RELIABLE TRIGGERING FOR EXERCISE ELECTROCARDIOGRAMS

The heavy noise content in many exercise electrocardiograms has hindered the development of diagnostic analysis techniques. Many of the computational methods require a reliable and minimumly variable time reference within each ECG cycle. For example, such a trigger signal is a prerequisite to average transient computing, and can also relieve a digital computer of the time-consuming task of digital filtering in the initial pattern recognition of R-waves. The purpose of this paper is to outline the development of reliable triggering system. The system employs linear filtering, nonlinear amplification, and discrimination of amplitude, slope, and duration of the i?-waves. Typical exercise records, taken both in the laboratory and in the field, were used to evaluate the system, whose performance was assessed by three measures: the number of false triggers, the number of missed triggers, and the variation in time of the derived triggers relative to the original ECG R-waves. Copyright © 1969 by The Institute of Electrical and Electronics Engineers, Inc.