A general method of determining the frequency-dependent propagation coefficient and characteristic impedance of an artery in the presence of reflections.

An iterative method of calculating propagation parameters at harmonics of heart rate for a uniform vascular segment from a combination of four arterial waveform measurements is presented. Measurements of blood pressure, vascular diameter, and blood flow-rate may be combined arbitrarily provided only that at least one measurement of pressure and one of flow-rate be included; the requirement of four measurements implies at least two measurement sites along the vessel. The analysis is thus a generalization of those associated with previous methods of determining propagation parameters, allowing for instance relaxation of the requirement of equal spacing in the three-point method. Results are presented for the propagation of an impulse along a rubber tube when the measurements are pressure at two sites, flow-rate and diameter.