Patent ID: 8747663

Claim:
A device for the extracorporeal treatment of blood comprising: a dialyser or filter divided by a membrane into a first chamber and a second chamber; an extracorporeal blood stream including the first chamber; a fluid system including the second chamber; a substituate pump connected to a substitution fluid line leading to the extracorporeal blood stream upstream or downstream of the dialyser or the filter; and a device configured to determine if a substitution fluid is supplied upstream or downstream of the dialyser or filter, wherein the device comprises: a control unit for at least one of shutting off the substituate pump and starting up the substituate pump; a measuring unit for measuring the pressure in the extracorporeal blood stream downstream of the dialyser or the filter; and a means for detecting a supply of substitution fluid upstream or downstream of the dialyser or the filter by determining an increase or decrease in the pressure after at least one of the shutting off the substituate pump which has been previously started up and the starting up the substituate pump which has been previously shut off.