[Method for the continuous measurement of the phase relation between heart beat and respiration (author's transl)]

A simple method for the continuous analysis of the phase relation between heart beat and respiration is described. By means of an analog computer the timing of the R wave of the ECG within the respiratory cycle is graphically displayed. In contrast to other investigations, the onset of the inspiration is used as starting signal. The results obtained with the analog computer were completed by a digital computer program, which allowed in addition to calculate histograms of the events. In order to evaluate our method we used an analog model of two coupled oscillators. Responses obtained at different coupling characteristics were compared with measurements in four subjects. The results indicate a mutual interaction between heart action and respiration as cause of the coupling of these two systems.