• 생물환경조절학회지
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• 제32권1호
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• pp.23-33
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• 2023

자당(suc)은 포도당(glu)과 과당(fru)으로 구성된 이당류로, 식물에서 양분으로 작용하여 탄수화물 공급을 공급하는 분자일 뿐만 아니라, 신호 분자로서도 작용하여 당 특이적 신호전달을 유도하고 유전자 발현과 대사물질을 변화시킨다. 본 연구에서는 쑥에서 생리활성물질의 증진이 뿌리를 통한 자당 흡수로 인한 당 특이적 신호전달로 인한 것인지 아니면 삼투 또는 생물학적 스트레스와 같은 다른 요인으로 인해 유도된 것인지를 확인하고자 수행되었다. 삼투 스트레스와의 비교를 위해 삽목을 통해 발근된 쑥 묘를 정식 4주 후 3일간 만니톨(man)과 suc을 3가지 농도로(10mM, 30mM, 50mM) 호글랜드 양액과 함께 처리하였다. 3일간의 man과 suc 처리는 쑥의 지상부 생체중에 유의적인 차이를 나타내지 않았다. 총 페놀 함량, 총 플라보노이드 그리고 항산화도는 man과 suc 처리구에서 서로 다른 증진 패턴을 보였으며, suc 처리가 man로 유도된 삼투 스트레스와는 다른 기작으로 생리활성물질을 증진시키는 것을 확인하였다. 또한, suc 50mM 처리된 쑥 추출물은 에탄올로 유도된 알코올 자극과 t-BHP로 유도된 산화 스트레스에 대해 각 1.7배, 1.6배 높은 HepG2 cell 보호 효과를 나타냈다. suc처리와 생물학적 스트레스의 비교를 위해 suc 30mM 처리된 용액에서 배양하여 미생물을 얻은 후 이를 suc 30mM과 같이 또는 미생물 만을 정식 후 3주된 쑥에 3일간 양액과 함께 처리하였다. 처리 3일 차에 지상부 생체중의 변화 없이 당 함량이 미생물 처리 여부와 상관없이 suc 처리구들에서 유의적으로 대조구와 미생물 처리에 비해 증가하였다. 또한, 총 페놀 함량과 항산화도 역시 suc 30mM과 suc 와 미생물 혼합 처리구에서 미생물 처리구에 비해 증가하였다. 따라서, 양액 내 suc 처리로 인한 생리활성물질의 증진이 부수적인 스트레스에 의한 것이 아닌, suc 신호전달 효과임을 확인하였다. 본 실험은, 수경재배에서 뿌리를 통한 자당의 신호전달 효과로 인한 생리활성물질의 증진이 유도된다는 가능성을 제시한다.

• 생명과학회지
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• 제33권6호
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• pp.471-480
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• 2023

본 연구에서는 LPS로 자극된 RAW 264.7 세포에서 생물전환 루모라고사리 추출물(B-RAE)의 항염증 효과 및 작용기전을 연구하였다. B-RAE의 총 폴리페놀과 총 플라보노이드 함량을 측정한 결과 379.26±7.77 mg/g과 50.85±3.08 mg/g으로 각각 나타났다. B-RAE의 항산화효과를 측정한 결과 DPPH, ABTS, superoxide anion radical을 농도의존적으로 소거하는 것으로 확인되었다. 또한, B-RAE는 세포생존에 영향을 미치지 않으면서 NO 생성을 처리 농도의존적으로 저해하였다. 전염증성 사이토카인(TNF-α, IL-1β, IL-6) 발현에 미치는 영향을 정량적 실시간 PCR로 측정한 결과 전염증성 사이토카인의 mRNA발현량을 LPS 처리군과 비교하여 B-RAE 처리 농도 의존적으로 유의성 있게 감소시키는 것으로 나타났다. 염증 관련 단백질(iNOS, COX-2)의 발현 및 전사인자인 NF-κB와 MAPK 신호경로 단백질의 인산화에 미치는 영향을 Western blot분석으로 평가하였다. 그 결과 LPS 처리에 의하여 증가된 iNOS와 COX-2의 발현을 유의적으로 억제하였다. 또한, LPS 처리에 의하여 증가된 NF-κB와 IκB의 인산화가 B-RAE 처리에 의하여 감소되는 것으로 나타났다. MAPK 신호경로 단백질의 인산화에 미치는 영향을 측정한 결과 ERK와 p38 MAPK 단백질의 인산화는 농도의존적으로 감소하는 것으로 나타났으나 JNK의 인산화는 증가하는 것으로 나타났다. 따라서 이러한 B-RAE의 항염증 효과는 높은 항산화 활성, iNOS와 COX-2 발현 억제를 통한 NO 생성 억제, NF-κB경로 저해, MAPK 신호경로 조절 및 전염증성 사이토카인 발현 저해에 의해 가능하다는 것을 제시한다.

