Fluke VT Plus HF, Operator'S Manual, Page: 77 / 134

Gas Flow Analyzer
6
6-13
Set a low breath rate to allow the distinction to be made between a
triggered assist breath and a mandatory breath.
Note:
You may wish to attach an external, motor-driven cam system, or a
pneumatic actuator to the top plate of the test lung to carry out a more
repeatable performance study, such as to determine work of breathing.
4. Allow ventilator to deliver breaths in a steady manner. Then, gently lift
the back of the test lung top plate during the expiratory hold period in a
smooth, steady pull to create negative pressure. Repeat several times
using different forces to approximate the minimum patient effort
required to trigger the ventilator.
The full test screen will show all the ventilator parameters. The minimum pressure and
the assist pressure are displayed on the lower left column.
6.
High Frequency Oscillator Mode
The VT PLUS HF has a function for testing high-frequency flow and airway pressure.
To access the high-frequency oscillator function, follow these steps:
1. Press the
MORE/4
key.
2.
Use the
∧
and
∨
soft keys to highlight
HIGH FREQUENCY
OSCILLATOR.
3. Press the soft key below
ENTER.
The high-frequency oscillator mode samples flow and airway pressure at a much faster
rate (5x) than the
VT PLUS HF does in normal operation. It is useful for monitoring the
function of extremely high-frequency breath rates, (up to 800 bpm). In HFO mode, the
VT PLUS HF collects two seconds worth of data at a time. After the data is collected, it
is processed to calculate parameters and the first half-second of data is plotted on the
display.
The mean, min, and max values are calculated for both the pressure and flow signals.
Please note that these values apply to the whole two seconds of data, not just the half-
second that is plotted. The breath rate is calculated and displayed in both breaths per
minute and Hz. The inspiratory time and tidal volume are also calculated.