Arena Service Manual
• Accept operating information and parameters from the user
via the video display touch screen and touch screen
controller (for example, blood flow rate, dialysate
temperature, UF rate).
• Display operating conditions and status on the video
display.
To ensure general integrity of the control system, the following
tests are performed during the pretreatment testing.
1. The watchdog function handled by each 8040
microcontroller is tested by individually halting
communication to each 8040 and verifying a resulting
system shutdown condition.
2. The system's A/D (analog to digital) converters are
compared with each other to verify accuracy. Each of the
three controller systems (BP, UF, and I/O) utilize A/D
converters to provide A/D functions. For Self Test
purposes, the A/D outputs from the I/O controller are
connected to the A/D inputs of the BP and UF controllers
simultaneously. Self testing involves outputting a range of
levels through the I/O A/D converter and verifying that
similar levels are read by the BP and UF A/D converters.
3. A self-test verification consists of verifying that each self
test has successfully executed prior to exiting the Self Test
state.
In addition to these pretreatment Self Tests, the following
safeguards are in place.
4. An inadvertent transition from the Dialyze state to Rinse is
unacceptable because in the Rinse Mode the air detector is
disabled and the bypass valve cycles independently of
temperature or conductivity alarms, therefore Dialysis
during Rinse is prevented by disabling the blood pump
when one or both of the dialysate lines are not on their
rinse fittings.
5. In addition to this safeguard, before the air detector can be
disarmed or the bypass valve can cycle, both the Pentium
and the I/O 8040 must be in the Rinse state. Before either
enters the Rinse state from Dialyze, the operator must press
the RINSE and VERIFY buttons and both dialyzer lines
must be verified on their rinse fittings (using the optical
interlock switches) and blood can not be sensed at the
saline detector.
5-22 157-1278-912 Rev A
November 2003
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