Welch Allyn Means ECG Physicians Manual for CP Series Electrocardiographs - User Manual - Manual (Page 60)

MEANS Physicians Manual
Welch Allyn
60
5 The Performance of MEANS
Development of the Modular ECG Analysis System (MEANS) is an ongoing process. While
the basic structure of the program has remained the same over the years, most program
modules have undergone important changes. In the past, the performance of the different
modules of MEANS has been assessed both by the program developers themselves and by
independent observers. An independent assessment has been carried out during the project
Common Standards for Quantitative Electrocardiography (CSE), an international study in
which all major ECG computer programs were evaluated with respect to signal-analysis and
diagnostic interpretation [1]. The final CSE results on waveform recognition were obtained in
1987 [2], those on diagnostic interpretation in 1990 [3]. Since then, many modifications have
been made in the MEANS package. This report describes the performance of MEANS
(version DB.AI) on the CSE waveform-recognition measurement and contour databases.
Methods
CSE waveform-recognition measurement database
The CSE database on waveform recognition contains 250 ECGs, but reference locations
(onset and offset of the P wave and the QRS complex and end of the T wave) have been
made public for only half of the ECGs. The 125 waveforms from the M01 data set have been
evaluated. Tests have been removed from the evaluation of the M01 data set per 60601-2-51
clauses 50.101.1.3 and 50.101.3.2. The removed tests include test numbers:
006, 010, 018,
020, 023, 045, 050, 052, 054, 056, 057, 067, 070, 092, 093, 094, 100, 109, 111, 117, 119, 120,
121, and 122.
CSE contour diagnostic database
The CSE contour diagnostic database consists of 1,220 ECGs, divided over eight categories:
normal (NOR), left ventricular hypertrophy (LVH), right ventricular hypertrophy (RVH),
biventricular hypertrophy (BVH), anterior myocardial infarction (AMI), inferior myocardial
infarction (IMI), combined infarction (MIX), and combined ventricular hypertrophy and
myocardial infarction (VH+MI). Two reference standards are available per ECG: one is based
on ECG-
independent clinical information (“clinical truth”), the other is the combination of
interpretations from a group of cardiologists (“combined referee”). These reference standards
remain under lock and key at the present CSE processing center in Lyon (head: Dr. P. Rubel).
Collection and composition of the database have been described in detail before [4, p 49-82].
All 1,220 ECGs were processed by MEANS using MEANS (version DB.AI). Diagnostic
statements produced by MEANS were mapped onto a set of diagnostic codes as prescribed
by the CSE protocol [4, p 83-104]. These codes were submitted to the CSE processing center
in Lyon where the program results were compared with the reference standards.
Classification matrices and summary statistics are documented below.