EVALUATING THE MECHANICAL BEHAVIOR OF A VENTRICULAR SIMULATOR

The mechanical performance of a ventricular simulator was characterized by recording Pressure-Volume loops for different preload and afterload conditions. The End Systolic Pressure-Volume Relationship was drawn to demonstrate a "physiological" behaviour. The external work of the artificial ventricle was calculated by the P-V loop area and the presence of the Frank–Starling mechanism was demonstrated. The P-V loop was obtained by recording the internal pressure and by integrating the flow signal recorded at the orifice of the artificial ventricular chamber. The preload was modified by increasing the level of the filling reservoir and the afterload was modified by shortening the thin tube that represents the hydraulic resistance. The measurements were repeated at two different volumes of the ventricular external chamber. The ventricular external work was calculated by measuring the P-V loop area in the different loading conditions. The sequence of the loops obtained by changing the preload and afterload show a well defined End Systolic Pressure-Volume Relationship that changes its slope by changing the volume of the ventricular external chamber. The ventricular mechanical simulator shows a "physiological" behaviour.