QUANTITATIVE INTERPRETATION OF ARTERIAL IMPEDANCE PLETHYSMOGRAPHIC SIGNALS

A discussion of the quantitative interpretation of impedance plethysmographic signals recorded on human limbs is presented. It is found that a short limb segment behaves, from an electrical point of view, as a system of two resistances in parallel the larger time-varying one corresponding to blood, and the smaller, approximately constant, corresponding to bones and tissues. Systolic dilation of arteries can be calculated from the signal amplitude and is found to correlate well with arterial distensibility determined from pulse velocity measurements. Signal reproducibility was found to be ±10% © 1979 IFMBE.