• 제목/요약/키워드: Cross-ventilation

검색결과 126건 처리시간 0.021초

호흡경로 상에 감지소자가 없는 새로운 호흡기류 계측기술 (Respiratory air flow measuring technique without sensing element on the flow stream)

  • 이인광;박준오;이수옥;신은영;김경천;김경아;차은종
    • 센서학회지
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    • 제18권4호
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    • pp.294-300
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    • 2009
  • Cardiopulmonary resuscitation(CPR) is performed by artificial ventilation and thoracic compression for the patient under emergent situation to maintain at least the minimum level of respiration and blood circulation for life survival. Quality of the pre-hospital CPR not only significantly affects the patient's survival rate but also minimizes side effects caused by CPR. Good quality CPR requires monitoring respiration, however, traditional respiratory air flow transducers cannot be used because the transducer elements are located on the flow axis. The present study developed a new technique with no physical object on the flow stream but enabling the air flow measurement and easily incorporated with the CPR devices. A turbulence chamber was formed in the middle of the respiratory tube by locally enlarging the cross-sectional area where the flow related turbulence was generated inducing energy loss which was in turn converted into pressure difference. The turbulence chamber was simply an empty enlarged air space, thus no physical object was placed on the flow stream, but still the flow rate could be evaluated. Both inspiratory and expiratory flows were obtained with symmetric measurement characteristics. Quadratic curve fitting provided excellent calibration formula with a correlation coefficient>0.999 (P<0.0001) and the mean relative error<1 %. The present results can be usefully applied to accurately monitor the air flow rate during CPR.

인공심폐소생술에 활용 가능한 호흡기류센서 (Respiratory Air Flow Transducer Applicable to Cardiopulmonary Resuscitation Procedure)

  • 김경아;이인광;이유미;유희;김영일;한상현;차은종
    • 전기학회논문지
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    • 제62권6호
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    • pp.833-839
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    • 2013
  • Cardiopulmonary resuscitation (CPR) is performed by thoracic compression and artificial ventilation for the patient under emergent situation to maintain at least the minimum level of respiration and blood circulation for life survival. Good quality CPR requires monitoring respiration, however, traditional respiratory air flow transducers cannot be used because the transducer elements are facing the whole area perpendicular to the flow axis. The present study developed a new air flow transducer conveniently applicable to CPR. Specially designed "sensing rod" samples the air velocity at 3 different locations of the flow cross-section, then transforms into average dynamic pressure by the Bernoulli's law. The symmetric structure of the sensing holes of the sensing rod enables bi-directional measurement simply by taking the difference in pressure by a commercial differential pressure transducer. Both inspiratory and expiratory flows were obtained with symmetric measurement characteristics. Quadratic curve fitting provided excellent calibration formula with a correlation coefficient>0.999 (P<0.0001) and the mean relative error<1%. The present results can be usefully applied to accurately monitor the air flow rate during CPR.

Comparison of the effects of different-sized airways in inspiratory trainers on maximal inspiratory pressure and rating of perceived exertion scale in healthy young people

  • Hwang, Young-In;Kim, Ki-Song
    • Physical Therapy Rehabilitation Science
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    • 제7권1호
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    • pp.18-22
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    • 2018
  • Objective: This study aimed to investigate the effect of different-sized airways of the inspiratory muscle trainer (IMT) on maximal inspiratory pressure (MIP) and the rating of perceived exertion, as measured by the modified Borg scale (m-Borg). Design: Cross-sectional study. Methods: Twenty healthy subjects (10 men, 10 women) volunteered for the study. The spirometry was used to measure MIP. The trial order of the three spirometry conditions was chosen randomly. After measuring the MIP and before taking the final break, each of the conditions were immediately measured using the m-Borg. All subjects used the IMT with an airway diameter of 5-, 6-, and 7-mm. Results: The MIP significantly decreased with the decreasing airway diameter of the IMT (p<0.001), and the differences in all three conditions (7- and 6-mm, 6- and 5-mm, and 7- and 5-mm airways) were significant (p<0.05). The RPE significantly increased with the decreasing airway diameter of the IMT (p<0.001), and the differences in all three conditions (7- and 6-mm, 6- and 5-mm, and 7- and 5-mm airways) were significant (p<0.05). Conclusions: Decreasing the airway diameter of the IMT decreased the MIP and increased the m-Borg. In regards to physical exercise within the clinical setting, the m-Borg could be a useful as a prior monitoring method to prevent dyspnea for patients with narrowed airways (blocked with secretion or sputum in pulmonary disease) and the different-sized airways of the IMT could be applied as a useful tool to improve MIP for prevention of pulmonary disease.

