Rotor for a fluid pump, and method and mold for manufacturing same
Disclosed is a rotor for a compressible fluid pump, in particular a blood pump that can be introduced into a patient's body through a blood vessel; said rotor comprises one or more impeller elements, is compressible and expansible between an expanded state and a compressed state, is made at least in part of a fiber-reinforced plastic material, is provided for rotating about an axis of rotation, and is characterized in that in the expanded state of the rotor, a first percentage, i.e. more than 30%, in particular more than 50%, of the fibers runs substantially straight between the first end thereof lying closest to the axis of rotation and a second end lying further away from the axis of rotation. According to the invention, the rotor retains its shape very well even when subjected to repeated mechanical stress.
1. A rotor for a compressible blood pump wherein the compressible blood pump can be introduced into a patient through a blood vessel and into a patient's body, the rotor comprising:
at least one impeller element for conveying blood, the at least one impeller element comprising a central plane,
wherein the at least one impeller element is configured to be radially compressed and expanded between a compressed state and an expanded state, the at least one impeller element further comprising a plastic material reinforced by strand-like reinforcement elements, the strand-like reinforcement elements disposed on the central plane of the at least one impeller element;
wherein the rotor is intended to rotate about an axis of rotation, and
wherein the plastic material has a Shore hardness of <100 D,
wherein, a rigidity of the strand-like reinforcement elements and the Shore hardness of the plastic material is selected such that when the at least one impeller element is radially compressed, a region of the at least one impeller element is bent and, in the bent region of the at least one impeller element, the strand-like reinforcement elements are deflected from the central plane.
2. The rotor of claim 1 , wherein a first proportion of more than 30% of the reinforcement elements in the expanded state of the at least one impeller element runs in a stretched manner from a first portion disposed closest to the axis of rotation to a second portion disposed further away from the axis of rotation.
3. The rotor of claim 2 , wherein in the expanded state, each reinforcement element of the first proportion deviates by at most 45° in an axial direction or azimuthal direction from a position radially aligned with the axis of rotation.
4. The rotor of claim 2 , wherein in the expanded state each reinforcement element of the first proportion runs perpendicularly to the axis of rotation.
5. The rotor of claim 2 , wherein in the expanded state each reinforcement element of the first proportion runs radially with respect to the axis of rotation.
6. The rotor of claim 2 , wherein each reinforcement element of the first proportion runs along a longitudinal axis of the at least one impeller element.
7. The rotor of claim 2 , wherein a length of the reinforcement element is at least 10% of a radius of the rotor.
8. The rotor of claim 1 , wherein a diameter of the reinforcement elements is less than 40 μm.
9. The rotor of claim 1 , wherein the at least one impeller element comprises a foam material.
10. The rotor of claim 1 , wherein a proportion of reinforcement elements in the expanded state of the at least one impeller element runs transversely to the reinforcement elements of a first proportion and enclose an angle therewith of at least 30° on average.
11. The rotor of claim 1 , wherein the reinforcement elements comprise fabric portions with fibers running longitudinally and transversely.
12. The rotor of claim 1 , wherein the reinforcement elements comprise film strips, and wherein a length of the film strips is at least three times greater than a width of the film strips.
13. The rotor of claim 1 , wherein the reinforcement elements are at least 90 percent surrounded by the plastic material from which the at least one impeller element is predominantly made.
14. The rotor of claim 1 , wherein the plastic material in which the reinforcement elements are embedded has different properties, at least in regions, on a side of the at least one impeller elements not loaded by a fluid counter-pressure during operation compared to a side of the at least one impeller elements that is loaded by the fluid counter-pressure.
15. The rotor of claim 1 , wherein the reinforcement elements in the expanded state of the at least one impeller element, without a fluid counter-pressure, are present in a form stretched to such an extent that when transitioning to a third state, which constitutes an operating state with the fluid counter-pressure, the reinforcement elements are lengthened by less than 5%, wherein the lengthening is measured on a basis of a distance between the two ends of a reinforcement element of the reinforcement elements.
16. The rotor of claim 1 , wherein in the expanded state of the rotor at least one impeller element and a third operating state with a fluid counter-pressure, at least a proportion of the reinforcement elements run in a stretched and straight manner in at least one region of an-the at least one impeller element in which said the at least one impeller element is curved.
17. The rotor of claim 16 , wherein the at least one region of the at least one impeller element includes at least two proportions of reinforcement elements angularly offset from each other, wherein within each proportion a direction in which the reinforcement elements of the proportions run parallel with one another.
18. The rotor of claim 1 , wherein a length of at least 30 percent of the reinforcement elements is greater than an average thickness of the at least one impeller elements.
19. The rotor of claim 1 , wherein the reinforcement elements are introduced into the plastic material in which said reinforcement elements are embedded via injection molding, and said reinforcement elements have a partially curved course along a flow of the plastic material into an injection mold when the rotor is disposed in the injection mold.
20. The rotor of claim 1 , wherein the plastic material in which the reinforcement elements are embedded has different properties, at least in regions, on a side of at least one impeller elements not loaded by a fluid counter-pressure during operation compared to a side of the at least one impeller elements that is loaded by the fluid counter-pressure, wherein the plastic material is more heavily cross-linked on the side not loaded by the fluid counter-pressure.
21. The rotor of claim 1 , wherein the plastic material in which the reinforcement elements are embedded has different properties, at least in regions, on a side of at least one impeller elements not loaded by a fluid counter-pressure during operation compared to a side of the at least one impeller elements that is loaded by the fluid-counter pressure, wherein the plastic material is more heavily shrunk on the side not loaded by the fluid counter-pressure, and wherein the side not loaded by the fluid counter-pressure comprises a film shrunk on the at least one impeller element.
22. The rotor of claim 1 , wherein the plastic material is configured to reduce breakage of the strand-like reinforcement elements upon compression of the at least one impeller element.
23. The rotor of claim 22 , wherein the strand-like reinforcement elements are configured, upon experiencing a bending or a buckling force, to push into the plastic material and thus limit a radius of curvature downwardly of the strand-like reinforcement elements.
24. The rotor of claim 1 , wherein a first group of the strand-like reinforcement elements comprise a first length and a second group of strand-like reinforcement elements comprise a second length, the first length is different than the second length.
25. The rotor of claim 1 , wherein at least one first strand-like reinforcement element of the strand-like reinforcement elements traverses over a plurality of second strand-like reinforcement elements of the strand-like reinforcement elements.