Statistical properties of pulsatile pressure and flow in the femoral artery of the dog.

Femoral pulsatile pressure and flow in anesthetized dogs were measured as time series. The computed cross products of pressure and flow were also expressed as time series. The statistical variance (<J-) of each of these was analyzed into a frequency spectrum. The spectral magnitudes at each frequency were used to compute the pressure-flow coherence, impedance magnitude and phase angle as a function of frequency. The high coherency between pressure and flow at most frequencies indicated that a linear deterministic model may suffice to express the opposition to flow pulsations. The impedance variation with frequency indicated that the model may be frequency dependent. Computed autocorrelation and cross correlation functions measured the statistical nature of the observed time series.