Abstract: A tissue stimulator including a sensing unit, wherein the sensing unit includes an A/D converter that samples an analog signal using a sampling clock and converts the analog signal into a digital signal. The tissue stimulator includes a digital filter with an input, wherein the input is connected to an output of the A/D converter. Using a filter clock, the digital filter filters the digital signal, and wherein the filter clock is a multiple of the sampling clock for a specific period of time T.

Abstract: A tissue stimulator including a sensing unit, wherein the sensing unit includes an A/D converter that samples an analog signal using a sampling clock and converts the analog signal into a digital signal. The tissue stimulator includes a digital filter with an input, wherein the input is connected to an output of the A/D converter. Using a filter clock, the digital filter filters the digital signal, and wherein the filter clock is a multiple of the sampling clock for a specific period of time T.

Abstract: An implantable medical device for processing picked-up electric heart signals and to a method of controlling sensitivity of a sensing stage of the device. The sensing stage is connected to an electrode picking up electric potentials inside the heart, has an adjustable sensitivity and generates a detect signal indicating detection of a sense event if the time course of the picked-up signal exceeds the detection threshold. A peak amplitude detector determines a peak amplitude. A peak amplitude comparator determines whether the peak amplitude exceeds a predetermined peak amplitude threshold value, and a control unit adapts the detection threshold by adjusting the sensing stage's sensitivity. The control unit sets the detection threshold for a first detection period to a high value, subsequently lowers the detection threshold stepwise for further detection periods.