| 摘要 |
An extracorporal, volumetrically regulated patient fluid treatment system and method are disclosed. Fresh fluid is metered into a patient fluid exchange unit by a first metering device (10) and spent fluid is drawn out by a pump (18). A back pressure regulator (30) is provided across the pump (18) to maintain its output pressure at a constant value. To the output of the pump (18) are connected a second metering device (20) and an open drain circuit (22). The second metering device (20) meters out of the patient fluid exchange unit a predetermined quantity of spent fluid. The open drain circuit (22) drains any fluid pumped by the pump (18), but not removed by the second metering device (20), to a drain (26) open to atmospheric pressure. When the dialysis unit (14) is deenergized, fluid in the dialyzer (14) returns rapidly to atmospheric pressure by virtue of the open path through the open drain circuit (22), pump (18) and back pressure regulator (30) to the dialyzer (14). |
