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2. VERIFICATION OF ECG SIGNAL QUALITY ANALYSIS
The VF/VT Analysis algorithm evaluates the signal quality of ECG. Artefacts in the ECG signal that
may have been introduced due to motion artefacts or noise are detected and taken into consideration.
The VF/VT algorithm requires 9 seconds to decide whether the ECG rhythm is shockable or non-
shockable. If artefacts are found in the signal, time taken for analysis is longer. The algorithm makes a
decision only if no artefacts are present in the signal and if an accurate decision can be made.
If no rhythm detection can be made 15 seconds after the analysis has begun, movement detection
error is logged. The user is again advised not to touch or move the patient and the ECG analysis
restarts. If artefacts are again found during the analysis re-run, the CPR cycle (Chest compressions
and Ventilation) automatically begins.
a. Objective
To evaluate and verify ECG signal quality analysis system.
b. Test Databank
In this test, ECG data from a test databank is tested. The test is executed embedding the analysis
algorithm Matlab/Simulink data is evaluated considering different parameters of the algorithms. The
source for the ECG data is the Physionet Databank:
1. MIT-BIH Noise Stress Test Database [Databank2]
This database includes 12 half-hour ECG recordings and 3 half-hour recordings of noise typical in
ambulatory ECG recordings. The noise recordings were made using physically active volunteers and
standard ECG recorders, leads, and electrodes; the electrodes were placed on the limbs in positions
in which the subjects' ECGs were not visible. The three noise records were assembled from the
recordings by selecting intervals that contained predominantly baseline wander (in record 'bw'),
muscle (EMG) artefact (in record 'ma'), and electrode motion artefact (in record 'em'). Electrode motion
artefact is generally considered the most troublesome, since it can mimic the appearance of ectopic
beats and cannot be removed easily by simple filters, as can noise of other types.
Noise was added at the beginning after the first 5 minutes of each record, consisting of two-minute
segments alternating with two-minute clean segments. Since the original ECG recordings are clean,
the correct beat annotations are known even when the noise makes the recordings visually
unreadable. The reference annotations for these records are simply copies of those for the original
clean ECGs.
2. Creighton University Ventricular Tachyarrhythmia Database [Databank1]
(http://physionet.org/physiobank/database/cudb/ )
c. Procedure
For the artefact free ECG signal, the analysis was complete in exactly 9 seconds. With the presence of
artefacts, the analysis took longer to complete. After 15 seconds, when no analysis result could be
determined, "Movement detected" was logged.
d. Results
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