Welch Allyn CP 200, Directions For Use Manual

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Directions for Use Glossary 81
pre-test. A test that provides a baseline for comparison with a post-test taken by the same patient.
Sometimes called pre-Rx or pre-BD (bronchodilator). Pre-tests and post-tests are commonly used to
evaluate the effectiveness of medication. See also reversibility .
reversibility. The percentage difference between pre-test and post-test data. This measurement indicates
the effect of medication on lung function. Reversibility applies to each parameter separately. The
reversibility formula, which determines the way in which reversibility is calculated, is user-selectable.
SVC. Slow (relaxed) vital capacity. (1) A type of test in which patients breathe normally several times, then
inhale maximally and exhale maximally, or vice versa. Sometimes SVC testing is used when forced
breathing is impossible. The patient inhales and exhales as completely as possible, as in FVC testing,
but the breathing is not forced. The goal of an SVC effort is to measure the volume of air inhaled and
exhaled, not the air flow (speed). (2) An important parameter (in liters): the maximum volume of air
exhaled from the point of maximum inhalation, or maximum volume of air inhaled from a point of
maximum exhalation.
test. A set of efforts — up to 6 efforts of each type (FVC and SVC) for a maximum of 12 efforts (6 FVC and
6 SVC). The 6 efforts of a given type can be a mixture of pre-medication and post-medication efforts.
Tex. Tidal breathing expiration time (in seconds). See also tidal breathing .
tidal breathing. Multiple breaths, normal breathing. May be used during FVC or SVC testing. After
measuring tidal breathing for several seconds, the following parameters can be extrapolated: MV, VE,
BF, and Tin/Tex. If you combine a VT measurement with a VC measurement, you can also calculate the
ERV, IC, and IRV. For example, COPD patients have a higher ERV and a lower IC and IRV.
tidal volume. See VT .
tidal volume curve. A flow loop that includes all data from all breaths, tidal and forced.
Tin. Tidal breathing inspiration time (in seconds). See also tidal breathing .
Tin/Tex. The ratio of Tin and Tex. See also Tin and Tex .
TV. See VT .
variance. The difference between the best and worst efforts for a parameter (FEV1, FVC, and so on). Pre-
test and post-test variances are reported separately. See also best effort .
VC. Vital capacity. See FVC or SVC .
VE. Ventilation in L/min. See also tidal breathing .
vital capacity. See FVC or SVC .
volume = f(t). See volume/time .
volume/time. Same as volume over time or volume = f(t) . A type of data curve available during both FVC
and SVC testing. The y axis represents liters; the x axis represents seconds.