Patent ID: 9616164
Date: 2017-04-11
CPC Classifications: A61M,B01D

Claim:
1. A device for detecting recirculation for an extracorporeal blood treatment apparatus, the extracorporeal blood treatment apparatus comprising an extracorporeal blood circuit with an arterial blood line, which leads to a first chamber of a dialyser or filter divided by a membrane into the first chamber and a second chamber, and a venous blood line, which leads away from the first chamber of the dialyser or filter, a fluid system, which comprises the second chamber of the dialyser or filter, a device for conveying blood at a preset blood flow rate Q b through the arterial blood line into the first chamber of the dialyser or filter and through the venous blood line from the first chamber of the dialyser or filter, and a device for supplying substituate to the blood at a preset substituate rate Q s in the arterial blood line upstream of the dialyser or filter, the device for detecting the recirculation comprising: a measuring unit adapted for measuring pressure in the extracorporeal circuit in the arterial and/or venous blood line; an evaluation unit adapted for detecting the recirculation based on the pressure measurement; and a control unit cooperating with the device for conveying blood and the device for supplying substituate, the control unit being adapted, in an operating mode for detecting the recirculation, to control the device for conveying blood such that in a preset time interval, a preset first blood flow rate Q wherein the evaluation unit is adapted to monitor the pressure measured by the measuring unit in the arterial and/or venous blood line for a change in the pressure and to calculate a ratio between an amount of the change in the pressure measured by the measuring unit in the arterial blood line and an amount of the change in the pressure measured in the venous blood line.