Sensitivity analysis of cardiovascular models for minimally invasive estimation of systemic vascular parameters

A sensitivity analysis technique was used to evaluate two simple cardiovascular models for model parameter estimation using minimal measurable signals. The purpose of this study is to determine a simple model, which can used with a left ventricular device (LVAD) model to identify the model parameters using signals from the LVAD, to characterize the systemic load. The control of the LVAD can then be adjusted based on patient's demand, represented by the systemic load, with minimum invasive sensors. The results obtained from the nominal parameter values of normal patients suggested that a model with a constant capacitance for the left atrium is suitable for parameter estimation if aortic pressure, aortic flow, and left atrial pressure are measurable. If only aortic pressure and flow are available, a simplified model, excluding the left atrium from the original model, provides more accurate estimates. An extended Kalman filter was used with computer simulation data to identify parameters of the models for verifying the results from the sensitivity analysis.