Lung Volume Measurements
Mostrando 25-36 de 150 artigos, teses e dissertações.
-
25. Intrasubject variability of pulmonary function testing in healthy children.
The intrasubject variability of repeat pulmonary function testing was examined in 20 healthy children aged 10 to 16 years. The children were tested a maximum of 11 times over a period of two months. The tests examined were spirometry, maximum expiratory flow-volume curves, body plethysmograph determination of lung volumes, and single breath nitrogen washout.
-
26. Dependence of maximal sniff generated mouth and transdiaphragmatic pressures on lung volume.
The maximal sniff generated mouth and transdiaphragmatic pressures of six healthy volunteers (three women and three men) were measured at various lung volumes between residual volume and 95% of total lung capacity. At residual volume the mean (SD) maximum transdiaphragmatic pressure was 163 (18) cm H2O (1 cm H2O = 0.0981 kPa). With increasing lung volume the
-
27. Pulsatile uptake of CO in the human lung
The instantaneous uptake of CO in the lungs was measured with a water-filled body plethysmograph in normal man. First, control measurements of plethysmograph pressure were made while the subject held his breath for 7 sec after breathing gas mixtures prepared to bring his alveolar PO2 and PCO2 close to mixed venous levels. Then, CO uptake measurements were ma
-
28. Pulmonary function and maximal transrespiratory pressures in ankylosing spondylitis.
Clinical measurements and pulmonary functions, including maximal transrespiratory pressures, were studied in 30 patients (age 43 (SD 10) years) with ankylosing spondylitis. Vital capacity (VC) was slightly reduced to 79 (16)% and forced expiratory volume in one second (FEV1) was similarly reduced to 82 (20)% such that the average FEV1/VC ratio was 77.8 (6.65
-
29. Lung tissue volume estimated by simultaneous radiographic and helium dilution methods.
The pulmonary total tissue volume (blood, extravascular water, and dry tissue volume) was measured by finding the difference between the radiographic displacement volume of the thorax (RDVT) and the lung gas volume. Simultaneous determinations of RDVT and gas volume were made in 10 healthy subjects sitting upright. RDVT was determined from posteroanterior an
-
30. Diagnosis of pulmonary hypertension from radiographic estimates of pulmonary arterial size.
The reported accuracy of radiographic measurements in predicting pulmonary hypertension is very variable. Measurements of right and left descending pulmonary artery diameter have been reported to provide a correct diagnosis in as many as 98% of patients. A study was carried out to determine the predictive value of measurements made from the chest radiographs
-
31. Closing volume during normal pregnancy.
Serial lung function studies were performed in ten healthy, primiparous women aged 21--28. Measurements were made at two-monthly intervals during pregnancy and included functional residual capacity (FRC), total lung capacity (TLC), vital capacity (VC), specific conductance (SGaw) and closing volume (CV) on each occasion. Closing volume expressed as formular:
-
32. Quantification of lung microstructure with hyperpolarized 3He diffusion MRI
The structure and integrity of pulmonary acinar airways and their changes in different diseases are of great importance and interest to a broad range of physiologists and clinicians. The introduction of hyperpolarized gases has opened a door to in vivo studies of lungs with MRI. In this study we demonstrate that MRI-based measurements of hyperpolarized 3He d
American Physiological Society.
-
33. Microscopic and macroscopic measurements of emphysema: relation to carbon monoxide gas transfer.
BACKGROUND: Studies of the relation between the severity of structural change in emphysema and physiological abnormality have been based on macroscopic assessments, which have not been truly quantitative or sensitive enough to detect early changes. With a highly reproducible method for measuring emphysema using histological sections and a semiautomatic image
-
34. Relation between distal airspace size, bronchiolar attachments, and lung function.
BACKGROUND--Smoking related fixed airway obstruction may be due to airway scarring and narrowing or decreased support due to loss of adjacent alveolar walls. In this study of resected specimens, preoperative pulmonary function was compared with results of a morphometric study of lung structure. METHODS--Morphometric measurements were made on 42 inflation fix
-
35. Lung volume and its subdivisions in normal and asthmatic males
Measurements of lung volume and its subdivisions were made in 89 asthmatic children and adults and 58 normal subjects. The asthmatics were divided into three groups according to the classification of Jones (1966). In this the FEV1 is used as an index of airways resistance which is divided into labile and fixed components. The compartment of lung volume showi
-
36. Regional lung function in patients with hepatic cirrhosis
The lung volume at which the dependent lung zones begin to trap gas as a result of airway closure (i.e., the “closing volume”) was measured with 133Xe in 10 seated patients with hepatic cirrhosis. In all of them the closing volume was increased above normal, and in eight it was greater than the functional residual capacity, indicating the presence of air