Introduction Biomedical signal analysis in practice (1)The complexity and non-stationary of biomedical signals; (2)Be impossible to obtain the prior information of signals and noise;Or (3)The statistical properties vary with time. Therefore,Wiener filter and Kaleman filter can not realize the optimum filtering in above situations. However,Adaptive filter can provide the excellent filtering performances. 55 Introduction Biomedical signal analysis in practice (1) The complexity and non-stationary of biomedical signals; (2) Be impossible to obtain the prior information of signals and noise; Or (3) The statistical properties vary with time. Therefore, Wiener filter and Kaleman filter can not realize the optimum filtering in above situations. However, Adaptive filter can provide the excellent filtering performances