LTV 1150 - Test Lung Operation

p/n 18603-001, Rev. C LTV
®
1200/1150 Ventilator Service Manual Page 7-43
Test Lung Operation
Symptoms Possible Causes What to Do
Delivered pressure
higher than set
pressure on test lung.
Pressure> 40 cmH
2
O used
on small test lung
(Pulmonetic Systems or
Siemens 190.)
The compliance characteristics of some
small test lungs (Pulmonetic Systems or
Siemens 190) cause incorrect readings
when high pressures are used. For these
lungs, use pressures under 40 cmH
2
O or
change to a larger lung.
Test lung with small
aperture connected directly
to wye.
Some test lungs have a narrow opening or
a restrictor which may cause jetting and
cause the flow differential to be read
incorrectly. To reduce the jetting effect,
add a short extension between the test
lung and the wye if clinically advisable.
Monitored volumes
very high on test lung.
Very small ET tube
connected directly to wye.
A very small ET tube connected directly to
the wye may cause jetting and cause the
flow differential to be read incorrectly. To
reduce the jetting effect, add a short larger
bore extension between the ET tube and
the wye if clinically advisable.