• Journal of Acupuncture Research
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• 제22권3호
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• pp.155-167
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• 2005

Cobrotoxin의 항염증 치료 기전에 대해 연구하기 위하여 성상세포에 LPS 및 SNP로 염증을 유도한 후 NF-${\kappa}B$와 DNA의 결합 능력, NF-kB Dependent Luciferase 발현, Astrocyte의 세포활성, NF-${\kappa}B$ 구성 단백질인 P50, P-$1{\kappa}B$, $1{\kappa}BB$ 및 염증(炎症)관련 유전자(遺傳子)인 Cox-2, iNOS, cPLA2의 발현과 GSH와 DTT로 sulf-hydryl기를 환원시 NF-${\kappa}B$와 DNA의 결합 능력, NF-${\kappa}B$ 구성 단백질인 P50 발현에 미치는 영향과 Cobrotoxin의 성상세포 내 유입 등을 관찰하여 다음과 같은 결론을 얻었다. 1. LPS 로 염증을 유발한 후 NF-${\kappa}B$와 DNA의 결합 능력을 관찰한 결과 Cobrotoxin 0.1${\mu}g/m{\ell}$ 처리군, Astrocyte 내에서의 Cobrotoxin 0.1, 0.5${\mu}g/m{\ell}$ 처리군에서 모두 대조군에 비하여 유의한 억제를 나타내었다. 2. LPS로 염증을 유발한 후 Astrocyte 내에서 NF-${\kappa}B$ Dependent Luciferase 발현을 살펴본 결과 Cobrotoxin 모든 처리군에서 대조군에 비하여 유의한 억제를 나타내었다. 3. SNP로 염증을 유발한 후 Cobrotoxin이 NF-${\kappa}B$ 구성 단백질인 P50, P-$1{\kappa}B$, $1{\kappa}B$ 발현에 미치는 영향을 살펴본 결과 P50와 $1{\kappa}B$는 Cobrotoxin 0.1, 0.5 및 $1{\mu}g/m{\ell}$ 모든 처리군에서 대조군에 비하여 유의한 억제를 나타내었고, P-$1{\kappa}B$는 Cobrotoxin $0.1{\mu}g/m{\ell}$ 처리군에서 대조군에 비하여 억제를, Cobrotoxin 0.5, $1{\mu}g/m{\ell}$ 처리군에서 각각 대조군에 비하여 유의한 억제를 나타내었다. 4. LPS로 염증을 유발한 후 Cobrotoxin이 NF-${\kappa}B$ 구성 단백질인 P50, P-$1{\kappa}B$, $1{\kappa}B$ 발현에 미치는 영향을 살펴본 결과 P50와 $1{\kappa}B$는 Cobrotoxin 0.5, $1{\mu}g/m{\ell}$ 처리군에서 각각 대조군에 비하여 유의한 억제를 나타내었다. 5. SNP로 염증을 유발한 후 Cobrotoxin이 염증(炎症) 관련 유전자(遺傳子)인 Cox-2, iNOS, cPLA2 발현에 미치는 영향을 살펴본 결과 Cox-2, iNOS, cPLA2 모두 Cobrotoxin $1{\mu}g/m{\ell}$ 처리군에서 대조군에 비하여 유의한 억제를 나타내었다. 6. LPS로 염증을 유발한 후 Cobrotoxin이 염증(炎症) 관련 견전자(遣傳子)인 Cox-2, iNOS, cPLA2 발현에 미치는 영향을 살펴본 결과 Cox-2와 cPLA2의 경우 Cobrotoxin 0.1, 0.5 및 $1{\mu}g/m{\ell}$ 모든 처리군에서, iNOS의 경우 Cobrotoxin 0.5, $1{\mu}g/m{\ell}$ 처리군에서 대조군에 비하여 유의한 억제를 나타내었다. 7. Astrocyte내에서 SNP로 염증을 유발한 후 GSH와 DTT로 sulf-hydryl기를 환원하여 NF-${\kappa}B$와 BNA의 결합 능력을 관찰한 결과 Cobrotoxin $0.5{\mu}g/m{\ell}$과 DTT 1mM Cobrotoxin $0.5{\mu}g/m{\ell}$과 DTT 5mM의 동시처리군은 각각 Cobrotoxin $0.5{\mu}g/m{\ell}$ 처리군에 비하여 유의한 증가를 나타내었다. 8. Astrocyte 내에서 LPS로 염증을 유발한 후 GSH와 DTT로 sulf-hydryl기를 환원하여 NF-${\kappa}B$와 DNA의 결합 능력을 관찰한 결과 cobrotoxin $0.5{\mu}g/m{\ell}$과 DTT 1mM Cobrotoxin $0.5{\mu}g/m{\ell}$과 DTT 5mM의 동시처리군과 Cobrotoxin $0.5{\mu}g/m{\ell}$과 GSH 1mM Cobrotoxin $0.5{\mu}g/m{\ell}$과 GSH 5mM의 동시처리군 모두에서 Cobrotoxin $0.5{\mu}g/m{\ell}$ 처리군에 비하여 유의한 증가를 나타내었다. 9. Astrocyte 내에서 SNP로 염증을 유발한 후 GSH와 DTT로 sulf-hydryl기 환원시 NF-${\kappa}B$ 구성 단백질인 P50 발현에 미치는 영향을 관찰한 결과 SNP, Cobrotoxin $1{\mu}g/m{\ell}$와 DTT 1 또는 5mM 동시처리군과 SNP, Cobrotoxin $1{\mu}g/m{\ell}$와 GSH 1 또는 5mM 동시처리군 모두에서 Cobrotoxin $1{\mu}g/m{\ell}$ 처리군에 비하여 발현의 유의한 증가를 나타내었다. 10. Cobrotoxin의 세포 내 유입 확인을 살펴본 결과 Astrocyte 내에서 Cobrotoxin이 세포내로 유입되는 것으로 나타났다. 이상의 결과로 보아 Cobrotoxin 처리는 성상 세포 들을 대상을 LPS 및 SNP로 유도된 NF-${\kappa}B$ 관련 염증 기전과 iNOS, COX-2, cPLA2와 같은 염증관련 유전자의 발현 및 NO, PGE2,에 유의한 변동을 나타내었고, 이들 결과는 Cobrotoxin의 항염증 효과 및 그 치료기전에 대하여 입증한 것이며, 향후 안전성 연구를 바탕으로 신경계 및 심혈관계 염증치료에 약침개발과 같은 적극적인 활용이 기대된다.

