Blood pumps
Inventors
Earles, Ronald G. • Heuring, Jason J. • Durst, Christopher A. • BENAVIDES, Omar M.
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-11779751-B2
Publication Date
2023-10-10
Expiration Date
Abstract
A blood flow assist system can include an impeller assembly including an impeller shaft and an impeller on the impeller shaft, a primary flow pathway disposed along an exterior surface of the impeller. The system can include a rotor assembly at a proximal portion of the impeller shaft. A secondary flow pathway can be disposed along a lumen of the impeller shaft. During operation of the blood flow assist system, blood can be pumped proximally along the primary flow pathway and the secondary flow pathway. The system can include a sleeve bearing distal the impeller. The system can include a drive unit having a distal end disposed distal a proximal end of the second impeller. The drive unit comprising a drive magnet and a drive bearing between the drive magnet and the impeller assembly.
Core Innovation
The invention relates to a blood flow assist system that includes an impeller assembly with a rotatable member carrying a first impeller and a second impeller. The first impeller pumps blood along a first flow pathway along an exterior surface of the first impeller, where a majority of the blood flowing along the first flow pathway is directed along a longitudinal axis of the blood flow assist system. The second impeller is disposed proximally on the rotatable member and spaced apart from the first impeller, and is configured to direct blood radially outward relative to the longitudinal axis from a second flow pathway in a lumen of the rotatable member.
The invention further provides drive and bearing structures configured to impart rotation to the rotatable member using a magnetically coupled drive unit that includes a drive magnet and a drive bearing. The drive bearing includes a convex bearing surface formed by a plurality of distally-projecting segments, where channels between adjacent segments form at least one second flow pathway. The impeller and bearing interfaces include concave and conical openings and mating concave/convex bearing surfaces to support operation while providing pathways for blood.
In addition, the invention addresses blood-related contact and flowpath behavior by specifying modified bearing arrangements that cyclically expose an exterior surface of the rotatable member to blood and by using bearing geometries designed to promote exchange of a lubricating-layer. A modified sleeve bearing arrangement allows a bearing surface to contact only part of a perimeter of the rotatable member at a selected axial location, so the exterior surface is cyclically exposed to blood as the rotatable member rotates. The rotor core architecture can be integrated to form a compact impeller shaft/flange with the second impeller, and the system can include optional pump housing outlet ports and a support structure using struts that contact a blood vessel wall to maintain spacing.
Claims Coverage
The document includes three independent claims. Each independent claim centers on a rotatable impeller assembly that defines an exterior first flow pathway and a lumen-based second flow pathway, with different structural specifics for impeller geometry and drive/bearing placement.
Exterior-surface first impeller and lumen-based radially-outward second impeller
A blood flow assist system with an impeller assembly comprising a rotatable member, a first impeller separate from and interfacing with an outer surface of the rotatable member configured to pump blood along a first flow pathway along an exterior surface of the first impeller with a majority directed along a longitudinal axis, and a second impeller disposed on the rotatable member spaced apart proximally from the first impeller configured to direct blood radially outward relative to the longitudinal axis from a second flow pathway in a lumen of the rotatable member, where the second impeller is disposed on a generally proximally-facing surface of the rotatable member.
Circular cylinder lumen impeller shaft and concave drive placement
A blood flow assist system including an impeller assembly with an impeller shaft comprising a circular right cylinder forming a constant inner diameter lumen extending proximally from a distal end, a first impeller extending outward from the impeller shaft, a second impeller disposed on the impeller shaft spaced apart proximally from the first impeller, and a drive unit configured to impart rotation to the impeller shaft, where the drive unit has a distal end disposed distal to a proximal end of the second impeller within a concave opening at a proximal end portion of the impeller shaft, the concave opening defined within a conical surface extending from a proximal end of the constant inner diameter lumen.
Proximally-facing second impeller extending radially beyond first-impeller outer surface
A blood flow assist system with a rotatable member having an outer surface and an inner surface along a longitudinal axis, a first impeller having an inside surface disposed on the outer surface of the rotatable member, and a second impeller disposed on the rotatable member spaced apart proximally from the first impeller along the rotatable member, where the second impeller is disposed on a proximally-facing surface extending radially beyond the outer surface upon which the first impeller is disposed.
Across the independent claims, the core claim coverage is directed to combining an exterior first impeller flow pathway with a lumen-based second flow pathway that directs blood radially outward, while specifying particular structural arrangements for the second impeller location and orientation and, in other independent claim sets, a cylindrical lumen impeller shaft with concave drive placement or a proximally-facing surface that extends radially beyond the first impeller mounting surface.
Stated Advantages
Reduced recirculation by directing primary and secondary flows in the same direction.
Improved bearing support while addressing thrombosis/hemolysis by cyclically exposing the shaft to blood and promoting lubricating-layer exchange.
Surface-area contact.
Integrated core provides compactness.
Thrust support reduction via magnetic coupling.
Documented Applications
Intravascular blood flow assist using a percutaneous deployment with a self-expanding localization system and retrieval feature geometry for deployment/retrieval.
Interested in licensing this patent?