인 작용을 가지며 종양 세포에 대한 세포 독성은 그 대표적인 기능중의 하나이다. TNF-$\alpha$는 생체외에서(in vitro) 몇몇 종양 세포주에 대하여 항암제, 특히 topoisomerase II targeted chemotherapeutic agent의 세포 독성 효과를 상승적으로 증가시키는 것이 알려져 있다. 최근 암세포에 대한 cytokine 유전자 요법에서 TNF는 중요한 대상으로 여겨지고 있으며, 유전자 이입에 의해 암조직이 TNF를 생성하게 될 경우 암 증식 억제 효과가 있음이 보고되고 있다. 연구자는 암세포에 TNF-$\alpha$ 유전자를 이입하여 자신이 TNF-$\alpha$를 생성하도록 형질을 변환시킨 암세포는 topoisomerase II 억제 항암제에 대한 김수성에 변화가 있을 것이라는 가설을 수립하였고 이를 검증하고자 본 연구를 수행하였다. 본 연구에서는 생체외로(in vitro) TNF-$\alpha$ 유전자를 이입하여 TNF-$\alpha$를 생성하는 암세포주에서 topoisomerase II targeted drug에 대한 항암제 감수성 효과가 모세포주에 비하여 증대될 수 있는지를 알아 보고자하였다. 방법: TNF-$\alpha$에 감수성을 보이는 것으로 알려진 인체 중피종 세포주인 NCI-H2058 세포주 및 생쥐의 섬유육종 세포주인 WEHI164 세포주와 인체 비소세포 폐암 세포주인 A549 세포주를 배양하여, 먼저 임상에서 흔히 폐암의 항암 화학 요법 치료에 널리 쓰이는 대표적인 topoisomerase II targeted chemotherapeutic drug인 etoposide(VP-16)와 doxorubicin(adriamycin)을 가하였을 때 관찰된 세포 독성을 MTT assay로 측정하고, 각 모세포주(parenta1 cell line)에 TNF-$\alpha$의 유전자를 이입시켜서 형절 변환한 세포주(transformed cell line)에 대하여 각각 동일한 항암제를 가하였을 때 관찰된 세포 독성의 정도를 같은 방법으로 측정하여, 그 결과를 비교 분석하였다. 또한 모세포주에 외부에서 TNF를 가하여 전처치한 후 동일한 항암제를 가하였을 때의 세포독성을 관찰하여 비교 분석하였다. 결과: H2058 세포주에서는 TNF-$\alpha$ 유전자를 이입한 세포주 topoisomerase II targeted drug을 가하였을 때, 항암제 감수성이 모세포주에 같은 항암제를 가하였을 때에 비하여 의미있게 증가함을 관찰할 수 있었으나(p<0.05), WEHI 세포주와 A549 세포주에 있어서는 TNF-$\alpha$ 유전자를 이입한 세포주에서 모세포주에 비하여 항암제 감수성이 증가하지는 않았다. 결론: TNF-$\alpha$ 유전자의 이입이 topoisomerase II targeted chemotherapeutic drug에 대한 항암제 감수성을 증가시키는 효과는 세포주에 따라 다양한 결과를 보이는 것을 알 수 있었으며, 적어도 선택된 특정 종류의 호흡기계 암세포에 있어서는 TNF-$\alpha$ 유전자의 이입으로 항암제 감수성(chemosensitivity)을 증가시킬 수 있을 것으로 사료된다.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
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• pp.224-230
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• 1998

This study showed the anti-invasive activity of ginseng components, panaxadiol (PD) and panamatrlol (PT) on the highly metastatic HT1080 human flbrosarcoma cell line. PD and PT reduced tumor cell invasion through a reconstitute basement membrane in the transwell chamber. A significant down regulation of MMP-9 by PD and PT was detected by northern blot analysis. However, MMP-2 was constantly expressed. Quantitative gelatin based zymography confirmed a marked reduced expression of MMP-9 but not MMP-2 in the treatment of PD and PT. Since the chemical structures of PD and PT are very similar to that of dexamethasone, a synthetic glucocorticoid, it was investigated whether PD and PT act through GR. Western blot analysis and immunocytochemistry showed that PD and PT increased the GR fraction in the nucleus. These results suggest that ursolic acid may induce repression of MMP-9 by stimulating the nuclear translocation of GR and hence inhibiting the activity of AP-1 to TPA-responsible element of MMP-9 promoter region. In conclusion, we suggest that CR-induced down-regulation of MMP-9 by PD and PT contributes to reduce the invasive capacity of HT 1080 cells.

