Patent ID: 8403824

Claim:
Heart assist apparatus suitable for implantation into a ventricle of a human heart, the apparatus comprising: (a) a pump comprising a housing having therein a radial impeller having a series of impeller blades arranged such there is a plurality of odd numbered impeller blades and a plurality of even numbered impeller blades alternating with said odd numbered impeller blades, and a rotor for driving said impeller, both said rotor and said impeller being arranged to be hydrodynamically suspended within the housing, the pump further including a stator for driving said rotor; (b) an inlet cannula section arranged to extend from an internal part of the ventricle to straddle the wall of the ventricle, the stator being within said inlet cannula section so as to be located in said internal part of the ventricle when said apparatus is implanted in said ventricle; (c) an outlet for blood driven by said impeller, said outlet being substantially transverse to said inlet cannula section, both said outlet and said impeller being arranged to reside outside of the heart when said apparatus is implanted in said ventricle, and (d) a shroud comprising a series of alternating front shroud members for alternate even-numbered ones of the impeller blades and a series of alternating rear shroud members for alternate odd-numbered ones of the impeller blades, each said blade being connected to an adjacent blade by a respective alternating one of the shroud members.