• Tuberculosis and Respiratory Diseases
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• 제45권2호
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• pp.404-415
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• 1998

연구배경: 수면 무호흡 증후군에서 고혈압, 허혈성 심질환, 심부정맥등과 같은 심혈관 합병증과 주간 과다 졸음증은 주간 사고와 사망율의 증가와 관계가 있다. 수면 무호흡 증후군 환자에서의 심혈관 합병증의 원인으로는 수면중의 저산소혈증과 자율 신경 장애가 중요한 역할을 한다. 현재까지 수면 무호흡 증후군 환자에서 자율 신경 장애 유무에 대해서는 상반된 결과가 발표되고 있으며 발생기전도 잘 밝혀져 있지 않다. 저자들은 수면 무호흡 증후군 환자에서 자율 신경 장애 검사로 심혈관 자율 신경 장애 검사법이 유용한 검사가 될 수 있을지를 알아보았고 자율 신경 장애의 유무를 확인하였으며 이들 장애가 의미있는 상관 관계가 있는 인자를 알아보았다. 방 법: 수면 다원 검사에서 수면 무호흡 증후군으로 진단된 환자와 건강한 대조군에서 심혈관 자율 신경 장애 검사를 실시하여 환자군에서 자율 신경 장애 유무를 관찰하였으며 또한 수면 무호흡 증후군에서 심혈관 자율 신경 장애 검사가 유효한 검사법이 될 수 있을지를 알아 보았다. 또한 심혈관 자율 신경 장애 검사 결과와 수면 다원 검사 결과를 비교 분석하여 자율 신경 장애와 관계있는 인자를 알아보았다. 결 과: 수면 무호흡 증후군 환자에서 심혈관 자율 신경 장애 검사법의 결과 환자군에서 대조군보다 Valsalva maneuver 에서 유의한 차이를 보이면서 낮게 측정되었으며 나머지 항목에서는 유의한 차이가 없었다. 자율 신경 장애의 정도를 나타내는 자율 신경 장애 접수는 환자군이 $1.10{\pm}0.55$점으로 대조군의 $0.30{\pm}0.36$ 점보다 의의있게 높았으며, 교정한 QTc 간격도 환자군이 $423.93{\pm}18.44msec$, 대조군이 $396.93{\pm}19.85msec$로 두 군간에 유의한 차이를 보였다 (p<0.001). 그러나 자율 신경 장애 접수와 교정한 QTc 간격사이에는 상관 관계가 없었다 (r=0.410, p=0.073). 자율 신경 장애 점수와 수면 다원 검사에서 측정된 항목사이에는 유의한 상관 관계를 가지는 항목을 관찰할 수 없었다. 자율 신경 장애 정도를 유형에 따라 5가지로 분류하고 환자의 분포를 당뇨병 환자와 비교해 본 결과 두 질환은 서로 다른 분포를 보였다. 결 론: 수면 무호흡 증후군 환자에서 심혈관 자율 신경 장애 검사법을 적용하여 자율 신경계의 장애가 있음을 확인할 수 있었으며 심혈관자율 신경 장애 검사법이 수면무호흡 환자의 자율 신경 장애를 평가할 수 있는 유용한 검사법이었다. 앞으로 자율 신경 장애의 발생에 관여하는 인자를 밝히기 위한 더 많은 연구가 시행되어야 할 것으로 생각된다.

• The Korean Journal of Physiology
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• 제2권2호
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• pp.33-43
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• 1968

