Noninvasive determination of arterial elasticity and blood pressure. Part II: elastogram and blood pressure...

The oscillometric method is used in the medical practice for measurement of arterial blood pressure and, rarely, for estimation of arterial elasticity. In the previous paper of this series, the relations between arterial volume pulsations and volume-to-pressure curve (elastogram) were examined resolving the problem for evaluation of arterial volume pulsations from known elastogram and systolic (ps)/diastolic (pd) blood pressure. Some features were found that are considered to be elastogram attributes. The aim of the present work is to resolve the inverse problem - graphical reconstruction of the elastogram from oscillometric data and determination of blood pressure.

The elastograms of an idealized arterial model as well as of experimental oscillometric records (five men, five women) are processed graphically.

The method for reconstruction is developed with the idealized volume pulsations of the arterial model, establishing full correspondence of the elastogram fixed in the model with those determined here. The accuracy of this reconstruction is assessed: a pulse pressure variability of 12% leads to an ~2-9% error of the reconstructed elastogram. Thereafter, experimental elastograms are reconstructed graphically, and the correct pulse pressure and blood pressure are determined. The experimentally determined blood pressure is statistically compared with that simultaneously auscultatory measured. Satisfactory correspondence between values of ps/pd is found. A method of objective comparison between elastograms after normalization is suggested.

A novel graphical, nonempirical method for a noninvasive reconstruction of the elastogram and determination of blood pressure is presented. The method can be applied easily in automated blood pressure measurement devices.