Patent GB-1537095-A (GB)
Title: Centrifugal blood processing apparatus
IPC: A61M1/36
Filed: 1976-03-25
Abstract: 1537095 Centrifuges for treating blood BAXTER TRAVENOL LABORATORIES Inc 25 March 1976 [27 March 1975 11 Feb 1976] 11952/76 Heading B2P A centrifugal blood processing apparatus 20, Figs. 2 and 5, comprises a rotor assembly 30 which includes one or more containers 80, 81 for receiving a blood specimen to be processed by centrifugation and which is rotatably mounted on a rotor drive assembly 50 the latter in turn being rotatably mounted on a stationary base 62. Liquid communication is maintained between the containers and a location external to the apparatus by means of a flexible umbilical cable 90 having liquid passageways 91-94 therethrough, Fig. 9, and extending from the containers to the said external location by way of a hollow drive shaft 40 of the rotor assembly and guide means 97, 98, 99 carried on the rotor drive assembly. The rotor assembly is rotatably driven in the same direction as, and at twice the rotational speed of, the rotor drive assembly to prevent the umbilical cable from becoming twisted during operation of the apparatus. The apparatus may be used, as shown in Fig. 8, for washing thawed, once-frozen, glycerolized red blood cells with a saline solution which displaces the glycerol preservative to form reconstituted blood. The rotor assembly 30 includes a bowl-shaped windshield 31 and a support bracket 32 attached to the drive shaft 40. Cylindrical support cups 33, 34, in which the containers 80, 81 in the form of wash bags are received, are mounted on bracket 32 by means of pins 35, 36 engaging in slots 37, 38 in the bracket. The rotor drive assembly 50 includes plates 51, 52, 53 held together by spacers 54 and bolts 55 and a bowl-shaped wind shield 56. A hub 57 extending between plates 51 and 52 forms a bearing for drive shaft 40. The rotor drive assembly is journalled to the base of a stationary housing 21 (which may be insulated and lined to permit refrigeration of its interior) along the same axis as the rotor assembly 30 by means of a shaft 60 which is attached by a flange 61 to plate 53 and is supported in bearings 63 in a hub assembly 62. Shaft 60 is driven through belt 65 and pulleys 64, 66 by an electric motor 68. The rotor assembly 30 is driven by a planetary drive shaft 73 which is journalled by means of a bearing assembly 74 to plate 53 and which carries, at its bottom end, a drive pulley 72 coupled by a belt 71 to a stationary ring-type pulley 70 fitted to the top of the hub assembly 62 and, at its top end, a drive pulley 75 coupled by a drive belt 76, via two idler pulleys, of which only one is shown at 77 journalled to plate 52, to a drive pulley 42 fitted to the bottom end of shaft 40. With this drive arrangement and selected relative diameters of the drive pulleys, the rotor assembly 30 is caused to turn in the same direction as, and at twice the rotational speed of the rotor drive assembly 50. Weights 100, 102 carried on threaded support members 101, 103 on plate 52 serve to balance the rotor drive assembly radially and laterally respectively. The wash bags 80, 81, Fig. 5, are connected by inlet and outlet tubes 84, 85 and 86, 87 to one end of respective axes of the passageways 91-94 in the cable 90 which is suspended by means of a clamp 95 located at the end of a stationary support arm 96. At the other end of cable 90, passageways 91-94 are connected to respective ones of plastics tubes 130-133, Fig. 8. Tubes 130, 131 are routed through a reversible roller pump 134 to a junction box 135 wherein communication is established between these tubes and glycerolized red blood cell containers 144, 153 or saline wash solution containers 147, 148, 156, 157 or washed or reconstituted blood reservoirs 150, 159. The tubes 132, 133 carry the spent wash solution containing the removed glycerol preservative to wash. An alternative drive arrangement for the rotor assembly 30 and alternative constructions of the guide means for the cable 90 are described.