• Title/Summary/Keyword: 순환 보조

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In Vitro Test of Seiong Pediatric Ventricular Assist Device (소아용 보조인공심장의 모의순환 실험에 관한 연구)

  • 권혁남;박표원
    • Journal of Biomedical Engineering Research
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    • v.12 no.1
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    • pp.29-34
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    • 1991
  • Ventricular assist device(VAD) has been clinically applied as a temporary circulatory sup- porting system in the patients with severe heart failure, but small sized VAD for infant is not available. The purpose of tilis paper is to introdIAce small sized VAD and presents the result of in vitro test. Sejong VAD is diaphragmatic type of pneumatic pump and stroke volume is 11cc. Cardiac outputs of the Sejong VAD were measured by overflow tank under variable conditions of driving parameters. The cardiac output was 1.3 1/min at the heart rate of 120 per minute, left atrial pressure of $15cmH_2O$, percent systole of 43%, driving pressure of 240 mmHg, vacuum pressure of -40 mmHg, and mean aortic pressure of 70 mmHg. No mechanical problem was developed during the continuous in vitro test for 3 months.

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성인병 뉴스 제311호

  • The Korea Association of Chronic Disease
    • The Korean Chronic Disease News
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    • no.311
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    • pp.1-18
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    • 2006
  • 경기도 평택시 송탄 보건소 김보섭 소장/만성질환 관리 중추적 단체 위상제고/“앞으로 국민연금 덜 받는다”/건강보험료 환급 사기‘주의’/전공의 보조수당 민간병원 확대/65세이상 60%에 월8만9천원 지급/“의료용 혈액이 부족하다”/남‘암’-여‘순환기’사망확률 높아/수면무호흡증, 남성 발기부전초래/독감백신 국내 생산기반 구축/정부 의약품 가격 정책‘위헌소송’/차별화 된 고품격 보건서비스 제공/보건소 의료기관 서비스 만족도‘1위’/초고령사회 대응, 본격 시동 걸었다/노인의료“의료적 접근 동반돼야”/겨울철 어르신 건강관리 수칙 발표/비영리 의료기관 M&A 근거 마련/병원 서비스산업 주요 육성방안/고령친화 모델지역 기본구상/

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Response Analysis of the Coronary Circulation Under the T-PLS Operation via a Lumped System Model (집중시스템 모델을 이용한 이중박동 생명보조장치 작동하의 관상순환계 반응해석)

  • Ko, Hyung-Jong;Park, Jong-Cheon;Shim, Eun-Bo
    • Journal of the Korean Society of Industry Convergence
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    • v.12 no.1
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    • pp.27-33
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    • 2009
  • In this paper, a computational analysis using a lumped system model is performed to investigate the hemodynamics of coronary circulation under the operation of T-PLS relevant to the cardiac arrest cases. The coronary circulation system is assumed to be comprised of three compartments: coronary arteries, coronary capillaries, and coronary veins. The effect of myocardial muscle contraction or relaxation is represented by temporal variations in the bias pressure. To verify the present method, we analyzed the coronary circulation for normal case and then compared the results with the existing data. Numerical results on the cardiac arrest model showed that T-PLS can increase LAD flow significantly.

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Stabilization Characteristics of the Diffusion Flame Formed in the Wake of Bluff Body with Fuel Injection (연료분출을 수반하는 보염기 후류에 형성되는 확산화염의 보염특성)

  • 안진근
    • Journal of Energy Engineering
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    • v.10 no.3
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    • pp.223-232
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    • 2001
  • To study the stabilization characteristics of diffusion flame formed in the wake of a cylindrical bluff body with fuel injection, the flame stability limits, length and temperature of recirculation zone of flame, turbulence intensity distribution near the recirculation zone of flame were measured and analyzed. The length of recirculation zone is independent on main fuel injection quantity, but it is dependent on fuel injection angles, air stream velocity, and auxiliary fuel injection into recirculation zone. For diffusion flame, in general, the flame stabilization is deteriorated with increase of he length of recirculation zone, but if the turbulence generator is installed, the flame stabilization is improved with increase of the length of recirculation zone. The temperature of recirculation zone is dependent on fuel injection angles, auxiliary fuel injection into recirculation zone, turbulence generators, and it dependent on fuel injection angles, auxiliary fuel injection into recirculation zone, turbulence generators, and it has a maximum value at the condition of each theoretical mixture. In general, the more temperature of recirculation zone is low, the more flame is stable. But when the turbulence generator is installed, the more temperature of recirculation zone is low, the more flame is unstable. The turbulence intensity in the wake of bluff body is increased with increase of diameter or blockage ratio of grid. The more turbulence intensity is increased by installation of turbulence generator, the more flame is unstable. Finally, It is clear that the stabilization characteristics of diffuser flame can be controlled by some parameters such as fuel injection angles, auxiliary fuel injection into recirculation zone, turbulence generators.