Histamine, 0.5 mg as histamine base in 4 ml of normal saline solution, was injected into rabbits anesthetized with nembutal and the mean blood pressure was kept in the range of $52{\sim}80\;mmHg$ for over one hour by supplemental additions. Following the injection of the test substances, 300 mg of urea and 200 mg of antipyrine intravenously, serial blood samples were obtained from the femoral artery and the internal jugular vein at $0.5{\sim}3$ minutes interval. The decreasing patterns in the concentrations of arterial and venous blood plasma samples were compared with each other. The ratio of the concentration of brain tissue to that of the final arterial plasma was also studied. By these measures the degrees of penetration of the test substances in the brain in the control and in the histamine treated rabbits were observed. The concentrations of antipyrine and urea in the arterial blood plasma were decreasing exponentially with respect to the time elapsed. The venous concentrations were anticipated to increase initially and to cross the arterial concentration curve in the point of equlibrium between the plasma and the tissue. On the contrary to the expectation venous concentration also revealed the decreasing tendency similar to that of arterial plasma. The similarity between these two curves, arterial and venous, would be atributable to the fact that the cerebral blood flow rate was large enough and the rising phase in the venous concentration curve was instantly over before serial blood samples were taken. Inspite of some similarity in the decreasing tedency in both concentration curves there were appreciable discrepancies between the arterial and venous plasma which would reflect the situation far from the equlibria among several compartments in the brain. Changes in plasma potassium levels caused by the injection of histamine or bleeding were observed, too. Using 8 rabbits as the control and 12 rabbits for the histamine treated group following results were obtained: 1. Both of the concentration curves, arterial and venous, declined rapidly at_first and slowly later on and approached same equilibrium concentration with the passage of time after a single injection. The time at which attained the same concentration was $2.0{\pm}0.54\;min.$ in the control and $4.3{\pm}1.92\;min.$ in the histamine treated group with respect to antipyrine. On the other hand in the case of urea they were $2.4{\pm}0.59\;min.$ in the control and $4.4{\pm}1.31\;min.$ in the histamine group, respectively. In the histamine treated group enlarged spaces for distribution of test substances were postulated. 2. The concentration of antipyrine in the brain tissue water revealed no significant differences between the control and experimental groups, showing $212{\pm}40.2\;mg/l$ in the control and $206{\pm}64.1\;mg/l$ in the histamine treated group. On the other hand urea revealed higher value in the histamine treated group than in the control, showing an enhanced penetration of urea into the tissue after injection of histamine. Urea concentration in the brain water was $32.3{\pm}3.36\;mg%$ in the control and $39.2{\pm}4.25\;mg%$ in the histamine treated group. 3. The distribution ratio of antipyrine in the brain tissue was very close to unity in the histamine treated animals as well as in the control. 4. The average of the distribution ratio of urea in the control animals was 0.77 and it showed the presence of blood-brain barrier with regard to urea. However in the histamine treated animals the distribution ratios climbed up to 0.86 and they were closer to unity than in the control animals. Out of 12 cases 5 were greater than 0.9 and 8 exceeded 0.85. It appeared that histamine enhanced the penetration of urea through the barrier. 5. Histamine injection and or hemorrhage caused an elevation of the concentration of potassium in plasma. In the event that histamine and hemorrhage were applied together the elevation of potassium exceed the elevation seen at the histamine alone. There was no evidence that the leakage of potassium from the brain tissue was dominant in comparison with the general leakage from the whole body.

• Journal of Chest Surgery
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• 제34권10호
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• pp.754-762
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• 2001

배경: 영낡치대 흥부외과학교실에서 1989년부터 1998년 사이에 대혈관전위로 동맥전환술을 받고 6개월 이상 추적관찰한 환자 8례를 대상으로, 동맥 전환술의 효용도를 평가하기 위해 반복적인 심초음파 검사를 시행한 후 그 자료를 후향적으로 분석하였다. 대상 및 방법: 추적관찰기간은 평균 4.1년이었고 최단 6개월에서 최장 11년이었다. 대성환자의 연령은 평균 29일(범위 3∼56일)이었고 체중은 평균 3.6kg(범위 2.6∼4.8kg)이었다. 술 전 진단은 TGA+VSD가 5례, TGA+IVS가 3례이었다. 좌심실 shortening fraction, 좌심실 수축기 시간간격(left ventricle systolic time interval, LVSTI), 우심실 수축기 시간간격(right ventricle systolic time interval, RVSTI), 그리고 좌심실구축률(EF)을 측정하여 좌심실의 기능을 평가하였다. 대동맥과 폐동맥의 최고 수축기압차 속도 (peak systolic pressure gradient velocity, PSPGV), 판막의 폐쇄부전상태, 좌심방/대동맥비(LA/Ao ratio), 대동맥과 폐동맥 근부의 크기, 등을 정상치와 비교하여 판막의 기능과 대혈관의 성장을 평가하였다. 결과: 좌심실구축률은 평균 65.0+9.03%이었으며 추적관찰 동안 시간이 경가함에 따라 대체로 증가하는 경향을 보였다. 좌심실상행대동맥압차는 평균 15.9mmHg이었고 우심실폐동맥압차는 평균 27.5mmHg이었다. 수축기말 대동맥근부 크기(aortic root dimension at end-systole)는 8례 중 6례에서 동일 연령군의 정상발육 평균치보다 발육이 증가하는 양상이었고 발육과정에 따라 증가하는 양상을 보였다. 수축기말 폐동맥 근부 크기(PA root dimension at end-systole)는 동일연령군의 정상발육 평균치와 비교할 때 비슷한 성장경과를 보였다. 술후 판막 폐쇄부전의 변동을 보면 폐동맥판막폐쇄부전은 8례 중 5례에서 있었고 1례에서 2도이었고 그 외는 1도 이하이었다. 대동맥판막폐쇄부전은 8례 중 술전 0도에서 술후 1도로 변동한 경우가 6례였다. 이상과 간이 폐쇄부전이 있더라도 대부분 1도 이하이었기 때문에 인상적인 의의는 없었다

