Patent ID: 7896808
Filing Date: 2011-03-01
Classification: A61B,A61N

Abstract:
1. An implantable medical device comprising: one or more implantable sensors arranged to sense first physiologic signals having a varying first magnitude in the presence of second physiologic signals having a second magnitude that varies with respect to the first magnitude and is at least at certain intervals greater than the first magnitude of the signals; a controller receiving sensed signals from the one or more sensors so as to receive a mixed signal including components from both the first and second physiologic signals; and a signal processing module arranged with respect to the one or more sensors such that the module provides an amplified signal to the controller and wherein, during intervals that the second physiologic signals exceed a threshold, the signal processing module suppresses amplification of the mixed signal provided to the controller so that the controller can evaluate the first physiologic signals with significantly reduced presence of the second physiologic signals; wherein the signal processing module comprises an amplifier providing the amplified signal, a threshold detector, and a switch arranged such that, upon the mixed signal exceeding the threshold, the threshold detector induces the switch to open and interrupt the amplified signal to the controller and, upon the mixed signal dropping below the threshold, the threshold detector induces the switch to close such that the amplifier again provides the amplified signal to the controller.