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Design and Evaluation of a Lung Assist Device for Patients with Acute Respiratory Syndrome using Hollow Fiber Membranes (중공사 막을 이용한 급성호흡곤란증후군 환자용 폐 보조 장치의 설계와 평가)

  • Lee, Sam-Cheol;Kwon, O-Sung;Kim, Ho-Cheol;Hwang, Young-Sil;Lee, Hyun-Cheol
    • Membrane Journal
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    • v.15 no.3
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    • pp.224-232
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    • 2005
  • The use of the lung assist device (LAD) would be well suited for acute respiratory failure (ARF) patients, combining the simplicity of mechanical ventilation with the ability of extracoporeal membrane oxygenators (ECMO) to provide temporary relief for the natural lungs. This study's specific attention was focused on the effect of membrane vibration in the LAD. Quantitative experimental measurements were performed to evaluate the performance of the device, and to identify membrane vibration dependence on blood hemolysis. We tried to decide upon excited frequency band of limit hemolysis when blood hemolysis came to through a membrane vibration action. The excited frequency of the module type 5, consisted of 675 hollow fiber membranes, showed the maximum gas transfer rate. We concluded that the maximum oxygen transfer rate seemed to be caused by the occurrence of maximum amplitude and the transfer of vibration to hollow fiber membranes. It was excited up to $25{\pm}5$ Hz at each blood flow rate of module type 5. We found that this frequency became the 2nd mode resonance riequency of the flexible in blood flow. Blood hemolysis was low at the excited frequency of $25{\pm}5$ Hz. Therefore, we decided that limit hemolysis frequency of this LAD was $25{\pm}5$ Hz.

A Study on the ZVZCS Three Level DC/DC Converter without Primary Freewheeling Diodes (1차측 환류 다이오드를 제거한 ZVZCS Three Level DC/DC 컨버터에 관한 연구)

  • Bae, Jin-Yong;Kim, Yong;Baek, Soo-Hyun;Kwon, Soon-Do;Kim, Pil-Soo;Gye, Sang-Bum
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.6
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    • pp.66-73
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    • 2002
  • This paper presents ZVZCS(Zero-Voltage and Zero-Current Switching) Three Level DC/DC Converter without primary freewheeling diodes. The new converter presented in this paper used a phase shirt control with a flying capacitor in the primary side to achieve ZVS for the outer switches. A secondary anxiliary circuit which consists of one small capacitor, two small diodes and one coupled inductor, is added in the secondary to provide ZVZCS conditions to primary switches, ZVS for outer switches and ZCS for inner switches. Many advantages include simple secondary auxiliary circuit topology, high efficiency, and low cost make the new converter attractive for high power applications. Also the circulating current flows through the circuit so that it causes the needless coduction loss to be occurred in the devices and the transformer of the circuit The new converter has no primary auxiliary diodes for freewheeling current. The principle of operation, feature and design considerations are illustrated and verified through the experiment with a 1[㎾] 50[KHz]IGBT based experimental circuit.

Spectral Properties of the Sound From the Mechanical Valve Employed in an Implantable Biventricular Assist Device (이식형 양심실 보조 장치에 사용된 기계식 판막의 음향 스펙트럼 특성)

  • 최민주;이서우;이혁수;민병구
    • Journal of Biomedical Engineering Research
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    • v.22 no.5
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    • pp.439-448
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    • 2001
  • This paper considers the acoustical characteristics of the closing click sounds of the mechanical valves employed in an implantable biventricular assist device (BYAD) and their re1evance to the Physical states of the valved. Bj rk Shiley Convexo Concave tilting disk valve was chosen for the study and acoustic measurement was made for the BYAD operated in a mock circulatory system as well as implanted in an animal (sheep). In the BYAD operated in the mock circulatory system. three different states of the valve were examined, ie. normal. mechanically damaged. pseudo-thrombus attached. Microphone measurement for the BVAD implanted in the animal was carried out for five days at a regular time interval from one day after implantation. Characteristic spectrum of the sound from the valve was estimated using Multiple Signal Classification (MUSIC) in which the optimal order was determined according to Bayesian Information Criterion (BIC) . It was observed that the mechanical damage of the valve resulted in changes of the structure of the acoustic spectrum. In contrast. the thrombus formed on the valve did not change much the basic structure of the spectrum but brought about altering the spectral Peak frequencies and energies. Maximum spectral Peak (MSP) with the greatest energy was seen at 2 kHz for the normal valve and it was shifted to 3 kHz for the calve attaching the Pseudo-thrombus. Unlike the normal valve, strong spectral Peak appeared around 7 kHz in the sound from the valve mechanically damaged. In the case of the BYAD implanted in the animal. as the thrombus grew, acoustic energy was reduced relatively more in the low frequency components (〈 2 kHz) and the frequencies of the 1st, 2nd and 3rd MSP were increased little. The thrombus formation would result in reduction in both the variability of the 1st, 2nd and 3rd MSP and the value of the BIC optimal order.

