Blood from a patient is treated extracorporeally by any selected one of a plurality of predetermined treatments. Each of the treatments involves the flow of blood from the patient into a primary chamber of a filtration unit, past a semipermeable membrane located in the filtration unit which separates...http://www.google.com.au/patents/US5679245?utm_source=gb-gplus-sharePatent US5679245 - Retention device for extracorporeal treatment apparatus
