Instructions for Use: GEV019-100
Page 11
4
System Overview
4.1
Operating Concept
In principle, the operation of the lung comprises the Inspiration and Expiration of air from the lungs. To achieve the best outcome
for the patient it is necessary to break down the operation into the component functions. Refer to the Process Flow Diagram for
reference as per the description below.
The GeVentor is designed to initialize the inspiration phase through the variable timer #1 (T1) which drives a solenoid valve that
in turn allows pressure regulated oxygen to activate the main Expiration Valve (V1), located at the left-hand side of the GeVentor.
This valve holds the pressure in the lungs and pressure transmitter (Pt1) ensures this pressure is achieved and maintained. The
Gas Inflow Valve (V2) is simultaneously activated which allows pressure and flow volume (Tidal Volume - Vt) of gas to be controlled
into the lungs. Typical time values of 0.5 to 2 seconds.
T1 times out and V2 closes and stops the flow of gas to the lungs. V1 stays activated and continues to hold pressure in the lungs
for the hold period (T2). Typical time (variable by the CPM controller) is in the range 0.1
–
3.0 seconds. The hold time is not included
in the default settings. Inspiration time is set to 1 second and the I:E ratio is set at 1:2.5.
T2 times out and deactivates V1, T3 activates, and times the expiration phase, the gas is released from the lung to flow back
through the mechanical PEEP which ensures PEEP (positive end expiratory pressure) pressure does not drop below the set pressure
prescribed and set on the PEEP valve.
Ventilation Modes:
Volume Controlled Ventilation (VCV)
Pressure Controlled Ventilation (PCV)
To facilitate patient ventilation and oxygenation, operators of the GeVentor can simply add the height and sex of the patient to
the unit settings and the unit will automatically calculate the default settings for Vti. RR and I:E are default and flow rate and FiO2
are set manually.
This is called the Quick Start Mode (QSM)
•
Volume Controlled Ventilation and Pressure Controlled Ventilation modes provided by this ventilator are mandatory
and intermittent
•
Volume Controlled Ventilation
•
Pressure Controlled Ventilation
•
Pressure Controlled / Hold
•
Suctioning
•
CPAP
The GeVentor can always remain pressurised. The pressure is maintained by the PEEP (Positive End Expiratory Pressure). PEEP is
set and adjusted by the operator on the right-hand side of the unit. The PEEP valve is a manual setting. If PEEP is not required, the
PEEP valve is simply removed from the unit.
For airway pressure safety, mechanical failsafe valves are incorporated into the GeVentor design.
A mechanical pressure relief valve (PRV) is located on the main manifold of the unit preventing over-pressure events from being
generated by the high-pressure delivery unit. Electronic pressure sensing on the patient circuit allows instant actuation of pressure
relief through the GeVentor Expiration valve.
