SLE 2000 HFO, Service Manual

Page: 49 / 258

Issue 10 (01/10/2004) Page 49 of 258
12. Stage 3: Pneumatic Module Final Setup
Monitor the proximal airway pressure with a standard test manometer. With the PIP regulator
turned fully anticlockwise, turn CPAP regulator fully clockwise and ensure that the CPAP
pressure exceeds 35cmH
2
O. Turn CPAP regulator fully anticlockwise and check that the
airway pressure is now less than 1cmH
2
O.
Set high pressure alarm fully clockwise. Turn PIP regulator to its maximum clockwise position
and the CPAP regulator fully anticlockwise. With air and O
2
pressures at 4Bar and the
inspiration time control set to 3.0 seconds, press the manual breath pushbutton and ensure
that the PIP pressure exceeds 60cmH
2
O. Then reduce air and O
2
input pressures to no
greater than 3.5Bar ensuring PIP pressure is at least 50-52cmH
2
O.
Connect oxygen analyser to fresh gas supply and by adjusting the blender control in 10%
steps, verify that the oxygen output is accurate to within ±3% of each step.
With the blender set to 60% O
2
, increase the air supply pressure to the ventilator and note that
the blender alarm is activated when air pressure is approximately 30psi greater than O
2
pressure. Gradually reduce air pressure until the alarm is de-activated. Note that O
2
concentration is between 57% and 63%. With the blender set to 60% O
2
, decrease the air
supply pressure to the ventilator and note that the blender alarm is activated when the air
pressure is approximately 30psi less than O
2
pressure. Gradually increase air pressure until
the alarm is de-activated. Note that O
2
concentration is between 57% and 63%. Restore air
pressure to 4 Bar.
Remove test lung from patient circuit and occlude the ET port.
Switch to HFO expiratory mode. Select an oscillatory rate of 3Hz, and turn the oscillator
pressure regulator fully clockwise. Verify that the resulting pressure wave as viewed on the
LCD display is at least ±45 cmH
2
O in amplitude.
Loosen the two screws locating the tachometer chopper wheel bracket. With the HFO still
running, adjust the assembly up and down in its slots to establish the two positions where the
pressure wave is de-activated by SV4. Position the assembly half-way between these limits
and re-tighten the bracket screws.
Reduce the oscillator pressure to ±10cmH
2
O and adjust the oscillator frequency to 10Hz. Refit
the test lung to the patient circuit and set the ventilator to CMV. Verify that solenoid valve SV4
operates to provide oscillation during the expiratory phase of the breath only.
Switch to HFO inspiratory mode and verify that oscillation occurs during the inspiratory phase
of the breath only. Finally, check for continuous oscillation ( i.e. in both expiratory and
inspiratory phases) when switched to HFO continuous mode.