Respiratory sinus arrhythmia as a surrogate measure of respiratory frequency: validity and robustness to activity in rats

Recording of breathing frequency is a basic requirement for respiratory physiology. Usual techniques are invasive and constraining. Respiratory sinus arrhythmia (RSA) has recently been demonstrated to be a simple way to obtain respiration frequency at rest. In this study, we investigated whether this correlation is also observed during activity. We first compared RSA to the respiration frequency obtained in anesthetized rats using a...