A physical model for the cardiovascular and the respiratory systems.

We propose a two degrees of freedom oscillating system to simulate the working of both respiratory and cardiovascular apparatus and to investigate the physico-mathematical characteristics of a possible decoupling between the physiological systems. We suppose a double mathematical pendulum with forced and damped oscillations, with the first frequency equal to four times the second one; not only, does the system not give resonance or beatings, but it also simulates with reasonable approximation the ratio between natural relative frequencies. The two Langragian equations, that have form: (formula; see text) cannot be solved in an analytical way, even if we suppose an approximation for little oscillations. Now we are studying another two d-o-f mechanical system, with only one suspension point; we are also studying both the electrical equivalent circuits.