Patent ID: 7248921
Filing Date: 2007-07-24
Classification: A61B,A61N

Abstract:
1. A method of signal detection enhancement for a cardiac rhythm device comprising: receiving a signal from electrodes implanted for cardiac observation; observing characteristic features of the signal; counting the characteristic features; comparing the number of characteristic features to a threshold to: wherein: the step of observing characteristic features includes identifying a number of points in the signal where the signal slope reaches a local maximum magnitude; the step of identifying a number of points in the signal includes identifying zero crossings of the second derivative of the signal; the step of observing characteristic features includes: the step of characterizing subsequent zero crossings includes application of a rule related to the signal shape between two points in the signal; and the rule calls for determining whether the path length from a most recent significant maximum slope point to the zero crossing under consideration exceeds the magnitude of the difference in amplitude between: