Geometrie analysis of cardiovascular dynamics during sleep and wakefulness

We have investigated dynamics of cardiovascular variables during physiological states such as sleep and wakefulness. Their dynamics is modeled as a multidimensional autoregressive time series. Mutual geometric relations among state-dependent dynamics are obtained by means of the Kullback-Leibler divergence. The dynamics during sleep is markedly consistent compared to waking states within a subject. State-dependencies of cardiovascular dynamics and their mutual relations are suggested to uniquely characterize the autonomie regulation of cardiovascular system.