Fluke VT Plus HF, Operator'S Manual

Page: 76 / 134

VT Plus HF
Operators Manual
6-12
5.
Assist Test
The assist test is used to determine the sensitivity of the ventilator in patient assist mode
and to calibrate the full range of assist pressures under which the ventilator can operate.
During an assisted breath, the airway pressure drops during the inspiration due to the
"spontaneous" breath.
Figure 6-1: Normal breath versus an assisted breath. The assist is triggered by a
negative pressure (relative to the end-expiratory pressure) during the expiratory
hold period.
To perform an assist test:
1. Press the
FULL
key to bring up the
FULL TEST
screen.
2. Connect the ventilator breathing circuit with the VT PLUS HF in the bi-
directional measurement configuration.
Outlet Inlet
Ventilator
Inspiratory Hose
Expiratory Hose
VT PLUS HF
TEST
LUNG
fig2-1.eps
Figure 6-2 Ventilator Breathing Circuit setup for Bi-directional measurements.
3. Adjust the ventilator controls so that an effort (negative pressure) at the
lung during the expiration hold period of the ventilator's breath cycle will
trigger the ventilator.
Note:
Use the Synchronized Intermittent Mandatory Ventilation (SIMV) mode
or Intermittent Demand Ventilation (IDV) mode if the ventilator
provides it.
Note:
You will need to test the control setting by applying upward force at the
back of the test lung and observing if the ventilator triggers as desired.