• Tuberculosis and Respiratory Diseases
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• 제46권5호
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• pp.636-644
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• 1999

연구배경 : 종양괴사인자(tumor necrosis factor ; TNF)는 다양한 생물학적 기능을 가지고 있는바, 그 중 생체 외에서 증명된 뚜렷한 항암 효과로 말미암아 최근 항암유전자요법의 중요한 대상으로 관심을 모으고 있다. 그러나 TNF의 세포독성의 기전에 대해서는 확실히 밝혀진 바가 없고 반응성 산소기가 관여할 것임을 시사하는 연구들이 있었으나, 항산화제에 의해서 TNF의 세포독성이 감소되는 지에 대해서는 상충되는 결과가 있었다. 본 연구는 TNF의 세포독성의 기전에서 반응성 산소기의 역할을 알아보기 위해 TNF 감수성 종양세포에 여러 가지 항산화제를 전처치한 후의 TNF 세포독성이 감소하는 지를 대조군과 비교하였다. 방 법 : TNF에 비교적 감수성을 보이는 세포주인 WEHI164(murine fibrosarcoma cell line)와 ME180(human cervix cancer cell line)을 배양하여 각각 3가지 항산화제로 전처치한 것과 대조군을 TNF 10ng/ml로 세포독성을 유도하고 그 정도를 MTT(dimethylthiazolyl-diphenyltetrazolium bromide) assay를 이용하여 세포독성 정도를 측정 비교하였다. 결 과 : 항산화제를 전처치하지 않은 대조군에서는 WEHI164 세포와 ME180 세포가 각각 $92.2{\pm}2.8%$와 $59.9{\pm}7.0%$의 세포독성을 보였고, TMTU를 전처지한 군은 각각 $91.4{\pm}3.7%$와 $74.6{\pm}7.0%$, PMZ을 전처치한 군은 $90.2{\pm}2.5%$와 $62.5{\pm}5.7%$, BHT을 전처치한 군은 $93.2{\pm}1.3%$와 $66.3{\pm}6.1%$로 세포독성의 유의한 감소는 없었다. 결 론 : 종양세포에 대한 TNF의 세포독성은 항산화제에 의해 감소되지 않으며 따라서 TNF의 세포독성은 반응성 산소기에 의한 것이 주된 기전은 아니라고 판단된다.

• Tuberculosis and Respiratory Diseases
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• 제44권6호
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• pp.1353-1365
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• 1997

연구배경 : 종양괴사인자(tumor necrosis factor ; TNF)는 다양한 생물학적 기능을 가지고 있는 바, 그 중 생체 외에서 증명된 뚜렷한 항암 효과로 말미암아 최근 항암 유전자요법의 중요한 대상으로 관심을 모으고 있다. 현재 유전자 이입의 기술적 문제로 생체 외에서 암세포에 유전자 이입을 시행한 후 이를 다시 환자의 생체내로 이식하는 방법이 연구의 주종을 이루고 있다. 그러나 저자들의 과거의 연구를 포함한 여러 연구에서 TNF가 이입된 암세포는 TNF에 대해 내성을 보이는 이에는 새로이 방어 단백질을 합성하는 것이 관여할 것이라는 시사가 있었다. 이 획득내성의 기전을 밝히는 것이 종양생물학의 이해를 넓히고 보다 효과적인 항암 유전자요법을 개발하기위한 매우 중요한 과제로 생각된다. 저자들은 TNF 유전자 이입에 따른 암세포의 TNF에 대한 획득내성에, 일부 세포에서 TNF에 의해 발현이 유도된다는 것이 밝혀진, 항산화효소의 하나인 MnSOD의 발현의 변화가 관여하는 지를 규명하고자 본 실험을 수행하였다. 방 법 : TNF에 다양한 감수성을 보이는 인체 및 생쥐 기원의 4가지 암세포주(WEHI164, NCI-H2058, A549, ME180)에 TNF-$\alpha$ 유전자를 retroviral 이용하여 이입하고 TNF의 발현을 시도하여 PCR, ELISA, MTT assay로 확인하였고, TNF 유전자가 이입된 세포(WEHI164-TNF, NCI-H2058-TNF, A549-TNF, ME180-TNF)는 TNF에 내성을 보이는지 역시 MTT assay로 검증하였다. TNF 유전자 이입 전후의 MnSOD mRNA 발현의 차이는 Northern blot analysis를 통하여 비교하였다. 결 과 : 1) TNF-$\alpha$ 유천자 이입 및 발현 확인 PCR을 시행한 결과 TNF 유전자가 이입된 각 세포 790 base pair 표기의 진한 DNA band를 보인 반면 모세포주는 보이지 않아서 retroviral vector를 이용한 유전자 이입이 DNA 수준에서 이루어 있었다. 그리고 TNF 유전자가 이입된 세포의 배양상층액에서 TNF양을 ELISA로 측정한 결과 TNF를 세포에 따라 1.91ng/24hr/$10^6\;cells$에서 3.91ng/24hr/$10^6\;cells$ 생산함을 알 수 있었다. 2) TNF 유전자 이입 전후, 암세포의 TNF에 대한 감수성 비교 TNF 농도 100ng/ml에서 WEHI164-TNF와 ME180-TNF 세포는 통계적으로 유의하게 (p<0.01) TNF에 대한 내성을 획득함을 알 수 있었다. 3) TNF 유전자 이입 전후외 MnSOD mRNA 발현양상 TNF에 감수성을 보이는 WEHl164와 ME180세포는 TNF 유전자 이입 후에 MnSOD mRNA 발현이 증가되지 않았으며, TNF에 내성을 보이는 NCIH2058과 A549 세포는 TNF 유전자 이입 후에 MnSOD mRNA 발현의 증가가 관찰되었으나 이는 모세포에 외부에서 TNF를 주었을 때도 관찰되었다. 결 론 : 세포주에 TNF 유전자를 이입하여 TNF를 발현하게 하였을때 세포 자신은 TNF에 대해 내성을 하게 되는데, 이 획득내성은 MnSOD 발현 능력의 향상에 의한 것은 아닐 것으로 판단되나 각 세포주의 자연 상태의 TNF에 대한 감수성 여부는 MnSOD의 발현 차이가 관련될 것으로 생각된다.

