Airway function is usually assessed by tests of forced expiration or, in more specialised laboratories, by measuring airways resistance by whole body plethysmography. Plethysmography depends on the patients' cooperation and requires expensive and bulky apparatus. An alternative non-invasive technique for measuring airflow resistance, using forced oscillation, was introduced by DuBois and collea...

PURPOSE Spirometry is sometimes difficult to perform in elderly patients and in those with severe respiratory distress. The forced-oscillation technique (FOT) is a simple and noninvasive method of measuring respiratory impedance. The aim of this study was to determine if FOT data reflect spirometric indices. PATIENTS AND METHODS Patients underwent both FOT and spirometry procedures prior to i...

BACKGROUND Impedance measurements by the forced pseudo random noise oscillation technique can be used to study the mechanical characteristics of the respiratory system. The objective of this study was to analyse the changes in impedance to a cold air provocation test in patients with asthma, and to correlate these changes with those in the forced expiratory volume in one second (FEV1). METHOD...

The forced oscillation technique (FOT) allows the noninvasive assessment of the mechanical properties of the respiratory system. Given that the technique does not require patient cooperation, it is suitable for the routine evaluation of respiratory function in a variety of clinical applications. In this paper, the rationale and the most conventional equipment and data processing of the techniqu...

Many studies have reported reference data for forced oscillation technique (FOT) in healthy children. The prediction equation of FOT parameters were derived from a multivariable regression model examining the effect of age, gender, weight and height on each parameter. As many of these variables are likely to be correlated, collinearity might have affected the accuracy of the model, potentially ...

This paper examines ‘functionally-based optimality theory’ (FOT), the version of optimality theory that requires that each constraint be paired with an external functional motivation. It argues that, at least as far as syntactic constraints are concerned, FOT suffers from severe deficiencies. Such a pairing incorrectly locates the form-function interplay in the mental grammar itself, rather tha...

Using differential magneto-optical imaging, we address the question of mesoscopic inhomogeneity in underdoped Bi2Sr2CaCu2O8 (Bi-2212) single crystals. Among other features, it is shown that an anomalous temperature dependence of the penetration field and of the first order transition (FOT) field of the vortex lattice in such crystals can be understood as arising from inhomogeneity. The effect o...

In a recent discussion concerning the use of the forced oscillation technique (FOT), PRIDE [ 1] stated that, although anaesthesia and intensive care are among the obvious areas of application of the method, there is very little information on these applications. The paper by PEsuN et al. [2] in the present issue of the Journal describes one of the first attempts to apply the FOT to mechanically...

This study was designed to determine whether nasal airflow resistance (Rn) which is nonlinear during tidal breathing, can be assessed by the forced oscillation (FO) technique. Rn values obtained by the FO technique and extrapolated to 0 Hz (Rn,FO) were compared to those assessed by posterior rhinomanometry at maximal tidal inspiratory flow (Rn,m), at a 0.5 L x s(-1) flow (Rn,F), and at a 1 hPa ...

The frequency dependence of effective resistance of the respiratory system was studied in seated and supine healthy subjects by use of a forced oscillation technique for the purpose of estimating the distribution of regional ventilation. Effective resistance determined at respective FRC levels of both these body postures fell with an increase in the breathing frequency, although the frequency d...