Patent ID: 7467009

Claim:
A device for association with a heart using at least one electrode, the device comprising: a cardiac signal detector coupled to the first electrode, and including a detector output providing a sampled cardiac signal; a signal processor circuit to determine, over a predetermined plurality of cardiac signal samples, whether an evaluation sample of the cardiac signal is a turning point with respect to previous and subsequent samples, and to deem a portion of the cardiac signal to be noisy if a number of turning points exceeds a threshold value for the predetermined plurality of cardiac signal samples; and wherein, if the cardiac signal is deemed noisy, the cardiac signal detector is additionally coupled to a different second electrode for detecting depolarizations, and wherein the cardiac signal detector includes independent first and second sensing channels that are respectively coupled to the first and second electrodes for independently sensing a depolarization at each of the first and second electrodes to corroborate depolarizations sensed at the first electrode using corresponding depolarizations independently sensed at the second electrode.