Article révisé par les pairs
Résumé : A new method for the analysis of heart rate variability in short-term recordings is presented which consists of an analysis of the respiratory sinus arrhythmia in the time domain by means of a polar representation. Its main advantage is that it is applicable in experiments in which the respiration of the subject is not controlled. The algorithm is applied to data recorded on two astronauts during the Euromir-95 space mission. Statistical hypothesis tests demonstrate that the presence of a mouthpiece induces an increase of the respiratory sinus arrhythmia amplitude.