Aspect A-2000 BIS, Operating Manual

Page: 67 / 104

SECTION 5 FEATURES AND CAPABILITIES
______________________________________________________________________
5-3
5.2.8 Density Spectral Array (DSA)
The Density Spectral Array (DSA) shows changes in the power spectrum distribution
over time. Brighter points on the display correspond to greater power content (on the
printout this is reversed, i.e., darker points correspond to greater power content). The
total amplitude of the signal is shown by an amplitude bar (based on a decibel scale)
that is displayed beside the DSA plot. A spectral edge frequency number and the
spectral edge line show the frequency at which 95% of the total power lies below it and
5% lies above it.
5.2.9 BIS Log Display
This display shows the BIS numeric values over time and is updated continually as each
value is calculated. Each line shows a one-minute sample of the minimum and
maximum BIS values along with the average BIS, EMG, SR (Suppression Ratio), SQI
(Signal Quality Index), and Burst Count values during the one-minute period. Event
markers (arrows) display when an event is noted. When signal quality is low, an asterisk
(*) appears at the end of the line. If signal quality is very low, BIS, SR, and Burst Count
values are not reported. If the Suppression Ratio is below 5, BURST is not reported.
Note that Burst Count is only reported when a BIS Extend sensor is in use.
The time interval at which the BIS is reported can be set to 1, 5, 15, or 60 minutes in the
Display Parameter screen. The default value of 1 minute is recommended for a
complete picture of the BIS over time.
5.2.10 Artifact Detection
The A-2000 is designed to provide only highly reliable data. It is therefore programmed
not to display data that has been corrupted by artifact. Artifact bars appear on the
display whenever this occurs.
5.2.11 Event Markers
Events may be marked on the Trend or DSA display using the Setup Menu. Events are
shown as arrows on the time scale of the Trend display, as well as the BIS Log display.
5.2.12 Start and End of Case Bars / Case ID
The A-2000 draws a thick line to mark the start of a new case and assigns a unique
Case ID number that displays at the top of the Graphic Display Region. If the DSC, the
PIC, or the sensor have been disconnected for more than 10 minutes, or when the
monitor is turned off, then on, the case is marked as ended. An end of case line marker
is shown in Review Mode and on printouts.
5.2.13 Limit Alarms
The A-2000 alerts you to a BIS alarm limit violation by flashing the BIS number and
sounding a tone. You can silence the audible alarms by pressing the Alarm Silence key.
Alarm limits are displayed in the graphic display area of the screen and may be changed
in the Alarm Menu.