The effect of measurement frequency on respiratory mechanics was investigated in six horses with reversible allergic airway disease. Total respiratory impedance was measured at 1.5, 2.0, 3.0, and 5.0 Hz by using the forced oscillation technique with the horses in remission, after acute antigenic challenge producing clinical heaves, and with heaves but after the administration of 2 mg fenoterol ...

By expressing the respiratory system as a two-compartment model and assigning a phasor in the complex plane to each impedance element in the model, the phasor of the respiratory impedance could be constructed graphically, the frequency characteristics determined from the locus of the latter and the effects of variations in the model elements on the frequency characteristics could also be expres...

HYPOTHESIS We hypothesized that there might be different effects on breathing control and respiratory mechanics after laparoscopic vs open cholecystectomy. DESIGN Randomized clinical trial. SETTING A general hospital in Greece. PATIENTS Of 53 patients assessed for eligibility, 18 and 10 were randomly allocated to the laparoscopic and open cholecystectomy groups, respectively. These 28 pat...

This study aims to elucidate the change in pulmonary function in stage 0 COPD patients. A total of 48 stage 0 COPD patients and 46 healthy adults were included in the study. The status of their pulmonary function was determined by an impulse oscillometry (IOS) system, and the spirometric indexes such as forced vital capacity, maximum expiratory flow-volume (MEFV) curve, total respiratory impeda...

The article deals with development, design and implementation of a mathematical model of the human respiratory system. The model is designed in order to simulate distribution of important intrapulmonary parameters along the bronchial tree such as pressure amplitude, tidal volume and effect of regional mechanical lung properties upon the efficiency of various ventilatory techniques. Therefore ex...

This report concerns the inference of geometric and mechanical airway characteristics based on information derived from a single transient planar wave recorded at the airway opening. We describe a new method to simultaneously measure upper airway area and respiratory input impedance by performing dual analysis of a single pressure wave. The algorithms required to reconstruct airway dimensions a...

Electrical impedance tomography (EIT), as a monitoring tool of regional lung ventilation, is radiation-free imaging with high temporal resolution. The most important purpose of EIT is to visualize the distribution of tidal volume in different lung regions especially between dependent (dorsal in supine patients) and non-dependent (ventral in supine patients) regions. Many clinical studies evalua...

A clinically useful diagnostic method has been developed for detecting and quantitating periods of apnea in pediatric patients. This procedure, called the pediatric pneumogram, permits the continuous recording on magnetic tape, for periods of up to 13 hours, of the respiratory pattern of infants utilizing an impedance technique. This test has been employed successfully in a variety of infants...

1. DuBois AB, Brody AW, Lewis DH, Burgess DF. Oscillation mechanics of lungs and chest in man. J Appl Physiol, 1956, 8, 587-594. 2. Michaelson ED, Grassman ED, Peters WR. Pulmonary mechanics by spectral analysis of forced random noise. J Clin Invest, 1975, 56, 1210-1230. 3. Peslin, Fredberg JJ. Oscillation mechanics of the respiratory system. In: Handbook of Physiology, Section 3, Vol. III. Mec...

In this contribution, a project task is presented for master students that follow the course on advanced control techniques. The aim of the project is to make students familiar with the non-parametric identification techniques – via spectral analysis. This method is usually very abstract, theoretical and un-appealing to the students. Therefore, an interesting application is proposed: identifica...