• Tuberculosis and Respiratory Diseases
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• 제49권3호
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• pp.332-342
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• 2000

연구배경 : 염증매개 사이토카인은 염증성 폐질환의 중요한 매개물질이다. 폐 상피세포는 염증세포에서 분비되는 사이토카인에 의해 interleukin, chemokines, colony stimulating factors와 growth factor등을 생산 및 분비함으로써 국소 염증 부위에서의 사이토카인 network에 중요한 역할을 한다. 따라서 폐 상피세포에서 염증매개 사이토카인의 발현 기전에 대한 이해는 염증성 폐질환의 기전규명과 이에 기초한 새로운 치료법의 개발에 생각된다. 대부분의 사이토카인은 NF-${\kappa}B$전사인자에 의해 발현되는데 폐 상피세포에서 염증매개 사이토키인의 발현과 NF-${\kappa}B/I{\kappa}B$ 경로와의 관련성에 관한 연구는 부족한 실정이다. 방법 : BEAS-2B, A549, NCI-H157, NCI-H719 세포에서 IL-1$\beta$와 TNF-$\alpha$ 자극에 의한 IL-8과 TNF-$\alpha$ mRNA의 발현 양상을 평가하였고 이들의 발현과 관찰하였고 NF-${\kappa}B/I{\kappa}B$ 경로와의 관련성을 평가하기 위하여 IL-l$\beta$와 TNF-$\alpha$ 자극에 의한 NF-${\kappa}B$의 활성화 및 $I{\kappa}B{\alpha}$와 $I{\kappa}B{\beta}$의 분해 양상을 관찰하였다. 폐 상피세포의 종류에 따른 NF-${\kappa}B/I{\kappa}B$ 경로 조절의 기전을 규명하고자 IL-1$\beta$와 TNF-$\alpha$ 자극에 의한 $I{\kappa}B{\alpha}$의 인산화와 기저상태에서 IKK$\alpha$의 발현을 평가하였다. 결과 : BEAS-2B, A549, NCI-H157 세포에서는 IL-1$\beta$와 TNF-$\alpha$ 자극으로 $I{\kappa}B{\alpha}$와 $I{\kappa}B{\beta}$가 분해되었고 NF-${\kappa}B$의 활성화가 관찰되었으며 IL-8과 TNF-$\alpha$mRNA의 발현이 유도되었다. NCI-H719 세포에서는 IL-1$\beta$와 TNF-$\alpha$ 자극으로 $I{\kappa}B$ 분해에 의한 NF-${\kappa}B$의 활성화 및 염증매개 사이토카인의 발현이 관찰되지 않았다. BEAS-2B, A549, NCI-H157 세포에서는 IL-1$\beta$와 TNF-$\alpha$ 자극으로 ${\kappa}B$의 인산화가 관찰되었지만 NCI-H719 세포에서는 관찰되지 않았다. 기저상태의 IKK$\alpha$ 발현은 세포간에 차이가 관찰되지 않았다. 결론 : 폐 상피세포에서 NF-${\kappa}B/I{\kappa}B$ 경로는 염증매개 사이토카인 발현에 매우 중요한 역할을 하고, 일부 세포에서는 NF-${\kappa}B/I{\kappa}B$ 경로 조절의 차이를 보이는데 이는 IKK보다 상위 단계의 세포내 신호전달체계의 이상에 기인한 것으로 생각된다.

