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sigamp - measure signal amplitudes of a WFDB record


sigamp -r record [ options ... ]


sigamp measures either baseline-corrected RMS amplitudes or (for suitably annotated ECG signals) normal QRS peak-to-peak amplitudes for all signals of the specified record. It makes up to 300 measurements (but see -n below) for each signal and calculates trimmed means (by discarding the largest and smallest 5% of the measurements and taking the mean of the remaining 90%).

Options include:

-a annotator
Measure QRS peak-to-peak amplitudes based on normal QRS annotations from the specified annotator.
-d dt1 dt2
Set the measurement window relative to QRS annotations. Defaults: dt1 = 0.05 (seconds before the annotation); dt2 = 0.05 (seconds after the annotation).
-f time
Begin at the specified time in record (default: the beginning of record).
Print a usage summary.
Read the signal files in high-resolution mode (default: standard mode). These modes are identical for ordinary records. For multifrequency records, the standard decimation of oversampled signals to the frame rate is suppressed in high-resolution mode (rather, all other signals are resampled at the highest sampling frequency).
-n nmax
Make up to nmax measurements on each signal (default: 300).
Print results in physical units (default: ADC units). -p may be followed by a single character to specifify a time format (used with -q and -v when printing individual measurements); choices are -pd (time of day and date if known), -pe (elapsed time in hours, minutes, and seconds), -ph (elapsed time in hours), -pm (elapsed time in minutes), -ps (elapsed time in seconds (default)), -pS (elapsed time in sample intervals).
Quick mode: print individual measurements only.
-t time
Process until the specified time in record (default: the end of the record). Processing will be terminated prematurely if 250 measurements are made before reaching the specified time.
Verbose mode: print individual measurements as well as trimmed means.
-w dtw
Set RMS amplitude measurement window. Default: dtw = 1 (second).


It may be necessary to set and export the shell variable WFDB (see setwfdb(1) ).

See Also

calsig(1) , setwfdb(1) , sigavg(1)


George B. Moody (


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