An artificial kidney system includes a dialyzer element through which blood of a patient and dialysate solution are circulated to enable transfer of waste, electrolytes, water and other components from the blood to the solution (and in some cases from the solution to the blood), blood pump and circulation apparatus for withdrawing blood from the patient and applying it to the dialyzer element and for returning blood from the dialyzer element to the patient, and dialysate pump and circulation apparatus for transporting dialysate solution from a dialysate source to the dialyzer element and from the dialyzer element to a dialysate sink. The blood and the dialysate pump apparatus each includes a flexible casing which, when compressed, forces fluid from the casing and which, when released, draws fluid into the casing. The dialysate circulation apparatus includes a variable volume accumulator jacket for receiving dialysate solution when the pump casing is compressed and for discharging dialysate solution when the pump casing is released. A pump actuator operates the blood pump apparatus and the dialysate pump apparatus to circulate blood and dialysate solution through the dialyzer element.

The present invention relates to a method of circulating organo-biological liquids, preferably blood, wherein a liquid contained in a reservoir is released to a pressure (head) level below its original fluid pressure (head) level, thereafter raised periodically or in steps to a pressure (head) level above the original level, then transferred from such level to a reservoir positioned at a predetermined, relatively lower pressure (head) level, and thereupon drained to an outlet positioned approximately at the level of the original pressure (head) level.

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.

Extracorporeal blood pumping apparatus for use, for example in cardiopulmonary bypass procedures, left ventricle assist, hemodialysis and the like. The pulsatile pump apparatus may comprise an elongated driver balloon and a similar blood pumping balloon positioned side by side in a rigid casing or housing having preferably a one-way air valve. The inlet and/or outlets of both balloons are off-set and sloping ballon end portions are provided, inter alia, to minimize folding and/or rubbing during use. The driver balloon is provided with a port for coupling to a pressure-vacuum source and the blood pumping balloon is provided with an inlet port and an outlet port and both balloons are of such a cross sectional size and construction as to provide non-occlusive action by the blood pumping balloon. The one-way valve in the housing permits the reduction of deflation time of the driver balloon when it is coupled to a vacuum source, the provision of counterpulsation, prevents the introduction of gas into the blood stream in the event of a failure of the blood pumping balloon and prevents actuation of the blood pumping balloon in the event of failure of the driver balloon.

Process/apparatus for the processing of body fluids, advantageously comprising plasmapheresis technique for the fractionation of whole blood, features (i) means, e.g., a common blood transfusion needle, for withdrawing and returning body fluid from and to a living patient; (ii) a body fluid separating module which comprises an upstream first compartment and a downstram second compartment, and having a semi-permeable membrane body fluid separator disposed therebetween; (iii) first conduit means communicating said withdrawal and return means (i) with the upstream first compartment of said separating module (ii); (iv) means provided along said first conduit (iii) for conveying body fluid in either direction therein; (v) means responsive to said conveying means (iv), adapted to monitor the pressure of body fluid circulating in said first conduit (iii), and provided between said withdrawal and return means (i) and said conveying means (iv); (vi) means for collecting body fluid transported across said semi-permeable membrane and communicating with the downstream second compartment of said separating module (ii); (vii) second conduit means communicating the upstream first compartment of said module (ii) to (viii) means for containing body fluid which has not been transported across said semi-permeable membrane thereof, (ix) third conduit means communicating said container means (viii) to said first conduit means (iii) at a point intermediate said conveying means (iv) and the upstream first compartment of said separating module (ii); (x) means provided along said first conduit (iii) at a point intermediate the upstream first compartment of said separating module (ii) and the juncture of communication between said container means (viii) and the said first conduit means (iii), for conveying body fluid therein in the direction of the said upstream first compartment; and (xi) means for ensuring that the pressure across the said semi-permeable membrane of any body fluid in contact therewith does not exceed predetermined value.