Calculating Cerebral Perfusion 12 Monitoring Invasive Pressure
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5Select the calibration pressure from the list, for example 200 mmHg.
6Select Confirm to recalculate the calibration factor using the applied pressure.
7When the monitor displays <Press> calibration done at <date and time>, remove
the manometer tubing, syringe and extra stopcock. We recommend you replace the transducer
dome and tubing with sterile ones.
8Label the transducer with the calibration factor shown in the Cal. Factor field in the pressures
setup menu.
9Reconnect the patient and start measuring again.

Troubleshooting the Pressure Calibration

The status line lists the probable cause of an unsuccessful calibration.
Calculating Cerebral Perfusion
The monitor can calculate the difference between mean arterial pressure and the intracranial pressure.
The difference is labeled CPP.
1In the Main Setup menu, select Measurements.
2In the Setup CPP menu, select AB P, ART, Ao, BAP or FAP as the arterial pressure source.
Calculating Pulse Pressure Variation
Note: The derived measurement Pulse Pressure Variation is not available in the USA.
Pulse Pressure Variation (PPV) is calculated from beat-to-beat arterial pressure values. Pulse pressure is
the difference between the systolic and the diastolic pressure values for a single beat. The average
variation in pulse pressure is calculated over periods of 32 seconds.
WARNING This monitor can calculate PPV from beat-to-beat values of any arterial pulsatile pressure. The
circumstances under which the calculation of a PPV value is clinically meaningful, appropriate and
reliable must be determined by a physician.
Message Corrective Action
unable to calibrate -
equipment malfunction Contact your service department. The pressure hardware is faulty.
unable to calibrate -
out of range Make sure that you have selected the value for Cal. Press that
you are applying to the transducer, and repeat the calibration.
unable to calibrate - no
transducer Make sure that the transducer is connected and try again.
unable to calibrate -
unstable signal Make sure there are no disturbances to the transducer, and repeat
the calibration.
unable to calibrate -
perform zero first No valid zero. Zero the transducer.