• Journal of Trauma and Injury
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• 제24권2호
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• pp.105-110
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• 2011

Purpose: Chest injuries in multiple trauma patients are major predisposing factor for increased length of stay in intensive care unit, prolonged mechanical ventilator, and respiratory complications such as pneumonia. The aim of this study is the evaluation of lung injury score as a risk factor for prolonged management in intensive care unit (ICU). Methods: Between June to August in 2011, 46 patients admitted to shock and trauma center in our hospital and 24 patients had associated chest damage without traumatic brain injury. Retrospectively, we calculated injury severity score (ISS), lung injury score, and the number of fractured ribs and performed nonparametric correlation analysis with length of stay in ICU and mechanical ventilator support. Results: Calculated lung injury score(<48 hours) was median 1(0-3) and ISS was median 30(8-38) in study population. They had median 2(0-14) fractured ribs. There were 2 bilateral fractures and 2 flail chest. Ventilator support was needed in 11(45.8%) of them for median 39 hours(6-166). The ISS of ventilator support group was median 34(24-34) and lung injury score was median 1.7(1.3-2.5). Tracheostomy was performed in one patient and it was only complicated case and ICU stay days was median 9(4-16). In correlation analysis, Lung injury score and ISS were significant with the length of stay in ICU but the number of fractured ribs and lung injury score were predicting factors for prolonged mechanical ventilator support. Conclusion: Lung injury score could be a possible prognostic factor for the prediction of increased length of stay in ICU and need for mechanical ventilator support.

• Tuberculosis and Respiratory Diseases
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• 제42권5호
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• pp.737-743
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• 1995

연구배경: 기계호흡을 하고 있는 환자에서 폐렴은 흔히 일어나는 병원 감염이며 사망률도 높은 것으로 알려져 있으나 임상적인 폐렴 진단 기준이나 일반적으로 시행하는 객담의 정성배양법은 폐렴 진단에 오류가 많기 때문에 PSB를 이용한 정량배양법이 진단에 이용되고 있으나, PSB를 쉽게 이용할 수 없는 경우가 있어 비교적 용이하게 이용할 수 있는 EA의 정량배양의 진단적 가치에 대하여 연구하였다. 방법: 72시간 이상 기계호흡을 하고 있는 환자중 임상적으로 폐렴이 의심되는 환자 10명과, 대조군 5명을 대상으로 EA와 PSB를 이용하여 추출한 객담을 정량 배양하였다. 결과: EA와 PSB의 정량배양에서 폐렴의 진단 기준을 각각 $10^5cfu/ml$, $10^3cfu/ml$으로 정할때 PSB에서 민감도 70%, 특이도 80%, 양성예측치 88%, 음정예측치 57%, 정확도 73%, EA에서 민감도 70%, 특이도 60%, 양성예측치 78%, 음성예측치 50%, 정확도 67%였다. 결론: 저자들의 조사결과 기계호흡을 하는 환자의 폐렴진단에서 객담의 정량배양시 cut-off point를 EA에서 $10^5cfu/ml$ 이상 배양된 경우로 정할때, 민감도 70%, 특이도 60%, 양성예측도 78%로서 특이도가 EA 보다 높은 PSB를 대치하지는 못하지만 기관지 내시경을 사용할 수 없는 환자에서 유용하리라고 추측되나 더 많은 연구가 필요하리라 사료된다.

• Neonatal Medicine
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• 제17권1호
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• pp.1-12
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• 2010

Graphic monitoring assists the clinician at the bedside in several ways. It can be helpful in fine-tuning or adjusting ventilator parameters. Graphic monitoring may help to determine the patient's response to pharmacologic agents. The clinician also has the ability to trend monitored events over a prolonged period of time. The neonatal patient's self respiration, synchrony to ventilator and respiratory efforts can be well recognized with graphic monitoring. Of all, it may enable detection of complications before they become clinically apparent. This article introduces the basics of real-time graphics.

