GE Datex-Ohmeda Aisys Carestation, Справочное руководство

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Aisys
2-36 04/08 M1046983
2.11 Gas flow through the anesthesia machine
2.11.1 Overview
Refer to Figure 2-27 and Figure 2-28.
Gas supplies
Gas comes into the system through a pipeline ( 1 ) or cylinder ( 6 ) connection. All
connections have indexed fittings, filters, and check valves (one-way valves). Pressure
transducers monitor the pipeline (
2 ) and cylinder ( 7 ) pressures.
The O
2
supply failure alarm is derived from the O
2
pipeline and the O
2
cylinder pressure
transducer inputs.
A primary regulator ( 8 ) decreases the cylinder pressures to approximately pipeline
levels. A pressure relief valve ( 3 ) helps protect the system from high pressures.
To help prevent problems with the gas supplies:
• Install yoke plugs on all empty cylinder connections.
• When a pipeline supply is adequate, keep the cylinder valve closed.
Gas flow
Pipeline or regulated cylinder pressure supplies O
2
or Air directly to the ventilator
engine ( 4a or 4b ) and as pilot pressure ( 4 ) for the SCGO
assembly ( E ). Connection points are also available for venturi
suction ( 5a or 5b ) drive gas supply. An additional O
2
regulator ( 18 ) decreases the
pressure for the O
2
Flush valve ( 19 ) and the auxiliary O
2
flowmeter ( 24 ).
The O
2
Flush valve supplies high flows of O
2
to the fresh gas outlet ( 22 or 23 ) through
the SCGO/ACGO assembly ( E/F ). The flush pressure switch ( 20 ) monitors activation of
the flush valve.
Gas mixing
Under normal conditions, with the system switch ( 10 ) in the On position, the Alternate
O
2
Disable valve ( 13 ) is energized to block alternate O2 flow. Normal gas flows are
enabled through their respective selector valves ( 11 ). The system controls gas flow
through the flow control valves ( 12 ) and derives the individual flow rates through the
hot-wire anemometers ( 14 ).
Under system failure conditions (or if Alt O
2
is selected), the normally-open Alternate
O
2
Disable valve ( 13 ) allows delivery of O
2
through the Alternate O
2
Flowmeter when
the system switch is in the On position.
Mixed gas
The mixed gas ( 15 ) flows through the electronic vaporizer ( D ) to the
SCGO/ACGO assembly ( E/F ). A pressure relief valve ( 17 ) on the electronic vaporizer
limits the maximum outlet pressure.
The SCGO assembly ( E ) directs the mixed gas to the selected circuit:
22 (ABS-circle) or 23 (to Inspiratory port of ABS). On SCGO assemblies, a relief valve
( 21 ) limits pressure in the breathing system to approximately
150 cmH
2
O.
The ACGO assembly ( F ) directs the mixed gas to the selected circuit:
22 (ABS-circle) or 23 (external ACGO port).