blood pump

Abstract

The present disclosure provides a blood pump according to claim 1, the blood pump comprises a pump housing, a free-floating piston slidable axially and rotationally, a linear motor unit, and at least one rotary motor unit; the pump housing comprises a pump housing having a cylindrical piston chamber; the axially and rotationally slidable free-floating piston is centrally disposed within a cylindrical piston chamber, thereby dividing the cylindrical piston chamber into a left chamber and a right chamber; the left chamber and the right chamber each include an inlet and an outlet disposed transversely to the right chamber and communicating with the left chamber; the linear motor unit is configured to generate electromagnetically driven translational movement of the piston along a longitudinal axis of a piston chamber alternately between a first end position and a second end position; The at least one rotary motor unit is configured to generate electromagnetically driven rotational movement of the piston about the longitudinal axis during translational movement of the piston between the first end position and the second end position.

Description

[Technical Field]

[0001] The present invention relates to a blood pump. [Background technology]

[0002] Cardiovascular disease, accounting for one-third of all deaths, is the most common cause of death worldwide. Heart failure is one of the most common cardiovascular diseases, affecting at least 26 million people. Heart transplantation is the treatment of choice for severe cases of heart failure where drug therapy is ineffective. However, donor organs are scarce. Therefore, mechanical blood pumps, such as ventricular assist devices (VADs) and total artificial hearts (TAHs), have been developed to bridge the gap until a donor heart becomes available or to completely replace the heart. The rise of small, implantable rotary blood pumps (RBPs) used as ventricular assist devices has reduced the importance of large pulsatile pumps in the treatment of end-stage heart failure. Available pulsatile systems are based on valved positive displacement pumps and require bulky pneumatic drives, significantly limiting quality of life.

[0003] Despite the effectiveness of RBP, patients suffer from several adverse events related to the impaired hemocompatibility of these devices, which lead to von Willebrand factor deficiency, platelet activation, and hemolysis, resulting in major bleeding, stroke, and pump thrombosis.1 Although the shear rates in modern clinical pulsatile devices are low, the long residence times and turbulent flow patterns around the valve disc and leaflets make the valve area susceptible to thrombosis.

[0004] Although existing mechanical circulatory support devices (MCS) ensure survival and improve quality of life for most recipients, current RBPs are associated with serious adverse events (thromboembolic and hemorrhagic complications) due to their poor hemocompatibility. Pulsatile devices have the potential to reduce trauma to blood cells. However, there remains a risk of thrombosis caused by interactions between the blood and the artificial components that make up the device.

[0005] Recent studies have demonstrated the need for hemocompatible blood pumps for use as ventricular assist devices and total artificial hearts. Significant complications compromise the long-term performance of all implantable rotary blood pumps. Serious adverse events are caused by nonphysiological flow patterns and interactions between the pump and the cardiovascular system. Only 20% of these patients are free of serious adverse events, including right heart failure, bleeding, or stroke, at 24 months. This significantly impairs quality of life, and new developments are urgently needed. A small, implantable, hemocompatible TAH with a low risk of complications constitutes an urgently needed treatment for adult patients with biventricular failure and children with congenital heart disease (e.g., Fontan patients).

[0006] It is therefore an object of the present invention to overcome or mitigate at least some of the drawbacks of the prior art and to develop a new pump concept for delivering pulsatile flow to the cardiovascular system. Summary of the Invention

[0007] Embodiments of the present disclosure seek to solve, at least to some extent, at least one of the problems present in the prior art. In particular, the present disclosure provides a blood pump as set forth in claim 1, comprising: the blood pump comprises a pump housing, a free-floating piston slidable axially and rotationally, a linear motor unit, and at least one rotary motor unit; the pump housing comprises a pump housing having a cylindrical piston chamber; the axially and rotationally slidable free-floating piston is centrally disposed within a cylindrical piston chamber, thereby dividing the cylindrical piston chamber into a left chamber and a right chamber; the left chamber and the right chamber each include an inlet and an outlet disposed transversely to the right chamber and communicating with the left chamber; the linear motor unit is configured to generate electromagnetically driven translational movement of the piston along a longitudinal axis of a piston chamber alternately between a first end position and a second end position; The at least one rotary motor unit is configured to generate electromagnetically driven rotational movement of the piston about the longitudinal axis during translational movement of the piston between the first end position and the second end position.

