Magnetically-levitated blood pump with optimization method enabling miniaturization

A method of optimizing a magnetically-levitated blood pump, said method comprising:

• providing a rotor for said blood pump including a radius Rr and a plurality of permanent magnet rings configured to increase rotor mass and for supercritical operation;
• providing stator permanent magnets located on a stator, said stator permanent magnets corresponding to a portion of said plurality of permanent magnet rings, said stator permanent magnets and said plurality of permanent magnet rings forming magnetic bearings having a reduced stiffness;
• forming a first permanent magnet bearing, to radially stabilize and center the rotor, formed from a first portion of said stator permanent magnets and a first corresponding portion of said rotor permanent magnet rings;
• forming a second permanent magnet bearing, to radially stabilize and center the rotor, formed from a second portion of said stator permanent magnets and a second corresponding portion of said rotor permanent magnet rings;
• positioning a motor magnet for interaction with a motor coil, and formed from a third corresponding portion of said rotor permanent magnet rings;
• positioning at least one voice coil for interaction with a fourth corresponding portion of said rotor permanent magnet rings, said at least one voice coil configured to additionally interact with said first corresponding portion of said rotor permanent magnet rings to stabilize the rotor in an axial direction;
• and
• forming a fluid gap Wg defined by a magnetic gap Sr minus the rotor radius Rr,
• configuring said rotor and said stator to enable said reduced stiffness, wherein the supercritical operation of the rotor and the fluid gap Wg provides for the blood pump to be adapted for miniaturization and for minimally-invasive implantation,
• wherein the blood pump includes an inflow end providing for entry of blood;
• an outflow end providing for exit of said blood;
• a first sensor coil located at a blood flow convergence adjacent said inflow end, and a second sensor coil located at a blood flow divergence adjacent said outflow end, the stator oriented in axial alignment with, and located between, the inflow end and the outflow end.

A method of optimizing a magnetically-levitated blood pump for supercritical operation, said method comprising:

• providing a stator oriented in axial alignment with, and located between, an inflow end providing for entry of blood and an outflow end providing for exit of said blood, and including a plurality of stator permanent magnets, at least one voice coil, and a motor coil;
• providing a rotor centered within said stator, including a plurality of rotor permanent magnets, the rotor configured for supercritical operation and to provide a ratio of rotor diameter to an outflow end diameter of less than 2;
• and
• providing a first permanent magnet bearing and a second permanent magnet bearing, said first permanent magnet bearing arranged near said inflow end and formed from a first portion of said stator permanent magnets and a first corresponding portion of said rotor permanent magnets, said second permanent magnet bearing arranged near said outflow end and formed from a second portion of said stator permanent magnets and a second corresponding portion of said rotor permanent magnets, and said first and second permanent magnet bearings having a reduced stiffness enabled by a gap configuration formed between said rotor and said stator, where a ratio of said gap to a diameter of the rotor is greater than 1/10 such that said gap provides for the reduced stiffness to lower a critical speed of the rotor;
• providing a motor magnet for interaction with the motor coil, and formed from a third corresponding portion of said rotor permanent magnets;
• and
• providing said at least one voice coil for interaction with a fourth corresponding portion of said rotor permanent magnets, said at least one voice coil configured to additionally interact with said first corresponding portion of said rotor permanent magnets;
• wherein the supercritical operation of the rotor and the gap configuration provides for the blood pump to be adapted for miniaturization and for minimally-invasive implantation,
• wherein the blood pump includes a first sensor coil located at a blood flow convergence adjacent said inflow end, and a second sensor coil located at a blood flow divergence adjacent said outflow end.

A magnetically-levitated blood pump, said blood pump comprising:

• an inflow end providing for entry of blood;
• an outflow end providing for exit of said blood;
• a stator oriented in axial alignment with, and located between, said inflow end and said outflow end, and including at least one stator permanent magnet, at least one voice coil, and a motor coil;
• a rotor centered within said stator, and including a plurality of rotor permanent magnets, the rotor being operational above at least one critical speed;
• at least one permanent magnet bearing formed from a first portion of said at least one stator permanent magnet and a first corresponding portion of said rotor permanent magnets;
• a motor magnet for interaction with said motor coil, and formed from a second corresponding portion of said rotor permanent magnets;
• a first sensor coil located at a blood flow convergence adjacent said inflow end, and a second sensor coil located at a blood flow divergence adjacent said outflow end, and
• an annular blood gap formed between an outermost surface of said rotor and an innermost surface of said stator, where a ratio of said annular blood gap to rotor diameter is greater than 1/10 such that said annular blood gap provides for a lower stiffness of the permanent magnet to lower said at least one critical speed,
• wherein the operating speed of the rotor and the ratio of said annular blood gap to rotor diameter allow for the blood pump to be miniaturized to allow for minimally-invasive implantation.