Adaptive Power Line Interference Canceller: a Survey

In this paper, we present a survey on implementation of adaptive power line interference canceller for ECG signals and recommends Least mean-square (LMS) algorithm for implementation of adaptive power line interference canceller using FPGA. Notch filters and adaptive interference cancellers are proposed in literature for power line interference canceller. Notch filters are ineffective, whenever the power line frequency is not stable or not accurately known, a mismatch between the suppression band and the power line frequency might lead to inadequate reduction of the power line interference therefore adaptive interference cancellers are beneficial. LMS algorithm is commonly used on adaptive filtering since it enables the design of modular systolic architectures. Adaptive interference cancellers are implemented using general-purpose microcontrollers or digital signal processors. These solutions are not optimum since they have low processing speed and sequential execution due to the fact that adaptive cancellers are implemented with a software program. Another solution is the implementation of the adaptive controller with field-programmable gate array (FPGA). The fundamental advantage that FPGAs offers is the parallel implementation of ECG signal processing algorithms without losing processing speed. It also provides additional control and management features in monitoring the ECG process. Use of systolic architectures in the implementation of LMS algorithm results in reduced area and high speed of operation.