Patent ID: 6950696
Filing Date: 2005-09-27
Classification: A61N,Y10S

Abstract:
1. A method for detecting cardiac rhythm abnormality, comprising the steps of: providing a plurality of electrodes at a tip of a cardiac lead, which are electrically separated from each other; placing said tip of said cardiac lead in contact with cardiac tissue so that all of said electrodes are simultaneously in substantially fixed contact with said cardiac tissue; obtaining individual unipolar electrical signals from said cardiac tissue respectively via said electrodes, said unipolar signals exhibiting a time relationship relative to each other; defining a time window; sampling one of said unipolar signals and another of said unipolar signals; correlating samples in said time window of said one of said unipolar signals with samples in said time window of said another of said unipolar signals to obtain a first correlation result; successively shifting said time window by one sample and, after each shift, again correlating the samples of said one of said unipolar signals in said time window with the samples of said another of said unipolar signals in said time window, to obtain a plurality of successive correlation results; identifying a time offset between said one of said unipolar signals and said another of said unipolar signals by a number of samples associated with a shift of said time window which produced a highest correlation result among said first and successive correlation results; and generating a signal indicating a cardiac rhythm abnormality dependent on said time offset.