Simulating the differences in directional cardiorespiratory coupling in the awake state and different stages of sleep using a comprehensive mathematical model.

We propose a mathematical model of the human cardiovascular and respiratory systems. The cardiovascular segment of the model simulates the main heart rate, oscillating blood pressure, peripheral vascular resistance, and nonlinear dynamics of the autonomic control of circulation, namely α- and β- sympathetic and parasympathetic control. The respiratory part includes central pattern generator, lungs, and a control loop sensitive to the concentration of CO2 and O2 in the arterial blood. Both parts of the model are linked in a physiological manner. The adequacy of the model is demonstrated by comparing the simulated time series to the experimental records of healthy subjects from the SIESTA database using spectral analysis, statistical analysis, and nonlinear measures of directional coupling. The proposed model can become a useful tool for investigation of the cardiovascular dynamics during sleep. [ABSTRACT FROM AUTHOR]