Distal bearing support
In various embodiments, a catheter pump is disclosed herein. The catheter pump can include an elongated catheter body having a distal portion including an expandable cannula having an inlet and an outlet. The expandable cannula can have a delivery profile and an operational profile larger than the delivery profile. An impeller assembly can include an impeller shaft, and an impeller body can include one or more blades. The impeller blades can draw blood into the cannula when rotated. Further, an expandable support can have a mounting portion disposed on the impeller shaft distal of the impeller body and a cannula contact portion for reducing a change in tip gap due to bending of the cannula. The cannula contact portion can be disposed distal of the mounting portion.
1. A catheter pump, comprising:
a motor;
an elongated catheter body coupled with the motor, the elongated catheter body comprising a distal portion;
an expandable cannula disposed at the distal portion and comprising an inlet and an outlet;
an impeller mounted on an impeller shaft coupled to the motor such that operation of the motor causes rotation of the impeller to draw blood into the expandable cannula, the impeller disposed within the expandable cannula between the inlet and the outlet, the impeller configured to be inserted into a subject while disposed within the expandable cannula; and
an expandable distal bearing support configured to provide radial support of the impeller shaft within the expandable cannula, the expandable distal bearing support comprising a support member having:
a proximal portion coupled to and axially overlapping a distal end of the impeller shaft, the impeller shaft configured to rotate relative to the proximal portion, and
a lobe extending distally from the proximal portion.
2. The catheter pump of claim 1 , wherein the lobe comprises distal struts configured to contact an internal wall of the expandable cannula and coupled to proximal struts, the proximal struts coupled to and extending distally from the proximal portion of the support member.
3. The catheter pump of claim 1 wherein the motor is disposed at a proximal end of the elongate catheter body, wherein the motor is configured to remain remote from the impeller and to remain outside a patient.
4. The catheter pump of claim 1 further comprising a re-sealable member disposed distally of the impeller within the expandable distal bearing support.
5. The catheter pump of claim 4 , wherein the re-sealable member is coupled to the impeller shaft to enable the impeller shaft to rotate in the expandable distal bearing support, wherein the re-sealable member is held stationary with respect to the impeller shaft and distal of but aligned with the impeller.
6. The catheter pump of claim 1 further comprising a mounting portion positioned over the distal end of the impeller shaft and with which the proximal portion of the support member interfaces when the impeller shaft and mounting portion turn.
7. The catheter pump of claim 1 further comprising a nose member coupled to the impeller shaft distal of the proximal portion of the support member, the nose member configured to smooth a flow of blood to the impeller and to retain the expandable distal bearing support on the impeller shaft.
8. The catheter pump of claim 7 , wherein the distal end of the impeller shaft comprises engagement features configured to secure the nose member onto the impeller shaft when engaged by the nose member.
9. The catheter pump of claim 7 , wherein the proximal portion of the support member comprises a flaring at a proximal end thereof, the flaring configured to enable the proximal portion to pass proximally over the nose member during assembly.
10. The catheter pump of claim 1 , wherein the expandable distal bearing support comprises first and second lobes spaced circumferentially from each other.
11. The catheter pump of claim 1 further comprising a spacer disposed between the impeller and the proximal portion of the expandable distal bearing support.
12. A catheter pump, comprising:
a motor;
an elongated catheter body coupled with the motor, the elongated catheter body comprising a distal portion;
an expandable cannula disposed at the distal portion and comprising an inlet and an outlet;
an impeller mounted on an impeller shaft coupled to the motor such that operation of the motor causes rotation of the impeller to draw blood into the expandable cannula, the impeller disposed within the expandable cannula between the inlet and the outlet, the impeller configured to be inserted into a subject while disposed within the expandable cannula; and
an expandable distal bearing support configured to provide radial support of the impeller shaft within the expandable cannula, the expandable distal bearing support comprising a mounting portion coupled to a distal end of the impeller shaft to enable the impeller shaft to turn relative to the mounting portion, and a support member having:
a proximal portion coupled to the mounting portion and axially displaced distally of a distal end of the impeller shaft, and
a lobe extending distally from the proximal portion.
13. The catheter pump of claim 12 , wherein the impeller shaft has an enlarged diameter at the distal end and the mounting portion has a diameter less than the enlarged diameter at a proximal end of the mounting portion.
14. The catheter pump of claim 13 , wherein the mounting portion comprises an enlarged distal end having an inner diameter greater than the enlarged diameter at the distal end of the impeller shaft.
15. The catheter pump of claim 12 further comprising a re-sealable septum disposed in the mounting portion of the expandable distal bearing support.
16. The catheter pump of claim 15 , further comprising a nose member coupled with a distal end of the mounting portion, the nose member having a rounded distal portion with an aperture for passage of a guidewire through the impeller and the re-sealable septum.
17. The catheter pump of claim 12 , wherein the lobe comprises distal struts configured to contact an internal wall of the expandable cannula and coupled to proximal struts, the proximal struts coupled to and extending distally from the proximal portion of the support member.
18. The catheter pump of claim 12 , wherein the expandable distal bearing support comprises first and second lobes spaced circumferentially from each other.
19. The catheter pump of claim 12 , wherein the impeller shaft comprises a flaring at the distal end thereof.
20. The catheter pump of claim 12 further comprising a spacer disposed between the impeller and the mounting portion of the expandable distal bearing support.