• Journal of Periodontal and Implant Science
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• 제33권2호
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• pp.277-288
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• 2003

It has been suggested that increased number and activity of phagocytes in periodontitis lesion results in a high degree of reactive oxygen species (ROS) such as superoxide anion, hydrogen peroxide, nitric oxide and peroxynitrite. There are few reports on the relationship between ROS and MMPs expressions in gingival fibroblast. We studied to elucidate whether and how ROS, especially nitric oxide affects the MMP expression. Human gingival fibroblasts and HTl080 cells (human fibrosarcoma sell line as reference) were grown in DMEM supplemented with 10 mM HEPES, 50 mg/L gentamicin, and 10% heat inactivated fetal bovine serum with addition of various reactive oxygen species (ROS). Culture media conditioned by cells were examined by gelatin zymography. HT1080 cells expressed proMMP-2 and proMMP-9, but human gingival fibroblasts (HGF) produced only proMMP-2. Hydrogen peroxide upregulated MMP-9 expression in HT1080 cells, whereas in human gingival fibroblast SNP treatment showed marked increase in MMP-2 level compared to other ROS. These results suggest that the effects of ROS on MMPs expressions are cell-type specific. RT-PCR for MMP-2 and TIMP-2 m-RNA were performed using total RNA from cultured cells under the influence various kinase inhibitors. In HT1080 cells, treatment with FPTI III (Ras processing inhibitor) and LY294002 (PI3-kinase inhibitor) resulted in inhibition of MMP-2 and MMP-9 expressions, suggesting that Ras/P13-kinase pathway is important for MMPs expression in HT1080 cells. In gingival fibroblasts, treatment with FPTI III and PDTC (NF-kB inhibitor) showed marked decrease in MMP-2 regardless of the of SNP , suggesting that Ras/NF-kB could be the key pathway for NO-induced MMP-2 expression in gingival fibroblasts. This study showed that ROS, especially nitric oxide, could be the critical mediator of periodontal disease progression through control of MMP-2 expression in gingival fibroblasts possibly via Ras/NF-kB pathway.

• Applied Biological Chemistry
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• 제49권2호
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• pp.91-96
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• 2006

