Mindray Passport V, Operating Instructions Manual

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Arrhythmia Algorithm ECG Monitoring
4 - 24 0070- 0-0704-02 Passport V Operating Instructions
4.6.3 Filtering Pacer Signals
In order to prevent pacer pulses from being mistaken for QRS complexes, they are removed
from the ECG data that is sent to the arrhythmia algorithm for analysis.
4.6.4 ECG Amplitude
The QRS detection threshold algorithm setting is fixed between 0.15 and 0.45 mV to avoid
detecting noise spikes or P-waves as valid beats. Changing the display gain on the monitor does
not affect the signal that is used by the algorithm for beat detection. For optimal performance, the
leads selected for monitoring should have an amplitude of 0.5 to 1 mV or more.
4.6.5 Learning
The process of learning is used to establish a normal beat template for a patient. The learn
period is dependent on the heart rate and the dominant pattern. Learning should not be
initiated during a primarily ventricular rhythm because an ectopic beat may be established
as normal.
A learn should be initiated when beats are not being properly detected, or when they are
being erroneously classified. However, if a signal is not strong enough, or lead data is
extremely noisy, better signal quality must be established before a learn can be effective.
4.6.6 Beat Detection and Typing
The following table describes the leads that are used to measure beat detection and beat
typing.
The search for the next beat begins after a refractory period to avoid detecting T- waves as
valid QRS complexes. For all patient sizes, the minimum QRS amplitude that can be detected
is between 0.15 and 0.45 mV depending on the width of the QRS complexes.
Beat typing aligns and compares each new heartbeat to reference templates that were
previously stored in the system. A beat typing algorithm classifies the beats.
• If an incoming beat matches a template that has already been classified, it is given the
same label as the template. The template parameters are updated with the features from
this new beat.
The real time ECG analysis library incorporates ventricular ectopic beat detection as a part
of arrhythmia analysis.
• Beats are measured for compensatory pause, QRS width, QRS positive and negative
areas, and R wave positive and negative amplitudes. This process uses multiple leads
when available.
• A scoring algorithm is then applied to those measurements to determine whether or not a
beat is ectopic.
DESCRIPTION 3-WIRE LEAD SET 5-WIRE LEAD SET
Leads used for Beat Detection Determined by viewed lead II and V
Leads used for Beat Typing Determined by viewed lead II, V, and I
Leads used for V-Fib Detection Determined by viewed lead II and V
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