복강경 담낭절제술에서 기복 유도로 인한 혈압 상승시 Bioimpedance에 나타난 혈역학지수의 임상적 고찰

변기수,임동건,윤영국 대한마취과학회 1998 Korean Journal of Anesthesiology Vol.35 No.6

Purpose : To analyze hemodynamic parameters of electrical bioimpedance on increased blood pressure induced by pneumoperitoneum and compare hemodynamic effects of propofol and isoflurane during laparoscopic cholecystectomy. Methods : Systemic vascular resistance index(SVRI), index of contractility(IC), end diastolic index(EDI), mean arterial pressure(MAP) and heart rate(HR) were measured after anesthetic induction, 5, 10, 15 and 30 minutes after CO2 insufflation and after CO2 removal. Results : In isoflurane group, MAP, IC, SVRI were increased but EDI was decreased after induction of pneumoperitoneum. In propofol group, MAP, SVRI were increased but IC was decreased after induction of pneumoperitoneum. HR was not changed during operartion. Conclusion : After induction of pneumoperitoneum, MAP is increased by increased IC and SVRI in isoflurane. In case of propofol, the MAP is increased by increased SVRI. It seems that increased transmural pressure of lymphatics and splanchnic vasculatures rather than sympathetic stimulation increases SVRI after pneumoperitoneum. (Korean J Anesthesiol 1998; 35: 1113∼1118)

Ketamine 마취 흰쥐에서 출혈시 심박수 및 혈압 변이도의 스펙트럼 분석

변기수,김형진,박성식,홍정길 대한마취과학회 1998 Korean Journal of Anesthesiology Vol.34 No.3

Background: This study was aimed to elucidate the effect of ketamine anesthesia on circulatory response to hemorrhage in rats by power spectral analysis of heart rate and blood pressure variability. Methods : Nineteen male Sprague-Dawley rats weighing 290∼475 g were divided into ketamine (100 mg/kg, im)-anesthetized(K, n=10) and conscious(C, n=9) groups. Hemorrhage was induced with a withdrawal pump from the femoral artery at 3 ml/kg/min for 5 min. Arterial pressure was measured with a pressure transducer connected to the contralateral femoral artery for 5 min before, during and after hemorrhage. The blood pressure signal digitized at 500 Hz through a data acquisition system was analyzed with fast Fourier transform algorithm to yield power spectra of sytolic(SP) and diastolic(DP) blood pressure and instantaneous heart rate(HR). Powers of very low frequency(VLF, 0.02∼0.26 Hz), low frequency (LF, 0.26∼0.75 Hz) and high frequency(HF, 0.75∼5.00 Hz) band were expressed as percent of total power. Results : Befoemorrhage blood pressure was higher in K(152.4 3.7/99.9 4.9 mmHg) than in C(143.3 5.7/95.5 4.1 mmHg) rats, but was changed by hemorrhage in both groups. Before hemorrhage HR in K and C rats were 361.4 17.5 and 363.4 18.5 beats/min . HR were significantly increased to 403.2 20.3 and 396.2 18.9 beats/min during and after hemorrhage in K rats, and increased to 409.1 20.9 beats/min during hemorrhage in C rats. Before hemorrhage total powers of blood pressure and HR variability were higher in K than in C rats. During hemorrhage, total powers of blood pressure and heart rate variability tended to increase in both groups. Before hemorrhage, percent powers of systolic pressure variability of HF and VLF were higher in K than in C rats and LF was lower in K than in C rats. During hemorrhage, K group showed no significant changes but C group showed significant changes. Before hemorrhage, percent powers of diastolic pressure variability of VLF was higher in K than in C rats, and HF and LF were lower in K than in C rats. During and after hemorrhage, K group showed no significant changes, but C group showed significant decrease in LF and increase in VLF. Before hemorrhage, percent powers of heart rate variability of K rats showed higher HF and VLF, and lower LF than C rats. During and after hemorrhage HF and VLF of both groups showed no significant changes except significant increase in VLF after hemorrhage in C rats, but LF of both groups showed significant decrease. Conclusions : It was concluded that autonomic activity, especially cardiac sympathetic activity, was increased in response to hemorrhage in K rats. Ketamine anesthesia stimulated overall autonomic activity, especially sympathetic activity and vasomotor tone. In C rats hormonal factor contributed to blood pressure and heart rate variability during hemorrhage. (Korean J Anesthesiol 1998; 34: 471∼478)

염료폐수처리 및 재활용을 위한 pilot 막분리공정의 전처리

변기수,노수홍 대한환경공학회 1994 대한환경공학회 학술발표논문집 Vol.1994 No.12

소아 생체 부분 간이식시 Propofol을 이용한 전정맥 마취 경험

변기수,임동건,김병권,백운이,박진웅,이근보,홍정길 대한마취과학회 1999 Korean Journal of Anesthesiology Vol.36 No.2