[0008] Further aspects of the disclosure can be seen from the dependent claims or the following description. [Brief explanation of the drawings]

[0009] These features will become apparent to those skilled in the art from the detailed description of exemplary embodiments which follows, taken in conjunction with the accompanying drawings.

[0010] [Figure 1A-1B] 1A-1B are cross-sectional views of an exemplary embodiment of a blood pump of the present invention.

[0011] [Figure 2A-2B] 2A-2B illustrate an electromagnetic drive system for a blood pump according to an exemplary embodiment.

[0012] [Figure 3A-3B] 3A-3B are cross-sectional views of a piston chamber and piston according to an example embodiment.

[0013] [Figure 4] FIG. 4 shows the change over time in the outlet flow rate and pressure of one of the chambers.

[0014] [Figure 5] FIG. 5 is a diagram showing the theoretical load capacity versus the eccentricity of the blood pump.

[0015] [Figures 6A-6D] 6A-6D illustrate another exemplary embodiment of a blood pump. DETAILED DESCRIPTION OF THE INVENTION

[0016] The features of the concepts of the present invention and how to achieve them may be more easily understood by referring to the following detailed description of the embodiments and the accompanying drawings. However, the present invention may be embodied in a variety of different forms and should not be construed as being limited to only the embodiments described herein. Rather, the present embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey the aspects and features of the present invention to those skilled in the art. Therefore, processes, elements, and techniques that are not necessary for those skilled in the art to fully understand the aspects and features of the present invention may not be described. Unless otherwise noted, like reference numerals refer to like elements throughout the accompanying drawings and documents and the description, and descriptions thereof will not be repeated. In the drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity.

[0017] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person skilled in the art to which this invention belongs. Furthermore, terms as defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the relevant art and / or context of this specification, and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0018] overview

[0019] The present disclosure generally relates to a blood pump comprising: the blood pump comprises a pump housing, a free-floating piston slidable axially and rotationally, a linear motor unit, and at least one rotary motor unit; the pump housing comprises a pump housing having a cylindrical piston chamber; the axially and rotationally slidable free-floating piston is centrally disposed within a cylindrical piston chamber, thereby dividing the cylindrical piston chamber into a left chamber and a right chamber; the left chamber and the right chamber each include an inlet and an outlet disposed transversely to the right chamber and communicating with the left chamber; the linear motor unit is configured to generate electromagnetically driven translational movement of the piston along a longitudinal axis of a piston chamber alternately between a first end position and a second end position; The at least one rotary motor unit is configured to generate electromagnetically driven rotational movement of the piston about the longitudinal axis during translational movement of the piston between the first end position and the second end position.

[0020] This new pump concept delivers pulsatile flow to the cardiovascular system with a single moving part, without risky valves, creating the potential for excellent hemocompatibility. The dimensions of the design theoretically facilitate implantation in pediatric and adult patients.

[0021] According to the present disclosure, a blood pump includes a first motor unit configured to generate an electromagnetically driven translational movement of a movable piston and at least one other second motor unit configured to generate an electromagnetically driven rotational movement of the movable piston about the longitudinal axis of a cylindrical piston chamber. The linear and rotational movements must be performed together only insofar as they lead to two end positions of the piston. In other words, during the translational movement or movement of the piston from one end position to the other, the rotational movement or movement can be performed uniformly or sequentially at different speeds. Preferably, the rotational movement can be a continuous rotational movement. The same applies to the translational movement.

[0022] By superimposing these two operating sequences, the blood pump of the present invention combines the advantages of both state-of-the-art pulsatile and rotary blood pumps. In particular, the size of the blood pump is comparable to other TAHs under development based on the rotary principle. The single moving part, the piston, enhances the reliability of the pulsatile valveless pump to the level of a rotary blood pump. The valveless design of this blood pump may prove superior to typical pulsatile devices in terms of reliability and risk of thrombosis. At the same time, the pulsatile pump principle, with much lower velocity and shear rates than RBPs, may reduce adverse events associated with the operating principles of modern RBPs. The pump size for adults may be approximately 10 x 5 cm, much smaller than comparable systems. Furthermore, the design may be miniaturized for pediatric patients.

