An autotransfusion bag is provided with semi-rigid side walls and flexible material interconnecting the side walls. The bag is provided with spreader arms which extend across the top of the bag and across the bottom of the bag engaging retainer elements mounted on the external face of the side walls....http://www.google.es/patents/US4955877?utm_source=gb-gplus-sharePatente US4955877 - Autotransfusion bag
