Bayer HealthCare Rapidlab 800 - Manual (Page 68)

1Ć46 Rapidlab 800 Operator's Manual
Flexible time performs calibrations at various intervals. The system uses an
algorithm to determine the number of minutes between calibrations. This algorithm
is based on sensor status and the change in drift values from previous calibrations.
Calibrations are performed at intervals necessary to avoid excessive drift to the
sensor that is experiencing the fastest rate of drift. The default time for the
minimum time between calibrations is 10 minutes. You can define the minimum
time between intervals for one-point calibrations in setup. The minimum time for
two-point calibrations is four times the value entered for one-point calibrations.
Refer to Selecting Calibration Frequency and Automatic Repeat in Section 5 for
more information about defining the time interval for automatic calibrations.
The system indicates that an automatic calibration is pending 5 minutes before the
calibration is scheduled and continues to display the time remaining until the
calibration starts. The sample door closes when a calibration starts. The timing bar
indicates the approximate time to calibration completion. During a calibration, you
cannot access the Menu mode.
You can defer or interrupt calibrations to analyze samples. You can defer automatic
calibrations for up to 30 minutes. After 30 minutes, the system is not in calibration.
The system then starts the required calibration automatically. The system does not
accept samples until the required calibration finishes.
Glucose Biosensor Calibrations
In addition to the regularly scheduled one-and two-point calibrations, the 860
system has a metabolite recal option. The metabolite recal option allows the system
to perform an automatic one-point metabolite calibration to minimize within run
drift during rapid sampling. Metabolite recal is particularly useful in controlling
within run drift for newly installed glucose biosensors. Turning off the metabolite
recal option will increase sample throughput time. With metabolite recal off,
glucose is calibrated only at the regularly scheduled one and two-point
calibrations.
Metabolite recal also decreases within run glucose drift when running many
replicates of QC material. Turning off the recal option does not significantly affect
QC sample results, as most QC samples are limited to 6 replicates in a run.
Individual laboratories should determine if glucose QC recovery is acceptable with
metabolite recal off.
Metabolite recal calibrates the glucose biosensor under two sets of criteria in a
cyclical manner. First, the system uses an algorithm to determine the frequency of
samples. If two consecutive QC samples or a combination of three QC and patient
samples are analyzed at an average rate of 4 minutes or less between samples, the
system begins a metabolite one-point calibration at the completion of the analysis.
If a regularly scheduled one- or two-point calibration is due, the system performs
the scheduled calibration instead.
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