• Journal of Nutrition and Health
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• 제31권7호
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• pp.1139-1150
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• 1998

본 연구에서는, 무분별하게 사용되고 있는 민간요법의 과학적인 접근의 일환으로 인슐린 비의존형 당뇨환자를 대상으로 당뇨치료약물을 복용하는 당뇨군과 당뇨치료약물을 복용하지 않는 당뇨군 그리고 정상군으로 나누어 각군 모두에게 누에분말을 복용시켜 혈당 및 혈중 당화헤모글로빈, 인슐린, 그리고 혈중 지질농도에 미치는 영향을 관찰하여 요약하면 다음과 같다. 1) 신장, 체중, BMI, 둔부둘레는 세군간에 차이가 없었다. 허리둘레는 기존의 당뇨치료약물과 누에분말을 동시에 투여받는 당뇨군에서 다른 두 군에 비해 유의적으로 높아 WHR은 당뇨치료 약물을 동시에 복용한 당뇨군>누에분말만 복용한 당뇨군>정상군의 순으로 나타났다. 누에분말을 투여받는 동안 체중의 변화는 관찰되지 않았다. 2) 당뇨군과 정상군 사이에 열량 및 열량구성비에는차이가 없었으며, 연구 진행동안의 유의적인 변화도 관찰되지 않았다. 실험기간동안 총열량 섭취량은 남자의 경우, 권장량의 87.7%, 여자의 경우, 권장량의 86.2% 를 섭취하고 있었다. 하루동안 누에분말로 공급된 단백질 함량은 0.279이었으며 식이로의 단백질섭취는 남녀 각각 권장량의 97.5%. 108.3%를 섭취하고 있었다. 총 열량구성비는 남자의 경우 탄수화물 단백질. 지방이 68 : 15 : 17, 여자의 경우 69 : 16 : 15이었다. 3) 당뇨치료 약물을 누에분말과 동시에 복용한 당뇨군에서 누에분말 복용후 공복시 혈당이 7.4%, 식사후 2시간의 혈당이 19.4% 감소하는 경향이었고, 누에분말만 섭취한 당뇨군은 누에분말 복용후 혈당이 공복시 9.7%, 식사후 2시간시 23.4%의 감소경향을 나타냈다. 공복시와 식사후 2시간의 혈당 모두 누에분말 섭취후에도 정상범위보다 다소 높았으나, 혈당감소율(%)은 당뇨치료약물을 동시에 복용한 당뇨군에 비해 누에분말만 섭취한 당뇨군에서 큰 경향이었다. 정상군의 혈당에 는 큰 변화가 없었다. 4) 당뇨치료 약물을 동시에 복용한 당뇨군이 누에분말만 복용한 당뇨군에 비해 당화 헤모글로빈이 낮았고 정상군은 더 낮았다. 4주동안 누에분말 복용 후 당화헤모글로빈의 변화는 관찰되지 않았다. 5) 본 연구 대상자들의 공복시 인슐린 농도는 당뇨치료 약물을 동시에 복용한 당뇨군에서 누에분말만 복용한 당뇨군과 정상군에 비해 높았다. 누에분말 복용에 따른 공복시 인슐린 농도의 유의적인 변화는 관찰되지 않았다. 6) 누에분말 복용에 따른 각 군간의 혈중 지질 농도의 유의적인 변화가 관찰되지 않았다. 혈중 중성지방의 농도는 당뇨치료 약물을 동시에 복용한 당뇨군의 경우 8.5%, 누에분말만 섭취한 당뇨군의 경우 9.0% 그리고 정상군은 3.4%가 감소되는 경향을 나타내었다.

