Patent ID: 7570990
Filing Date: 2009-08-04
Classification: A61B,A61N

Abstract:
1. A detector for atrial fibrillation or flutter (AF) comprising: an impedance measuring unit comprising a measuring input, to which an atrial electrode line having an electrode for a unipolar measurement of an impedance in an atrium is connected and is implemented to generate an atrial impedance signal, obtained in a unipolar manner, in such a way that an impedance signal for each atrial cycle, comprising an atrial contraction and a following relaxation of said atrium, comprises multiple impedance values detected by said impedance measuring unit at different instants within a particular atrial cycle; said impedance measuring unit comprising a signal input, via which a ventricle signal is to be supplied to said detector, which reflects instants of ventricular contractions in chronological assignment to said impedance signal; an analysis unit configured to average multiple sequential impedance signal sections of a unipolar atrial impedance signal, in which each impedance signal section is delimited by two sequential ventricular contractions, with one another, and to determine a maximum amplitude of an averaged unipolar atrial impedance signal section; and said analysis unit configured to compare said maximum amplitude to a comparison value, and if said maximum amplitude of said averaged unipolar atrial impedance signal is less than said comparison value, generate an AF suspicion signal.