GB1373837A - Centrifuge - Google Patents

Abstract

1373837 Centrifugal separators; mixing apparatus SEPAREX SA 16 Feb 1972 [19 Feb 1971] 7129/72 Headings B1C and B2P A centrifuge for treating fluid, e.g. blood, comprises a rotor 14; a flexible tube 23 passing through the rotor and projecting from its ends in alignment with the rotor spin axis, the tube inside the rotor being bent at 24 to form a treating chamber and being mounted to permit rotation about its own axis independently from the rotor; means 26, 40 for the admission of the fluid to be treated and for discharging the fluid after treatment and brake means 27, 31 dapted to engage the tube to cause the portion of the tube in the rotor to revolve about the axis of the tube in relation to the rotor. The rotor 14 is mounted in a housing 12. 13 firmly connected to an upper block 11 and is driven by a motor 15 through a belt 16. The tube 23 which is of polypropylene extends through a smooth PTFE tube 21 in the rotor and, when not engaged by the brake means 27, 31, participates in the spin of the rotor without revolving about its own axis. The lower end of the tube 23 extends through the cap portion 13 of the housing into a tubular guide element 25 and is connected to a capillary tube 26. The bottom end of the cap contains a bearing for the tube and a brake 27 of the coil spring type which is operable by a lever (not shown). The upper end of the tube widens into, and is rigid with, a bearing bush 30 which is surrounded by a brake 31 similar to brake 27. A syringe 32 actuated by a screw 41 is used to disperse a reagent into the tube 23, the capillary tube 35 of the syringe extending into sleeve 33 of elastic material which has. a closed bottom narrower portion provided with a self-closing slit 34 through which, when the plunger 36 of the syringe is pushed down, reagent is forced into the bend 24 of the tube 23. The upper wider portion of the sleeve 33 defines a chamber 37 which communicates via an opening 38 with the interior of the tube 23 and through a tube 39 with a channel 40 connected to a pump which permits suction or pressure to be generated inside the channel and the tube 23. In operation, e.g. when performing a Coombs test on a blood sample, the brakes 27, 31 are released to permit the tube 23 to rotate with the rotor. The centrifuge, or a sample holder 17, is vertically moved until the end of the capillary tube dips into a blood dish 18. Suction is applied to the channel 40 and a blood sample is drawn into the tube 23 in which it is held in the bend 24. The centrifuge and/or holder 17 is/are then moved vertically and horizontally and washing fluid is drawn from a dish 19 into the tube 23. Brakes 27, 31 are applied so that the tube 23 revolves about the spin axis of the rotor and at the same time about its own axis whereby centrifugal force during each revolution fluctuates, changing in direction towards and away from the tube axis and causing thorough mixing of the blood corpuscles and washing fluid. The brakes are then released causing the corpuscles by centrifugal force to be packed against a wall portion of the tube. A fresh quantity of washing fluid is drawn up the tube displacing the used washing fluid via the opening 38, the chamber 37, the tube 39 and the channel 40. When washing is completed the rotor is braked and the used washing fluid sucked out. The rotor is then restarted and AHG serum is injected by the syringe through the slit 34 into the tube 23. The brakes are re-engaged to effect mixing and finally, when the capillary tube 26 is moved over an empty dish 20 in the holder 17, the motor 14 is stopped and pressure is applied to the channel 40 to allow discharge of the blood and serum into the dish 20 for further analysis. A number of centrifuges may be assembled together, the rotor of the centrifuge that is directly driven by a motor driving the rotor of the next centrifuge by means of a belt and so forth.