US 2015/0031936 A1 · AXIAL FLOW PUMP WITH MULTI-GROOVED ROTOR

Abstract

An axial-flow blood pump for pumping blood includes a substantially cylindrical outer enclosure. A tubular housing concentric with and located within the outer enclosure has at one end an inlet and at an opposite end an outlet. A motor stator is concentric with and located between the outer enclosure and the tubular housing. An impeller is concentric with and located within the tubular housing. The impeller is suspended in operation by a combination of passive magnetic forces between magnets within the impeller or magnetized regions of the impeller and the motor stator and hydrodynamic thrust forces generated as blood flows between the tubular housing and a plurality of hydrodynamic thrust bearing surfaces located on the impeller. A volute may be in fluid-tight connection with the outlet of the tubular housing for receiving blood in the axial direction and directing blood in a direction normal to the axial direction. The volute has a flow-improving member extending axially from the volute and into and coaxially with the tubular housing.

Claims36

Dependent claims

1-46. (canceled)

A blood pump comprising:

a cannula defining a pump chamber lumen;
a rotor within said lumen rotatable on a rotation axis concentric with said lumen and having a blood upstream end and a blood downstream end, said rotor having magnetic drive poles by which said rotor is rotated and being configured to direct blood flow axially within said lumen said rotor having one or more of each of a magnetic and hydrodynamic bearing surface to enable said rotor to rotate freely suspended within said lumen, and a tapered axial extension at said blood downstream end to enhance downstream blood flow characteristics in an axial direction when said rotor is rotating;
a magnetic stator ring surrounding a portion of said lumen within which said rotor is centered;
a volute in fluid flow communication with said pump chamber lumen downstream of said tapered axial extension of said rotor to minimize thrombus and increase pressure of pumped blood;
and
a blood flow straightener element within said volute and extending axially into the pump chamber lumen toward said tapered axial extension of said rotor to affect blood flow discharge from said rotor.

3 more elements

The blood pump of claim 1 comprising a cannula-like cylinder that encloses said magnetic stator ring and said tubular housing.

The blood pump of claim 1 in which said volute defines a central substantially annular chamber configured to redirect the blood flow from the pump chamber lumen in a direction normal to the rotational axis of the rotor to a volute outlet.

The blood pump of claim 1 in which said blood flow straightener element comprises a center post extending into said pump chamber lumen from the base of said volute along the rotational axis of the rotor.

The blood pump of claim 4 in which said center post is cylindrical having a dome-topped distal end portion.

The blood pump of claim 4 in which said center post comprises a double-tined distal end portion, said tines being located on opposite sides of the axis of said center post.

The blood pump of claim 6 in which each tine extends generally parallel to the axis of the center post.

The blood pump of claim 4 in which said center post comprises a generally rectangular-shaped distal end portion.

The blood pump of claim 8 in which the short axis of said rectangular-shaped distal end portion is aligned with and parallel to the axis of said center post portion.

The blood pump of claim 1 in which said blood flow straightener element comprises a dual legged stator element projecting into said pump chamber lumen along the axis thereof.

The blood pump of claim 10 in which the legs of said dual legged stator element are parallel and extend co-axially with the rotational axis of the pump.

The blood pump of claim 11 in which the distal end of each leg of said dual legged stator element is curved to an angle of 45° to the axis of said pump chamber lumen.

The blood pump of claim 12 in which the axis of curvature of the distal end of one leg of said dual legged stator element is perpendicular to the axis of curvature of the distal end of the other leg of said dual legged stator element.

A blood pump comprising:

a tubular housing defining a pump chamber lumen;
a rotor within said lumen rotatable on a rotation axis concentric with said lumen and having a blood upstream end and a blood downstream end, said rotor having magnetic drive poles by which said rotor is rotated and being configured to direct blood flow axially within said lumen, said rotor having one or more of each of a magnetic and hydrodynamic bearing surface to enable said rotor to rotate freely suspended within said lumen, and a tapered axial extension at said blood downstream end to enhance downstream blood flow characteristics in an axial direction when said rotor is rotating;
a magnetic stator ring surrounding said lumen within which said rotor is centered;
and
a blood flow straightener element communicating with and extending away from the pump chamber lumen to affect blood flow discharge from said rotor.

2 more elements

The blood pump of claim 14 in which said blood flow straightener element comprises a straight cylindrical tube defining a flow chamber and a blade carrying center post extending axially through at least a portion of the flow chamber and axially into said pump chamber lumen, said blade carrying center post comprising a pair of symmetrical diametrically opposed blade sections extending longitudinally along at least a portion of the length of said center post and axially into said pump chamber lumen beyond said center post by a predetermined amount.

The blood pump of claim 15 in which each blade section comprises a pointed distal end extending into said pump chamber lumen toward said tapered axial extension of said rotor.

The blood pump of claim 16 in which the distal ends of said blade sections are contoured to curve in opposite directions away from the axis of said center post.

The blood pump of claim 14 in which said blood flow straightener element comprises a straight cylindrical tube defining an axial flow chamber therethrough.

The blood pump of claim 18 in which said straight cylindrical tube has a circular outlet opening.

The blood pump of claim 18 in which said straight cylindrical tube has an oval outlet opening.

The blood pump of claim 18 in which said straight cylindrical tube comprises a blade element projecting radially inwardly from an inner sidewall of the flow chamber.

The blood pump of claim 21 in which said blade element is configured with a transverse axis aligned co-axial with the axis of said flow chamber.

The blood pump of claim 14 in which said blood flow straightener element comprises a bent tube having a constricted portion to diminish the rotational momentum of blood flow output from the pump chamber lumen.

The blood pump of claim 14 in which said rotor comprises a radially projection-free cylindrical circumference defined by a plurality of curved surface areas spaced apart by axially extending grooves defining blood flow channels across the rotor.

The blood pump of claim 24 in which the average depth of each groove is within the range of from about 1 mm to about 5 mm.

The blood pump of claim 24 in which said rotor has an outer diameter of about 10 mm.

The blood pump of claim 24 in which said grooves are substantially parallel.

The blood pump of claim 25 in which the depth of each groove is greater at said blood upstream end of said rotor than at said blood downstream end.

The blood pump of claim 14 in which the rotor comprises four of said grooves.

The blood pump of claim 14 comprising a plurality of rotors within said lumen axially aligned and spaced apart in the direction of blood flow within the lumen.

The blood pump of claim 30 in which said rotors are ganged together on a common shaft to rotate together as one in the same direction.

The blood pump of claim 30 comprising at least two of said rotors.

The blood pump of claim 30 in which each rotor is suspended to rotate independently.

The blood pump of claim 33 in which each rotor rotates in a different rotational direction from immediate upstream and downstream adjacent rotors.

The blood pump of claim 33 in which each rotor rotates at a different rotational speed from the immediate upstream and downstream adjacent rotors.

Dependencies are inferred from the claim text.

Axial flow pump with multi-grooved rotor

Life of this patent

Axial flow pump with multi-grooved rotor

Life of this patent

Abstract

Claims36