상황버섯에 대한 다양한 추출방법별 항산화 활성과 항돌연변이성, 세포독성 등의 생물학적 활성을 S. typhimurium과 인체암세포주들을 이용하여 측정하였다. DPPH free radical scavenging 활성을 통한 항산화 효과를 조사한 결과 열수로 추출한 것보다ethanol로 처리한 것이 높게 나타났으며, ethanol 추출과 열수 후 ethanol 추출 시 각각 17.14, $17.79\;{\mu}g/ml$로 매우 높은 항산화 활성을 나타내었다. S. typhimurium TA97과 TA100을 이용한 Ames test에서는 직접변이원 물질인 MNNG와 4NQO에 대한 돌연변이 억제효과를 조사한 결과는 2가지 변이원 물질에 대한 억제율은 추출물의 농도와 양이 증가함에 따라 비례적으로 증가함을 보여주었고, MNNG에 대해서는 ethanol 추출물이 70.7%로 가장 높은 억제율을 보였고, 열수후 ethanol 추출 시에도 50% 이상의 억제율을 보였다. 4NQO에 대해서는 ethanol 추출물이 62.9%, 열수후 ethanol 추출물이 52.9%로 50% 이상의 억제율을 나타내었다. 간접변이원 물질인 $B({\alpha})P$에 대한 항돌연변이 효과는 TA98과 TA100 두 균주 모두 ethanol 추출물이 가장 높은 억제율을 보였다. 즉 TA98 균주는 ethanol 추출물 61.5%, 열수후 ethanol 추출물이 50% 이상의 항돌연변이 효과를 나타내었으며, TA100 균주에서는 ethanol 추출물과 열수 후 ethanol 추출물이 50% 이상의 억제율을 보였다. 상황버섯 추출물에 의한 암세포 성장 억제효과를 사람의 결장암 세포인 HT-29와 간암세포인 HepG2에 미치는 영향으로 검토한 결과 각 추출물들이 추출농도에 따라 증가함을 보여주었고, ethanol 분획물이 열수 분획물보다 상대적으로 높은 억제율을 보였다. 반면 시료 0.5 mg/ml 투여 시 HT-29 세포에 대해서 ethanol 추출물 59%, 열수 추출물 54%, 열수후 ethanol 추출물 57%로 50% 이상의 억제율을 나타내었고, 특히 ethanol 추출물과 열수 후 ethanol 추출물에서는 0.25 mg/ml 농도에서 50% 이상의 암세포 증식 억제효과를 나타내었다. 그리고 간암세포 HepG2의 경우 ethanol 추출물이 30%로 결장암세포인 HT-29에 비해 비교적 낮은 활성을 나타내었다. Ethanol 추출물과 열수추출물은 다양한 pH 조건에서 아질산염 소거증을 보여주었으며, 대체로 ethanol 추출물이 열수추출물 보다 높은 효과를 보여주었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권4호
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• pp.314-320
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• 2001

Matrix metalloproteinases have long been viewed as ideal candidates for proteinases that enables tumor cells to permeated basement membrane defenses and invade surrounding tissue. There is growing evidence that the MMPs have an expanded role, as they are important for the creation and maintenance of a microenvironment that facilitates growth and angiogenesis of tumors at primary and metastatic sites. MT-MMPs are not secreted but instead remaining attached to cell surfaces. Although not all of the MT-MMPs are fully characterized, MT-MMPs have important role in localizing and activating secreted MMPs. The MMP genes are transcriptionally responsive to a wide variety of oncogene, growth factors, cytokine, and hormones. Currently, a number of MMP inhibitors are being developed and some have reached clinical trials as anti-metastatic or anti-cancer therapies. MT1-MMP is involved in the activation of proMMP-2. MT1-MMP is significant not only as a tumor marker but as a new target for chemotherapy against cancer. The purpose of this study was to evaluate the effects of protein kinase C inhibitor(genistein) on the proliferation of HT1080 and expression of MT1-MMP mRNA. Human fibrosarcoma cell line HT1080 was cultured and divided 2 groups. The experimental group was treated with $100{\mu}M$ genistein and incubated 12h, 24h for $[3^H]-thymidine$ uptake assay and northern hybridization individually. And the control group was treated with same amount of PBS for the above procedures. $[3^H]-thymidine$ incorporation was measured with ${\beta}$ ray detector. And RT-PCR and northern blotting for MT1-MMP mRNA was performed. The results were as follows 1. $[3^H]-thymidine$ uptake was reduced in experimental group with statistical significance. 2. MT1-MMP mRNA expression was significantly reduced in experimental group. These results showed that protein kinase C inhibitor (genistein) inhibited proliferation of HT1080 and almost completely blocked transcription of MT1-MMP mRNA. So, it is possible to use the protein kinase inhibitor (genistein) as anti-metastatic and anti-proliferative agent.

