• 제목/요약/키워드: Vital capacity

검색결과 459건 처리시간 0.023초

Modeling of heated concrete-filled steel tubes with steel fiber and tire rubber under axial compression

  • Sabetifar, Hassan;Nematzadeh, Mahdi;Gholampour, Aliakbar
    • Computers and Concrete
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    • 제29권1호
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    • pp.15-29
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    • 2022
  • Concrete-filled steel tubes (CFSTs) are increasingly used as composite sections in structures owing to their excellent load bearing capacity. Therefore, predicting the mechanical behavior of CFST sections under axial compression loading is vital for design purposes. This paper presents the first study on the nonlinear analysis of heated CFSTs with high-strength concrete core containing steel fiber and waste tire rubber under axial compression loading. CFSTs had steel fibers with 0, 1, and 1.5% volume fractions and 0, 5, and 10% rubber particles as sand alternative material. They were subjected to 20, 250, 500, and 750℃ temperatures. Using flow rule and analytical analysis, a model is developed to predict the load bearing capacity of steel tube, and hoop strain-axial strain relationship, and axial stress-volumetric strain relationship of CFSTs. An elastic-plastic analysis method is applied to determine the axial and hoop stresses of the steel tube, considering elastic, yield, and strain hardening stages of steel in its stress-strain curve. The axial stress in the concrete core is determined as the difference between the total experimental axial stress and the axial stress of steel tube obtained from modeling. The results show that steel tube in CFSTs under 750℃ exhibits a higher load bearing contribution compared to those under 20, 250, and 500℃. It is also found that the ratio of load bearing capacity of steel tube at peak point to the load bearing capacity of CFST at peak load is noticeable such that this ratio is in the ranges of 0.21-0.33 and 0.31-0.38 for the CFST specimens with a steel tube thickness of 2 and 3.5 mm, respectively. In addition, after the steel tube yielding, the load bearing capacity of the tube decreases due to the reduction of its axial stiffness and the increase of hoop strain rate, which is in the range of about 20 to 40%.

일산화탄소 폐확산능검사에서 단회호흡법과 호흡내검사법의 비교 (Comparison of Single-Breath and Intra-Breath Method in Measuring Diffusing Capacity for Carbon Monoxide of the Lung)

