Galil Visual-ICE MRI, User Manual

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5-4 User Manual
11. Perform the Needle Integrity and Functionality Test on each needle by pressing the Test button
on the channel containing the needle(s). The 90-second test automatically conducts a series of
flush,freeze,andthawphases.Thedurationsofthesephasesare:45secondsflushwithhelium,
15 seconds freeze with argon, and 30 seconds thaw with helium.
CAUTION. Toachieverapidtransitionsfromheliumflushtoargonfreezeandfromfreeze
to helium thaw, the gas in the Junction Box Harnesses is vented through the Console. The
venting sound might be startling to people in the vicinity. The duration of venting depends on the
combined length of the two Junction Box Harnesses. A typical venting duration for argon, after
freezing, is about 10 seconds. Helium vents more quickly, usually in about 3 seconds.
OPTIONAL: Alternatively, all needles may be tested simultaneously by pressing the
Test
button
onthechannellabeledALL.Amessagerequestsconfirmationtotestallneedles.Ifappropriate,
choose YES.
OPTIONAL:
If additional testing is required, press the Test button again to repeat the test.
NOTE:
When helium is not connected, the two-minute test consists of 50 seconds low-pressure
argonflow,15secondsfreezewithhigh-pressureargon,and55secondsoflow-pressureargon
flow.
NOTE: If a previously tested needle is moved to a new channel at any time during a procedure,
the Needle Integrity and Functionality Test must be conducted again on that needle.
Duringtesting,carefullywatcheachneedleforthefollowing:
Flush: Ensure no bubbles are formed along the needle shaft and tip. Ensure that no
iceball is formed during the Flush phase.
WARNING. A defective MRI cryoablation needle that has a gas leak can
cause a gas embolism in the patient. Never use a defective needle for
a cryoablation procedure. Return defective needles to Galil Medical for
evaluation.
CAUTION.
Ice formation during the Flush phase indicates that argon gas
is connected to the helium inlet. Before proceeding change the cylinders
and ensure that each gas supply line is connected to the correct cylinder
(reference Section 5.4.1).
Freeze: Ensure that ice begins to form around the tip of the needle.
WARNING. A needle is defective if there is no ice formation during the
Freeze phase. Do not use a defective needle. Obtain a new needle and
repeat the testing procedure.
Thaw:
Ensure that the iceball detaches from the tip of the needle and that no bubbles
escape from the needle tip.
CAUTION. Ice formation during the Thaw phase indicates that the argon gas
is connected to the helium inlet. Before proceeding change the cylinders and
ensure that each cylinder is connected to the correct inlet (reference Section
5.4.1).
During the Needle Integrity and Functionality Test, the Gas Indicators for both gases provide
estimates of the time remaining before depletion of the cylinders assuming that all connected
needles are operated simultaneously (reference Section 3.3.1).