Patent ID: 7822475

Claim:
An implantable medical device comprising: at least two sensing channels for receiving sensed first and second location electrical signals originating from two different locations of a heart; a control unit connected to said sensing channels and being adapted to process the sensed electrical signals originating from the first and second locations of the heart, wherein the control unit incorporates an adaptive filter compensator adapted to generate an estimate signal for compensating a far-field contribution of the second location signal to the first location signal, and adapted to generate an output signal representing a near field signal originating from the first location using said estimate signal to reduce inter-chamber interference; and a gate connected to the second location sensing channel and being adapted to enable the adaptive filter compensator only if a predetermined signal is sensed via the second location sensing channel; wherein the device includes a morphology restoration block to restore an original morphology of the first location sensed after any said inter-chamber interference encountered in the implantable medical device is reduced by the adaptive-filter compensator; and wherein the morphology restoration block includes an on/off switchable integrator, said integrator being adapted so that the integrator's output tracks the output signal while the adaptive filter compensator is not enabled, but sums the basic output signal values to the integrator's output whenever the adaptive filter compensator is enabled.