초록 ▼

An apparatus for controlling the ultrafiltration rate in machines for the extracorporeal purification of blood in which the difference obtained in the blood circuit by an electromagnetic flow meter is used for controlling the ultrafiltration rate. The ultrafiltration rate is controlled by controllin

An apparatus for controlling the ultrafiltration rate in machines for the extracorporeal purification of blood in which the difference obtained in the blood circuit by an electromagnetic flow meter is used for controlling the ultrafiltration rate. The ultrafiltration rate is controlled by controlling the transmembrane pressure across the membrane separating the blood chamber from the dialysis fluid chamber in a dialyzer. In one embodiment, the pressure in the blood circuit is varied to change the transmembrane pressure. In a second embodiment, the pressure in the dialysis solution circuit is varied.

대표청구항 ▼

In a hemodialysis apparatus comprising a first chamber, a second chamber, a dialysis solution circuit, a blood circuit, means for preparing a fresh dialysis solution, and means for withdrawing ultrafiltrate from said dialysis circuit, said first chamber being separated by means of a membrane from sa

In a hemodialysis apparatus comprising a first chamber, a second chamber, a dialysis solution circuit, a blood circuit, means for preparing a fresh dialysis solution, and means for withdrawing ultrafiltrate from said dialysis circuit, said first chamber being separated by means of a membrane from said second chamber, said first chamber being connected into said dialysis solution circuit, and said second chamber being connected into said blood circuit, said blood circuit including a first blood side upstream of said second chamber and a second blood side downstream of said second chamber, the improvement comprising: a single sensor coupled between a single connection with a patient and a branch of said blood circuit into said first and second blood sides, said sensor alternately sensing inflowing blood quantities and outflowing blood quantities; an ultrafiltrate controller coupled to said sensor for receiving signals from said sensor and being operative during a first time interval to recognize a first output signal from said sensor representing outflowing blood quantities and being operative during a second time interval to recognize a second output signal from said sensor representing inflowing blood quantities and being operative after said first and second time intervals to compare said first output signal with said second output signal to determine the actual ultrafiltration rate; a control unit connected to said ultrafiltrate controller, said control unit having input means for inputting a predetermined ultrafiltration rate; and a dialysis solution pump coupled in said dialysis circuit downstream of said first chamber and operatively coupled to said ultrafiltrate controller for changing the pressure in said dialysis solution circuit, thereby changing the transmembrane pressure to cause the actual ultrafiltration rate to approach said predetermined ultrafiltration rate.