• 청정기술
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• 제27권4호
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• pp.341-349
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• 2021

연소시설에서는 화석연료에 포함된 질소와 황이 산소와 반응하여 대기 오염물질인 질소산화물(NO_X)과 황산화물(SO_X)을 발생시킨다. 인체에 유해하고 환경 오염을 야기하는 NO_X, SO_X를 저감하기 위해 전세계적으로 환경규제를 시행 중이며, 규제를 충족하기 위해 다양한 기술들을 적용하고 있다. 상용화된 NO_X 및 SO_X 저감방식들로 SCR (selective catalytic reduction), SNCR (selective non-catalytic reduction), WFGD (wet flue gas desulfurization) 등이 있으나 이 방식들의 단점들 때문에 NO_X, SO_X를 동시제거하는 연구가 근래 많이 수행되고 있다. 그러나 NO_X, SO_X 동시 제거 방식에서도 산화제 및 흡수제로 인한 폐수 발생에 대한 문제점, 특정 산화제를 활성화 하기 위한 촉매 및 전기분해 사용에 따른 비용 발생, 마지막으로 기체 산화제들 자체 유해성의 문제점을 가지고 있다. 따라서 본 연구에서는 NO_X, SO_X 동시처리 방식의 단점들을 보완하고자 고압분산기에서 생성된 마이크로버블과 환원제를 이용하여 비용절감 및 폐수처리 시 환경부하저감 가능성을 확인해 하고자 하였다. 분산기가 마이크로버블을 생성하는 것을 이미지 프로세싱과 ESR (electron spin resonance) 분석을 통해 확인하였으며, 마이크로버블만을 이용하여 온도에 따른 NO_X, SO_X 제거율 성능 테스트도 진행하였다. 뿐만 아니라 폐수를 저감하기 위해 환원제와 마이크로버블을 이용하여 습식으로 NO_X 제거율 약 75%, SO_X 제거율 99%를 달성하였다. 본 마이크로버블 시스템에 산화제를 함께 투여할 경우 NO_X, SO_X제거율 모두 99%이상을 달성 하였다. 이러한 연구 결과를 토대로 습식산화제거방식을 적용하는 시설의 단점이었던 비용 및 환경 문제를 해결함에 기여할 수 있을 것으로 기대 된다.

• 한국방사선학회논문지
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• 제13권3호
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• pp.339-348
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• 2019

본 연구는 건강검진을 목적으로 내원하여 경동맥초음파를 실시한 113명을 대상으로 하였다. 경동맥의 내중막 두께는 심혈관 질환 및 뇌혈관 질환과 유의한 상관관계를 보이는 것으로 알려져 있다. 임상에서 선별 검사로 많이 이용되고 있는 경동맥 초음파를 이용하여 경동맥 내중막 두께와 체질량지수, 허리둘레, 혈청지질수치, 공복 혈당, 당화혈색소, 혈압등이 갖는 연관 관계에 대하여 알아보고자 하였다. 경동맥초음파상 IMT두께가 0.8 mm 이상을 비정상으로 간주하고 죽상경화증(atherosclerosis)의 유무를 평가하였으며, 혈청검사를 통하여 지질학적 수치 및 공복혈당수치, 당화혈색소를 분류하여 상관관계를 알아보았다. 그 결과 허리둘레(p=.022), 저밀도 콜레스테롤(p=.004), 공복혈당수치(p=.019), 당화혈색소 수치(p=.002)가 죽상경화증(atherosclerosis을 일으키는 예측인자로 분석되었다. ROC 곡선 분석에서 허리둘레에서 민감도 87.80%(95% CI : 73.8-95.9), 특이도 41.67%(95% CI : 30.2-53.9), 저밀도 콜레스테롤에서 민감도 78.05%(95% CI : 62.4-89.4), 특이도 50.00%(95% CI : 38.0-62.0 공복혈당에서 민감도 73.11%(95% CI : 57.1-85.8), 특이도 61.11 (95% CI : 48.9-72.4)), 당화혈색소에서 민감도 82.93%(67.9-91.8), 특이도 43.06%(31.4-55.3)를 나타내었다. 로지스틱 회귀분석에서 죽상경화증(atherosclerosis) 발생위험성은 허리둘레(WC)>76 cm에서 0.248배, 저밀도 콜레스테롤(LDL-C)${\geq}124mg/dL$에서 3.475배, 당화혈색소(HbA1C)>5.4%에서 0.618배로 나타났다. 향후 심뇌혈관질환의 효과적인 일차예방 역할을 위해 다수의 대상자를 대상으로 혈액검사수치를 고려하여 혈관의 추적관찰이 용이한 경동맥초음파를 통한 전향적연구가 필요할 것으로 사료 된다.

