Specifications

7 Theory of Operation and Specifications
1006-0939-000 7-13
7-13
Breathing system
There are two types of breathing circuit modules (Figure 7-8):
1. Circle
2. Mapleson D or Bain (With Mapleson D/Bain circuits one flow sensor measures
Inspiratory and expiratory flows. The other measures fresh gas.)
Tabs on the circuit modules fit into infrared switches on the breathing system bulkhead.
The ventilator uses these switches to identify the circuit module.
Direct fresh gas
connections
(common and
auxiliary outlets)
When you make a direct connection to one of these outlets:
•Mechanical ventilation is not available.
• The pressure gauge, Bag/Vent switch, APL valve, and bag arm are not part of the circuit.
• Volume and pressure monitoring are not available.
• Flow from the auxiliary outlet to the O
2
sensor is:
Module Patient Circuit
Connections
One-Way Valves
Circle Left: inspiratory
Right: expiratory
Inspiratory and expiratory check
valves
Mapleson D/ Bain Left: to-fro
Right: fresh gas
None
3 L
2L
1 L
10
20
30 40
50 60 70 80
cmH
2
O
Back pressure vs. flow to O
2
sensor