Danmeter CSM 2, User Manual

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Cerebral State Monitor - CSM DFU Page 12
4.9
CSM Parameters
BS% Indicator
The amount of Burst Suppression (very low-amplitude or “flat” EEG) is displayed in all Display Modes
at the top left hand side. Please refer to Section 5.5 for further information on the BS%
measurement.
EMG% and EMG bar
The EMG level is displayed either as a numerical percentage (0-100%) value in Display Mode A or
graphically as a bar at the right hand side in Display Mode B. Please refer to Section 5.4 for further
information on the EMG measurement.
Signal Quality Indicator (SQI%)
SQI% measures the quality of the acquired EEG signal. The calculation is based on the number of
artifacts during the last minute. The electrode-to-skin impedance is included in the SQI% calculation.
Higher electrode-to-skin impedances reduces the SQI%. Only electrode-to-skin impedances at 1 and
1 k
Ω
will result in a SQI% at 100. This quantity is displayed numerically as a percentage (0-100%,
100% equals best signal quality) in Display Mode A.
If the impedance of the white or black sensors exceeds 1k
Ω
, the SQI will fall gradually. Poor
impedance conditions may cause the SQI to fall to 50%.
Sensor Impedance
The impedance of the white and black sensors is continuously measured and displayed in Display
Mode E. Low sensor impedance values (typically between 1 and 3 k
Ω
) are essential for good
monitor operation. A “<1k
Ω
” readout means that sensor impedance is optimal.
Sensor Alarm
The Sensor Alarm signals the interruption of reliable CSI calculation due to corrupted or interrupted
EEG. This is usually caused by the use of diathermia or a faulty sensor connection (high sensor
impedance or disconnection of sensor leads). Should any of these situations occur, the Red Error
light (2) will turn on. The CSI is not calculated during these periods, but is replaced by
-?-.
Alarms (High / Low)
Alarms can be set to signal the moment when the CSI rises above and/or falls below preset limits.
The High and Low Alarms can be turned on or off from the Alarm Menu, where the High and Low
Alarm limits can also be set. The High Alarm is ONLY activated when the current CSI has been lower
than the High Alarm value. This is convenient when the High Alarm is set in the awake patient. If High
Alarm is set to 60 and High Alarm ON, then the CSI must be lower than 60 once before the High
Alarm is activated. If the current CSI goes higher than 60 the CSM monitor alarm sounds.
Same functionality is present for Alarm Low.