  • 이재호;정희순;심영수
    • Tuberculosis and Respiratory Diseases
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    • 제42권4호
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    • pp.555-568
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    • 1995
  • 연구배경: 폐확산능은 산소를 이용하여 측정하는 것이 가장 생리적이지만 폐모세혈의 산소분압측정이 어려워 임상에서는 일산화탄소를 이용하여 측정하고 있으며, 단회호흡(single-breath)폐확산능검사법이 가장 널리 사용되고있는 방법이다. 그러나 총폐용량까지 흡기한후 10초간 숨을 참는 과정을 기침, 호흡곤란 등이 있는 환자로선 수용하기 곤란하므로 이러한 과정없이 낮은 유량의 일회호기만을 필요로 히는 호흡내(intra-breath)폐확산능검사법이 고안되었다. 본 연구에서는 단회호흡법과 호흡내법으로 측정한 폐확산능간에 유의한 차이가 있는지 그리고 차이가 있다면 어떤 인자가 영향을 미치는지를 알아보고자 하였다. 방법: 특정질환과 무관하게 임의로 73명을 선택하고 유량-용적곡선 검사를 3회 시행한후 노력성 폐활량(FVC)과 1초간 노력성호기량($FEV_1$)의 합이 가장 큰 검사에서 노력성폐활량, 1초간 노력성호기량, 1초간 노력성호기량의 노력성 폐활량에 대한 비($FEV_1$/FVC)를 구했다. 폐확산능은 5분간격으로 각각 3회씩 단회호흡법과 호흡내법으로 측정하였으며, 선형적 상관분석으로 어떤 인자가 두 방법간의 폐확산능의 차[단회호흡법과 호흡내법에 의한 각각의 폐확산능의 차이의 평균치(mL/min/mmHg)]에 영향을 미치는지를 평가하여 다음과 같은 결과를 얻었다. 결과: 1) 단회호흡법 및 호흡내법 모두 검사내 재현성은 우수하였다. 2) 단회호흡법과 호흡내법으로 측정한 폐확산능간에는 전체적으로 유의한 상관관계가 있었지만, 두 방법의 측정치간에는 의미있는 치아가 있었다($1.01{\pm}0.35ml/min/mmHg$, p<0.01). 3) 단회호흡법과 호흡내법간의 폐확산능의 차이는 노력성폐활량과는 상관관계가 없었지만, 1초간 노력성호기량, $FEV_1$/FVC 및 환기배분의 지표인 메탄농도의 기울기와는 유의한 상관관계가 있었고 다중상관분석결과 $FEV_1$/FVC에 의한 영향이 가장 컸다(r=-0.4725, p<0.01). 4) 단회호흡법과 호흡내법간의 폐확산능의 차이와 $FEV_1$/FVC를 도식화하면 두 방법간의 폐확산능의 차이는 $FEV_1$/FVC가 50~60%인 구간에서 두 군으로 분리됨을 알수 있으며, $FEV_1$/FVC가 60% 이상에서는 두방법간에 유의한 차이가 없으나($0.05{\pm}0.24ml/min/mmHg$, p>0.1) 60% 미만에서는 유의한 차이가 있었다($-4.65{\pm}0.34ml/min/mmHg$, p<0.01). 5) 메탄농도의 기울기가 정상범위인 2%/L이내에선 단회호흡법과 호흡내법의 폐확산능이 모두 $24.3{\pm}0.68ml/min/mmHg$로 측정방법에 따른 차이가 없지만 2%/L를 초과한 경우에는 단회호흡법에 의한 폐확산능이 $15.0{\pm}0.44ml/min/mmHg$ 호흡내법에 선 $11.9{\pm}0.51ml/min/mmHg$로 두 방법간에 유의한 차이가 있었다(p<0.01). 따라서 $FEV_1$/FVC가 60% 미만일때는 호흡내법으로 측정한 폐확산능이 단회호흡법보다 의미있게 낮은 값을 보이는데, 그 이유는 주로 환기배분의 장애로 추정되지만 폐확산능 이 단회호흡법에서 과대평가되거나 폐확산능의 감소가 호흡내법에서 더 예민하게 나타 났을 가능정도 배제할수 없다. 결론: 73명을 대상으로 폐확산능을 단회호흡법과 호흡내법으로 측정해본 결과 호흡내법은 검사의 재현성도 우수하고 폐기능이 정상이거나 제한성 장애, 그리고 경도의 폐쇄성장애가 있는 경우에는 단회호흡법을 대체해서 사용할수 있지만, 중등도 이상의 폐쇄성장애가 있는 경우에는 단회호흡법보다 유의하게 낮은 검사치를 보였다. 호흡내법과 단회호흡법에 의한 폐확산능의 차이가 호흡내법이 단회호흡법에 비해 폐확산능의 감소를 예민하게 나타내주는 것인지 혹은 환기의 불균형에 의한 영향을 많이 받아서인지는 연구가 더 필요할 것이다.

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Spirometry and Bronchodilator Test

  • Sim, Yun Su;Lee, Ji-Hyun;Lee, Won-Yeon;Suh, Dong In;Oh, Yeon-Mok;Yoon, Jong-seo;Lee, Jin Hwa;Cho, Jae Hwa;Kwon, Cheol Seok;Chang, Jung Hyun
    • Tuberculosis and Respiratory Diseases
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    • 제80권2호
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    • pp.105-112
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    • 2017
  • Spirometry is a physiological test for assessing the functional aspect of the lungs using an objective indicator to measure the maximum amount of air that a patient can inhale and exhale. Acceptable spirometry testing needs to be conducted three times by an acceptable and reproducible method for determining forced vital capacity (FVC). Until the results of three tests meet the criteria of reproducibility, the test should be repeated up to eight times. Interpretation of spirometry should be clear, concise, and informative. Additionally, spirometry should guarantee optimal quality prior to the interpreting spirometry results. Our guideline adopts a fixed normal predictive value instead of the lower limit of normal as the reference value because fixed value is more convenient and also accepts FVC instead of vital capacity (VC) because measurement of VC using a spirometer is impossible. The bronchodilator test is a method for measuring the changes in lung capacity after inhaling a short-acting ${\beta}-agonist$ that dilates the airway. When an obstructive ventilatory defect is observed, this test helps to diagnose and evaluate asthma and chronic obstructive pulmonary disease by measuring reversibility with the use of an inhaled bronchodilator. A positive response to a bronchodilator is generally defined as an increase of ${\geq}12%$ and ${\geq}200mL$ as an absolute value compared with a baseline in either forced expiratory volume at 1 second or FVC.

