4
Estimated Tidal Volume
The estimated tidal volume is a calculated value, based on time and calibrated flow
values. The constant leak through the breathing circuit exhalation port is subtracted
from this calculation to give a reasonably accurate estimation of tidal volume. The
estimated tidal volume is displayed above the bargraph display.
Inspiratory Trigger
The NIPPY ST+ employs flow triggering, detecting the start of the patients inspiratory
effort when the flow rate exceeds the level set by the Inspiratory Trigger sensitivity.
Expiratory Trigger
The expiratory trigger is used in Pressure Support mode only. Towards the end of
inspiration, when the inspiratory flow rate drops to the baseline (standing flow caused
by exhale port leak) minus the expiratory trigger sensitivity the ventilator will cycle into
the expiratory phase.
The inspiratory and expiratory effort required to cycle the ventilator can be adjusted
via the Trigger option in the Menu.
For simplicity the trigger sensitivity is scaled 1
– 10, with 1 requiring the least patient
effort and 10 requiring more patient effort.
