Patent ID: 7623913

Claim:
A method of cardiac signal analysis comprising: capturing a cardiac signal using implanted electrodes; conditioning and amplifying the signal; performing analog-to-digital conversion on the signal; and applying a heuristic filter to the captured cardiac signal by repeatedly performing the following at a predetermined interval: a) calculating an actual quiescent point of the analog-to-digital converted signal; and b) adjusting the analog-to-digital conversion of the signal to modify the actual quiescent point toward a desired quiescent point; and adjusting the predetermined interval by calculating a quiescent distance between the actual quiescent point and the desired quiescent point; and: x) reducing the predetermined interval if the quiescent distance is greater than a first threshold; y) increasing the predetermined interval if the quiescent distance is less than a second threshold; or z) if the quiescent distance is between the first and second thresholds, making no adjustment to the predetermined interval.