복부 운동 방법에 따른 호흡기능 변화 비교 (Effects of Abdominal Exercise Methods on Breathing Ability)

  • 배원식;문현주;이건철
    • 대한통합의학회지
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    • 제8권1호
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    • pp.137-146
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    • 2020
  • Purpose : The enhancement of abdominal muscles increases the activation and contraction of respiratory muscles, including the diaphragm. Generally, diaphragm exercises are applied to increase the breathing ability of patients with respiratory disease. Previous studies have shown that breathing capacity can be increased through abdominal muscle strengthening exercises. However, studies on breathing ability are rare and it is doubtful whether these affect respiratory ability more than diaphragm exercises. Therefore, this study seeks to compare whether abdominal exercises can improve breathing ability and whether any increase is comparable to diaphragm exercises. Methods : After selecting subjects, the place of intervention was separated for blindness. The plank group was allowed to relax for 30 seconds after 30 seconds of planking; this was set at three and increased by one set each week. Subjects in the draw-in group were allowed to relax for 30 seconds after maintaining the draw-in contraction state for 30 seconds and this was done for 15 minutes. Subjects in the control group underwent abdominal dilation for five seconds of inspiration time and expired air for five seconds by exposing the lips; breathing was performed repeatedly for 15 minutes. Subjects in each group measured their respiration function three times before intervention, three weeks after the commencement of intervention and after intervention. Spirovit SP-1 was used to measure respiratory function. In each group, repeated ANOVA was used to compare the respiratory function over time and one-way ANOVA was used to compare the respiratory function between groups. The post hoc was conducted using the LSD method. Results : There was a significant increase in respiratory ability between the forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF), forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) according to the six-week period. However, there was no difference between each group. Conclusion : For patients with low respiratory muscle strength, plank exercises and abdominal draw-in are beneficial exercises for improving respiratory function. These are expected to be widely used in clinical practice for patients with weak respiratory muscles.

대학생의 폐활량에 대한 기초체력과 신체활동량의 관계 (Pulmonary function is related to basic physical fitness and physical activity in college students)

  • 배주용;박경진;김지영;이율효;김지선;하민성;노희태
    • 한국응용과학기술학회지
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    • 제38권4호
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    • pp.1165-1175
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    • 2021
  • 본 연구의 목적은 한국 대학생들의 기초체력과 신체활동량이 폐기능과 상관관계가 있는지를 분석하고, 성별에 따른 차이를 검증하는데 있다. 건강한 참여자 312명(남성 150명[평균연령: 19.29±1.72세], 여성 160명[평균연령: 19.05±1.17세])은 신체조성, 기초체력, 신체활동량 설문지, 그리고 노력성폐활량(FVC)과 1초간 강제호기량(FEV1)의 폐기능 검사를 수행하였다. 연구결과, 남학생의 폐기능은 우악력과 좌악력, 그리고 배근력과 관련이 있었고, 여학생의 폐기능은 모든 기초체력 하위 요인과 관련이 있었다. 또한 여성의 폐기능은 중강도 신체활동량과 관련이 있는 반면 남성의 폐기능은 신체활동량의 모든 하위 요인과 관련이 있었다. 본 연구의 주요 발견은 폐기능을 개선하기 위해서 남학생은 신체활동량을 증가시키고, 여학생은 기초체력을 향상시킬 필요가 있음을 제안한다. 대학생들의 폐기능을 유지하고 개선시키기 위해서는 폐기능 관련 인자에 대한 성별의 차이를 이해하고, 성별에 맞는 교육적 노력이 필요할 것이다.

