Patent GB-1371678-A (GB)
Title: Blood processing apparatus
IPC: B04B5/04
Filed: 1972-11-17
Abstract: 1371678 Centrifugal separator INTERNATIONAL BUSINESS MACHINES CORP 17 Nov 1972 [23 Dec 1971] 53122/72 Heading B2P A blood processing apparatus, Figs. 1 and 2, comprises a centrifuge bowl 1, having a flexible membrane 7(15) therein under which fluid may be forced to alter the volume above the membrane; a collapsible blood bag 11, 13 adapted to fit in the centrifuge bowl above the membrane; a rotatable seal RS for connecting the blood bag to a tubing manifold; valves V 1 -V 4  for controlling the flow of fluids to and from the blood bag; a pump assembly HP(31-37), Fig. 4, for supplying and removing fluid from the space below the membrane; and a controller, Fig. 7, for a plurality of possible modes of operation during a cycle of operation comprising a plurality of manually operated switches, one for each mode of operation, electrically interlocked control means for providing a sequence of output control signals corresponding to each mode of operation, and automatic programming means effective to operate the interlocked control means in a predetermined sequence corresponding to a cycle of individual modes of operation. The apparatus is used for washing preservatives from thawed red blood cells with various solutions and resuspending the cells in isotonic solution, albumin or plasma in preparation for blood transfusion to a recipient. The disposable flexible bag is retained over bosses 23 in the bowl by a cover 21 which is held in position by hold-down screws which cooperate with a hole and slot arrangement in the cover. A tube 19 leads from the flexible bag to the tubing manifold connected via the valves V 1 , V 2 V 3  to various washing fluid receptacles 1, 2, 3 and via a valve V 4  to a waste receiver. Hydraulic fluid is admitted to, and removed from, the space below the membrane via the centrifuge hollow shaft 9 which communicates via a tubing 17 connected to the pump assembly HP and fluid reservoir HR (41) via valves such as V 5 . The centrifuge shaft is driven via belting . from a variable speed reversible electric motor and is supported in bearings 25, 27. The hydraulic control pump assembly HP comprises a pair of cylinders 31 with pistons tied by a yoke 33 which in turn is fastened to a rack 35 moved up and down by a pinion driven by a motor and gear assembly associated with suitable control circuitry whereby fluid may be forced into, or removed from, the bowl. A stepping switch 45 is uitilized in conjunction with a plugboard 43 by which varying operating programs may be arranged by the operator by connecting various jacks with suitable jumper wires. A relay mounting gate 47 is provided for mounting the various relays in the apparatus control circuit which is described in detail.  In operation, the flexible bag is placed in the centrifuge bowl either already filled with the blood cell-preservative mixture or filled via the tubing 19 from a blood container connected via a valve to the tube manifold. The centrifuge bowl is spun so that the blood cell mixture is pressed against the outside wall of the bowl. A negative pressure results in the fluid system under the flexible membrane 7(15) and, with the valve V 5 open during spinning and the reservoir HP(41) connected to atmosphere, fluid is forced into the bowl until the latter is full. Valve V 5  is closed and fluid is pumped into the bowl by the control pump HP. The resulting expansion of the membrane forces supernatant solution to flow to the waste receiver through valve V 4  which is open at this time. The centrifuge bowl is then stopped and put into an agitation mode in which it revolves for a few cycles in alternate directions on a continuing basis and waste solution is supplied to the bag by opening a suitable one of valves V 1 , V 2  and V 3  and pumping hydraulic fluid out from under the membrane by the pump HP. During the agitation mode valve V 5  is open. This process is repeated as many times as desired and the operation of the entire system is variably controlled either by manual control or through the internal programming of the system.