Maquet Servo ventilator 900 C, Руководство по обслуживанию

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Electronic unit – Reference level generation
Ref. level adjust
(front panel; INSP. TIME % selector)
In this block, the constant (n5V) value from INSP.
MINUTE VOLUME REF. LEVEL is converted into INSP.
TIME ADJUSTED REFERENCE LEVEL by the voltage
divider on the front panel selector.
The square wave reference signal as well as the
accelerating flow reference signal is inversly propor tional
to the preset INSP. TIME %, since a constant tidal volume
(area) should be maintained regardless of the setting of
the INSP TIME % front panel knob. See dia gram.
If the set respiratory rate increases, the tidal volu-
mes decreases, so that a constant minute volume
is maintained regardless of the respiratory rate. See
diagram.
Constant flow pattern (PC board no 5)
Inputs are INSP. TIME ADJUSTED REFERENCE LEVEL and
the digital control signal INSP. TIME.
The output, (V23:8), is the reference value (negati-
ve) used in the block ACCELERATING FLOW PATTERN
and during INSP. TIME as a reference value (V31)
CONSTANT FLOW PATTERN to the INSP. FLOW ERROR
CALCULATOR and to the VOLUME COMPENSATOR.
Accelerating flow pattern (PC board no 5)
The reference signal (V23:1) ACCELERATING FLOW
PATTERN is generated during INSP. TIME.
The accelerating flow pattern reference signal rises
with a constant slope (staircase generator) during the first
two thirds of the ispiration time. During the remainder of
the ispiration time, the reference signal decreases. See
the diagram, in which the corresponding CONSTANT
FLOW PATTERN reference signal is also indicated.
The maximum amplitude (B) of the accelerating flow
signal is approximately 50% higher than the amplitude
(A) of the square-wave shaped signal. NOTE! Both on the
front panel and in the diagrams, the square-wave shaped
flow reference signal and the accelerating flow reference
signal are represented as positive-going signals. In
reality, these signals are negative-going.
= Not valid for SV 900 E
= Not valid for SV 900 D
Accelerating flow pattern (PC board no 5)
The reference signal (V23:1) ACCELERATING FLOW
PATTERN is generated during INSP. TIME.
The accelerating flow pattern reference signal rises
with a constant slope (staircase generator) during the first
two thirds of the inspiration time. During the remainder
of the inspiration time, the reference signal decreases.
See the diagram, in which the corresponding CONSTANT
FLOW PATTERN reference signal is also indicated.
The maximum amplitude (B) of the accelerating flow
signal is approximately 50% higher than the amplitude
(A) of the square-wave shaped signal. NOTE! Both on the
front panel and in the diagrams, the square-wave shaped
flow reference signal and the accelerating flow reference
signal are represented as positive-going signals. In
reality, these signals are negative-going.
Insp. time
Time
A
B
2/3 of insp. time
Flow