Chest wall kinematics and Hoover's sign.
ABSTRACT No attempt has been made to quantify the observed rib cage distortion (Hoover's sign) in terms of volume displacement. We hypothesized that Hoover's sign and hyperinflation are independent quantities.
Twenty obstructed stable patients were divided into two groups according to whether or not they exhibited Hoover's sign during clinical examination while breathing quietly. We evaluated the volumes of chest wall and its compartments: the upper rib cage, the lower rib cage and the abdomen, using optoelectronic plethysmography.
The volumes of upper rib cage, lower rib cage and abdomen as a percentage of absolute volume of the chest wall were similar in patients with and without Hoover's sign. In contrast, the tidal volume of the chest wall, upper rib cage, lower rib cage, their ratio and abdomen quantified Hoover's sign, but did not correlate with level of hyperinflation.
Rib cage distortion and hyperinflation appear to define independently the functional condition of these patients.
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ABSTRACT: The aperture orthogonal polynomials (AOPs) method, a new technique for phase control of antenna systems, is reviewed; and several problems solved with this method are considered. It is demonstrated that phase control algorithms that ensure the beam orientation of linear and planar phased arrays (PAs) with various geometrical parameters in the prescribed directions and simultaneous beam ing in the directions of jamming signals are more accurate in comparison with traditional phase control algorithms. The criterion is obtained that provides for suppression of broadband jamming signals by forming the sector-shaped s of linear and planar PAs beams. Algorithms for determining the laws of optimal elements arrangement in non-uniformly spaced PAs, thus securing against parasitic side lobes of high intensity in wide-angle scan and for an extended (up to 2-3 octaves) frequency band, arc considered.Antenna Theory and Techniques, 2003. 4th International Conference on; 10/2003