• 자원환경지질
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• 제56권3호
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• pp.239-257
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• 2023

상동 텅스텐(W)-몰리브덴(Mo) 광산은 태백산 광화대에 위치하는 스카른 광상으로, 광화 작용 최후기에 수직적 분포양상을 보이는 회중석-석영맥을 산출한다. 본 연구에서는 이 석영맥의 조직 관찰과 LA-ICPMS를 통한 석영의 미량원소 함량 분석을 통해 석영맥을 형성한 유체의 조성 및 이들의 침전 기작에 대해 파악하고자 하였다. 석영맥 조직 관찰 결과, 상동광산의 상반맥과 하반맥에서는 각각 괴상조직과 신장형 괴상조직이 주로 발달하고, 본맥에서는 두가지 조직이 모두 관찰된다. 이러한 석영맥의 조직적 특징으로 볼 때, 괴상조직을 나타내는 상반맥의 석영맥은 맥상스카른 형성 단계에서 화성암체의 H₂O 포화로 인한 수압 파쇄작용들 중 초기에 발생한 작용에 의해 침전되었고, 신장형 괴상조직을 나타내는 본맥과 하반맥의 석영맥은 상반맥의 석영맥 형성 이후 발생한 반복적 수압파쇄작용에 의해 형성된 것으로 생각된다. 석영의 미량원소 분석 결과 대부분 Li⁺ +Al³⁺↔Si⁴⁺의 치환관계를 만족하지만, 하반맥에서는 Li⁺이 우세하게 치환되는 경우와, Na⁺과 K⁺이 우세하게 치환되는 경우로 뚜렷하게 구분된다. 이는 하반맥의 신장형 괴상조직에 기반하여, 서로 다른 조성을 가지는 유체의 반복적 유입에 의한 결과로 해석된다. 석영의 Ti 함량은 상반맥, 본맥, 그리고 하반맥에서 각각 평균 28.6, 8.2, 그리고 15.7 ppm이며, 침전온도와 Ti 함량이 비례관계를 가진다는 점에서, 상반맥의 석영맥이 가장 고온환경에서 침전된 것으로 고려된다. 유체의 pH와 반비례관계를 가지는 석영의 Al 함량은 상반맥, 본맥, 그리고 하반맥에서 각각 평균 162.3, 114.2, 그리고 182.5 ppm으로 큰 차이를 보이지 않으며, 타 열수 광산들의 석영과 비교하여 매우 낮은 함량을 나타낸다. 이는 상동광산의 석영맥을 구성하는 석영 및 회중석이 약산성 내지 중성의 비교적 일정한 pH조건에서 침전되었음을 지시한다.

• 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.

• The Korean Journal of Physiology
• /
• 제15권1호
• /
• pp.27-36
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• 1981

