resistant material such as teflon the engagement between the drive mechanism 223 and the drive shaft 227 may be accomplished by means of a threaded connection set screw and collar connection or a snap fit engagement the drive shaft 227 may be press fit welded threaded or adhesive bonded to the rotor 221 0094 fig1 is a detailed view of the screw pump rotor 221 the rotor is a single helix rotor having a hub 232 and a blade 233 the rotor generally is about 1 cm to about 5 cm preferably about 2 cm to about 4 cm long the diameter of the rotor is about 0 1 inch to about 0 25 inch preferably about 0 15 inch to about 0 2 inch the distance on the hub 232 between blade 233 turns may be uniform in some embodiments the distance between blade 233 turns is not uniform in certain embodiments the rotor is a single helix progressive pitch rotor and the kick area 234 has a greater distance on the hub 232 between blade 233 turns fig1 illustrates an alternative embodiment of the catheter of the invention wherein the screw pump 218 is located distal to the distal balloon 216 blood outlet 229 is still located between proximal balloon 215 and distal.