Applying the Resonance Equation to the Blood Pressure Waveform Variation in Aorta Bending and Renal Ligation of Rats

In the resonance theory, the radial dilatation is emphasized, and the blood pressure wave is transmitted in the form of “moving windkessel”. Based on this conjecture, we developed a semi-empirical procedure to describe the pressure distribution in a complex simulated model composed of a main tube and attached organs. Now we try to apply this fitting method to hemodynamics in vivo, and we tested our equations by two sets of experiments on the rats: ligating a renal artery and bending the aorta transversely. Abdominal aortic blood pressure of rat was measured through tubes inserted from the caudate artery and compared with curve-fitting deduced from semi-empirical resonance equations. The good fitting result illustrates that in spite of various complex structures of the arterial system, we can still provide good description for the blood pressure distribution by dividing the arterial system into sub-units and describing with few elastic parameters. It reinforces the conjecture of the resonance theory.