GE HEALTHCARE E-PSMP, Technical Manual

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Entropy Module, E-ENTROPY (Rev. 01)
11 - 3
2062973-004
1.2.4 Impedance measurement
The impedance measurement is performed for all leads at the same time and the EntrEEG is
stopped for no longer than 5 seconds during the impedance measurement.
Differences in the electrode impedance of the electrodes cause common mode noise coupling
to the measured signal. To minimize this, the electrode impedance is measured and a warning
of an unsatisfactory impedance level is generated when necessary. The impedance of an
electrode is measured by applying a known current through the electrode and measuring the
voltage drop over the electrode. This way the impedance of a single electrode can be resolved.
1.3 Main components
1.3.1 Controls and connectors
Figure 3 Front panel of Entropy Module, E-ENTROPY, and the back of the
module
Module key Module Description
Entropy E-Entropy Opens the Entropy menu on
the screen
Check Sensor E-Entropy Starts the manual sensor
check
Connector Module Description
Entropy E-Entropy Entropy connector
D25 connector E-Entropy Module bus connector