Negative pressure valving system and transmembrane pressure alarm system

摘要

There is disclosed herein a negative pressure dialysis machine which includes a negative pressure valving system and transmembrane pressure alarm system. An electromagnetically controlled flapper valve is disclosed herein for use as a negative pressure control valve. The flapper valve permits accurate control of negative pressure and changes in negative pressure to be affected rapidly. Transmembrane pressure alarm systems are provided which detect the difference in pressure between the blood and dialysate in the dialyzer and activate alarms and prevent dialysis (a) if the dialysate pressure exceeds the blood pressure and/or (b) if a blood pressure signal is not received which would permit actual transmembrane pressure to increase beyond a predetermined limit.