Evaluation of pulse wave morphology by Fourier's harmonic analysis: methodological procedure and results of a physiological test.

Evaluation of the pulse wave on five segments of the lower limb by means of Fourier's harmonic analysis showed that the following phenomena can be observed in resting (recumbent) healthy subjects: 1) Almost constant, marked accentuation of the amplitude of the second harmonic in every single spectrum. Tjis can evidently be attributed to the resonance properties of the arterial pathway, as a mechanical oscillating circuit; 2) Distinct dimunution of the amplitudes of further, higher harmonics; 3) When studying the reciprocal amplitude ratio in every single harmonic, from the proximal to the distal segment of the limb, we can observe striking relative augmentation of amplitude in a distal direction, as a manifestation of mounting impedance towards the periphery. This provides good conditions for the prevention of rebounds and of undesirable stationary waves.