Blood pump systems and methods
The present invention relates to a rotary blood pump with a double pivot contact bearing system with an operating range between about 50 mL/min and about 1500 mL/min. The rotary blood pump is part of a blood pump system that includes blood conduit(s), a control system with optional sensors, and a power source. Embodiments of the present invention may include elements such as wear resistant bearing materials, a rotor back plate for magnetic attraction of the rotor to reduce bearing pivot bearing forces and wear, a rotor size and shape and a bearing gap that combine to create a hydrodynamic bearing effect and reduce bearing pivot bearing forces and wear, improved intravascular conduits with increased resistance to thrombosis, conduit insertion site cuffs to resist infection, and conduit side ports amenable to the easy insertion of guidewire and catheter-based medical devices.
1. A blood pump system comprising:
a centrifugal blood pump with an operating range between 50 milliliters per minute and 1500 milliliters per minute, comprising:
a pump housing defining a pump inlet to receive blood and direct blood onto an impeller, the pump housing having a top pivot bearing extending from a top of the housing into the inlet, and a bottom pivot bearing extending from a bottom of the housing into the interior space of the housing, wherein an axial load can be shared between the top pivot bearing and the bottom pivot bearing, and wherein 0 to 100% of the axial load may be distributed to each pivot bearing;
the impeller suspended within the housing wherein a first gap between the impeller and a top portion of the housing is in a range between 0.05 mm and 0.2 mm, the impeller having:
an impeller pivot having a first end to engage the top pivot and a second end to engage the bottom pivot;
a plurality of blades on the top surface of the impeller and extending radially away from a center of the impeller, the blades to force blood received at the inlet through the pump housing and to the outlet; and,
at least one lumen extending parallel to a central axis of the impeller from the bottom surface through the impeller to a top surface;
at least one magnet mechanically engaged to the impeller; and
an electric motor, formed from a magnet assembly comprising the at least one magnet and an electric coil assembly to magnetically engage the at least one magnet, wherein the electric motor rotates the at least one magnet and the impeller; and
a first conduit having two ends, one end configured for a fluid communication with the pump inlet and the other configured for making a fluid connected to a peripheral vein by a surgical anastomosis; and
a second conduit having two ends, one end configured for a fluid communication with the pump outlet and the other configured for insertion into a peripheral vein.
2. The blood pump of claim 1 , wherein an axial force of the portion of the impeller pivot on the bottom pivot bearing is between 2N and 8N when the impeller speed is 0 rpm.
3. The blood pump system of claim 1 , wherein a force on the top pivot bearing in is less than 3N when an impeller speed is less than or equal to 6000 rpm.
4. The blood pump of claim 1 , wherein the ratio of the summed area of the top surface of the blades to the total area of the rotor top surface, including the top surface of the blades, is less than one of 0.5, 0.4, 0.3, 0.2, 0.15, and 0.10.
5. The blood pump system of claim 1 , wherein the pump inlet comprises an inflow diffuser.
6. The blood pump system of claim 1 , further comprising one or more attachable conduit cuffs to engage at least one of the first conduit or the second conduit.
7. The blood pump system of claim 6 , wherein each of the one or more attachable conduit cuffs comprises an upper portion and a lower portion configured to mechanically engage, wherein when engaged the upper portion and lower portion define a channel to receive a conduit in fluid communication with the blood pump.
8. The blood pump system of claim 1 , further comprising one or more side ports in fluid communication with at least one conduit.
9. The blood pump system of claim 8 , wherein the one or more side ports is configured to enable the insertion of guidewires and catheters into the conduits.
10. The blood pump system of claim 1 , wherein a rate of hemolysis across a flow range of 0.1-1000 mL/min is <4.4 BP-50 units.
11. The blood pump system of claim 1 , wherein 10% or less of the impeller top surface area forms a hydrodynamic bearing during operation.
12. The blood pump system of claim 11 , wherein the rate of hemolysis across a flow range of 0.1-1000 mL/min is <4.4 BP-50 units.
13. The blood pump system of claim 1 , wherein 50% or more of the impeller top surface area forms a hydrodynamic bearing during operation.
14. The blood pump system of claim 13 , wherein the rate of hemolysis across a flow range of 0.1-1000 mL/min is <4.4 BP-50 units.
15. The blood pump system of claim 1 , wherein 10% to 50% of the impeller top surface area forms a hydrodynamic bearing during operation.
16. The blood pump system of claim 15 , wherein the rate of hemolysis across a flow range of 0.1-1000 mL/min is <4.4 BP-50 units.
17. The blood pump of claim 1 , wherein the first gap between the impeller and a top portion of the housing is in a first range between 0.05 mm and 0.125 mm.
18. The blood pump system of claim 17 , wherein the rate of hemolysis across a flow range of 0.1-1000 mL/min is <4.4 BP-50 units.
19. The blood pump system of claim 1 , wherein a second gap between the impeller and the bottom of the housing is in a second range between 0.1 mm and 0.4 mm.
20. The blood pump system of claim 19 , wherein the rate of hemolysis across a flow range of 0.1-1000 mL/min is <4.4 BP-50 units.
21. The blood pump of claim 1 , wherein an axial force of the portion of the impeller pivot on the bottom pivot bearing is >0.1 N when the impeller speed is 0 rpm.
22. The blood pump of claim 1 , comprising a ferromagnetic backplate to magnetically engage the at least one magnet.
23. The blood pump system of claim 22 , wherein an axial force of the portion of the impeller pivot on the bottom pivot bearing is between 2N and 8N when the impeller speed is 0 rpm.
24. The blood pump system of claim 22 , wherein the force on the top pivot bearing in is less than 3N, 2.2N, or 1N when the impeller speed is less than or equal to 6000 rpm.
25. The blood pump of claim 22 , wherein an axial force of the portion of the impeller pivot on the bottom pivot bearing is >0.1 N when the impeller speed is 0 rpm.
26. The blood pump system of claim 22 , wherein the electric coil assembly is positioned between the ferromagnetic backplate and the at least one magnet.
27. The blood pump system of claim 1 , wherein the pump housing further comprises a top bezel where the top pivot bearing extends from a top of the housing into the inlet and a bottom bezel where the bottom pivot bearing extends from a bottom of the housing into the interior space of the housing.
28. The blood pump system of claim 1 , wherein a portion of the top pivot bearing, the bottom pivot bearing, or the impeller pivot comprises alumina toughened zirconia.