Uma contribuição à modelagem e estimação de parâmetros de válvulas cardíaca.

Abstract

This work aims to propose a lumped parameter model (0D) of biological prosthetic heart valves to obtain a more precise model of a pulsatile pediatric ventricular assist device (pVAD). The 0D model consists of the cannula-valve inlet and cannula-valve outlet configurations, which are represented by discrete transfer functions related to the conduction and non-conduction states of the input and output valves, respectively. The flow and pressure curves in the inlet and outlet cannulas of the heart valves are measured from a hydraulic simulator connected to a pVAD. To obtain this model, a methodology is developed which includes the data pre-processing, the structure model choice and it parameters refinement. From the simulation of the refined model, the regurgitation phenomenon was represented with fidelity of 90% of the value measured in the nominal condition test. The great importance of pVAD modeling is the possibility of coupling to the 0D model of the human cardiovascular system, so that its interactions can be studied and more robust automatic control strategies developed.