Patent ID: 6337996
Filing Date: 2002-01-08
Classification: A61N

Abstract:
An active implantable medical device, comprising:a stimulation circuit to stimulate the myocardium; a detection circuit to detect an activity of the myocardium including an operation of the stimulation circuit and a residual potential event having a potential greater than a threshold potential; and means for applying a refractory period to the detection circuit in response to a detected operation of the stimulation circuit, said refractory period having an absolute refractory period and a relative refractory period, the relative refractory period further comprising at least one elementary period corresponding to a time period during which the absence of a residual potential event defines the end of the relative refractory period, said elementary period comprising a number of successive sub-periods, each sub-period having a duration that is shorter than said elementary period, and means for retriggering the elementary period in response to a detected residual potential event during said elementary period, wherein the means for applying the refractory period: a) produces, on each retriggering of an elementary period, a sequence of said successive of sub-periods, b) examines each triggered sub-period for an occurrence of a possible residual potential, and c1) in response to a detected residual potential event, retriggers the elementary period to restart at the end of the sub-period during which the residual potential event was detected, and c2) in the absence of a detected residual potential event, retriggers the sub-period to restart as of the end of the sub-period during which the residual potential event was not detected until the end or the sequence of sub-periods defining said elementary period.