고위험 산모 신생아 통합치료센터(MFICU) 간호사의 교육 요구와 직무역량 인식조사 (A Survey on the Educational Needs and Competence of Nurses in Maternal Fetal Intensive Care Unit)

  • 김윤미;김증임;정금희;강희선;김미종;문소현;김미옥
    • 여성건강간호학회지
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    • 제25권2호
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    • pp.194-206
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    • 2019
  • Purpose: Maternal Fetal Intensive Care Unit (MFICU), which provides intensive care to high-risk mothers with increasing maternal age and high-risk newborns, has become a new field of nursing work in South Korea. The present study was conducted to identify the educational needs and self-assessing clinical competence of nurses in MFICU. Methods: The education needs and competencies of MFICU nurses were measured through prepared questionnaires by researchers based on the previous studies on job analysis of nurses in MFICU. Data were collected from January 2019 to March 2019. The study involved 168 nurses working in MFICUs at 12 hospitals nationwide as study subjects. The data were analyzed using the SPSS WIN 23.0 program. Results: The education needs of nurses in MFICU had an average of 4.21 points (${\pm}0.50$) and their nursing competence was average 3.38 points (${\pm}0.60$). The items reported as high education needs but low competency by nurses in MFICU were as following: 'postpartum hemorrhage and shock,' 'cardiopulmonary resuscitation (CPR) for neonate,' 'CPR during pregnancy,' 'disseminated intravascular coagulation,' 'sepsis,' and 'mechanical ventilation during pregnancy.' Conclusion: Based on these results, it is proposed that a comprehensive education program for nurses in MFICU should be developed by considering low capabilities among MFICU nurses as a priority factor.

Predictive factors of death in neonates with hypoxic-ischemic encephalopathy receiving selective head cooling

  • Basiri, Behnaz;Sabzehei, Mohammadkazem;Sabahi, Mohammadmahdi
    • Clinical and Experimental Pediatrics
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    • 제64권4호
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    • pp.180-187
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    • 2021
  • Background: Severe perinatal asphyxia results in multiple organ involvement, neonate hospitalization, and eventual death. Purpose: This study aimed to investigate the predictive factors of death in newborns with hypoxic-ischemic encephalopathy (HIE) receiving selective head cooling. Methods: This cross-sectional descriptive-retrospective study was conducted from 2013 to 2018 in Fatemieh Hospital of Hamadan and included 51 newborns who were admitted to the neonatal intensive care unit with a diagnosis of HIE. Selective head cooling for patients with moderate to severe HIE began within 6 hours of birth and continued for 72 hours. The required data for the predictive factors of death were extracted from the patients' medical files, recorded on a premade form, and analyzed using SPSS ver. 16. Results: Of the 51 neonates with moderate to severe HIE who were treated with selective head cooling, 16 (31%) died. There were significant relationships between death and the need for advanced neonatal resuscitation (P=0.002), need for mechanical ventilation (P=0.016), 1-minute Apgar score (P=0.040), and severely abnormal amplitude-integrated electroencephalography (a-EEG) (P=0.047). Multiple regression of variables or data showed that the need for advanced neonatal resuscitation was an independent predictive factor of death (P=0.0075) and severely abnormal a-EEG was an independent predictive factor of asphyxia severity (P=0.0001). Conclusion: All cases of neonatal death in our study were severe HIE (stage 3). Advanced neonatal resuscitation was an independent predictor of death, while a severely abnormal a-EEG was an independent predictor of asphyxia severity in infants with HIE.

포스트 코로나 시대 신종 감염병 대비를 위한 기존 의료시설의 비상시 운영사례 조사 및 분석 (Investigations on the emergency operation status of existing medical facilities to prepare for emerging infectious diseases in the post-COVID-19 era)

