Siemens Servo Ventilator 300 - Page 52

50 Siemens-Elema AB E382 E380E 061 01 03 01
Description of functions Servo Ventilator 300/300A
2
Pressure regulation
For pressure regulation the signal PRESSURE
REGULATION
PRESSURE REF is used by the block 6.4
PRESSURE PID CONTROL.
Pressure regulation is used during inspiration
time when Flow regulation (as described
above) is not used. In this case the PRESSURE
REGULATION
PRESSURE REF , P
REF
used by the block
6.4 PRESSURE PID CONTROL during inspiration time
is generated as follows depending on the
mode in use.
Note  During Pressure regulation the above
mentioned slope at the beginning of
Inspiration time (when using Insp. rise time)
always starts at a pressure level = PEEP.
Pressure Control mode
The PRESSURE REGULATION PRESSURE REF signal will
adopt the value
P
REF
=
= PEEP+ Pressure Control Level
above PEEP
using values according to corresponding
settings from the main block 1 FRONT PANEL.
Volume Control mode
If on-demand-flow is activated the PRESSURE
REGULATION
PRESSURE REF signal will adopt the
value
P
REF
= PEEP
using PEEP value according to Front panel
setting.
Pressure Reg. Volume Control (PRVC) mode
and Volume Support (VS) mode
The value of PRESSURE REGULATION PRESSURE REF,
P
REF
is handled as the sum of two parts
according to the following addition:
P
REF
= PEEP+ P
IN USE
PEEP is the Positive End Expiratory Pressure
level according to Front panel setting and
P
IN USE
is an additional Pressure level above
PEEP.
P
IN USE
is assigned a new calculated value
each breath.
P
IN USE
keeps a constant value during each
inspiration time (except during Insp.rise time).
P
IN USE
is generally limited to fulfill the
following two conditions:
P
IN USE
> 0.1 cm H
2
O
(= minimum value for P
IN USE
)
P
REF
< P
max
 5 cm H
2
O
(implies a maximum value for P
IN USE
)
where P
max
= Upper pressure limit (Front
panel setting).
The value of the parameter P
IN USE
used during
breath number n (during inspiration number n)
is
P
IN USE (n)
= P
REF (n)
 PEEP
where P
REF (n)
is the value of the parameter
P
REF
calculated to be used during breath
number n (during inspiration number n).