Respironics ESPRIT, Руководство по обслуживанию, Страница: 18 / 329

Chapter 3
3-4
Esprit® Ventilator Service Manual © Respironics, Inc. REF 580-1000-02 G
Theory of Operation
Cooling Coil The cooling coil is a copper tube connected to the outlet of the blower
that reduces the temperature of the gas from the blower before it
reaches the air valve.
Cooling Coil Fan The 24 V DC cooling coil fan removes the heat dissipated by the cooling
coil and blower.
Air Valve Assembly
(AV) The air valve assembly contains a stepper motor that meters air flow
from the blower to achieve the target flow under CPU control, based on
operator selected parameters. It can deliver up to 200 LPM of flow.
Air Flow Sensor (FS1) The air flow sensor measures flow from the air valve. The ventilator uses
this measurement to provide closed loop control of the air valve and to
compute the flow and volume delivered to the patient. A thermistor in
the flow sensor measures the temperature of the air and provides the
microprocessor with information to compensate the delivered flow.
Oxygen Inlet
Connector (O
2
)
The oxygen inlet connector provides a country-specific connection point
for an external oxygen gas supply of 40 to 90 psig (276 to 620 kPa).
Oxygen Water Trap/
Inlet Filter Assembly
(F2) The oxygen water trap/inlet filter assembly consists of a 5-micron (µ)
filter to remove particulate (both dry and liquid) from the oxygen gas
supply, a bowl with drain for accumulated water, and an oxygen inlet
connector.
Oxygen Supply
Pressure Switch (PS1) The oxygen supply pressure switch is part of the oxygen regulator. PS1
is a normally open (NO) switch that closes when measured pressure is
greater than 40 psig (276 kPa), and provides a digital signal to the
sensor PCB indicating whether supply pressure is adequate at the
oxygen inlet.
PS1 opens if measured pressure is less than 35 psig (241.3 kPa). If the
oxygen supply pressure switch opens during normal ventilation (at O
2
>
21%), a Low O
2
Supply alarm results.
Delivery System Components