Catheter blood pumps
Catheter blood pumps that include an expandable pump portion. The pump portions include a collapsible blood conduit that defines a blood lumen. The collapsible blood conduits include a collapsible scaffold adapted to provide radial support to the blood conduit. The pump portion also includes one or more impellers. The collapsible scaffold and/or an elongate member extending proximally from the pump portion may include portions of differing radial stiffness or flexibility.
1 . A catheter blood pump, comprising:
a pump portion comprising a blood impermeable conduit extending between an inflow and an outflow, and an impeller disposed at least partially within the blood impermeable conduit;
an elongate body coupled to and extending proximally from the pump portion and being disposed proximal to the outflow and blood impermeable conduit of the pump portion, wherein a distal region of the elongate body includes a preferential bending region that is more flexible than a first region of the elongate body adjacent to and proximal to the preferential bending region and more flexible than a second region of the elongate body adjacent to and distal to the preferential bending region, the second region adjacent to and proximal to the outflow of the pump.
2 . The blood pump of claim 1 , wherein the preferential bending region is more flexible than the outflow region of the pump portion.
3 . The blood pump of claim 1 , wherein the preferential bending region includes at least one of material or structure that contributes at least partially to the relatively greater flexibility in the preferential bending region.
4 . The blood pump of claim 1 , wherein the preferential bending region has a flexibility such that when the pump portion is positioned across an aortic valve, the preferential bending region assumes a bent configuration in an ascending aorta so as to maintain as co-linear an impeller long axis and a blood impermeable conduit long axis at the location of the impeller.
5 . The blood pump of claim 4 , wherein a proximal end of the impeller, including a blade, is only partially covered by the blood impermeable conduit.
6 . The blood pump of claim 1 , wherein the first region includes a distal end of an elongate outer catheter shaft.
7 . The blood pump of claim 1 , wherein the first region includes a distal end of drive cable tube, the drive cable tube extending around a drive cable.
8 . The blood pump of claim 7 , wherein the first region includes a distal end of the drive cable tube.
9 . The blood pump of claim 1 , wherein the first region includes a clean fluid path and a fluid return pathway.
10 . The blood pump of claim 1 , wherein the preferential bending region includes a clean fluid pathway.
11 . The blood pump of claim 1 , wherein the second region comprises a bearing housing that houses at least one bearing.
12 . The blood pump of claim 11 , wherein the bearing housing is a proximal bearing housing, the catheter blood pump further comprising a distal bearing housing disposed distal to a distal end of the blood conduit.
13 . The blood pump of claim 1 , wherein the second region that is distal to the preferential bending region comprises a rigid cylindrical member disposed about a bearing.
14 . The blood pump of claim 1 , wherein the preferential bending region has a length from 0.5 inches to 7 inches, optionally from 1 inch-5 inches.
15 . The blood pump of claim 1 , wherein the preferential bending region comprises a flexible tubular member with a plurality of gaps formed through the flexible tubular member, the plurality of gaps at least partially contributing to the flexibility of the flexible region.
16 . The blood pump of claim 15 , wherein the plurality of gaps are part of a continuous gap formed in the flexible tubular member.
17 . The blood pump of claim 16 , wherein the continuous gap includes at least a section with a helical configuration.
18 . The blood pump of claim 16 , wherein the plurality of gaps are formed by a plurality of interlocking structural elements.
19 . The blood pump of claim 18 , wherein the plurality of interlocking structural elements are spaced so as to allow for some axial movement therebetween and further prevent axial movement therebetween beyond a certain amount.
20 . The blood pump of claim 1 , wherein the plurality of interlocking structural elements are spaced so as to allow for some rotational movement therebetween and further prevent circumferential movement therebetween beyond a certain amount.
21 . The blood pump of claim 1 , wherein the blood pump is sized and configured to be inserted into a heart of a subject, and wherein the preferential bending region is configured to extend at least partially along an aortic arch of the subject when the pump portion is positioned across an aortic valve of the subject.