Mechanical simulator of the cardiovascular system.

To devise and to build a mechanical simulator of the cardiovascular system of increasing complexity is a fascinating experience for a medical Physicist. We did it, and the effort to match the solutions with the objectives forced us to deepen the knowledge of the physiological aspects, to devise different solutions and to compare their results. This paper describes the final solution and shows the results, discussing the theoretical and practical aspects of the different choices. The ventricle is simulated by a pumping syringe with an external pulsing chamber to accomplish the Frank-Starling mechanism; the coronary circulation by a nonlinear hydraulic resistance device; the aorta by different wall thickness rubber tubes; the arterial vascular resistance by a thin, variable length tube; the venous reservoir by a variable volume chamber connected to a reservoir simulating the atrium. The simulator was mainly devoted to teaching purposes, but the possibility to modify the mechanical characteristics of the single components moved it to be used also for research, with an unexpected satisfaction.