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A Study on the In-Vitro Test of Thrombogenesis in Centrifugal Biopump (원심성 바이오 펌프를 이용한 혈전 생성의 생체 외 검사에 관한 연구)

  • Na, Myung-Hoon;Kim, Won-Gon;Kim, Joo-Hyun;Kim, Mee-Hyung;Yu, Jae-Hyeon;Lim, Seung-Pyung;Lee, Young
    • Journal of Chest Surgery
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    • v.32 no.10
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    • pp.863-873
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    • 1999
  • 배경: 혈전 생성은 심혈관계 삽입물이나 순환 보조장치의 발전에 있어서 중요한 문제이므로 이러한 장치들의 혈전성에 대한 평가는 필수적이다. 따라서 이러한 장치들의 혈전성 연구를 시행하기 위한 효과적인 생체 외 실험 방식이 개발되어 원심성 순환 펌프의 발전에 큰 도움이 되고 있으며, 최근 엄밀하게 혈액과 공기의 접촉을 차단하는 방식이 믿을 수 있는 생체 외 실험 방식으로 강조되고 있다. 본 논문에서는 모의 순환 회로를 이용하여 기존에 행해진 연구 방법 상의 공기 접촉에 따른 핼액 응고 기전의 활성화 여부를 알아보기 위하여 공기 접촉 여부에 따른 혈액 인자의 변화를 관찰하여 확인하고, 또한 회로 내에서 생성된 혈전을 생체 내에서 형성된 혈전과 비교 분석하여 이 모의 순환 회로를 이용한 생체 외 검사가 새로 고안된 심혈관계 장치들의 혈전성을 평가하는데 있어서 동물실험을 대신할 수 있다는 기존의 주장을 검증하고자 하였다. 연구재료 및 방법: 바이오펌프를 이용한 같은 모의 순환 회로 한 쌍을 준비하고 동일 개체에서 얻은 헤파린을 첨가한(1u/$m\ell$) 신선한 혈액을 공기와 접촉시키지 않도록 한 A-회로와 공기와 접촉시킨 B-회로에 충전시켜 실험을 동시에 진행하여 결과를 얻었으며 총 12번 시행하였다. 회로에 충전한 혈액의 activated clotting time(ACT)은 정상의 3~5배였으며 ACT가 정상 범위의 1.5배가되면 실험을 끝냈고, Hematocrit(HCT), 혈소판, 동맥혈가스분석(ABGA), factor Ⅷ, factor \ulcorner, 섬유소원, thromboxane B2(TXB2), free hemoglobin(fHb) 등을 측정하였다. 실험이 끝난 후 A-회로와 B-회로에서 얻은 각 검사를 평가하고 분석하였으며 생성된 혈전을 생체 내에서 생성된 혈전과 조직 검사로 비교하였다. 본 연구의 자료분석은 SPSS 통계 프로그램을 이용하였고 유의수준 0.05를 기준으로 유의도를 판단하였다. 결과: 정상 ACT는 186.9$\pm$20.5초(평균$\pm$표준편차)이었고, 헤파린을 넣은 초기 ACT는 982.2$\pm$165.5초이었으며, 실험시간은 보통 60분에서 180분 사이였다. HCT, fHb, 혈소판, TXB2, factor Ⅷ, factor \ulcorner, 섬유원소의 초기값은 35.5$\pm$3.2%, 12.4$\pm$6.5 mg/dL, 354$\pm$56($\times$103)/$\mu$L, 72.6$\pm$15.1 mg/dL, 29.3$\pm$1.2%, 137.9$\pm$42.1 mg/dL, 그리고 17.7$\pm$9.7%이었다. 공기 접촉에 따른 차이를 보았을 때 ACT(p=0.398), HCT(p=0.988), fHb(p=0.898), 혈소판 (p=0.904), TXB2(p=0.985), factor Ⅷ(p=0.872), factor \ulcorner(p=0.489), 섬유원소(p=0.973)으로 전 예에서 통계적 유의성이 없었다. 실험 후 양 군에서 생성된 혈전의 현미경 소견은 B-회로의 혈전에 여러 군데 공기 방울이 관찰되는 것 이외에 A-회로에서 생성된 혈전과 차이가 없었고, 생체에서 생성된 혈전과 비교했을 때 그 양상이 같았다. A-회로와 B-회로에서 생성된 혈전의 총 량은 8.4$\pm$3.7 mL와 9.4$\pm$3.1 mL로 통계상 유의성은 없었다. (p=0.624). 결론: 모의 순환 회로를 이용한 혈전성 평가를 위한 생체 외 실험에 있어서 공기와의 접촉 여부는 혈액 응고 기전의 활성화나 혈전 생성에 별다른 영향을 미치지 않는다. 모의 순환 회로에서 형성된 혈전과 문헌에 있는 인체 내에서 형성된 혈전을 비교한 결과 그 형태가 일치하므로 이 모의 순환회로를 이용한 실험이 동물실험을 대신할 수 있다고 판단된다.