• Tuberculosis and Respiratory Diseases
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• 제42권6호
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• pp.862-870
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• 1995

연구배경: 산소기의 작용은 과거에는 세포독성이 주로 알려져 있었던 반면, 최근 들어 산소기의 세포내 신호전달체계에서의 역할에 많은 사람의 관심이 모이고 있다. 여러 cytokine의 전사인자(transcription factor)로 작용하는 $NF{\kappa}B$는 기저상태에서는 세포질에 존재하는데 $I{\kappa}B$와 결합되어 핵내로의 이동이 억제되고 있다. 여러 연구에 의해 $NF{\kappa}B$의 $I{\kappa}B$로부터의 분리는 외부자극에 의해 생성된 산소기에 의한 것으로 알려졌는데, 이렇게 하여 분리된 $NF{\kappa}B$가 핵내로 이동하면 핵내에서 전사인자로 작용하여 여러 유전자의 전사를 증가시키는 것이 보고되었다. IL-8 유전자는 5'flanking promotor region에 $NF{\kappa}B$-like motif가 있어 핵내 $NF{\kappa}B$ activity의 증가로 IL-8 유전자의 전사가 증가되는 것으로 알려졌고, 또한 내독소는 핵내의 $NF{\kappa}B$ activity의 증가와 함께 호중구에서의 산소기의 분비를 가져온다. 이러한 사실로부터 내독소에 의한 IL-8 유전자의 발현은 세포내에서 생성된 산소기에 의해 $NF{\kappa}B$가 $I{\kappa}B$로부터 분리되어 핵내로 이동하고 이로 인해 IL-8 유전자의 전사가 증가되는 가설을 생각할 수 있다. 저자들은 이러한 가설 검정의 첫번째 단계로써 체내 염증반응에서 중요한 역할을 하는 말초혈액 단핵구의 IL-8 및 IL-$1{\beta}$ 유전자 발현에 세포내의 산소기가 관여하는지의 여부를 평가하고자 본 연구를 시행하였다. 방법: Ficoll-Hypaque density gradient 법과 plastic 부착법을 이용하여 말초혈액 단핵구를 분리하였다. 외부에서 투여한 산소기의 농도에 따른 IL-8 및 IL-$1{\beta}$ mRNA 발현의 유무를 관찰하기 위하여 $H_2O_2$를 0, 10, 100, $300{\mu}M/L$, 1mM/L의 농도로 투여하고 6시간이 경과한후 IL-8 및 IL-$1{\beta}$에 대한 Northern blot analysis를 시행하였다. 시간에 따른 IL-8 및 IL-$1{\beta}$ mRNA 변화를 관찰하고자 $H_2O_2$를 $100{\mu}M/L$의 농도로 투여하고 0, 2, 4, 6, 8, 24시간이 경과한 후 Northern blot analysis를 시행하였다. 항산화제가 내독소에 의한 IL-8과 IL-$1{\beta}$ mRNA 발현에 미치는 영향을 평가하기 위하여 TMTU(10 mM/L) 1시간; PDTC($100{\mu}M/L$) 1시간, NAC(10 mM/L) 2.5시간, ME(10mM/(L) 2.5시간, Desferrioxamine(100mM/L) 15시간 동안 전처치 한 디음 내독소를 투여허여 4시간이 경과한 후 IL-8 및 IL-$1{\beta}$ mRNA에 대한 Northern blot analysis를 시행하였다. 결과: $H_2O_2$농도 및 시간에 따른 말초혈액 단핵구에서의 IL-8 및 IL-$1{\beta}$ mRNA의 발현에는 유의한 차이가 관찰되지 않았지만 항산화제로 전처치하였을 때 내독소에 의한 말초혈액 단핵구에서의 IL-8 및 IL-$1{\beta}$ mRNA의 발현이 억제되었고 그 억제정도는 TMTU에서 가장 현저하였다. 결론: 이상의 결과에서 말초혈액 단핵구에서의 IL-8 및 IL-$1{\beta}$ mRNA 발현에 $H_2O_2$가 아닌 다른 산소기가 일부 관여할 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)
• /
• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
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• 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.