Instructions for Use: GEV019-100
Page 19
5
User Interface
5.1
Gas Control Knobs
FiO
2
Mixture:
The FiO
2
mixture (Air Oxygen Mix) control is located on
the front panel of the enclosure. This controls the
Air/Oxygen mixture being fed to the patient. The
internal circuit mixes the two gases under pressure and
delivers the mixture to the flow control circuit. The
control of this mixture is simple and should be set
initially before start of the ventilation phase. FiO
2
can be
adjusted at any time.
CAUTION
Oxygen concentration (%) delivered may vary from
the % indication oxygen shown on the control knob
depending on oxygen gas supply pressure and flow.
To operate FiO
2
Air Oxygen Mixture control knob:
Gas Flow Control:
The Gas Flow control valve is located on the front panel
of the enclosure. This controls the rate at which the gas
is injected into the system. The gas is pressurised and
released across an orifice to generate a highly
reproducible flow rate. This flow rate dictates the Vti
when measured over time. Also, it dictates the slope of
the inflow during the inspiration flow.
Lower flow rates produce flatter inflow curves as well
as having the added advantage of lower peak pressure
being achieved above the plateau pressure. The peak
to peak variability of the pressure during pressure hold
function is also reduced with lower flow rates. If lower
peak pressure is required then low flow rates with
longer inspiration times will give the best result.
