MAC ® 1200 Operations Manual - Jaken Medical...

Preparations for ECG Recording
4.3 Artifact Due to Poor Electrode Application
The resting ECG analysis system is equipped with
state-of-the-art electronic utilities that ensure artifact-free
recordings. Among these are the automatic
baseline adjustment and the anti-drift system (ADS
or cubic spline).
At the beginning of the recording the automatic
baseline adjustment algorithm verifies the incoming
signal and adjusts the baseline position accordingly.
During the recording, the anti-drift system (cubic
spline) continuously checks the baseline position
and returns it to the normal level, if required (Figure
4-6).
For the 6 Lead Mode, the anti-drift system (cubic
spline) can be enabled and disabled from the setup
menu, in the 12 Lead and Arrhythmia Modes, it is
always enabled.
When electrodes are not properly applied, these
measures may not fully compensate for artifact.
High polarization voltages induced by electrodes
applied without conductive gel may cause the amplifier
to overrange, so that a straight line will be
recorded instead of the ECG (see Figure 4-6). The
device will then automatically block and return the
baseline to its normal position. A baseline is then
recorded for approx. 1 second. It is possible to block
the amplifiers manually by disconnecting the RL
electrode.
On the display this condition is indicated by ****
instead of the electrode label (e.g. at i, Figure 5-1).
Remedy
• Apply the electrodes according to instructions.
• Do not apply the electrodes on top of clothing.
• Use a contact agent with reusable electrodes (e.g.
moistened electrode paper, electrode cream,
spray, etc.).
• Wait approx. 10 seconds before initiating a
recording. After the 10-second period, the automatic
functions are enabled and the polarization
voltages have stabilized, provided the electrodes
are properly applied. In case of improper electrode
application, an error message will appear
on the display (RL, LL, LA, LL, V1 to V6).
• If required, the ADS (cubic spline) and the filters
(20/40 Hz, 60 Hz) can be disabled to verify the
“raw” ECG signal.
approx.1 s
Figure 4-6. Sample recording
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