US 4,135,253 AGranted

Centrifugal blood pump for cardiac assist

AssigneeMedtronic, Inc.

InventorsSanford Reich, William H. Gates

Life of this patent

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Abstract

A centrifugal blood pump and method of pumping blood is disclosed to provide assistance for a dysfunctional heart. The pump is provided with a magnetic drive system which permits a synchronous magnetic coupling with a separate power unit disposed immediately adjacent the pump housing. The pump has a single moving part which includes the combination of an impeller connected to a magnetic drive rotor. The impeller is of improved blade and hub design to automatically move blood, and minimize formation of blood clots and fibrous amalgamation in the region of blood flow. Further, the impeller blades are configured to extend almost completely across the bottom surface of the impeller hub to enhance efficiency and clot-free operation. The magnetic drive system floats on a fluid surface of saline solution, which hydrodynamically supports and lubricates the magnetic drive rotor contained in a compartment separate from the impeller and facilitates a prolonged period of service-free operation.

Claims17

Dependent claims

A centrifugal blood pump comprising:

(a) pump housing means having a first chamber, a second chamber and baffle means disposed therebetween and having an aperture communicating between said first and second chamber including an inlet and an outlet for receiving and dispensing blood into and from said first chamber respectively;
(b) rotor means rotatively mounted within said second chamber and adapted to be rotated by drive means coupled thereto;
(c) an impeller rotatively disposed within said first chamber and connected by coupling means to said rotor means through said aperture of said baffle plate to be rotated thereby, said impeller including a plurality of blades extending from an axis thereof, whereby blood is pumpled from said inlet to said outlet;
(d) seal means disposed between said coupling means and said aperture for isolating a lubricating solution disposed within said second chamber from the blood pumped through the first chamber;
and
(e) said impeller includes a hub having a shank end connected via a shank to said impeller, and a conical end, said plurality of blades extending from said hub, each of said plurality of blades having an edge extending from a point disposed relatively close to said baffle plate and adjacent to said shank along a countour corresponding to that of said baffle plate, said shank end of said hub configured to extend from said adjacent points and increasingly away from said baffle plate to thereby define a portion of each of said plurality of blades disposed between said shank end of said hub and said baffle plate for rapidly moving the blood in the vicinity of said shank.

3 more elements

A centrifugal blood pump comprising:

a) a cylindrical pump housing having a scroll pump chamber within said housing, a rotor housing connected to said pump housing having a rotor chamber and a baffle plate separating said pump housing from said rotor housing, an axially disposed aperture in said baffle plate, an impeller having a first shank and disposed in said pump housing;
b) a rotor having a second shank and disposed in said rotor housing, said impeller being connected to said rotor by passing said first shank through said axially disposed aperture in said baffle plate and connected to said second shank;
c) a seal surrounding said first shank and affixed in said axially disposed aperture of said baffle plate to prevent blood in said pump chamber from seeping into said rotor chamber;
d) an axially disposed first inlet in said pump housing for bringing blood into said pump chamber;
e) a transverse first outlet in said pump housing for removing blood from said pump chamber;
f) a second inlet in said rotor chamber for bringing a saline solution lubricant into said rotor chamber;
and
g) a second outlet in said rotor chamber for removing the saline solution lubricant from said rotor chamber.

5 more elements

A centrifugal blood pump comprising:

a housing;
a scroll pump chamber within said housing;
an axial inlet to and tangential outlet from said scroll pump chamber;
pump means within said scroll pump chamber for moving blood therethrough comprising an impeller mounted for rotation in said chamber;
magnetic drive means for driving said pumping means;
a rotor chamber within said housing for enclosing said drive means and for receiving a liquid lubricant;
and
at least the portion of said housing enclosing said drive means being electrically non-conductive whereby said drive means may be driven by a mechanically unconnected external source of magnetic energy, wherein an improvement comprising:
a baffle plate disposed between said scroll pump chamber and said rotor chamber and including a center aperture, and said impeller having an impeller shank extending through said center aperture in said baffle plate, said magnetic drive means including a rotor and connected to said impeller shank, a seal disposed in said aperture of said baffle plate to surround said impeller shank and having the property of substantially blocking the passage of the lubricant into said scroll pump chamber, said impeller including a hub from which said shank extends and a plurality of radiating blade members, said hub having a conical end and a shank end, said blade members being secured to the shank end of said hub and said conical end of said hub, said blade members extend from said shank of said hub to maintain said hub out of contact with said baffle plate.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/746,008Filed 30 Nov 1976
Granted: 23 Jan 1979
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

F04D 13/024
Containing a coupling: a magnetic coupling
A61M 60/178
Implantable in, on, or around the heart: drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to…
A61M 60/232
The blood flow through the rotating member having mainly radial components: centrifugal pumps
A61M 60/419
For non-positive displacement blood pumps: the force acting on the blood contacting member being permanent magnetic, e.g. from a rotating magnetic…