A contribution to the technique of recording of the E.C.G. and heart rate in physiology of work and sport

Abstract

In physiological research the continuous recording of the E.C.G. or at least of the heart rate during work or physical exercise is sometimes desirable. Standard electrocardiographic electrodes and derivations are, however, often unsuitable: modified electrodes must therefore be used for the recording. In the paper two types of such electrodes are described, which have been proved both in laboratory experiments and in field research. — The first type — special chest electrodes — may be worn by the subject under his usual dress for several hours without causing any discomfort. The second type — localisation forehead-left leg — is suitable for examinations of shorter duration in subjects sitting at their work. — When the artefacts make the evaluation of the E.C.G. waveforms impossible, it is still possible to registrate the heart rate and the pulse intervals by means of a band-pass filter. A simple filter for this aim, designed for connection to the output of a standard symmetrical differential-input preamplifier of bioelectrical potentials, is described.