Blood pump
This invention concerns an intravascular blood pump for percutaneous insertion into a patient's blood vessel. The blood pump comprises a pump casing having a blood flow inlet and a blood flow outlet, an impeller arranged in said pump casing so as to be rotatable about an axis of rotation. The impeller has blades sized and shaped for conveying blood from the blood flow inlet to the blood flow outlet. The blood pump comprises a drive unit for rotating the impeller, the drive unit comprising a plurality of posts arranged about the axis of rotation and a back plate connecting rear ends of the parts, the posts and the back plate together forming a magnetic core of the drive unit. A coil winding is disposed around each of the posts. The coil windings are controllable so as to create a rotating magnetic field, wherein the impeller comprises a magnetic structure arranged to interact with the rotating magnetic field so as to cause rotation of the impeller. The magnetic core or a part of it comprises a discontinuous soft magnetic material which is discontinuous regarding electric conductivity in a cross-section, wherein at least one weld is provided at a surface of the discontinuous soft magnetic material. The weld bridges at least one discontinuity regarding electric conductivity in the discontinuous soft magnetic material. Further, the invention concerns a method of manufacturing the magnetic core.
1 . An intravascular blood pump for percutaneous insertion into a patient's blood vessel, comprising:
a pump casing having a blood flow inlet and a blood flow outlet,
an impeller arranged in said pump casing so as to be rotatable about an axis of rotation, the impeller having blades sized and shaped for conveying blood from the blood flow inlet to the blood flow outlet,
a drive unit for rotating the impeller, the drive unit comprising a plurality of posts arranged about the axis of rotation and a back plate connecting rear ends of the plurality of posts, wherein the plurality of posts and the back plate form a magnetic core of the drive unit, and
a coil winding disposed around each of the plurality of posts, the coil windings being controllable so as to create a rotating magnetic field,
wherein the impeller comprises a magnetic structure arranged to interact with the rotating magnetic field so as to cause rotation of the impeller, and
wherein at least one post of the plurality of posts comprises a discontinuous soft magnetic material which is discontinuous regarding electric conductivity in a cross-section of the at least one post, wherein at least one weld is provided at a surface of the discontinuous soft magnetic material, the at least one weld bridging at least one discontinuity regarding electric conductivity in the discontinuous soft magnetic material, wherein the discontinuous soft magnetic material comprises a plurality of electrically conducting wires disposed within the at least one post, the plurality of electrically conducting wires insulated from each other by an insulating material.
2 . The intravascular blood pump of claim 1 , wherein at least one of the at least one weld is arranged at a rear end surface of the at least one post.
3 . The intravascular blood pump of claim 1 , wherein at least one of the at least one weld is arranged at an impeller-side end surface of the at least one post.
4 . The intravascular blood pump of claim 1 , wherein at least one of the at least one weld is arranged at an impeller-side end surface of the at least one post and at least one further weld is arranged at a rear end surface of the at least one post.
5 . The intravascular blood pump of claim 1 , wherein two of the at least one weld are arranged at one end of the at least one post spaced apart from each other.
6 . The intravascular blood pump of claim 1 , wherein at least one of the at least one weld extends over a side surface of the at least one post.
7 . The intravascular blood pump of claim 1 , wherein more than one of the at least one weld is arranged on a same surface side of the at least one post.
8 . The intravascular blood pump of claim 1 , wherein the at least one weld comprises a weld seam bridging the at least one discontinuity regarding electric conductivity in the discontinuous soft magnetic material.
9 . The intravascular blood pump of claim 1 , wherein the plurality of electrically conducting wires include at least a first wire and a second wire that have different diameters.
10 . The intravascular blood pump of claim 1 , wherein the plurality of electrically conducting wires each have a circular cross-sectional shape.
11 . The intravascular blood pump of claim 1 , wherein the plurality of electrically conducting wires each have a polygonal cross-sectional shape.