In experiment 2, the time between successive maneuvers was varied (<1 min, 2 min, 5 min, 10 min, 15 min, and 20 min). The first ATS standard waveform was forced through the sensors, but five consecutive repeats, instead of ten (as in experiment 1), were conducted. This experiment was repeated on four different flow sensors and results were averaged for the four sensors Here canadian health and care mall. In both experiments 1 and 2, the flow sensors were flushed with room air and allowed to cool to ambient temperature before repeating the ten (five) consecutive maneuvers.
In experiment 3, to obtain a range of flow sensor (ceramic element) temperatures and a larger range of flows and volumes, 11 different ATS standard waveforms (1, 2, 3, 4, 12, 15, 17, 18, 21, 23, and 24) were forced through the sensor with less than a 2-min wait between consecutive simulated FVC maneuvers. The flow sensor was then flushed with room air and allowed to cool before the 11-waveform sequence was repeated (5 replicates).
In experiment 4, one flow sensor was cooled overnight to approximately 0°C and then tested in a fashion similar to experiment 3. These tests were conducted almost immeidately after the flow sensor had been removed from the cool environment, before the room environmental temperature (20°C) could significantly increase the temperature inside the ceramic element. The same 11-waveform sequence (1—*“24) was performed once and then the 11 waveforms were immediately repeated in reverse order (24—*-1). These tests provided lower exit air temperatures for our regression of percent difference in FEVi (equation 1) vs 1-s exit air temperature. For the regression analysis, all of the data from experiments 1 through 4 were used. Linear regression analysis consisted of a linear least squares fit to these data using a software package (MATLAB, The MathWorks, Inc; Natick, Mass). In experiment 5, six subjects performed five coached FVC maneuvers on a dry rolling seal spirometer and, after a brief rest period, three additional FVC maneuvers on the flow spirometer using a ceramic flow sensor. Subsequently, repeated FVC maneuvers were self-administered by the subjects on a portable flow spirometer every 2 h while awake for up to 12 days. The subjects were instructed to perform at least three FVC maneuvers at each test session.