(10) Self-test device. The self-test device (C in figure 1-7) is a spring-loaded
rolling diaphragm in a housing. The spring holds the diaphragm collapsed. On the
ambient side of the diaphragm is an indexed shaft which slides within a calibrated
transparent tube. The area to the rear of the diaphragm and reset spring is such that a
mechanical approximation of an infant lung is created. A functional volume display from
0 to 40cc is incised in the tube to demonstrate tidal volume of gas mixtures delivered to
the patient. The self-testing device is used to demonstrate the controlled IMV mode of
operation, or to provide a functional checkout of the ventilator. Individual operator
proficiency can be raised by practicing with this device.
c. Breathing Circuit. The breathing circuit (figure 1-8) is powered by five power
source sockets, indexed A through E. Each socket is carefully labeled to prevent
(1) Tee connections. There are two important tee connections. The master
tee (item 3, figure 1-8) mates with the pin-indexed quick-disconnect adapter in only one
position. The nebulizer mounting tee (item 1, figure 1-8) serves two purposes. The
inside therapy bifurcation (two routes) provides for attachment of the Bird micronebulizer
to the rear port.
Figure 1-8. Breathing circuit.