Dräger VITALERT 2000, Инструкция оператора

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OPERATING INSTRUCTIONS (continued)
ECG Waveform
The VITALERT 2000 displays the ECG
signal at the trailing edge of a
blank bar which moves from left to right
across the screen. The previous sweep’s data
is erased at the leading edge of the
“blank bar.” This method of waveform
refresh allows the operator to view a
stationary waveform. In the event that
multiple passes of the ECG waveform are
made, the waveform remains stationary as
the “blank bar” moves from trace to trace.
The sweep rate is configurable to 12.5, 25 or
50 mm/sec. The sweep rate can be manually
selected using the Trace Speed function in
the
Monitoring Options Configuration
screen. If artificial pacemaker pulses are
present in the ECG signal, their effect on
the
waveform is suppressed by the
VITALERT 2000. If desired, a mark can be
displaced on the ECG waveform to represent
a pacemaker pulse. This feature can be
activated
using the Pacemaker Mark
function in the Monitoring Options
Configuration screen.
The amplitude, shape, and polarity of the
waveform are affected by the patients age,
size,
and physical condition. Skin
preparation, electrode placement, lead
selection, and noise will also affect
waveform detection.
Heart Rate
The VITALERT 2000 derives the heart rate
from the ECG waveform. Following R wave
detection, a signal is generated to other
portions of the VITALERT 2000 to produce
the heart audio and flashing heart symbol.
The interval between R waves is measured,
recorded
and then used to compute the
displayed heart rate. The value of the heart
rate is displayed, in large characters, to the
right of the ECG waveform. The displayed
heart rate is based on the rate of the most
recent beats with asystole factored in after
two seconds. Averaging is performed with
more weight applied to the interval rate of
the
most recent beats. This method
provides quick response to tachycardias,
bradycardias and the tracking of rate
changes.
The R-wave detection module requires a few
seconds to characterize the incoming signal.
Heart Rate Alarm Limits
The heart rate alarm limits are displayed, in
small characters, directly to the right of the
heart rate. The high and low alarm limits
can either be adjusted in the Configuration
mode, or directly on the Monitor screen
using the HI, LO, INC, and DEC keys in the
HEART RATE ALARM section of the main
keyboard. While being adjusted on the
Monitor screen, the selected limit is enclosed
in a box.
Flashing Heart
To denote the detection of an R wave, the
VITALERT 2000 can be configured to flash
a heart-shaped symbol in the upper right
corner of the Monitor screen and annunciate
a brief audio tone. The VITALERT 2000
registers beats on the R waves of the ECG
waveform.
The flashing heart can be
independently selected, using the
Configuration mode. The heart audio tone,
selected in the Configuration mode, may
also be disabled when the VITALERT 2000
operates
in conjunction with a pulse
oximeter (see Configuration section).
ECG Lead
The VITALERT 2000 displays the selected
ECG lead in the upper left hand corner of
the screen (Fig. 13). The operator can adjust
ECG functions through the following keys.
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