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Heart Rate Calculation, Statistic File
Hourly Statistic File
The ACT device generates an hourly statistic file (not applicable to
CEM mode) which contains the following information:
1. For every minute of operation, a HR histogram is attached (the
Min HR, Average HR and Max HR).
2. The number of heart beats (QRS) per minute.
3. The status of active events per minute.
4. Counter of events that were opened during that hour.
5. Counter of disconnections at that hour.
6. Impedance status per minute.
HR Histogram
The instantaneous HR is calculated in each lead separately as the
average between 16 consecutive RR intervals.
Heart statistics are calculated for every minute.
The computation of the average HR over one minute is done by
calculating the harmonic average of the instantaneous HRs found
during this period.
Max HR calculation:
Due to the fact that Max HR is sensitive to extreme values (that are
also caused by noise and other artifacts), for every minute, the Max
HR is calculated as follows:
Where: UpperX is defined as the maximal HR of (100-x)% of the
HR values, while x=12.
And: RawMaxHR is the direct maximal value of HR.
When a Tachy event is detected, there will not be any extreme
values filtering for max HR (i.e. the raw max HR is being used).
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