These may be of different types but the one used at Groote Schuur Hos pital (figure 1) is the NCI-IBM 2997 model which uses disposable pre sterilised plastic tubing and a sepa ration band (figure 2) which is as sembled, inserted into the machine and all air flushed out with physio logical saline. The machine func tion, integrity of the tubing, and the alarm systems are tested before the s...