• 한국산업보건학회지
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• 제16권4호
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• pp.364-374
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• 2006

Natural ventilation technique could be the substitute for or the complement to the local exhaust ventilation system in the sense of protecting work environment. Moreover, it has many strong points ; almost no mechanical parts, no energy use and no noise. If applied appropriately, it could have the very high ventilation rate and save a lot of energy expense. But, it depends on the outdoor environment, especially temperature and wind speed/direction. Predicting the capacity of natural ventilation is not an easy job because it comes from both buoyancy and wind effect. Another problem is too much flow through the ventilator especially in winter time due to too much difference between indoor and outdoor temperature. Thus some ventilators in industries are sealed by door or plastic sheet, resulting in bad work environment. Various types of dampers are used to control the flow rate through ventilators. The capabilities of flow control by damper has not been estimated. In addition, it was not tested whether the damper could obstruct the flow through ventilator when fully opened. To answer these questions, 4 types of dampers were tested by using computational fluid dynamics. 10 different configurations includes no damper, full open and half open. Flow rates were estimated and airflow fields were analysed to clarify the before-mentioned questions. The dual type damper was the best choice for controling the capability of ventilator. In addition, the upward grill type damper was the best for not obstructing the air flow when fully opened.

• 상하수도학회지
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• 제28권3호
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• pp.325-337
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• 2014

The research on the actual condition of indoor asbestos concentration in Korea has not been thoroughly accomplished up to now. In this research the ratio of asbestos-containing buildings and indoor asbestos concentration was studied. This investigation was conducted in 2012 and 2013 and buildings were categorized based on region, building type by use, existing space(ground or basement), and construction year, respectively. Also the indoor asbestos concentration change was monitored to evaluation the efficiencies of two types of asbestos-concentration abatement devices. As a result, the ratio of asbestos-containing buildings in Seoul was largely decreased. The ratio of asbestos-containing buildings was higher in hospitals and schools regionally and in ground buildings than in basement. The average indoor asbestos concentrations were 0.0011, 0.0008 piece/cc in 2012 and 2013 investigation, respectively. Those values were much lower than standards(0.01 piece/cc), therefore the threat of indoor asbestos concentration might be negligible. In asbestos-concentration abatement experiments, the circulation velocity of ventilator were changed 2-6.7 m/sec. With 6.7 m/sec of velocity of ventilator, the concentration of indoor asbestos was fluctuated and maximum value was 2.4 piece/cc. With 4.5 and 2 m/sec of velocities of ventilator, the maximum concentration of indoor asbestos was fluctuated and maximum value was 0.9 piece/cc. This indicated that the concentration of indoor asbestos was decreased partly due to the free drop of asbestos. From these results, the proper velocity of ventilator seems to be between 4.7 and 6.5m/sec under this circumstance and further research is required. These research results may be used to guideline of asbestos management policy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1080_1081
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• 2009

This paper proposes a cooling system using self tuning PI controller for improving the output of BIPV module. The temperature characteristics in regard to improving the output of BIPV system has rarely been studied up to now but some researchers only presented the method using a ventilator. The cooling system efficiency of BIPV module applied to a ventilator mainly depends on the weather such as wind and insolation etc. Because the cooling system of BIPV module using a ventilator is so sensitive, that is being set off by wind speed at all time but is unable to operate in the nominal operating cell temperature(NOCT) which is able to make the maximum output. The paper proposes the cooling system using thermoelectron by self tuning PI controller so as to solve such problems. The thermoelectron control of self tuning PI controller can be controlled independently in the outside environment because that is performed by micro-controller. The temperature control of thermoelectron, also, can be operated around NOCT through algorism of the temperature control. Therefore, outputs of the whole system increase and the efficiency rises. The paper demonstrates the validity of proposed method by comparing the data obtained through a experiment of the cooling method of BIPV using a ventilator and proposed thermoelectron

• 한국태양에너지학회 논문집
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• 제31권3호
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• pp.126-132
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• 2011

