Percutaneous axial flow blood pump

Claim 1

A cable-driven percutaneous insertable intravenous axial flow blood pump preloadable to provide a substantially constant purge pressure unaffected by manipulation of the pump drive cable or cable sheath, comprising: (a) a static housing; (b) a rotor disposed in said static housing; (c) a drive cable for driving said rotor, said drive cable terminating in a cable fitting having a thrust bearing surface; (d) rotor extension means for connecting said rotor to said drive cable through said static housing, said rotor extension means being resiliently extendable; (e) movable bearing means disposed in said static housing, said rotor extension being journalled in said bearing means, and said bearing means having thrust bearing surface means for mating with said cable fitting thrust bearing surface to form a thrust bearing; (f) shoulder means on said rotor extension means for engaging said movable bearing means when said extension is extended; and (g) means for selectively fixedly interconnecting said movable bearing means and said static housing to immobilize said movable bearing means within said static housing; (h) whereby said thrust bearing can be preloaded to a predetermined load by pulling said cable fitting to extend said extension with a force greater than said predetermined load, relaxing said force to said predetermined load, and then immobilizing said bearing means.