User Manual

86 Lumax Technical Manual
2.5.1 VF Classifications
Detection of ventricular fibrillation (VF) utilizes programmable X
out of Y criterion. For the Lumax 300/340 & 500/540 models, both
X and Y are programmable. For the Lumax 600/640 and 700/740
models there are fixed combinations of X out of Y criterion. If X
number of intervals within the sliding window (defined by Y) are
shorter than the programmed VF rate interval (>bpm), VF is
detected. After fibrillation is detected, the programmed therapy
sequence for VF is initiated.
Nominal settings for classification of ventricular fibrillation (VF)
are 8 of 12 intervals; meaning that within a sample window of
12 intervals, 8 intervals must meet or exceed the VF zone rate
criteria.
2.5.2 VT Interval Counters
The VT Interval Counters are separately programmable for VT-1
and VT-2 rate classifications. The Counter: Detection is the
number of intervals required to declare a tachyarrhythmia as VT.
A tachyarrhythmia must meet the rate/interval criteria and the
programmed Counter/Detection criteria, in addition to any other
detection enhancements to be declared a tachycardia.
2.5.3 VT Classification
Both VT-1 and VT-2 classification zones utilize separately
programmable detection parameters. Classification of VT-1 or
VT-2 is based on the last interval average preceding declaration
of tachyarrhythmia detection. If this average falls within the VT-1
zone, the programmed VT-1 therapy is delivered. If the average
falls within the VT-2 limits, the programmed VT-2 therapy is
delivered. If additional detection parameters are activated, each
of these supplemental criteria must also be satisfied before a VT
rhythm can be classified and treated.