The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 15, 1998
Filed:
Aug. 29, 1996
Ralf Wamsiedler, Schonungen, DE;
Bernd Mathieu, Spiesen-Elversberg, DE;
Fresenius AG, , DE;
Abstract
A method for testing filters arranged in the dialysis solution system of an extracorporeal blood treatment apparatus is described, in which the filter membrane being tested is fully wetted with an aqueous solution, in which the branch of the dialysis solution system housing one of the two chambers of the filter being tested is closed off from the remaining branches, in which gas is conducted into the closed-off branch until a predetermined excess pressure has formed in the one chamber of the filter being tested. Simultaneously, the aqueous solution previously conducted into the chamber to fully wet the filter membrane is expelled. The excess pressure in the one chamber of the filter is monitored, in which the pressure drop per unit time is compared with a given reference value which is characteristic of a fully intact filter membrane. If the reference value is exceeded, this provides and indication of a leak in the filter membrane. Further, a dialysis solution system of an extracorporeal blood treatment apparatus is described which comprises at least one filter (16, 35) and a means (21) for closing off a branch of the dialysis solution system housing one of the two chambers (18, 37) of the filter (16, 35) from the remaining branches of the dialysis solution system. The dialysis solution system also includes an air pump (42) for conducting air through at least one hydrophobic filter (43) in the closed-off branch of the dialysis solution system. Moreover, a monitoring device (56) is provided which compares the pressure drop value measured by a pressure sensor (54) and signals a leak in the filter membrane being tested if the given reference value is exceeded.