[An attempt on the normalization of the moduli spectrum of pulmonary pressure and flow waveforms in canine].

There is no reference of the standard function as the input and/or output control for the pressure and flow waveforms employed by a circulation duplicator or a computational fluidddynamics investigator. The author suggested a hypothesis that the Fourier series with limited terms should be the normalization function of ventricular and great artery pressure and flow waveforms in every cardiac cycle when sinus rhythm is normal, and that the square root of the amplitudes at each harmonic of the heart rate equals to C1-C2 square root of n, where n is the ratio of harmonic/heart rate, C1 and C2 are constants. This article is to provide some procves. The main pulmonary pressure and flow waveforms of 9 mongrel canines were divided into a single cardiac cycle, electrocardiography accordingly, then harmonic was expanded by using a Fourier series with 15 harmonic terms, and the moduli and phrase spectrum of each waveform was obtained respectively and statistically processed. The results support the hypothesis. We also found that the phrases of the pressure and flow waveforms have less variation at the basic harmonic of heart rate, but the higher the frequency of the harmonics comes out, the more variable the phrases appear.