Verfahren und Vorrichtung zur unblutigen Messung des Arterienblutdrucks.

摘要

The method for establishing the blood pressure in an artery uses the measurement results from two non-invasive sensors (5, 6) which determine the diameter of the artery and are placed at two positions (3, 4) close to one another and separated by a distance DELTA x. The method envisages measuring the time difference DELTA t (7) which exists between each pair of diameter measurements and establishing the value of the propagation speed of the pressure wave (9). This value is then compared with an expression (11) of the form c (D) = c(D, alpha , beta , gamma ,...) taking into account the physical behaviour of the artery. After adjustment (12) using a mathematical procedure for minimising the differences, this comparison makes it possible to calculate the parameters alpha , beta , gamma ,... of the relation given hereinabove. By replacing the parameters alpha , beta , gamma ,... with their values in a relation (10) D(p) = D(p, alpha , beta , gamma ,...) and by using the measurement results from a diameter sensor, it is possible to deduce the blood pressure value p(t) at each instant in the cardiac cycle. The blood pressure value, together with the corresponding value of the diameter of the artery, makes it possible to trace a pressure-diameter curve (14) by means of which the mechanical properties of the artery can be measured.