ihr - calculate instantaneous heart rate
ihr -r record -a annotator
[ options ... ]
ihr reads an annotation file (specified by the
annotator and record arguments) and produces an instantaneous heart rate
signal (from the reciprocals of the interbeat intervals.) Unlike tach(1)
however, ihr does not resample its output in order to obtain uniform time
intervals between output samples. (If there is any variation whatsoever
in heart rate, the intervals between output samples will be non-uniform.)
This property makes the output of ihr unsuitable for conventional power
spectral density estimation, but ideal for PSD estimation using the Lomb
periodogram (see lomb(1)
- -d tolerance
- Reject beat-to-beat
heart rate changes exceeding tolerance (in beats per minute; default: 10).
Any intervals for which the calculated heart rate would differ by more
than the specified tolerance are simply excluded from the output series.
To disable this behavior, use a large value for tolerance (e.g., 10000).
- -f time
- Begin at the specified time in record (default: the beginning of
- Print a usage summary.
- Include all intervals bounded by QRS
annotations (default: include intervals bounded by consecutive supraventricular
- -p type ...
- Include intervals bounded by annotations of the specified
types only. The type arguments should be annotation mnemonics (e.g., N) as
normally printed by rdann(1)
in the third column. More than one -p option
may be used in a single command, and each -p option may have more than one
type argument following it. If type begins with ‘‘-’’, however, it must immediately
follow -p (standard annotation mnemonics do not begin with ‘‘-’’, but modification
labels in an annotation file may define such mnemonics).
- -t time
until the specified time in record (default: the end of the record).
the output sample number before each output sample value.
- -v, -vs, -vm, -vh,
-V, -Vs, -Vm, -Vh
- Print the elapsed times from the beginning of the record
to the annotations that begin each interval, as sample number (using -v),
or in seconds (using -vs), minutes (using -vm), or hours (using -vh) before
each heart rate value. The options -V, -Vs, -Vm, and -Vh work in the same way,
but the printed times are those for the annotations that end the intervals.
Only one of these options can be used at a time; if none is chosen, -vs
mode is used by default.
- Exclude the interval immediately following each
rejected interval. (Rejected intervals are those bounded by excluded beats
on at least one end, and those that do not satisfy the tolerance criterion).
By default, intervals following rejected intervals are included (unless
they are rejected by the tolerance criterion), and a third column is used
to flag these intervals (a zero in the third column means the interval
is normal, a one means it follows an excluded interval).
annotation files can be used as input to ihr, but files that contain manually-inserted
annotations are less suitable, since annotation placement is likely to
be less consistent than in annotation files generated by programs such
It may be necessary to set and export the shell
variable WFDB (see setwfdb(1)
George B. Moody (firstname.lastname@example.org)
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Updated 22 February 2013