Spacelabs Healthcare Lifecard 12, Service Manual

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18-0583 Rev.C
3.4 User Level Tests
Before commencing the recording the recorder checks all aspects that
are under the user’s control, and will display warning or error
messages as described in the user manual. Items checked include:
• Battery voltage
• Loss of time and date since last use
• CF card needs conditioning
• CF card contents- have they been read out for analysis?
• Patient cable type
If a recorder frequently requires the time and date to be entered or
corrected, it should be returned for service.
3.5 Fault Protection While Recording
During recording the recorder operation is supervised in various ways,
to ensure that all recorded data is correct and the recording is as
complete as possible:
• The battery level is continually monitored. Low battery shutdown
is described in the user manual.
• If the LCD is found to be in the wrong state the recorder will
re-load the display.
• Data written to the CF card includes error detection information
which is checked before analysis.
• The recorder shuts down immediately if the cable is removed.
• If the patient cable is removed and then replaced, the recorder
will continue after a countdown message. The analyser will dis-
play a corresponding blank period in the ECG.
• The 32768Hz crystal is monitored via a watchdog to ensure that
it is operating correctly.
Other transient faults can cause a short blank in the ECG while the
recorder resets and restarts:
• Intermittent power supply, due to contact corrosion, bad joints,
or possibly severe shock.
• The recorder software running improperly (watchdog timer).
• Error messages from the CF card that cannot be resolved.
• Any other unexpected condition such as data errors due to large
electrostatic discharge.