US 5,017,103 A · Centrifugal blood pump and magnetic coupling

Abstract

A centrifugal blood pump having a pumping chamber provided with an axial inlet and a circumferential outlet and provided with a rotatable impeller having a plurality of radially extending blood propelling vanes. The vanes are configured to each have a blade angle which varies monotonically toward the periphery of the chamber. The pumping chamber is delimited by an impeller housing provided with an opening through which the impeller shaft extends into the chamber, the opening having an outline which conforms closely to the outline of the shaft, and the pump further includes a bearing housing secured to the impeller housing and delimiting a bearing chamber into which the shaft extends; bearings disposed in the bearing chamber and rotatably supporting the shaft; and a seal located in the bearing chamber adjacent the opening and surrounding the shaft to form a fluid seal between the blood pumping chamber and the bearing chamber. The impeller is driven by a plurality of magnetizable plates secured to the impeller and spaced apart about the longitudinal axis, and a rotatable magnetic drive assembly disposed outside of the impeller housing and mounted for rotation about the longitudinal axis, the drive assembly producing a magnetic field which passes through each plate for attracting the plates to the drive assembly and rotating the impeller with the drive assembly.

Claims26

Dependent claims

In a centrifugal blood pump composed of an impeller housing having a generally circular cross section and a longitudinal axis and delimiting a blood pumping chamber having a blood inlet port extending along the longitudinal axis and a blood outlet port located at the periphery of the chamber, an impeller provided with a plurality of radially extending curved vanes disposed in the chamber, each said vane having a first end adjacent said blood inlet port and a second end extending toward the periphery of the chamber, an axial shaft supporting the impeller for rotation about the longitudinal axis of the blood pumping chamber, and drive means for rotating the impeller in a sense to cause the vanes to propel blood radially from the inlet port to the outlet port, the improvement wherein said vanes are configured according to the formula:

R=R1+C1.multidot..THETA.+C2.multidot..THETA..sup.C3
where:
R is the radial distance from each point along each vane to the axis of rotation of said shaft;
R1 is the radial distance from the first end of each vane to the axis of said shaft;
.THETA.is the angle, in radians, about the axis of rotation of the shaft, between a line extending between the shaft axis on the first end of each vane and a line extending between the shaft axis and the point on the same vane whose radial distance from the shaft axis is R;
C1=R1.multidot.tan B.sub.1, where B is the angle, at a point along a vane, between a line tangent to the blade surface and a line tangent to a circle passing through that point and centered on the axis of said shaft, B.sub.1 is the blade angle in radians, of each vane at its first end;
C2=(R.sub.2 tan B.sub.2 -C1)/(C3.multidot..THETA..sub.2 (C3-1)), where R 2 is the radial distance from the second end of each vane to the shaft axis, B.sub.2 is the blade angle, in radians, of each vane at the second end, and .THETA..sub.2 is the value for .THETA. associated with the radial distance R2;
and wherein
C3=(R2.multidot.tan B.sub.2 -C1).multidot..THETA..sub.2 /(R.sub.2 -R.sub.1 -C1.multidot..THETA..sub.2).

6 more elements

In a centrifugal blood pump composed of an impeller housing having a generally circular cross section and a longitudinal axis and delimiting a blood pumping chamber having a blood inlet port extending along the longitudinal axis and a blood outlet port located at the periphery of the chamber, an impeller provided with a plurality of radially extending vanes disposed in the chamber, a shaft supporting the impeller for rotation about the longitudinal axis of the blood pumping chamber, and drive means for rotating the impeller in a sense to cause the vanes to propel blood radially from the inlet port to the outlet port, the improvement wherein said drive means comprise:

a plurality of magnetizable plates secured to said impeller and spaced apart about the longitudinal axis;
and a rotatable magnetic drive assembly disposed outside of said impeller housing and mounted for rotation about the longitudinal axis, said drive assembly comprising means producing a magnetic field which passes through each said plate for attracting said plates to said drive assembly and rotating said impeller with said drive assembly.

In a centrifugal blood pump composed of an impeller housing having a generally circular cross section and a longitudinal axis and delimiting a blood pumping chamber having a blood inlet port extending along the longitudinal axis and a blood outlet port located at the periphery of the chamber, an impeller provided with a plurality of radially extending vanes disposed in the chamber, a shaft supporting the impeller for rotation about the longitudinal axis of the blood pumping chamber, and drive means for rotating the impeller in a sense to cause the vanes to propel blood radially from the inlet port to the outlet port, the improvement wherein said drive means comprise:

a plurality of magnetizable plates secured to said impeller and spaced apart about the longitudinal axis;
and a rotatable magnetic drive assembly disposed outside of said impeller housing and mounted for rotation about the longitudinal axis, said drive assembly comprising means producing a magnetic field which passes through each said plate for attracting said plates to said drive assembly and rotating said impeller with said drive assembly.

Dependencies are inferred from the claim text.

Centrifugal blood pump and magnetic coupling

Life of this patent

Centrifugal blood pump and magnetic coupling

Life of this patent

Abstract

Claims26