Ventricular assist device and method
A ventricular assist device includes a stent for placement within a cardiac artery and arranged for placement, the stent arranged to have an open configuration defining a flow path, a rotor sized to fit within the stent and arranged for percutaneous placement the flow path, the rotor including a surface disposed about a central portion and angled with respect to the flow path and having a first plurality of magnets. A collar is sized for placement about the cardiac artery and includes a stator. A power source is coupled to the stator, and the stator and the rotor are arranged to rotate the rotor about an axis. A timing control module controls a rotational speed of the rotor. Accordingly, the surface of the rotor is arranged to move blood along the flow path in response to rotation of the rotor.
1. A ventricular assist device for a human heart comprising:
a flow housing having a generally cylindrical wall with an inner surface defining a portion of a flow path, the flow housing having an outer surface and sized for placement within a blood vessel;
a stator disposable within the flow housing, the stator having a plurality of support struts operatively coupling the stator to the flow housing;
a rotor including an outer surface facing the inner surface of the cylindrical wall of the flow housing, the rotor rotatably coupled to the stator and rotatable with respect to the stator about a rotational axis, the rotor defined in part by at least one blade angled with respect to the rotational axis;
one of the rotor and the stator comprising a field magnet and the other of the rotor and the stator comprising windings; and
the windings arranged for operative coupling to a power source and a controller, the controller operatively coupled to the power source to vary the rotational speed of the rotor, wherein the stator is operatively coupled to a power cord, and at least a portion of the power cord is disposed within a selected one of the support struts.
2. The device of claim 1 , wherein the rotor comprises the field magnet and the stator comprises the windings, the windings operatively coupled to the power source.
3. The device of claim 1 , wherein the stator has an upstream end and a downstream end, the plurality of support struts depending from the downstream end and connected to the flow housing.
4. The device of claim 3 , wherein at least a portion of the support struts are angled with respect to the rotational axis of the rotor.
5. The device of claim 1 , further comprising at least first and second bearings disposed between the stator and the rotor to rotatably mount the rotor on the stator, the first bearing disposed toward an upstream end of the rotor and the stator and the second bearing disposed toward a downstream end of the rotor and the stator.
6. The device of claim 5 , wherein the first bearing is a mechanical pivot and the second bearing is a magnetic bearing and comprises first and second magnets, the first magnets attached to the rotor and the second magnets attached to the stator, the first and second magnets having aligned polarities.
7. The device of claim 5 , wherein the first bearing is a hydrodynamic pivot and the second bearing is a magnetic bearing and comprises first and second magnets, the first magnets attached to the rotor and the second magnets attached to the stator, the first and second magnets having aligned polarities.
8. The device of claim 5 , wherein the first and second bearings are each a magnetic bearing that comprises first and second magnets, the first magnets attached to the rotor and the second magnets attached to the stator, the first and second magnets having aligned polarities.
9. The device of claim 1 , wherein the stator has an elongate body with a mechanical bearing disposed adjacent a first end and a magnetic bearing and the plurality of support struts disposed adjacent a second end, and wherein the rotor has an elongate, hollow body defining an enclosed space in which the elongate body of the stator is disposed with the rotor connected to the stator via the mechanical bearing at the first end of the rotor and the magnetic bearing at the second end of the rotor.