BACKGROUND Most portable bi-level positive airway pressure devices are not equipped with air-oxygen blenders for precisely regulating oxygen concentrations, and supplemental oxygen must be added to increase the F(IO2). Very few studies have investigated the factors that affect F(IO2), and their conclusions have been inconsistent. We investigated in vitro noninvasive ventilation (NIV) parameters...

1. Airway resistance was measured close to functional residual capacity before and after a full inhalation of total lung capacity, as well as before and after a full exhalation to residual volume. 2. The effects of these volume manoeuvres upon airway resistance (and associated lung volume) were determined in four resting normal male subjects and in six normal men during experimentally induced b...

INTRODUCTION Spirometry is the basic method used to diagnose and monitor obstructive diseases. Spirometric tests are performed in more and more people of advanced age (more than 65 years old). The objective of the study was to assess the quality of spirometry (measurement of the flow-volume curve) in subjects of the aforementioned age group, with reference to applicable quality criteria specifi...

To study the effects of exercise on pulmonary diffusing capacity, we measured the lungs' diffusing capacity for carbon monoxide (DLCO) during exhalation from 30 to 45% exhaled vital capacity in eight healthy subjects at rest and during exercise while both sitting and supine. We found that DLCO at these lung volumes in resting subjects was 26.3 +/- 3.2% (mean +/- SE) higher in the supine than in...

Radon gas concentrations and uranium-238 concentration in soil samples at the surface (depth = 15 cm) were determined for fifteen three refineries (Al-Kasak, Al-Qayarah, Baiji) using “sealed can technique”. CR-39 solid-state nuclear pathway detectors. The of radon Al-kasak refinery ranged from (1509 to 8323.2 Bq/m3) with an average (4916.1 Bq/m3), exhalation rate (1110.3 612.7 (861.5 Bq/m3). ef...

was identifi ed in 1 sample. These results enabled us to compare DHPS genotypes for 6 pairs of samples. A full match was found for these 6 pairs. DHPS and ITS genotype matches were found for 4 pairs. Several lines of evidence suggest that P. jirovecii is exhaled by infected patients and transmitted by the airborne route to susceptible persons (4). In the study reported here, ITS or DHPS genotyp...

The diffusing capacity, DL, is a critical physiological parameter of the lung used to assess gas exchange clinically. Most models developed to analyze experimental data from a single breath maneuver have assumed a well-mixed or uniform alveolar region, including the clinically accepted Jones-Meade method. In addition, all previous models have assumed a constant DL, which is independent of alveo...

PURPOSE To image respiratory dynamics and three-dimensional (3D) ventilation during inhalation, breath-hold, and exhalation for evaluation of obstructive lung disease using a single dose of hyperpolarized (HP) He-3 during MRI. MATERIALS AND METHODS A single 2D-3D projections inside Z encoding (PRIZE)-2D acquisition was performed that consisted of a rapid 2D radial acquisition phase during inh...

We aimed to optimize internal margin (IM) determination for respiratory-gated radiotherapy using end-expiratory phase assessments using a motion phantom. Four-dimensional computed tomography (4D CT) data were acquired using a GE LightSpeed RT CT scanner, a respiratory-gating system, and a motion phantom designed to move sinusoidally. To analyze the accuracy of 4D CT temporal resolution, a 25.4 ...