A Nonlinear Circulatory Model for Artificial Heart Studies

Summary

Animals with total artificial heart replacement (TAH) have survived for up to 9 months with manually controlled driving systems. A certain physiological control is provided by the animals intact peripheral regulation resulting in pathological venous hemodynamics, expressing the needs for a technical automatic control system, replacing the natural sympathetic stimulation and Starlings Law of the heart. A nonlinear dynamic mathematical model of the human cardiovascular system (CVSM) containing the systemic and pulmonary components was outlined and verified, which is employable to analyse the hemodynamic behaviour under normal and abnormal states. By modifying this model, assuming that cardiac output is constant at a preset level, the hemodynamic behaviour of a circulation system with an artificial heart was simulated. Comparing the simulation results with those from TAH experiments, a good accordance in the response of right atrial and aortic pressure under exercise conditions could be proven. This gives hope, that the modified and tested cardiovascular system model can be used as a tool for computing optimal control parameters under given conditions.