Recently, high-rise apartment is being briskly built but there are problems such as lack of ventilation, stack effect and much energy consumption. Therefore It is recommended to develop a Small Wind Power System Combined Ventilator as a solution to solve these problems. The purpose of this study is to provide basis for Small Wind Power System Combined Ventilator in super high-rise apartment. This study conducted CFD simulation (Star-CCM) according to the shape of structures, building height and distance of two structures to identify the effect of wind speed increase when the structure is installed. As a result, pyramidal type was best suited for increase of wind speed. The best place was the front of the roof to main wind direction, and the best building height was 200m rather than 300m. If two or more small wind turbines combined ventilator are installed closely, vertical position to main wind direction is recommended. Horizontal position must necessarily be avoided, but height difference between two blades more than 3m showed good performance.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.440-447
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• 2002

본 연구에서는 호흡량 측정에 영향을 주는 요인들로부터 정확한 유량을 산출해내는 방법에 대해 고찰하고, 마취용 인공호흡기에 적용하여 수술환자의 호홉특성을 알아내는 호흡측정기를 구현하였다. 차동압력형 유량센서를 이용하여 압력, 온도, 가스구성의 상관관계에 따라 호흡량을 계측하였으며, 휴대형 기기에 적합하도록 전력 효율을 최대화 할 수 있게 시스템을 설계하였다. 구현 시스템은 크게 아날로그 인터페이스(analog interface)부, 신호처리부, 그리고 화면출력부로 나눌 수 있다. 아날로그 인터페이스부는 차동 압력 유량 센서와 차동 압력 센서로 구성된다. 전력소모를 최소화하기 위하여 여러 가지 기능을 단일소자로 수행할 수 있고, 저전력의 8비트 RISC 계열인 AVR프로세서를 중앙처리장치로 선택하였다. 데이터 전송부에서는 직렬(serial)통신(RS232, SPI)으로 측정된 값들의 출력 파형을 PC화면에 표시하거나 마취기로 전송한다. 차동 압력과 유량의 비선형적 관계를 선형화하였고, 센서 보정 기능은 일정 주기로 보정을 자동적으로 수행함으로써, 보다 안정적인 동작이 가능하게 한다. 아날로그 필터와 고속의 디지털 신호처리 알고리즘 구현으로 생체신호의 노이즈를 줄일 수 있었다. 작고, 가벼우며, 저전력인 시스템의 특징은 응급 환자나 이동중인 환자에게 적용될 수 있으며, 가래, 침, 습기와 같은 이물질에 영향이 적은 유량 센서의 사용으로 점액의 발생이 많은 마취기에서 유용하게 사용될 수 있다.

• 융합정보논문지
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• 제8권6호
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• pp.187-192
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• 2018

본 논문은 풍량 및 운전시간을 제어할 수 있는 방폭 타입 배풍기의 인버터 단자함 연구에 관한 것이다. 국내에서는 열악한 환경에서 작업 시에 풍량 및 운전 시간을 조정할 수 있는 배풍기가 없는 실정이다. 유해가스 및 폭발 위험성이 있는 환경에 적정한 방폭 배풍기의 운전 시간과 풍량을 제어할 수 있는 방폭 단자함을 제작하는 것이 목적이다. 2개의 방폭형 스위치를 사용하여 운전시간을 1 시간, 3 시간, 그리고 연속 시간으로 운전할 수 있도록 하였고, 유도전동기 회전 속도는 2000rpm, 2600rpm, 그리고 3000rpm으로 3 단계로 설정하여 풍량 제어하였다. 실험한 모터는 1/2 마력 3상 유도전동기 사용하였으며 풀 브리지 인버터를 제작하여 원하는 풍량과 운전시간 설정할 수 있도록 연구하였다.

• 한국태양에너지학회 논문집
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• 제25권1호
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• pp.27-34
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• 2005

This study aims to evaluate application of a heat recovery ventilator(HRV) using photovoltaic(PV) system. To this end, we analyzed performance of a PV system, which it was evaluated by monthly power wattage and conversion efficiency according to design capacity of a HRV. The results of this study can be summarized as follows. (1) A conversion efficiency of the PCS was evaluated about 86% in rated power. (2) A maximum, minimum and average output power were respectively analyzed 49.2W, 47.3W, and 48.8W. (3) Total power wattage of 200W PV system was 211kW and it was 316kW in case of 300W PV system. (4) Insufficient electrical power of a duct and window type ventilation system was respectively calculated 133.5kW and 147.7kW.