  • 이세진;이원석;김은석;여명석
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제29권1호
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    • pp.43-51
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    • 2023
  • Purpose: To accommodate the increasing number of patients during the COVID-19 pandemic, numerous portable HEPA filter units (PHUs) were installed in the general wards of existing medical facilities(EMFs) to convert them into emergency conversion facilities (ECFs). The purpose of this study was to build a dataset in preparation for emerging infectious diseases in the post-COVID-19 era by analyzing the construction and operation of ECFs. Methods: Field investigations were conducted during ECF operation periods based on the analysis of heating, ventilation, and air conditioning (HAVC) system design documents for six ECFs across Korea. Interviews were conducted with facility managers during the field investigations. Results: When constructing an ECF within an EMF, the installation status and characteristics of the existing system should be considered. Field investigations and verifications of the operation of HAVC systems must be conducted beforehand for smooth ECF operations. If heating and cooling are required with indoor air circulation type equipment in an ECF zone, the implementation of a heating and cooling method that can satisfy the comfort requirements of the occupants while minimizing cross-contamination is essential. When using PHUs that do not meet the performance standards required by medical equipment, the noise level resulting from such equipment operation must be evaluated and improved. Implications: For EMFs, various guidelines that can be referred to for the construction and operation of ECFs must be developed to prepare for emerging infectious diseases in the future.

설비공학회 분야의 최근 연구 동향 : 2015년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2015)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제28권6호
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    • pp.256-268
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    • 2016
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2015. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering were carried out in the areas of flow, heat and mass transfer, cooling and heating, and air-conditioning, the renewable energy system and the flow inside building rooms. Research issues dealing with air-conditioning machines and fire and exhausting smoke were reduced. CFD seems to be spreading to more research areas. (2) Research works on heat transfer area were carried out in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the economic analysis of GHG emission, micro channel heat exchanger, effect of rib angle on thermal performance, the airside performance of fin-and-tube heat exchangers, theoretical analysis of a rotary heat exchanger, heat exchanger in a cryogenic environment, the performance of a cross-flow-type, indirect evaporative cooler made of paper/plastic film. In the area of pool boiling and condensing, the bubble jet loop heat pipe was studied. In the area of industrial heat exchangers, researches were performed on fin-tube heat exchanger, KSTAR PFC and vacuum vessel at baking phase, the performance of small-sized dehumidification rotor, design of gas-injection port of an asymmetric scroll compressor, effect of slot discharge-angle change on exhaust efficiency of range hood system with air curtain. (3) In the field of refrigeration, various studies were carried in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, a cold-climate heat pump system, $CO_2$ cascade systems, ejector cycles and a PCM-based continuous heating system were investigated. In the alternative refrigeration/energy system category, a polymer adsorption heat pump, an alcohol absorption heat pump and a desiccant-based hybrid refrigeration system were investigated. In the system control category, turbo-refrigerator capacity controls and an absorption chiller fault diagnostics were investigated. (4) In building mechanical system research fields, eighteen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the user and location awareness technology applied dimming lighting control system, the lighting performance evaluation for light-shelves, the improvement evaluation of air quality through analysis of ventilation efficiency and the evaluation of airtightness of sliding and LS window systems. The subjects of building energy were worked on the energy saving estimation of existing buildings, the developing model to predict heating energy usage in domestic city area and the performance evaluation of cooling applied with economizer control. The studies were also performed related to the experimental measurement of weight variation and thermal conductivity in polyurethane foam, the development of flame spread prevention system for sandwich panels, the utilization of heat from waste-incineration facility in large-scale horticultural facilities.

도로터널 화재 시 집중배기방식의 배기포트 통과풍속이 배연성능에 미치는 영향에 관한 연구 (A study on the effect of air velocity through a damper on smoke extraction performance in case of fire in road tunnels)

  • 류지오;나광훈
    • 한국터널지하공간학회 논문집
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    • 제22권4호
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    • pp.347-365
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    • 2020
  • 도시지역의 교통난 해소와 녹지공간의 확보를 위해 도심지 터널이 증가하면서 차량의 정체 가능성이 높은 터널에 대한 제·배연방식으로 대배기구에 의한 집중배기방식의 적용이 증가하는 추세에 있다. 집중배기방식의 배연성능은 배연풍량 뿐만 아니라 배기구(댐퍼)의 형상이나 배기풍속 등 다양한 인자에 의해서 영향을 받는 것으로 알려져 있다. 이에 본 연구에서는 각국의 배연시스템 설계기준 및 설치현황을 알아보고 배연풍량이 동일한 경우에 배연댐퍼 사이즈에 따른 배연성능을 연기 이동거리 측면에서 수치시뮬레이션을 수행하여 비교·평가하였으며, 다음과 같은 결과를 얻었다. 배연댐퍼의 단면적이 증가할수록 배기팬에 근접한 댐퍼에서 배기풍량이 집중되어 화재 하류의 댐퍼의 배연풍량이 감소하여 하류측의 연기 이동거리가 증가하는 현상이 발생한다. 이와 같은 현상을 방지하기 위해서는 배연댐퍼의 단면적을 작게하여 통과풍속을 높게 함으로써 댐퍼통과 시 압력손실이 증가하도록 하여 배기구간에서 배연풍량의 불균일성을 완화할 필요가 있다. 본 해석범위에서는 배연댐퍼의 설치간격이 50 m인 경우에는 설계통과풍속이 4.4 m/s (댐퍼면적: 2.34 ㎡ = 1.25 × 1.85 m) 이상, 댐퍼의 설치간격이 100 m인 경우에는 설계통과풍속이 4.84 m/s (댐퍼면적: 3.38 ㎡ = 1.5 × 2.25 m) 이상일 때 배연성능확보에 유리한 것으로 나타났다.

