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摘要

A method and device for detecting stenoses in a tubular line system during an extracorporeal hemotherapy. The tubular line system has an arterial branch going out from the patient and leading to a hemotherapeutic unit, and a venous branch going out from the hemotherapeutic unit and leading to the patient, where an oscillating pressure signal is generated in the tubular line system, and the oscillating pressure signal is measured. To detect stenoses, the frequency spectrum of the oscillating pressure signal is analyzed, in response to a change in the frequency spectrum. This method is based on the principle that, in response to the existence of a stenosis, the dynamic performance of the tubular line system changes, the higher frequency components of the pressure signal generated by the rollers of the blood pump, which propagates across the tubular line system, being attenuated due to the compliance of the line system.