Alcohol 의 급성중독(急性中毒)으로서 폐기능중(肺機能中) 특(特)히 폐용압률(肺容壓率)과 폐포활성물질(肺胞活性物質)(surfactant)의 변화(變化)를 살펴봄으로써 alcohol 이 폐기능(肺機能) 또는 폐대사(肺代謝)에 미치고 효과(效果)의 일단(一端)을 알기 위(爲)하여 흰쥐를 재료(材料)로 하여 50% alcohol 을 체중(體重) 100 gm 당(當) 1.5 ml 씩 경구적(經口的)으로 단회투여(單回投與)하여 급성(急性) Ethyl alcohol 중독(中毒)을 일으켰다. Alcohol 중독과정(中毒過程)에서 24 시간(時間)까지 경시적(經時的)으로 혈중(血中) alcohol 농도(濃度)와 hematocrit(Hct)치(値)를 측정(測定)하고, 폐용압률(肺容壓率) 및 surfactant 중(中)의 단백량(蛋白量)과 무기인(無機燐)(Pi)를 측정(測定)하여, 정상군(正常群)과 비교(比較)하여 다음과 같은 결과(結果)를 얻었다. Alcohol 혈중농도(血中濃度)는 정상치(正常値)인 $0.17{\pm}0.01\;gm%$(평균(平均)${\pm}$표준오차(標準誤差) 이하동일(以下同一))에 비(比)하여 중독(中毒) 1시간(時間)에서 $0.71{\pm}0.02\;gm%$로 최고치(最高値)에 달(達)하고, 그후(後) 차차(次次) 낮아져서 24 시간(時間)에서는 $0.36{\pm}0.02\;gm%$이었으나, 전실험치(全實驗値)는 정상(正常)에 비(比)해서는 유의(有意)하게 높았다. Hct 치(値)는 1시간(時間)에서 $64.86{\pm}2.45%$로서 최고치(最高値)를 나타내었고, 그후(後) 계속(繼續) 정상치(正常値)인 $48.87{\pm}0.28%$에 비(比)하여 유의(有意)하게 높은 값을 유지(維持)하였다. 폐중량대(肺重量對) 체중비(體重比)(L/B 비(比))는 중독(中毒) 3시간(時間)부터 $5.49{\pm}0.61$로서 정상치(正常値)인 $7.57{\pm}0.56$에 비(比)하여 유의(有意)하게 낮아지고, 24시간(時間)까지 유의(有意)한 감소(減少)를 나타내었다. 폐용압률(肺容壓率)은 확대(擴大)(inflation)와 축소(縮小)(deflation)에서 모두 3시간(時間)까지 정상(正常)과 큰 차이(差異)가 없었으나, 6및 12 시간(時間)에서는 증가(增加)된 값을 나타내었고, 특(特)히 12 시간(時間)에서는 유의(有意)하게 높은 값을 나타내었다가, 24시간(時間)에는 정상(正常)에 가까워지는 경향(傾向)을 나타내었다. 폐세척액(肺洗滌液)의 단백량(蛋白量)은 정상(正常)의 $10.65{\pm}0.62\;mg/gm$에 비(比)하여 3시간(時間)에서 $12.36{\pm}0.35\;mg/gm$, 12시간(時間)에서 $12.70{\pm}0.74\;mg/gm$ 및 24시간(時間)에서는 $12.65{\pm}0.88\;mg/gm$로서 유의(有意)하게 높은 값을 나타내었고, Pi치(値)도 중독(中毒) 6시간(時間)부터는 높은 값을 나타내었으며, 특(特)히 12 시간(時間)에서는 $7.65{\pm}0.63\;{\mu}mol/gm$, 24시간(時間)에서는 $6.70{\pm}0.36\;{\mu}mol/gm$로서, 정상(正常)의 $5.32{\pm}0.20\;{\mu}mol/gm$에 비(比)하여 유의(有意)하게 높은 값을 나타내었다. 한편, 폐추출액(肺抽出液)의 단백량(蛋白量)은 1및 3시간(時間)에서 낮은 값을 나타내었으나, 대체(大體)로 정상(正常)과 비슷한 경향(傾向)을 나타내었고, Pi 치(値)는 대체(大體)로 높은 양상(樣相)을 나타내었으며, 특(特)히 중독(中毒) 6, 12 및 24 시간(時間)에서는 각각(各各) $17.77{\pm}1.54\;{\mu}mol/gm$, $13.92{\pm}0.78\;{\mu}mol/gm$ 및 $14.57{\pm}5.53\;{\mu}mol/gm$로서, 정상(正常)의 $10.34{\pm}0.37\;{\mu}mol/gm$에 비(比)하여, 모두 유의(有意)하게 높은 값을 나타내었다. 이상(以上)의 결과(結果)로서 alcohol 급성중독(急性中毒)에서는, surfactant 의 활성도(活性度)나 폐용압률(肺容壓率)이 증가(增加)되어 폐기능(肺機能)에 변화(變化)가 초래(招來)된다고 하겠다.