A reverse flow pump comprising two concentric passageways and an interior compartment having cut out portions in communication with a pump passageway for the directional flow of fluid relative to the pump, and a rotor positioned within the interior compartment for reversing the directional flow of fluid...http://www.google.com.au/patents/US6123725?utm_source=gb-gplus-sharePatent US6123725 - Single port cardiac support apparatus
