Siemens Servo i, Руководство по обслуживанию, Страница: 20 / 70

Siemens-Elema AB
Description of functions Servo …
E382 E407E 061 01 01 02
3 - 4
3
Nozzle unit
The plastic N
OZZLE
U
NIT
contains a valve diaphragm.
The valve diaphragm, controlled by the I
NSPIRATORY
S
OLENOID
, regulates the gas flow through the G
AS
M
ODULE
.
The complete plastic nozzle unit must be replaced
during the ”Preventive maintenance”.
After replacement, allow the diaphragm to settle
during approx. 10 minutes before gas pressure is
connected to the G
AS
M
ODULE
.
Inspiratory solenoid
The gas flow through the G
AS
M
ODULE
is regulated by
the I
NSPIRATORY
S
OLENOID
via the N
OZZLE
U
NIT
.
The current supplied to the solenoid is regulated so
that the gas module will deliver a gas flow according
to the settings on the User Interface.
Gas module key
The G
AS
M
ODULES
are provided with a mechanical key
to prevent that the module is mounted in the wrong
slot.
The key consists of a plastic guide mounted under-
neath the module and a corresponding guide
mounted in the patient unit.
Connector muff
The C
ONNECTOR
M
UFF
connects the G
AS
M
ODULE
outlets
to the I
NSPIRATORY
P
IPE
inlet.
Inspiratory pipe
The I
NSPIRATORY
P
IPE
leads the gas from the C
ONNECTOR
M
UFF
to the I
NSPIRATORY
O
UTLET
.
The I
NSPIRATORY
P
IPE
comprises:
• Housing and locking lever for the O
2
C
ELL
with its
bacteria filter.
• Housing for the S
AFETY
V
ALVE
.
• Connection for measurement of inspiratory
pressure.
The pipe is provided with internal flanges with the
purpose to improve mixing of O
2
and Air.
O
2
cell
The O
2
C
ELL
is mounted in a housing on the I
NSPIRATORY
P
IPE
and is protected by a bacteria filter.
Maintenance including exchange of bacteria filter
according to the User´s manual. The bacteria filter
must also be replaced during the ”Preventive
maintenance”.
The O
2
cell gives an output voltage proportional to the
partial pressure of oxygen inside the Inspiratory pipe.
At constant ambient pressure this output is
proportional to the O
2
concentration in percent. In
each O
2
cell, the output signal will stay at a fairly
constant level usually within 10–17 mV in normal air
and at standard barometric pressure during the life
time of the cell. The cell should be replaced when the
output level has started to decrease. In this situation,
repeated calibration (i. e. Pre-use check) of the O
2
concentration is required. The life time of the cell is
affected by the O
2
concentration. With a
concentration (at the cell) in % and expected cell life
time in hours the following applies at 25
o C (77 o F):
O
2
Conc. x Expected cell life = 500 000% hours.
The O
2
cell is automatically calibrated each time a Pre-
use check is performed (if O
2
is connected to the
ventilator).
An ID PROM is integrated into each O
2
cell. Its ID
information and remaining lifetime can be read by the
Servo
… System.
Temperature sensor
A T
EMPERATURE
S
ENSOR
is integrated into the connector
on top of the O
2
C
ELL
. This sensor measures the
temperature inside the I
NSPIRATORY
S
ECTION
.
The output signal, corresponding to the temperature
in the I
NSPIRATORY
S
ECTION
, is used for regulation of the
I
NTERNAL
F
AN
.
Inspiratory pressure tube
The I
NSPIRATORY
P
RESSURE
T
UBE
connects the I
NSPIRATORY
P
IPE
with the I
NSPIRATORY
P
RESSURE
T
RANSDUCER
.
A bacteria filter protects the pressure transducer on
PC 1781 P
RESSURE
T
RANSDUCER
from contamination.
Maintenance including exchange of bacteria filter
according to User´s manual. The bacteria filter must
also be replaced during the ”Preventive
maintenance”.