Practical Biomedical Signal Analysis Using MATLAB

2

Single channel (univariate) signal

2.1 Filters

Signals may contain many frequency components. Some of them may be of in-

terest like frequency bands of EEG rhythms; others like power line artifacts may be

undesired. To remove the unwanted part of spectral contents of the signal one usu-

ally uses filters. In order to be implementable the filter must be causal.Thatis,the

filter response must only depend on the current and past inputs. If the filter has to

depend also on the past outputs it still can be causal by introducing the feedback

with appropriate delays.

We shall discuss here only the digital filters implemented in software (not the

hardware electronic ...