Deterministic chaos in the hemodynamics of an artificial heart

The hemodynamic parameters that occur during prosthetic circulation are analyzed as an entity using non linear mathematical techniques. For purposes of comparing natural and prosthetic circulation, two pneumatically actuated ventricular assist devices were implanted as ventricular bypasses in several experiments using goats. All hemodynamic parameters were recorded during awake conditions. Arterial blood pressure waveform was embedded into a four dimensional space and then projected into a three dimensional phase space. Analysis of the state phase showed the incidence of deterministic chaos during natural circulation, however during artificial circulation a simple tractor was observed. These results suggest that hydrodynamic parameters must be controlled during prosthetic circulation when unexpected stimuli are fed from the outside.