New Method for Combined Quantitative Assessment of Air-Trapping and Emphysema on Chest Computed Tomography in Chronic Obstructive Pulmonary Disease: Comparison with Parametric Response Mapping

  • Hye Jeon Hwang;Joon Beom Seo;Sang Min Lee;Namkug Kim;Jaeyoun Yi;Jae Seung Lee;Sei Won Lee;Yeon-Mok Oh;Sang-Do Lee
    • Korean Journal of Radiology
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    • 제22권10호
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    • pp.1719-1729
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    • 2021
  • Objective: Emphysema and small-airway disease are the two major components of chronic obstructive pulmonary disease (COPD). We propose a novel method of quantitative computed tomography (CT) emphysema air-trapping composite (EAtC) mapping to assess each COPD component. We analyzed the potential use of this method for assessing lung function in patients with COPD. Materials and Methods: A total of 584 patients with COPD underwent inspiration and expiration CTs. Using pairwise analysis of inspiration and expiration CTs with non-rigid registration, EAtC mapping classified lung parenchyma into three areas: Normal, functional air trapping (fAT), and emphysema (Emph). We defined fAT as the area with a density change of less than 60 Hounsfield units (HU) between inspiration and expiration CTs among areas with a density less than -856 HU on inspiration CT. The volume fraction of each area was compared with clinical parameters and pulmonary function tests (PFTs). The results were compared with those of parametric response mapping (PRM) analysis. Results: The relative volumes of the EAtC classes differed according to the Global Initiative for Chronic Obstructive Lung Disease stages (p < 0.001). Each class showed moderate correlations with forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FVC) (r = -0.659-0.674, p < 0.001). Both fAT and Emph were significant predictors of FEV1 and FEV1/FVC (R2 = 0.352 and 0.488, respectively; p < 0.001). fAT was a significant predictor of mean forced expiratory flow between 25% and 75% and residual volume/total vital capacity (R2 = 0.264 and 0.233, respectively; p < 0.001), while Emph and age were significant predictors of carbon monoxide diffusing capacity (R2 = 0.303; p < 0.001). fAT showed better correlations with PFTs than with small-airway disease on PRM. Conclusion: The proposed quantitative CT EAtC mapping provides comprehensive lung functional information on each disease component of COPD, which may serve as an imaging biomarker of lung function.

고령 편마비 환자에 대한 호흡운동 적용의 효과 (The Efficacy of Respiratory Exercise Programs in the Elderly Persons with Hemiplegia)

  • 김수민
    • PNF and Movement
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    • 제5권2호
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    • pp.63-71
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    • 2007
  • Objective : Respiratory muscle weakness and decreased chest mobility has been suggested to result from the deconditioning that accompanied activity level in chronic elderly stokes. The benefits of respiratory exercise programmes on exercise capacity and muscle strength in hemiplegia. This study aimed to determine the effects of selective inspiratory and expiratory muscles training and chest mobility exercise on patients with strokes to establish if an improved exercise capacity can be obtained in patients that are not limited in their daily activities. Methods & Intervention : Twelve patients were assigned to the intensive respiratory exercise group participated in a measures design that evaluated the subjects with pre-treatment and post-treatment. Thirteen subjects who were assigned to a control group received training with breathing exercise and resistance exercise of skeletal muscles. The subjects performed spirometry then undertook a 6-week programme of respiratory muscle and chest mobility training. Training for the two groups was carried out 2 times a week for 6 weeks. Measurements and Results : Spirometry(Forced Vital Capacity: FVC and Closed Circuit Spiromety: CCS) and thoracic mobility were measured before and after the 6 weeks. The experimental group improved significantly compared to control group in FVC, $FEV_1$, MVV, IRV and ERV, and upper chest wall expansion(p<0.05). No significant improvement was seen in thoracic mobility or lung function in control group(p>0.05). Conclusion : The major findings in this study were that a intensive 6week exercise programme of resistive breathing and chest mobility in patients with hemiplegia led to an increase in lung capacity. The resistive breathing exercise programme used here resulted in a significant increase in the chest excursion during breathing.

