A compact blood pump includes a flexible bladder mounted within a rigid metal housing. Pneumatic pulses between the bladder and the housing produce pumping action in association with appropriate inlet and outlet valves. The bladder is configured to provide a stiffness characteristic which produces a...http://www.google.fr/patents/US4104005?utm_source=gb-gplus-shareBrevet US4104005 - Pneumatic bladder pump having stiffness symmetry