[0023] According to one embodiment, the linear motor unit is interpreted (configured) as a multi-phase (e.g., two- or three-phase) linear induction motor (LIM) including an axially polarized ring-shaped permanent magnet array disposed within the piston and segmented windings routed around the cylindrical piston chamber. Typically, the primary side of a linear electric motor consists of a flat magnetic core with linearly cut transverse slots, into which coils are woven, providing alternating polarity for each phase so that the different phases physically overlap. The secondary side is often an aluminum plate, often with an iron backing. Some LIMs are double-sided, with one primary on each side of the secondary, eliminating the need for an iron backing. However, according to this embodiment, a tuned electromagnet serves as the stator (i.e., representing the primary side), while the secondary side includes a permanent magnet disposed within the moving piston. The electric motor is therefore a brushless motor, avoiding not only spark formation but also any wear.

[0024] In addition to or alternatively to the use of the previously described polyphase linear induction motor, the rotary motor unit can be interpreted as a polyphase (e.g., two- or three-phase) rotary induction motor including a radially polarized permanent magnet array disposed within the piston and segmented windings wound around the axial side and circumference of the cylindrical piston chamber. The segmented windings may include a soft magnetic back yoke and polyphase (e.g., two- or three-phase) wiring coils wound around the axial side and circumference of the cylindrical piston chamber. The radially polarized permanent magnet arrays may be positioned near the base surfaces of the pistons facing the left and right chambers. In this way, the stator of the rotary motor unit is represented by the arrangement of wound coils, and the moving part includes the permanent magnets. Again, such an arrangement allows for a brushless implementation of the rotary motor unit.

[0025] According to another embodiment, the inlet and outlet of the left chamber are located on opposite sides of the cylindrical piston chamber, and the inlet and outlet of the right chamber are located on opposite sides of the cylindrical piston chamber.

[0026] Furthermore, the piston length may be 60-100 mm, and the piston radius may be 40-60 mm. Alternatively or additionally, the volume of the left or right chamber may be 5-50 ml. If the aforementioned dimensions are maintained, the blood pump can be used as a complete implant.

[0027] Another embodiment provides a translational motion frequency of the piston of 2-10 Hz, which ensures the generation of sufficient hydrodynamic forces to support the piston within the cylindrical housing.

[0028] Furthermore, the piston may be interpreted such that in a first end position, the side of the piston closes the inlet of the left chamber and the outlet of the right chamber, while the outlet of the left chamber and the inlet of the right chamber are open, and thereby the closed state of the inlets and outlets is exactly reversed in a second end position. In other words, the inlets and outlets of each chamber are alternately opened and closed. That is, when the inlet of one chamber is open, the outlet of that chamber is closed. Also, when the inlet of one chamber is open, the inlet of the other chamber is closed.

[0029] In particular, the piston has a left base surface facing the left chamber and a right base surface facing the right chamber. According to an embodiment, the curved portion of the left base surface is curved inward such that (i) when the inlet of the left chamber is closed at the first end position of the piston, the outlet of the left chamber is open, and (ii) when the outlet of the left chamber is closed at the second end position of the piston, the inlet of the left chamber is open. Furthermore, a portion of the right base surface is curved inward such that (i) when the outlet of the right chamber is closed at the first end position of the piston, the inlet of the right chamber is open, and (ii) when the inlet of the right chamber is closed at the second end position of the piston, the outlet of the right chamber is open. In other words, the left and right base surfaces of the piston do not extend perpendicular to the longitudinal axis of the piston. Furthermore, the base surfaces are not flat, but have a surface contour including an inwardly curved region (i.e., toward the piston). This makes it possible to avoid pressure peaks during pumping.

[0030] The surface contour of the left base surface and the surface contour of the right base surface may be point-symmetric to each other, which can simplify the manufacturing process.

[0031] According to another embodiment, a shunt is connected between at least one of the left and right chambers or the inlets of the left and right chambers. The shunt is configured to allow pressure equilibrium between the two chambers. For example, the shunt may be realized by a groove in the pump housing extending between the two chambers and terminating in the left and right inlets, respectively.

[0032] Alternatively, or additionally, during the translational movement of the piston between the first and second end positions, the rotational movement of the piston around the longitudinal axis is asynchronous or non-uniform. In other words, at least one of these two movements exhibits discontinuous behavior. This allows for strict balancing of the outputs of the left and right chambers. That is, by adapting the rotational speeds, the pumping efficiency of each chamber can be adapted, thereby adapting the amount of blood ejected. This method may, for example, prevent pulmonary congestion or so-called aspiration events.

