Effect of posture on the cardiorespiratory system using canonical correlation analysis

This research investigates the influence of body posture on cardiorespiratory regulation using canonical correlation analysis (CCA). Electrocardiogram (ECG) and blood pressure (BP) were recorded on 6 subjects in supine, sitting and standing position during 8 periods of 120 s. For each period, the tachogram, the systogram, the diastogram and an ECG-derived respiratory (EDR) signal were computed. CCA was applied to investigate the influence of the systogram, diastogram and respiration on the tachogram. The results show that a large amount of the variance in the tachogram can be explained by the influence of the sys-togram, diastogram and respiration (EDR) in standing position with respect to the other postures. It also shows an increased linear relationship between systolic BP and HR in standing position than in other postures. This relationship was in all cases positive, indicating that an increase in systolic BP results in a lower HR. Stronger linear RSA effects are present in sitting against supine position.