Datascope - Mindray

Theory of Operation The Breathing System
1.9.5 Pneumatic PEEP
The PEEP valve regulates the pressure at which the exhaust valve opens, therefore the exhaust
valve opens only when the pressure exceeds the set PEEP pressure.
1.9.6 Ventilator in Standby
When the AS3000 is in the standby mode, monitoring will be inactive, The patient should
not be ventilated when the system is in standby mode.
1.9.7 Breathing System Components
1.9.7.1 Ventilation Bellows System
The ventilator's driving system is a flow generator. Driving gas fills the bellows dome to
compress the bellows. The breathing gas is pressed out of the bellows into the patient
breathing circuit. The bellows is refilled with fresh gas and the expired gas from the patient.
1.9.7.2 Manual Breathing Bag
In manual mode, this device acts as a normal breathing bag, enabling the user to ventilate
the patient manually. In mechanical ventilation mode, this bag is cut off from the breathing
circuit by the reversing valve.
1.9.7.3 CO 2 Absorber
The soda lime inside the absorber retains the carbon dioxide from the exhaled gas. The
AS3000 accommodates standard sized Pre-Paks or loose-fill CO2 absorbent.
1.9.7.4 Inspiratory and Expiratory Valves
To ensure correct gas flow direction to and from the patient, one-way-valves are integrated in
the inspiratory and expiratory limb of the Breathing System.
1.9.7.5 APL (Airway Pressure Limiting) valve
In manual mode, the APL Valve acts as a normal spring loaded pressure relief valve, limiting
the maximum pressure in the Breathing System.
AS3000 Service Manual 0070-10-0683 1 - 39