Intérêt vectocardiographique du dispositif de Boothroyd

Abstract

Analysing the function of the instrument described by Boothroyd and coworkers, allows to understand how a finite isomorph can be substituted for an infinite extension of a conducting medium. First, we show the consistency between the results obtained from the resistive network and from the mathematical model which are equivalent to the electrolytic tank originally proposed. Among our observations, we underline the one reporting that the zero equipotential always reaches the isomorph center at least when the conductivity is the same in the passive compartment and in the activated disk energized by a dipole of any position. The potential differences picked up around the isomorph center are well suited to a vectorcardiographic application such as Rijlant's one. A simultaneous use of the integration of the potential on the boundary by means of the Gabor & Nelson method provides the reference to which the vectorcardiographic approximation can be compared and so, leads to objectively probe the practical merits of the latter approximation. For instance, at the attenuation level used by Rijlant, the vectorcardiogram images within a 1 % relative error, the magnitude and the orientation changes of a dipole rotating on a pivot the eccentricity of which amounts to 0.5 R. Our validation of Rijlant's method in the conducting systems with radial symmetry from which he started, is the first step in fully anwering Bürger who called for such a proof in his celebrated book on heart and vector.