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Out-of-Hospital Resuscitation of Cardiac Arrest by 119 Emergency Medical Service System (119구급대에 의해 소생한 병원 전 심장정지 환자 1례)

  • Yun, Hyeong-Wan;Lee, Jae-Min;Jung, Ji-Yeon
    • Fire Science and Engineering
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    • v.24 no.5
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    • pp.142-149
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    • 2010
  • The aim of this study was to report the out-of-hospital resuscitation of cardiac arrest along with literature consideration. CPR is technology of resuscitating patient by maintaining oxygen supply to organ, by preventing progression from clinical death to biological death, and by recovering heart beat and circulation, through circulatory support of mechanical ventilation. It is not what every patient with cardiac standstill is revived even if being implemented CPR. Patient's survival rate is decided by how quickly and correctly CPR was executed. A patient, who wasn't witnessed the cardiac arrest on the field, was performed 5-cycle CPR for 2 minutes on the field before being transferred to hospital, and was allowed to be used AED. A person, who was observed, is recommended to be used AED immediately, and then is said to be needed ACLS (advanced cardiac life support). In the Out-of-Hospital stage, it is rare in a case that 119 Emergency Medical Service System transfers by being ROSC and in a case of executing ACLS. Cardiac arrest was witnessed on the field, but CPR wasn't executed. First-aid staff executed CPR after arriving, and led to ROSC on the field with ACLS, there by having experienced 1 case of a patient's surviving to leave hospital by being ROSC on the field.

Fuel Production Using Sewage Sludge and the Utilization of Co-Firing Fuel in Coal-Fired Power Plant (하수슬러지 연료화 및 발전소 혼소기술)

  • Yoon, Hyungchul;Cho, Sangsoon;Kang, Sukju;Kim, Jinhoon;Kim, Kyongtae;Ko, Daekwun;Lee, Sihun;Han, Gwangchun
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.185.2-185.2
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    • 2011
  • 1900년대 이후 산업발전에 따른 인구의 도시 집중화로 인한 하수량 증가에 따라 하수슬러지 발생량이 점차 증가하게 되면서 하수슬러지 처리에 관한 문제 등이 제기되기 시작하였다. 국내의 경우 2003년 하수슬러지의 매립이 금지된 후, 발생슬러지 대부분을 해양투기 등을 통해 처리하여왔다. 2009년 기준으로 국내에서 발생되는 하수슬러지량과 처리 분포를 살펴보면 전국 433개소 하수처리장에서 1일 평균 8,295톤(3,028천톤/년)이 발생되고 있으며, 이 중 47%가 해양투기 되고 있는 실정이다. 그러나 해양투기마저도 런던협약'96의정서 가입으로 2012년부터 금지됨에 따라 국내에서는 슬러지처리 및 재활용 방안과 관련한 연구개발이 활발히 진행되고 있는 중이다. 하수슬러지 처리 및 재활용기술의 경우 다양한 공법 등이 개발 중에 있으나 설비의 불안정 및 높은 투자비 등으로 인해 아직까지 상용화 된 설비 등은 많지 않은 실정이다. 이에 따라 본 연구에서는 POSCO 건설에서 개발한 슬러지 연료화 기술을 통해 생산된 슬러지 탄을 석탄 화력발전소 등에 석탄 보조연료로 활용할 수 있는 방안을 강구하여 상용화 가능한 혼소 기술을 개발하고자 하였다. 슬러지탄(발열량 3.000kcal 이상)을 석탄 화력발전소 보일러에 일정 비율로 혼소하여 슬러지탄의 품질평가, 중금속 용출시험 및 함량분석, 잔재물의 중금속 용출시험 등을 실시하였으며, 그 결과 모든 시험항목에서 연료화 관련 법적기준을 만족하는 것으로 나타났다. 슬러지탄을 화력발전소에 혼소하여 사용할 경우, 2012년부터 시행예정인 RPS(Renewable Portfolio Standard)법 대응 및 석탄사용량 저감 등을 통한 $CO_2$ 저감으로 저탄소 녹색성장의 자원순환사회를 구축하는 데 이바지 할 것으로 판단된다.

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