Patent ID: 8761867

Claim:
A method of correcting power line interferences in an ElectroCardioGram (ECG) signal comprising: providing an input signal comprising an ECG signal and an interference signal to a digital filter configured to filter the input signal at a an initial preset frequency, the digital filter comprising an adaptive digital line filter with configurable filter coefficients; identifying a current power line frequency, if any, from the filtered input signal; providing a frequency look up table with a frequency index number for each frequency in a set of different frequency levels and a filter coefficient table with filter coefficients corresponding to each frequency index number, the set of frequency levels including incremental steps in the range of possible variations on the power line frequency; determining if an amplitude of the interference signal is above a threshold value; and if so, approximating the identified line frequency to a frequency index number in the frequency look up table corresponding to a closest frequency level to the identified current power line frequency; identifying a filter coefficient from the filter coefficient table corresponding to the identified frequency index number; re-configuring the digital filter using the identified filter coefficient; and filtering the input signal with the re-configured digital filter to correct the power line interference, wherein the reconfigured digital filter filters the input signal at a frequency corresponding to the identified current power line frequency in real time without buffering data.