RESPIRATORY SOUNDS AS A SOURCE OF INFORMATION IN ASTHMA DIAGNOSIS

Around 300 million people all over the world at all age level suffer from asthma [1]. Patients with this disease have primarily difficult breathing with wheezing in respiratory sounds, cough and feeling of constricted chest. Therefore their physical activity is strongly limited [2]. Nowadays, there are several methods for asthma diagnosis, for example spirometry, measuring of peaks of expiratory velocity or measuring of bronchial reactivity. Although these methods are sufficiently reliable in most cases, they have also some imperfections, which are obvious especially by diagnosing of badly collaborating patients, e.g. small children aged up to three years. These infants can’t provide operations required for diagnosis, so results performed diagnosis are not reliable. For this reason, there is an idea of developing non invasive method of asthma diagnosis and other pulmonary diseases that would not need collaboration of patient [3]. One of the most probably working usable principles is comparison of air flow in airways of healthy and ill person. The difference of the air flow is caused by bronchial obstruction and constriction of airways of patient. There are other sounds and wheezing in the respiratory sounds detectable during breathing as a typical manifestation of the disease [4]. These phenomena can be detected by hearing of sound or by harmonic analysis

Optymalizacja za pomocą MES przyporu zazębienia przekładni jednostopniowej stosowanej w pociągach podmiejskich

This article describes the methodology, calculations and results of gear-mesh optimization by finite element method for single-stage gearbox – type AGV-250. Gearbox is meant for regional trains. Results of the calculations are used for examination of changes in the gear-mesh of the tooth flank under load, particularly in term of improved uniform load distribution through a width of the tooth. The aim of the methodology is to design optimized tooth profile with application of longitudinal, transverse and angular modifications of tooth flank on the basis of analysis of calculation model by FEM. The article compares several variants of modifications according to distribution of contact pressure (stress).Artykuł opisuje metodykę, obliczenia oraz rezultaty optymalizacji przyporu zazębienia za pomocą metody elementów skończonych dla przekładni jednostopniowej – typ AGV-250. Przekładnia ta jest przeznaczona dla pociągów podmiejskich. Wyniki obliczeń deformacji elementów przekładni zostały zastosowane podczas modyfikacji boku zębów, aby osiągnąć lepszy przypór zazębienia. Uzyskano to z wykorzystaniem optymalizacji rozłożenia nacisków stykowych na szerokości i wysokości zęba. Celem metodyki jest zaproponowanie optymalnego kształtu powierzchni zęba za pomocą modyfikacji podłużnej, poprzecznej lub kątowej zgodnie z obliczeniami MES. W artykule porównano kilka wariantów modyfikacji, opierając się na rozłożeniu ciśnienia stykowego na powierzchni zęba

Posouzeni napjatosti pruzneho kola harmonickeho ozubeneho prevodu komparacni metodou

This study deals with a state of stress of a flexspline of harmonic drive. The principle, function and utilization of the harmonic drive are briefly described in Chapter 2. Examples of construction of those with segmental wave generators are presented. Discussion of the state of stress of a shell of flexspline based on linear elasticity is presented in Chapter 3. The study is focused on evaluation of it in the harmonic drive based on a comparative method. Possibilities of it for optimalization of a design of highly stressed parts are described in Chapter 4 devoted to method oy. This chapter precedes both experimental and calculation both the study. In the former part finding out of a stress in a given point of the shell of flexspline by a tenzometrical measuring is given. In the latter one a model constructed by a finite elements method is described. It is evaluation with regard to global quantities is described in comparison with the results of the experiment. Results of computation of the shell of flexspline based on the finite elements method are presented. There are also a discussion and comparison of results obrained both in computation and experiment presented in the frame of the comparative methodAvailable from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi