Impeller for catheter pump
An impeller for a pump is disclosed herein. The impeller can include a hub having a fixed end and a free end. The impeller can also have a plurality of blades supported by the hub. Each blade can have a fixed end coupled to the hub and a free end. The impeller can have a stored configuration and a deployed configuration, the blades in the deployed configuration extending away from the hub, and the blades in the stored configuration being compressed against the hub.
1. A catheter pump comprising:
a catheter; and
an impeller mounted at an end of the catheter, the impeller comprising:
a hub having a proximal end portion and a distal end portion; and
a plurality of blades supported by the hub, each blade of the plurality of blades comprising a curved surface having a radius of curvature and a height defined as extending from a fixed end proximate the hub and a free end opposite the fixed end, wherein the radius of curvature and the height are selected such that the plurality of blades do not overlap when in a stored configuration.
2. The catheter pump of claim 1 , wherein the impeller comprises at least three blades.
3. The catheter pump of claim 1 , wherein the impeller comprises a second row of blades.
4. The catheter pump of claim 3 , wherein each blade of the plurality of blades in the second row of blades comprising a curved surface having a radius of curvature and a height defined as extending from a fixed end proximate the hub and a free end opposite the fixed end, wherein the radius of curvature and the height are selected such that the plurality of blades do not overlap when in a stored configuration.
5. The catheter pump of claim 1 , wherein the curved surface is sized and shaped to conform to the shape of the hub when in the stored configuration.
6. The catheter pump of claim 1 , wherein each blade of the plurality of blades wraps helically around the hub.
7. The catheter pump of claim 1 , wherein each blade of the plurality of blades wraps helically around the hub by a wrap angle measured along a circumference of the hub.
8. The catheter pump of claim 7 , wherein each blade of the plurality of blades wraps helically around the hub by a wrap angle measuring between about 150 degrees and about 220 degrees.
9. The catheter pump of claim 7 , wherein each blade of the plurality of blades wraps helically around the hub by a wrap angle measuring between about 180 degrees and about 200 degrees.
10. The catheter pump of claim 1 , wherein each blade comprises:
a first blade angle defined near a distal end of the blade and extending between a plane perpendicular to the free end of the blade and a plane perpendicular to the hub;
a second blade angle defined near a proximal end of the blade and extending between a plane perpendicular to the free end of the blade and the plane perpendicular to the hub; and
a third blade angle defined mid-way between the distal end of the blade and the proximal end of the blade, and extending between a plane perpendicular to the free end of the blade and the plane perpendicular to the hub.
11. The catheter pump of claim 10 , wherein the first blade angle is between about 30 degrees and about 60 degrees, wherein the second blade angle is between about 25 degrees and about 55 degrees, and wherein the third blade angle is between about 30 degrees and about 45 degrees.
12. A method of storing an impeller within a sheath for a catheter pump, the method comprising:
providing a hub having a proximal end portion and a distal end portion, the hub supporting a plurality of blades;
inserting the hub into the sheath; and
collapsing the plurality of blades into a stored configuration, each blade of the plurality of blades comprising a curved surface having a radius of curvature, and a height defined as extending from a fixed end proximate the hub and a free end opposite the fixed end, wherein the radius of curvature and the height are selected such that the plurality of blades do not overlap when in a stored configuration.
13. The method of claim 12 , wherein collapsing the plurality of blades comprises:
collapsing a first blade row comprising a first blade and a second blade; and
collapsing a second blade row comprising a third blade and a fourth blade.
14. The method of claim 13 , wherein the first blade row further comprises three blades, and wherein the second blade row further comprises three blades.
15. The method of claim 12 , wherein collapsing the plurality of blades comprises collapsing each blade of the plurality of blades helically around the hub, wherein each blade wraps helically around the hub by a wrap angle measured along a circumference of the hub.
16. The method of claim 15 , wherein each blade wraps helically around the hub by a wrap angle measuring between about 150 degrees and about 220 degrees.
17. The method of claim 15 , wherein each blade wraps helically around the hub by a wrap angle measuring between about 180 degrees and about 200 degrees.
18. The method of claim 12 , wherein each blade comprises:
a first blade angle defined near a distal end of the blade and extending between a plane perpendicular to the free end of the blade and a plane perpendicular to the hub;
a second blade angle defined near a proximal end of the blade and extending between a plane perpendicular to the free end of the blade and the plane perpendicular to the hub; and
a third blade angle defined mid-way between the distal end of the blade and the proximal end of the blade, and extending between a plane perpendicular to the free end of the blade and the plane perpendicular to the hub.
19. The method of claim 18 , wherein the first blade angle is between about 30 degrees and about 60 degrees, wherein the second blade angle is between about 25 degrees and about 55 degrees, and wherein the third blade angle is between about 30 degrees and about 45 degrees.
20. The method of claim 12 further comprising:
forcing the hub from the sheath; and
expanding the plurality of blades from the stored configuration to a deployed configuration.