Effects of Tropical Climate on Reproduction of Cross- and Purebred Friesian Cattle in Northern Thailand

  • Pongpiachan, P.;Rodtian, P.;Ota, K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권7호
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    • pp.952-961
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    • 2003
  • In the first part of the study, rates of estrus occurrence and success of A.I. service in the Thai-native and Friesian crossbred, and purebred Friesian cows fed in the National Dairy Training and Applied Research Institute in Chiang Mai, Thailand were traced monthly throughout a year. An electric fan and a water sprinkler cooled the stall for the purebred cows during the hot season (March-September). Both rates in pure Friesians were at their highest in the cold-dry season (October- February), but they decreased steadily during the hot-dry season (March-May) and were at their lowest in the hot-wet season (June-September). Seasonal change of a similar pattern was observed in the incidence of estrus, but not in the success rate of insemination in the crossbred cows. By the use of reproductive data, compiled in the same institute, on the 75 % cross- and purebred Friesian cows, and climatological data in Chiang Mai district, effects of ambient temperature and humidity on the reproductive traits of cows were examined by regression analysis in the second half of the study. Significant relationships in the crossbred, expressed by positive-linear and parabola regressions, were found between reproductive parameters such as days to the first estrus (DTFE), A.I. service (DTFAI), and conception, the number of A.I. services required for conception and some climatic factors. However, regarding this, no consistent or intelligible results were obtained in purebred cows, perhaps because electric fans and water sprinklers were used for this breed in the hot season. Among climatic factors examined, the minimum temperature (MINT) in early lactation affected reproductive activity most conspicuously. As the temperature during one or two months prior to the first estrus and A.I. service rose, DTFE and DTFAI steadily became longer, although, when MINT depleted below $17-18^{\circ}C$, the reproductive interval tended to be prolonged again on some occasions. The maximum temperature also affected DTFE and DTFAI, but only in limited conditions. The effect of humidity was not clear, although the inverse relationship between DTFE and minimum humidity during 2 months before the first estrus in the crossbred seemed to be significant. Failure to detect any definite effect of climate on the reproductive traits of pure Friesians seemed to indicate that forced ventilation by electric fans and water sprinklers were effective enough to protect the reproductive ability of this breed from the adverse effects of a hot climate.

표고 톱밥재배용 신품종 '농진고' 특성 (Characteristic of a new variety Lentinula edodes, 'Nongjin-go')

  • 문지원;이찬중;정종천;공원식;김길자
    • 한국버섯학회지
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    • 제13권3호
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    • pp.228-232
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    • 2015
  • 모본 ASI 3305mut와 L5(3265-238701-2)-16을 2011년에 교잡하여, 2012년부터 2013년까지 생산력 검정시험을 통해 PM-L5(농진고)를 출원하였다. 농진고의 균사배양 최적온도는 $30^{\circ}C$이며, 버섯 발생온도는 $15{\sim}23^{\circ}C$로 중고온성이다. 자실체의 갓은 평반구형이며 색깔은 황갈색이고, 인피는 갓의 둘레에 생긴다. 버섯의 배양은 1.5kg 배지에서 최소 90~100일이 소요되며, 갈변이 다소 늦은 편이다. 버섯 발생형은 집중형이나 산조701에 비하여 초기 발생이 다소 늦으면서 개체수가 10개 내외이고, 주기별 발생이 고른 편이다. 톱밥 봉지재배 품종으로 지면 재배, 균상재배에서 모두 적합하다.