Apparatus for suppression of data deviations caused by external disturbances in in the measured signals in an implantable cardiac pacemaker

摘要

In a method and apparatus for removing data outliers in measured signals in an implanted medical apparatus, such as data outliers produced by GSM disturbance picked up by an implanted cardiac stimulator lead and superimposed on the sensed cardiac activity signal, the signal from the implanted lead is subjected to median filtering. The median filtering minimizes, or eliminates, the effect of highly aberrational data points in the incoming signal, without the necessity of actually removing the components in the signal produced by the disturbance from the incoming signal itself. Since no portion of the actual incoming signal is removed by the median filtering, the data integrity of the sensed cardiac signal is preserved. The signal processed by median filtering, possibly subjected to subsequent post filtering, is then supplied to a detector within the implanted stimulator, which performs the desired detection on the filtered signal, with the result of the detection then being used to control operation of the implanted stimulator.