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Contributions upon Determination of the Flow-Parameters on the Principal Bronchial Stems in Man

The main goal of present dissertation is to furnish explicitly quantitative relationships on Reynolds number's dependence of bronchial bifurcation asymmetrical angles, as well as versus bronchial tube's diameter, airflow-temperature and viscosity of blood or air medium. This approaching of above problematic is a truly alternative to the previous researches (Phillips and Kaye 1997) on the formed angles within human bronchial tree, not predicted in the past theoretical models; they having unfortunately a qualitatively character, only. To work and answer these objectives, I developed an expert-system program entitled VLI-EXPSYS.EXE in MS Visual C++ 6.0, which is basing on an innovative self-developed implementation on the Microsoft EN_CHANGE messages concept to perform correct interchanging dialogs between edit and spin control fields. The new aroused formulas are represented in graphic forms being dependent of air temperature and viscosity, atmospheric pressure and the right main bifurcation angle.

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Vincentiu-Lucian Ionescu: Doctoral Thesis - Contributions upon Determination of the Flow Parameters on Bronchial Stems in Man: Page 7 of 177 1. INTRODUCTION 1.1. GOALS OF DISSERTATION The task of the bronchial tree is it to bring air from outside into the gas exchange units, the alveoli. Its structure can approximately be describing by a dichotomical tree of seventeen generations, each seventeenth generation branch being connecting to an alveolus. Moreover, this geometry is not passive and air is bringing into and out of the bronchial branching tree by dilatation and contraction of the alveoli, which act as little pumps (Mauroy 2005, 2003 in [45] and [46]). The factors that might determine the parameters on bronchial and arterial bifurcations have recently paid enough attention, and the local bifurcation characteristics have been proposing to determine scaling laws for some biologically important variables (West 1997, [90]). Many studies of the bifurcation parameters depend on ordering schemes (West 1997, Murray 1926, Uylings 1977 and Horsfield 1976; [90], [59], [86] and [26]) which, although usefully for certain purposes, do not directly consider the dependence of the angular bifurcation parameters on the scale. The goal of the present dissertation is to furnish explicitly relationships on Reynolds number’s dependence of bronchial bifurcation asymmetrical angles, as well as versus bronchial tube’s diameter, airflow-temperature and viscosity of blood or air medium. The studies are focusing on the right main bronchus, especially. The left main bronchus angular parameter were obtained by simply measuring with a digital goniometric device or protractor, each of the three most interesting natural angles of arisen adjacent ramifications, referenced to the tracheal symmetry-axis, downwards oriented. The whole angle amount between left bronchus and tracheal axis was good enough approximated by calculating the middle value of the above mentioned three main ramification angles as they in chapter 4 depicted are. This approaching of the above problematic is a truly alternative to the previous observations (Phillips and Kaye 1997, [63]) on the formed angles within human bronchial tree, not predicted in the past theoretical models, they having unfortunately a qualitatively character, only. To answer these objectives, I developed an expert-system program entitled VLI- ESPSYS, which is basing on an innovative self-developed implementation on the Microsoft EN_CHANGE message concept to perform correct interchanging dialogs between different edit- and spin control fields. This program covers three specific thematic: two on bio-medical engineering and one of the industrial airflow in closed pipes. The working model of the respiration tree in Man is basing on the natural

International thesis/dissertation

Facoltà: Bio-Medical Engineering

Autore: Vincentiu Ionescu Contatta »

Composta da 177 pagine.

 

Questa tesi ha raggiunto 45 click dal 08/04/2008.

Disponibile in PDF, la consultazione è esclusivamente in formato digitale.