Impedance of the arterial system in terms of Fourier harmonic analysis of the pulse wave.

The results obtained by analysis of pulse waves by means of Fourier harmonics in healthy subjects and patients with aortic insufficiency show good agreement between input impedance of the aorta and the initial segment of the femoral bed in both groups. This means that in this region there is no marked increase in impedance, which provides a favourable background for energy transfer (blood content) in the distal direction. Impedance in healthy subjects increases in vessels of the lower extremity. In patients with aortic insufficiency there is a marked decrease in amplitude of all higher harmonic frequencies. This practically means that the second harmonic is no longer the main accumulator of energy of the pulse wave as in healthy subjects, and the same is also true, to a proportionate degree, for the third, fourth and fifth harmonics.

Measurement of systolic time intervals through non-invasive polygraphic techniques in healthy subjects and in patients with ischaemic heart disease. Comparison of results obtained by conventional and computer assisted means.

Computer processing of carotidograms is an incontestable methodical asset. Electronic detection of systolic time intervals excludes human errors, makes possible evaluation of a greater number of systoles, and reduces the effect of nonlinearities of recording. The proposed computerized system saves tedious manual calculations and can yield results with mutual correlations within a short period of time.