ECG Database Applications Guide Table of Contents


rxr - ANSI/AAMI-standard run-by-run annotation comparator


rxr -r record -a reference-annotator test-annotator [ options ... ]


This program implements the run-by-run comparison algorithm described in Testing and Reporting Performance Results of Ventricular Arrhythmia Detection Algorithms, an AAMI Recommended Practice (AAMI ECAR-1987). Using options -C, -L, or -S, rxr implements the run-by-run comparison algorithm specified by the current American National Standard for ambulatory ECG analyzers (ANSI/AAMI EC38-1994). rxr is the reference implementation of these algorithms, and must be used to obtain the run-by-run performance statistics cited in EC38 in order to be in compliance with the standard. The EC38 comparison algorithm includes all of the ECAR statistics (so that both sets of requirements are satisfied by using the EC38 algorithm), with additional statistics on detection of runs of supraventricular ectopic beats (SVE runs).

Input to this program consists of two annotation files associated with the same record. One of these is designated the reference annotation file, the other the test annotation file (called the `algorithm' annotation file in EC-38 and in ECAR).

Options include:

-c file
Append condensed reports (ECAR Table 10 format) to file.
-C file
As for -c, but report SVE run statistics also.
-f time
Begin the comparison at the specified time (default: 5 minutes after the beginning of the record).
Print a usage summary.
-l file
Append line-format reports (ECAR Table 13 format) to file (see below).
-L file file2
As for -l, but report SVE run statistics in file2.
-s file
Append standard reports (ECAR Table 3 format) to file.
-S file
As for -s, but report SVE run statistics also.
-t time
Stop the comparison at the specified time (default: the end of the record if it is defined, the end of the reference annotation file otherwise; if time is 0, the comparison ends when the end of either annotation file is reached).
Verbose mode (list all discrepancies; see below).
-w time
Set the match window (default: 0.15 seconds; see below).

At most one of -c, -C, -l, -L, -s, and -S can be given as an option. If `-' is given as a file argument, reports are written on the standard output. If no options are specified, rxr writes standard reports on the standard output (equivalent to using the option -s -). The output generated by selecting -l or -L includes column headings only if a file other than `-' is specified, and only if the specified file does not already exist. In this way, rxr can be used repeatedly to build up a line-format table for multiple records, for further processing by sumstats(1) .

The -v option specifies that each mismatch is described on the standard output in a format similar to:
where the first number is the reference run length, the second is the test run length (each of these is between 0 and 6), and the numbers in parentheses indicate the location of the match window in sample intervals.

The shell variable DB should be set and exported (see setdb(1) ).


Since rxr performs multiple passes over its input files, it cannot be used at the end of a pipe.


bxb(1) , ecgeval(1) , epic(1) , mxm(1) , setdb(1) , sumstats(1)
Evaluating ECG Analyzers (in the ECG Database Applications Guide)
Testing and Reporting Performance Results of Ventricular Arrhythmia Detection Algorithms (publication AAMI ECAR-1987)
American National Standard for Ambulatory Electrocardiographs (publication ANSI/AAMI EC38-1994)
The last two publications are available from AAMI, 3330 Washington Blvd., Suite 400, Arlington, VA 22201 USA.

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