High gradient magnetic separation of red cells from whole blood

It is demonstrated that red blood cells may be separated from other blood components using a high gradient magnetic separator. The (SI) magnetic susceptibility of red blood cells is estimated to be 3.88×10^-6when the haemoglobin is in the completely deoxygenated state. The magnetic separation effects have been studied using a filter of circular stainless steel wire with flow rates between 10^-4ms^-1and 6×10^-4ms^-1and magnetic fields in the range 0.6 to 2.4 T. The results indicate that the filter quickly saturates and the variation of filter performance with field and flowrate is discussed in terms of the force balance and the particle trajectory model. Scanning electron microscopy and free haemoglobin tests on the filtered red blood cells show no evidence of serious damage or cell rupture.