| 摘要 |
The invention relates to a device and method for monitoring access to a patient and/or an extracorporeal bloodstream and/or a dialysis liquid system during an extracorporeal blood treatment. The device according to the invention and the method according to the invention are based on the use of a centrifugal pump (9) for delivering blood or dialysis liquid in the extracorporeal bloodstream or dialysis liquid system instead of an occluding pump. The known centrifugal pumps are characterised in that even a small change in the differential pressure over the pump results in a large change in the flow rate. The device according to the invention has means (21) for measuring the flow rate of the blood or dialysis liquid delivered by the centrifugal pump and a control and processing unit (20), which is designed such that, when the measured flow rate Q changes by more than a predetermined amount, improper vascular access or a malfunction in the extracorporeal bloodstream or dialysis liquid system is inferred. A slight pressure drop occurs in the venous blood line, for example, during the extracorporeal blood treatment leads to a marked rise in the flow rate of the centrifugal pump. Said significant rise in the flow rate, which is apparent from the characteristic flat delivery curve of the centrifugal pump, is used according to the invention as a basis for recognising improper vascular access. |