• Tuberculosis and Respiratory Diseases
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• 제41권2호
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• pp.87-96
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• 1994

연구배경 : 종양괴사인자(tumor necrosis factor ; TNF)는 여러 암세포에 대해서 세포독성을 보임이 알려져 있다. 그리고, 최근 분자생물학적 발전에 힘입어 TNF 유전자를 암세포에 이입하고 발현시키는 연구가 그 동안 진행되었다. 이들 연구의 목적은, TNF를 전신적으로 쓸 경우 전신 부작용이 심하여 인체에 쓸 수 없는 현 단계에서 암세포 자체에서 TNF를 만들어 내어서 암세포 주위에서만 작용하게 함으로써 연체에 미치는 전신독성을 최소한으로 줄이고 암세포를 사멸시키는 것이었다. 암세포에 TNF 유전자를 이입함으로써 예상되는 항암효과가 성공을 거두기 위해서는 첫째, TNF 유전자가 이입된 암세포에서 분비된 TNF가 주위 암세포를 성공적으로 사멸시켜야 하고 둘째는 분비된 TNF가, TNF 유전자가 이입된 암세포 자신을 사멸시켜야 한다. 본 연구는 이 중 두번째 기전, 즉 TNF 유전자가 이입된 암세포가 자신이 분비한 TNF에 의해서 사멸되거나 또는 세포 독성이 나타날 수 있는가를 검증하는데 목적을 두었다. 방법 : TNF에 감수성을 보이는 인체의 중피종 세포주인 NCI-H2058과 생쥐 섬유육종 세포주인 WEHI164에 TNF-$\alpha$ 유전자를 retroviral vector를 이용하여 이입하고 TNF를 발현을 시도하였다. DNA 수준과 단백질 수준에서 TNF-$\alpha$ 유전자가 제대로 이입되어 발현되는지 PCR과 ELISA 및 bioassay(MTT assay)로 확인하였다. 그리고, TNF 유전자가 이입된 세포주가 자신이 분비하는 TNF에 사멸되는지 아니면 생존하는지 MTT(dimethylthiazolyl diphenyltetrazolium) assay로 알아보았다. 그리고, 만일 TNF 유전자가 이입된 암세포가 자신이 분비한 TNF에 사멸되지 않고 생존할 경우, TNF 유전자가 이입된 NCI-H2058-TNF와 WEHI164-TNF 암세포주가 외부에서 준 TNF에도 내성을 보이는지도 추가로 MTT assay 방법으로 확인해 보았다. 결과 : 1) TNF-$\alpha$ 유전자 이입 및 발현 확인 PCR을 시행한 결과, TNF 유전자가 이입된 NCI-H2058-TNF와 WEHI164-TNF 세포주는 790 base pair 크기의 진한 DNA band를 보인 반면 각각의 모세포주에서는 보이지 않아서 retroviral vector를 이용한 유전자 이입이 DNA 수준에서 이루어졌음을 확인할 수 있었다. 그리고, NCI-H2058-TNF와 WEHI164-TNF의 상층 배양액의 TNF양을 ELISA와 bioassay(MTT assay)로 측정한 결과, 생물학적 활성을 지닌 TNF를 각각 $23.6{\pm}0.84ng$/24h/$10^6cells$, $12.2{\pm}0.36ng$/24h/$10^6cells$ 생산함을 알 수 있었다. 2) TNF 유전자 이입 전후, 암세포의 TNF에 대한 감수성 비교 TNF 유전자 이입 전후의 TNF에 대한 세포주의 감수성(세포사망율)을 TNF의 농도 변화에 따라 비교한 결과, NCI-H2058의 경우 TNF 농도 100ng/ml에서 모세포는 $25{\pm}3%$의 세포독성을 보인 반면 TNF 유전자 이입 후에는 $3{\pm}2%$의 세포독성을 보여 통계적으로 유의한 차이가 있었다(p<0.01). 그리고, WEHI-164의 경우도 TNF 농도 100ng/ml에서 모세포는 $73{\pm}5%$의 세포독성을 보인 반면 TNF 유전자 이입 후에는 $3{\pm}2%$의 세포독성을 보여 통계적으로 유의한 차이가 있었다(p<0.01). 결론 : TNF에 감수성을 보이는 암세포주인 NCI-H2058과 WEHI164에 TNF 유전자 이입을 시행하고 TNF가 발현되게 하였을 때, TNF 유전자를 이입받은 두 암세포주 모두에서 자신이 생산해 내는 TNF에 내성을 보여 생존하였다. 뿐만 아니라 생존한 이들 세포는 외부에서 준 TNF에 대해서도 내성을 보였다. 따라서, 암세포에 대한 TNF 유전자 이입을 통한 유전자 요법이 성공을 거두려면 유전자 이입된 세포에서 분비하는 TNF의 면역 세포 동원 방법 등의 간접적인 항암기전이 필요할 것으로 생각된다.

• 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)
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• 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.