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배선용 차단기 개폐기구의 동특성 향상방안 및 해석 (Study on the Dynamic Modeling of MCCB)

  • 박진영;조해용
    • Journal of Advanced Marine Engineering and Technology
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    • 제36권2호
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    • pp.315-320
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    • 2012
  • 일반적으로 저압 회로 보호용 장치로는 ICCB(Insulated case circuit breakers), PCB(Power circuit breakers) 그리고 MCCB(Molded case circuit breakers)를 들 수 있다. 이들 중 가장 보편적으로 사용되는 배선용 차단기(MCCB)는 휴즈 또는 개폐기의 단점인 안전성, 제어성, 협조성 등을 보완한 것이다. 차단기의 성능은 사고전류 발생 시 트립 동작이 순간적이고, 절연능력이 뛰어나야 하므로 매우 중요하다. 따라서 차단기의 개폐 성능은 매우 중요하므로 개폐 기구부의 접촉자 구조 및 접점 그리고 링크구조 등에 대한 기구학적 연구가 필요하다. 본 논문에서는 저압차단기의 기구적 동역학 모델링과 해석을 수행하여 가동자의 개리속도가 빠를수록 차단특성에 유리하다는 결론을 얻었으며, 실제 실험을 통하여 이를 검증하였다.

Effects of Five-month Training of Playing Harmonica on Pulmonary Function in Patients With Neuromuscular Disease: A Pilot Study

  • Kim, Bit-na-rae;Cynn, Heon-seock
    • 한국전문물리치료학회지
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    • 제25권3호
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    • pp.60-67
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    • 2018
  • Background: Progressive muscle weakness is aggravated not only in the skeletal muscles but also in the respiratory muscles in many patients with neuromuscular diseases (NMD). Inspiratory muscle training (IMT) has been reported as therapy for pulmonary rehabilitation to improve respiratory strength, endurance, exercise capacity, and quality of life, and to reduce dyspnea. Objects: The purpose of this study was to determine the effect of playing harmonica for 5 months on pulmonary function by assessing the force vital capacity (FVC), peak cough flow (PCF), maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and maximal voluntary ventilation (MVV) in patients with NMD. Methods: Six subjects with NMD participated in this study. The subjects played harmonica once a week for 2 hours at a harmonica academy and twice a week for 1 hour at home. Thus, training was performed thrice a week for 23 weeks. The examiner assessed pulmonary function by measuring FVC in the sitting and supine positions and PCF, MIP, MEP, and MVV in the sitting position at the beginning of training and once a month for 5 months. Results: Both sitting and supine FVC significantly increased after playing harmonica (p=.042), as did MIP (p=.043) and MEP (p=.042). Conclusion: Playing harmonica can be used as an effective method to improve pulmonary function in patients with NMD.

Effects of Gym Ball Stabilization Exercises on the Physical Functions of Elementary School Baseball Players

  • Kim, Se-Hun;Park, Jea-Cheol
    • The Journal of Korean Physical Therapy
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    • 제34권2호
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    • pp.51-56
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    • 2022
  • Purpose: This study examined the effects of gym ball stabilization exercises on the physical functions of elementary school baseball players. Methods: The elementary school baseball players were assigned to an experimental group (n=21). The group performed gym ball stabilization exercises and the changes in the physical functions were measured using the visual response speed test, functional movements, physical balance ability, and pulmonary function. Results: The results of the visual response speed test showed changes in the time response speed. There was a significant change in the number of touches in 15 seconds in the upper arms and left and right legs (p<0.05) after 10 weeks. Also, there was a significant change in the reaction times of the left and right legs after 10 weeks (p<0.05). Further, there were significant differences in functional movements involving rotational stability and the total functional scores after 10 weeks (p<0.05). The player's body balance ability showed a significant difference after 10 weeks in the posterior-lateral and posterior-medial composite scores of the left and right legs (p<0.05). There was a significant change in the forced lung capacity and forced expiratory volume in 1 second after 10 weeks (p<0.05). Conclusion: These results show that the gym ball stabilization exercises effectively improved the visual response speed and functional movements, balance, and vital capacity of elementary school baseball players.