Commercially available nasal masks have a large mask volume and give rise to considerable air leaks around the mask during nasal intermittent positive pressure ventilation (NIPPV) which may reduce alveolar ventilation (VA per breath). The effects of a custom-fabricated nasal mask (F-mask) versus a commercially available mask (C-mask) on arterial blood gas measurements, dead space including both...

The concept of matched devices is one of the most important features in analog circuit design, as most analog circuits operation rely on the similarity of electrical behavior of close devices [1]. However, in practice, the characteristics of designed matched transistors are slightly different. Therefore, the design of precise analog circuits requires studies into the matching behavior of device...

BACKGROUND Positive expiratory pressure (PEP) and CPAP are used to enhance breathing parameters such as functional residual capacity (FRC) in patients. Studies comparing effects of PEP and CPAP on FRC are few and variable. One reason for this may be that sophisticated equipment, not suitable in the clinical setting, is required. Because total lung capacity (TLC) consists of inspiratory capacity...

Although gratings beyond the Nyquist limit of the peripheral retina are visible as aliased percepts when presented in isolation, the reported lack of aliasing for targets with complex spectra (edges, lines, letters) suggests that aliased frequency components are invisible in the presence of sub-Nyquist image components. We tested this hypothesis by systematically exploring a range of stimulus p...

background: various studies are seeking to find new methods to improve techniques of laryngeal mask airway (lma) insertion and reduce possible complications. in this study, we embarked on a clinical study to investigate the advantages of a new insertion method of laryngeal mask and to compare it with the classic method. materials and methods: two hundred patients aged 20-60 years old in 2012 we...