Intravascular blood pumps and methods of use and manufacture
Devices for moving blood within a patient, and methods of doing so. The devices can include a pump portion that includes an impeller and a housing around the impeller, as well as a fluid lumen. The impeller can be activated to cause rotation of the impeller and thereby move fluid within the fluid lumen.
1. An intravascular blood pump, comprising:
a collapsible housing including a fluid impermeable fluid conduit coupled to an expandable member, the expandable member having an open structure permitting flow therethrough, the fluid conduit including a distal end and a proximal end, a proximal portion of the expandable member extending proximally beyond the proximal end of the fluid conduit; and
a collapsible distal impeller axially spaced from a collapsible proximal impeller, the distal impeller having an expanded configuration and the proximal impeller having an expanded configuration,
the proximal impeller having an axial length in the expanded configuration, from 20% to 50% of the proximal impeller, measured along the axial length, being disposed outside of the fluid conduit while a remaining portion of the proximal impeller is disposed in the fluid conduit,
at least a portion of the distal impeller being disposed in the fluid conduit.
2. The blood pump of claim 1 , wherein from 20% to 45% of the proximal impeller, measured along the axial length, is disposed outside of the fluid conduit.
3. The blood pump of claim 1 , wherein from 20% to 40% of the proximal impeller, measured along the axial length, is disposed outside of the fluid conduit.
4. The blood pump of claim 1 , wherein about 20% of the proximal impeller, measured along the axial length, is disposed outside of the fluid conduit.
5. The blood pump of claim 1 , wherein about 25% of the proximal impeller, measured along the axial length, is disposed outside of the fluid conduit.
6. The blood pump of claim 1 , wherein about 30% of the proximal impeller, measured along the axial length, is disposed outside of the fluid conduit.
7. The blood pump of claim 1 , wherein about 35% of the proximal impeller, measured along the axial length, is disposed outside of the fluid conduit.
8. The blood pump of claim 1 , wherein about 40% of the proximal impeller, measured along the axial length, is disposed outside of the fluid conduit.
9. The blood pump of claim 1 , wherein a distal portion of the distal impeller extends distally beyond the distal end of the fluid conduit.
10. The blood pump of claim 1 , wherein the proximal impeller has a tapered proximal end region.
11. The blood pump of claim 10 , wherein the tapered proximal end region is disposed at least partially within a flared proximal end of the fluid conduit.
12. The blood pump of claim 1 , wherein the fluid conduit has a flared proximal end region.
13. The blood pump of claim 1 , wherein the fluid conduit has a flared distal end region.
14. The blood pump of claim 1 , wherein the proximal impeller is disposed entirely within the expandable member.
15. The blood pump of claim 14 , wherein the proximal portion of the expandable member tapers inward proximal to a proximal end of the proximal impeller and the distal portion of the expandable member tapers inward distal to the distal end of the distal impeller.
16. The blood pump of claim 1 , wherein the expandable member has a distal portion extending distally beyond the distal end of the fluid conduit.