Datex-Ohmeda Anesthesia Delivery Unit S/5, Technical Reference Manual

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Datex-Ohmeda ADU
B-12
Document No. 8502854
If the cassette is empty or overfilled, a user alarm is displayed:
If the cassette is overfilled to a 160% according to maximum limit (100% = 250 ml), the alarm
message ‘Draining Cassette´ is displayed. The alarm message will disappear when the cassette is
120% over the maximum limit.
If there is less than 10% of liquid (25 ml approximately) left in the cassette, the alarm message
´Cassette Empty´ is displayed.
Liquid chamber, Aladin Cassette
The liquid chamber flow is conducted into the Aladin Cassette, which is the only agent specific part of
the vaporizer. The agent cassette contains liquid agent, which is vaporized when the gas flow passes
through the cassette. It can be categorized as a flow-over vaporizer, using wicks inside the cassette to
increase the surface area. The large vaporizing surface in the liquid chamber guarantees that the
agent flowing through is vaporized over the entire operating range.
Each Aladin cassette is magnetically coded for its specific agent. There is a cassette identification
sensor board (11) with five Hall sensors in the cassette housing which identifies a unique
combination of magnets for every anaesthetic agent. By using a combination of two magnets in five
positions in the cassette, an erroneous identification is avoided in any single sensor failure case. The
name field of the anaesthetic agent on the main screen is updated according to the name and the
color of the cassette.
There are keyed filling systems for filling the cassette with anaesthetic agent. A level window indicates
the amount of liquid in the cassette and for the Desflurane cassette there is also an electronic liquid
level measurement. Changing the Aladin cassette in the vaporizer cassette housing easily changes
anesthetic agent.
The cassette does not include any flow channels for the bypass gas flow which means that the liquid
cannot escape in any hazardous positions during handling. No specific attention to the carrying
position of the cassette is required.
Aladin Cassette
Different Aladin cassettes are needed for different agents and keyed filling systems.
Halothane A-VHAL, Isoflurane A-VISO, Enflurane A-VENF, Sevoflurane A-VSEV, Sevoflurane A-VSEVQ
and Desflurane A-VDES.
The Aladin locking mechanism locks the cassette firmly into the cassette slots. The connection is
automatic when the cassette is pushed into locked position.
The cassette is unlocked by squeezing the trigger in the handle.
Since the cassette does not include any flow channels for the bypass gas flow, the liquid cannot
escape in during handling. This means that no special attention, as to the position of the cassette
when it is carried, is required.
The large vaporizing surface in the liquid chamber guarantees that the agent flowing through is
vaporized over the entire operating range.
All Aladin cassettes are equipped with a liquid level window where a ball changes its position
depending of the amount of liquid in the cassette.
When the ball is in top position, the cassette contains about 250 ml, whereas the cassette contains
about 80 ml with the ball in bottom position.
The diagram below shows the parts common to all Aladin cassettes.