Subjects were asked to breathe quietly, with the nose occluded, through a mouthpiece connected to the
pneumotachograph (Fleish Lausanne, Switzerland) with a two-way low- resistance breathing valve (0.9 cm[H.sub.2]Ox[L.sup.-1] s, dead space of 50 ml, model 9340 occlusion valve, Hans Rudolph inc, Kansas City, Missouri, U.S.A).
USA) that was calibrated according to the manufacturer's recommendations and a
pneumotachograph (2 to 30 L x [min.sup.-1]).
Respiratory gas exchange was sampled from a mouthpiece connected to a medium flow
pneumotachograph (Medgraphics, Minnesota, USA) and a gas analyzer (V02000, Medgraphics, Minnesota, USA), calibrated before each test with gas standards of known concentrations [oxygen ([O.sub.2]) = 12.0%; carbon dioxide (C[O.sub.2]) = 5.3%].
Sciurba, "The accuracy of
pneumotachograph measurements during mechanical ventilation," American Journal of Respiratory and Critical Care Medicine, vol.
Cough volume acceleration is difficult to measure clinically as it requires a
pneumotachograph and related equipment.
Artificial thorax chamber pressure was measured with a differential pressure transducer (Validyne DP 45-24, Validyne Engineering, Northridge, CA, USA), and airflow velocity with a
pneumotachograph tube connected to the differential pressure transducer.
Respiratory air flow was measured by a
pneumotachograph (Hans Rudolph RSS 100 0-160 L/min) attached on a facemask (Respironics Spectrum medium size).
Computerized flexiflow machine with
pneumotachograph was used to perform the dynamic PFTs.
Flow was measured with a heated
pneumotachograph (Ventrak 1550, Novametrix Company, USA) connected to a differential pressure transducer inserted between the Y-piece of the ventilator circuit and the endotracheal tube.
Breathing patterns were monitored using a Buxco mouse
pneumotachograph with a Buxco pressure transducer coupled to automated Iox 2 software (emka TECHNOLOGIES S.A.S).
the reduction of the mass of the bell and the addition of graphic and timing devices), and the Fleisch
pneumotachograph is also widely used in modern commercial analysers.
Expiratory flow-volume curves were recorded by a spirometer with a
pneumotachograph sensor (Model ST90, Fukuda Sangyo Co.