A signal filtering device acquires one or more pressure signals that comprise first pulses originating from a first pulse generator associated with a fluid containing system and second pulses. The signal filtering device populates (504) signal vectors by signal segments in the pressure signal(s) and computes (505) principal components for the signal vectors by Principal Component Analysis (PCA). A filtered signal is generated by selecting (506) a first subset of principal components mainly representing the first pulses, determining (507) associated weights, and subtracting (508) the principal components in the first subset from the pressure signal as a function of the weights. Alternatively, a filtered signal is generated by selecting (506) a second subset of principal components that are excluded from the first subset, determining (507) associated weights, and combining (508) the principal components in the second subset as a function of the weights. The signal filtering device may be associated with or included in an apparatus for extracorporeal blood processing, such as a dialysis machine.
