| 摘要 |
An extracorporeal blood circuit including a haemodialyser and a pump for pumping blood to and from the haemodialyser, and a single needle for the passage of the blood to and from the body. The single needle is connected to the stem of a Y-shaped coupling, the first branch of which is connected to an inlet pipeline for the pump, an intermediate pipeline connecting the pump to the inlet of the haemodialyser, the outlet of which is connected to the second branch of the Y, a bubble trap being included in the outlet pipeline. A device is provided which seals the inlet and outlet pipelines intermittently and this is driven in a cyclic manner at a predetermined frequency. The haemodialyser and/or the pump and/or the intermediate or outlet pipeline has a variable internal volume which is sensitive to the variations in the differential pressure instantaneously existing between its interior and atmosphere. This may be effected by making some of these elements resilient, so that they can expand when the pressure increases. By this means it is unnecessary to provide pressure detectors which control the alternate occlusion of the pipelines. This substantially reduces the cost of manufacture and running the blood circuit. |