We have experienced one case of anesthesia for living related liver transplantation with propofol. The recipient was 18-month-old girl and 10.5 kg. She was suffered from congenital liver disease (biliary atresia). We decided propofol as an anesthetic agent of the recipient with permission of the recipient's parents. Total anesthetic time was about 13 hours and anhepatic phase was 110 min. Careful attention was paid to prevent infection, hypothermia, hepatic artery thrombosis and to keep proper lung function. Hemodynamic changes were relatively stable throughout the operation and postoperative mechanical ventilatory support was required for about 2 days. (Korean J Anesthesiol 1999; 36: 354∼359)

텅스텐과 비스무트 입자 배치 및 크기에 따른 방사선 차폐 해석

변기수,김재민,서한복,이승엽 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4

의료용 및 산업용 방사선 차폐 소재에서 인체에 유해한 납 대신 금속입자와 폴리머의 복합소재가 사용되고 있다. 본 연구에서는 MCNP 코드 시뮬레이션 해석을 활용하여 나노 텅스텐 및 비스무트 입자의 무작위 배치 기법을 사용하여 입자 크기에 따른 방사선 차폐 해석을 진행하였다. 무작위 입자 배치 모델링 방법은 기존 차폐 해석 방법에 비해 더 정확한 차폐율을 보이는 것으로 나타났으며 나노 금속 입자의 중량비에 따라 차폐 성능이 변하는 것을 확인하였다. 또한 동일 중량비에서 입자 크기가 작아질수록 차폐율이 증가한다는 기존 결과와는 다르게 특정 입자 크기 구간에서 차폐 성능이 감소하는 것을 확인하였고 이는 나노 금속입자 크기에 따른 최적 차폐조건 설계에 응용될 수 있을 것이다.

胃炎性出血과 胃內視鏡 檢査

卞基洙 仁川基督病院 1977 仁川基督病院誌 Vol.1 No.1

Vibrio Parahaemolyticus의 增菌培地에 關한 硏究

卞基洙,全燾基 中央醫學社 1972 中央醫學 Vol.23 No.2

It is sometimes neccessary to enrich pathogenic organisms in feces and other specimens of patients suffering from enteric infections. It is also true in case of food poisoning due to Vibrio parahaemolyticus, especially in the later stage of the infection. As we experienced that already reported enrichment media for vibrios are not always satisfactory, some experiments were carried out to lead the development of better enrichment media. V. parahaemolyticus can grow in the presence of sodium chloride in phosphate buffer and the growth was accelerated at around 3 per cent of sodium chloride. Even though this organism showed a luxariant growth in peptone water containing sodium chloride, Escherichia coli and other organisms also grew very well in peptone water. Therefore, the selective enrichment of V. parahaemolyticus over E. coli and other enteric flora would not be obtained in peptone water containing sodium chloride. The growth of V. parahaemolyticus and total microorganisms in feces was compared in the presence of sodium chloride in phosphate buffer and in peptone water, and the results showed that the growth rate of V. parahaemolyticus was more prominent than that of total microorganisms in phosphate buffer containing 3-5 per cent sodium chloride than in peptone water containing sodium chloride. From these results, we propose the successful enrichment of V. parahaemolyticus in phosphate buffer containing 3-5 per cent sodium chloride.

氣管支喘息과 아드레나린作動受容體

卞基洙,李海宣 仁川基督病院 1977 仁川基督病院誌 Vol.1 No.2

증례 : 흑수열을 동반한 뇌형 마라리아의 1 예

변기수 ( K. S. Byun ),백영수 ( Y. S. Paek ),이공석 ( K. S. Lee ),장원익 ( W. I. Chang ),박영 ( Y. Park ),손태동 ( T. D. Sohn ),이경율 ( K. Y. Lee ) 대한내과학회 1967 대한내과학회지 Vol.10 No.10

STFT를 통한 합성곱 신경망 기반의 포터블 에어컨 고장 진단

변기수(Gi-Soo Byun),조성우(Sung-Woo Cho),서한복(Han-Bok Seo),이승엽(Seung-Yop Lee) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

Various machines and home appliances experience aging and failure due to their continued use. Electronic problems such as circuit failures are easy to diagnose on the product itself, but mechanical defects and faults are difficult to diagnose. Since acoustic signals generated from a machine include inherent operating characteristics, the unwanted mechanical faults can be diagnosed by analyzing different patterns between normal and fault signals. In this study, the mechanical failure diagnosis of a commercial portable air conditioner has been implemented based on a deep learning-based image classification technique. Short-time Fourier transform (STFT) is used to effectively analyze the frequency characteristics that occur in the event of machine failures, and then the fault status of the air conditioner is examined by classifying the extracted spectrogram images through convolution neural network (CNN). The proposed method shows a precise fault diagnosis without additional devices and can be effectively applied for fault diagnostic algorithms of various home appliances.