Device and method for inspecting a filter for an extracorporeal blood treatment device

摘要

The present invention relates to devices and methods for inspecting filters for extracorporeal blood treatment devices, e.g., filters for filtering dialysis fluid. The inspection of the filter according to the present invention is based on the measurement of the flow potential before and after changing the fluid flow of an electrolytic fluid between a transversal flow through the semi-permeable membrane of the filter and a longitudinal flow along the semi-permeable membrane of the filter, or vice versa. Changing the flow direction of the electrolytic fluid results in a change to the conductivity proceeding from a base value P to a higher value P2 or a lower value P1, wherein the conductivity readjusts to the base value P after a certain time interval T1, T2. An improper state of the filter is determined on the basis of the change in conductivity after changing the flow direction of the electrolytic fluid.

主权项

1. A device for checking a filter having a semipermeable membrane which separates a primary side and a secondary side of the filter, the device comprising:
a flow direction changing system configured to generate:
a change in a flow direction between a transverse flow of an electrolytic fluid through the semipermeable membrane of the filter and a longitudinal flow of the electrolytic fluid along the semipermeable membrane of the filter; anda change between the longitudinal flow of the electrolytic fluid along the semipermeable membrane of the filter and the transverse flow of the electrolytic fluid through the semipermeable membrane of the filter; a measurement system arranged downstream of the filter and configured to measure a conductivity of the electrolytic fluid flowing in the transverse direction downstream of the filter and of the electrolytic fluid flowing in the longitudinal direction downstream of the filter; and a computing and evaluation unit configured to monitor a change in the conductivity after the change in the flow direction of the electrolytic fluid from a base value, said unit being configured such that a presence of an incorrectly functioning state of the filter is ascertained based on the change in the conductivity after the change in the flow direction of the electrolytic fluid.