[The function of respiratory muscles in healthy persons during tube breathing].

Background: Tube breathing (added dead space of 600 ml) stimulates ventilation by hypercapnia and is proposed as a new test of respiratory chemosensitivity. In this study the increase of respiratory work during tube breathing was evaluated by two methods.

Methods And Results: In the first one respiratory values were measured and the rate of respiratory work was calculated according Otis, Crosfill and Widdicombe.

[Does exogenous airflow resistance reduce endogenous airway resistance in healthy persons?].

The aim of our investigation was to assess whether a preinserted model resistance of a certain magnitude will expand the airways during inspiration and thus reduce the resistance of the airways conceived as the sum of the value of the endogenous airway resistance without obstruction and the value of the exogenous pre-inserted model resistance. The model resistance and resistance of the airways were assessed by means of a whole-body plethysmograph. The airway resistance was evaluated in 10 healthy men during inspiration and expiration, using a dictated breathing pattern.

[Glomerulonephritis in sarcoidosis].

The renal involvement in sarcoidosis can be demonstrated as nephrocalcinosis, nephrolithiasis, granulomatous nephritis, and glomerulonephritis. The clinical signs of a renal manifestation are inferior than the morphological findings, so that the reported frequency of 9-25% is an approximate value. In the literature the glomerular changes are rare.

Collection of data in investigations done in the Research Institute's laboratory of the clinical physiology of breathing, and their computerization.

The authors discuss the problem of the need for and utilization of a computer in the research and clinical laboratory, of the Research Institute's department of the clinical physiology of breathing. They report on their own way of an economical use of computers for the collection, storage and evaluation of data. Most important is a uniform approach to the arrangement of data in the databank, which makes it possible, even with a different number and type of data about the patients examined and with different kinds of sets, to use a wide range of statistical, computing, sorting and graphic methods without any modifications and without the development of new programmes.

Fibrocapnography in the control of the respiratory airways passage.

With the authors' method of a fibrobronchoscopic investigation using a translucent catheter in the fibrinoscope Olympus with an operational channel of 1.9 mm there were determined in 8 patients in the sitting position possibilities of estimating the degree of free passage in the respiratory tract. Patients with relapsing bronchial inflammations were examined before and after the aspiration of bronchial secretions that was restricting the passage in the respiratory tract prior to the investigation.

Importance of mathematical models and multivariant statistical analysis for the diagnosis of ventilation disorders.

The authors present results of a comprehensive, mostly mathematical, solution of problems of the mechanism of breathing and ventilation. The need for a multivariant approach is based on the knowledge of disorders of the individual factors influencing ventilation. The authors are convinced that this approach means a useful contribution to the establishment of diagnosis and to economization of treatment.

Influence of the speed of expiration on the magnitude of the total resistance (Rt) assessed by means of a whole-body plethysmograph.

The authors demonstrate by comparing results of the mathematical model FMAR 8G and curves recorded during examination by means of a whole-body plethysmograph the influence of the expiration speed on value Rt in patients with an altered elasticity in the alveolar area and with an enhanced collapsibility of the respiratory pathways.

Simulation of human reactions under extreme conditions.

Lung mass determination in cooperative subjects is possible by computation from the "flow-volume" loop, if total lung resistance (Raw) is known. The model is applicable to tracking changes in weightlessness. Modifications for improving the result are discussed.

[Longitudinal control of a selected group of young men in view of chronic bronchitis incidence (author's transl)].

Report on a prospective longitudinal study of a group fo 16 years old men of Prague, followed up to 6 years. Every two years questionnaires were checked and fluorography, ECG and breathing function tests had been done, too. The group of 341 young men, whose data were complete, had been divided into smokers and nonsmokers, in students and apprentices as well as in healthy persons and people, who suffered from chronic bronchitis.

The problem of airways collapse during expiration.

In this work there are described two models of breathing mechanics which are aimed to the collapse problem of airways during expiration. The first model (FMAR 7) in the solution respects only the resistance problem of the airways walls against the ambient pressure. The second model (FMAR 8) takes account of the influence of elasticity of alveolar walls.

The influence of endobronchial fluid on the ventilation.

We evaluated the influence of 2 0ml contrast substance Dionosil aq. on the ventilatory function of lung 21 patients who suffered from relapsing bronchial inflammations. The spirographic examination before the local anaesthesia was accomplished with Vitalograph apparatus, the same examination after local anaesthesia of 3 ml 3% cocaine and 60 mg lidocaine and after the bronchoscopy and bronchography and simultaneously was made the bronchocinematographic recording.

[An unhomogeneous model of the respiratory mechanics (author's transl)].

Mechanics of the respiratory system was simulated on analogue computer by a two-compartmental model. Each compartment expresses a functionally (not anatomicall) different part of the lungs, corresponding to some unhomogeneity within the system. The influence of this unhomogeneity on characteristics parameters of the lung (resistance, compliance) was analysed in simulated experiments.

Results of simulation of non-homogeneous ventilatory mechanics for a patient-computer arrangement.

A model of the ventilatory mechanic system was realised on the MEDA TC 41 analogue computer; it consists of 2 structurally identical compartments, differing in the values of their coefficients. By changing the values of coefficients and the relations between the 2 compartments, it was possible to simulate the non-homogeneity of a real, pathologically-changed system of the body afflicted by disease. Complex resistance loops with phase shifts.