A monitoring device detects a disruption of a fluid connection between first and second fluid containing systems using one or more pressure sensors arranged in the first fluid containing system to detect first pulses from the first fluid containing system and second pulses from the second fluid containing system. The monitoring device receives (501) pressure signal(s) from the pressure sensor(s), populates (504) signal vectors by signal segments in the pressure signal(s) and computes (505) one or more eigenvectors and/or one or more eigenvalues for the signal vectors by a source separation algorithm. The monitoring device detects (506) the disruption based on a monitoring parameter, which is computed as a function of the eigenvector(s) and/or eigenvalue(s) to be responsive to the second pulses in the pressure signal(s). The monitoring device may be associated with or included in an apparatus for extracorporeal blood processing, such as a dialysis machine.
