Cardiovascular regulation in response to multiple hemorrhages: analysis and parameter estimation.

Cardiovascular regulation in response to multiple hemorrhages: analysis and parameter estimation. Biol Cybern. 2018 Sep 12;: Authors: Ciocanel MV, Docken SS, Gasper RE, Dean C, Carlson BE, Olufsen MS Abstract Mathematical models can provide useful insights explaining behavior observed in experimental data; however, rigorous analysis is needed to select a subset of model parameters that can be informed by available data. Here we present a method to estimate an identifiable set of parameters based on baseline left ventricular pressure and volume time series data. From this identifiable subset, we then select, based on current understanding of cardiovascular control, parameters that vary in time in response to blood withdrawal, and estimate these parameters over a series of blood withdrawals. These time-varying parameters are first estimated using piecewise linear splines minimizing the mean squared error between measured and computed left ventricular pressure and volume data over four consecutive blood withdrawals. As a final step, the trends in these splines are fit with empirical functional expressions selected to describe cardiovascular regulation during blood withdrawal. Our analysis at baseline found parameters representing timing of cardiac contraction, systemic vascular resistance, and cardiac contractility to be identifiable. Of these parameters, vascular resistance and cardiac contractility were varied in time. Data used for this study were measur...
Source: Biological Cybernetics - Category: Science Authors: Tags: Biol Cybern Source Type: research

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Source: International Journal of Aging and Human Development - Category: Geriatrics Tags: Int J Aging Hum Dev Source Type: research
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