Dynamic powerline interference subtraction from biosignals.

The performance of a previously developed and widely used method for powerline interference subtraction from the ECG is slightly reduced in the presence of continuous well-expressed EMG noise. Applying automatic adaptation of the 'linearity criterion' value in accordance to the ECG/noise ratio, the best conditions for application of the procedure can be obtained. The proposed method allows for reduction of possible distortions when applied on noise-free ECG and enhances its efficiency in the presence of non-powerline noise. Apart from ECG, it is applicable to impedance-cardiogram, plethysmogram, EEG and other biosignals.