Once tidal breathing is complete the
display will change and an audible beep
heard to instruct the patient to start rapid
fast breathing. The start button should
be touched using the stylus to start
registering the MVV manoeuvre.
The current manoeuvre will be displayed
in black, during the manoeuvre the breath
rate (BR) will be displayed in green if the
breath rate is acceptable (> 65 breaths
per min) if the breath rate falls below this
level it will be displayed in red to show
the operator that the patient needs to
be instructed to breath harder and faster
during the manoeuvre. After 12 seconds
of hard, fast and rapid breathing the
display will show a green line indicating 12
seconds of the manoeuvre have elapsed
– the patient should be encouraged to
continue until the display changes to
signify the end of the test. The MVV rate,
the % variation between manoeuvres the
breath rate and an ATS quality warning for
the manoeuvre will be displayed.
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