Patent ID: 8489188

Claim:
An active implantable medical device for cardiac pacing, resynchronization and/or defibrillation, comprising: ventricular pacing means for delivering stimulation pulses of low energy to be applied to an electrode implanted in the right and/or left ventricular cavity of a patient and means for testing ventricular capture, for detecting the onset of ventricular contraction resulting from delivery of a stimulation pulse, comprising: an acceleration sensor having as an output an EA signal representative of a patient's endocardiac acceleration; and means for analyzing the EA signal for determining a presence and an absence of a ventricular capture, Wherein: the means for analyzing the EA signal comprises means for: isolating the EA signal at least one EA component of endocardial acceleration corresponding to a first major noise of the heart, and at least one EA component describing the continuous variation of said EA signal in a bounded temporal window corresponding to a fraction of a cardiac cycle; extracting from said at least one EA component n indicators (PEA_i, LEA 13 i), with n ≧2, representative of the EA signal, and forming a vector EA (X 13 i) of dimension n from the n indicators thus extracted; the device further comprising a classifier means for, during a preliminary phase: acquiring a plurality of EA signals at a stimulation energy level high enough to cause a capture and forming a corresponding plurality of first reference EA vectors (X 13 capt_ref_p); acquiring a plurality of EA signals in a spontaneous rhythm of the patient in the absence of ventricular pacing and forming a corresponding plurality of second reference EA vectors (X 13 spont ref_p) and from the first and second vectors thus acquired, partitioning the n-dimensional space of the EA vectors into two subspaces corresponding respectively to the presence and absence of a capture; and wherein the means for testing ventricular capture further comprises means for: acquiring at least one EA signal at a current level of stimulation energy, and forming a least one corresponding current EA vector (X 13 i), and discriminating the presence or absence of ventricular capture based on the position of the current EA vector in one of said two sub-spaces of said n-dimensional space of EA vectors.