[0033] According to another embodiment of the present disclosure, a fluid bearing may be provided between the outer surface of the piston and the inner surface of the piston chamber of the pump housing. This bearing ensures smooth piston movement without the risk of dry friction and material wear. Specifically, the fluid bearing may have a gap clearance of 100 μm or less. In this case, only a small amount of blood components may enter such a small fluid bearing, potentially resulting in less blood trauma in these areas.

[0034] Illustrative Embodiments

[0035] 1A and 1B are cross-sectional views of an exemplary embodiment of a blood pump 100. The blood pump 100 includes a pump housing 10 having a cylindrical piston chamber 12. An axially and rotationally slidable free-floating piston 20 is centrally disposed within the cylindrical piston chamber 12, thereby dividing the cylindrical piston chamber 12 into a left chamber 30 and a right chamber 40. The left chamber 30 and the right chamber 40 include inlets 32, 42 and outlets 34, 44 disposed transversely to and communicating with the right chamber 40 and the left chamber 30, respectively.

[0036] The linear motor unit 50 is configured to generate electromagnetically driven translational (or rectilinear) movement of the piston 20 along the longitudinal axis of the piston chamber 12 alternately between a first end position shown in Figure 1A and a second end position shown in Figure 1B. Here, the linear motor unit 50 is interpreted as a three-phase linear induction motor including an axially polarized ring-shaped permanent magnet array 52 disposed within the piston 20 and a segmented winding 54 routed around the cylindrical piston chamber 12.

[0037] The rotary motor unit is configured to generate an electromagnetically driven partial rotational movement of the piston 20 about the longitudinal axis during translational movement within the piston 20 between the first and second end positions. For clarity, details of the rotary motor unit are not shown in Figures 1A and 1B, but will be described in detail below. For understanding the pumping mechanism of Figures 1A and 1B, it is only important that the rotary motor unit is capable of rotating the piston 180° during movement from the first end position to the second end position, and from the second end position to the first end position, respectively.

[0038] The pump 100 has two inlets 32, 42 connected to the left and right atria, respectively. The outlets 34, 44 are anastomosed to the pulmonary artery and aorta. The piston 20 is electromagnetically driven by a reciprocating translational motion and a uniform rotational motion within the cylindrical piston chamber 20. The piston 20 thus divides the pump housing 10 into left and right chambers 30, 40, each with an inlet 32, 42 and an outlet 34, 44. Translational motion from a first end position shown in FIG. 1A to a second end position shown in FIG. 1B simultaneously fills one chamber, here the right chamber 40, and empties the other, here the left chamber 30. Because rotation controls the opening of the inlets 32, 42 and outlets 34, 44 of both chambers 30, 40, mechanical check valves are no longer required. This combination of rotation and translation achieves the entire pumping function for both the right and left hearts with only one moving part.

[0039] 1A and 1B, the pumping and operating principles are indicated by arrows. The right chamber 40 fills simultaneously with the left chamber 30 being evacuated. Translational motion is achieved by energizing the wire coils of the winding 54, which exert a Lorentz force FL on the piston 20. The translational motion is superimposed by a 180° rotational motion of the piston 20. The inlet 42 of the right chamber 40 and the outlet 34 of the left chamber 30 are closed at the second end position of the piston 20 without the need for valves. When the current in the wire coils is reversed, the piston 20 is pushed back to the first end position, evacuating the right chamber 40 while filling the left chamber 30. The dashed lines indicate the magnetic flux paths of the permanent magnet array 52.

[0040] The movement frequency of the piston 20 is 3-5 Hz to support a patient at rest, producing a relatively low speed compared to state-of-the-art rotary blood pumps, potentially resulting in significantly less blood trauma. The minimal stagnation area within the pump 100 and low priming volume promise excellent flushing potential. The simple geometry allows for ultra-high precision use, and the smooth blood-contacting surfaces reduce the risk of clot formation.

[0041] The outer surface of the piston 20 and the inner surface of the piston chamber 12 of the pump housing 10 can be manufactured with ultra-high precision due to their simple rotational symmetry. A fluid bearing may be provided between the outer surface of the piston 20 and the inner surface of the piston chamber 12 of the pump housing 10 (not shown). The fluid bearing may have a gap clearance of less than 100 μm. This bearing ensures smooth piston movement without risk of dry friction or material wear. Recent findings suggest that only small amounts of blood components may enter such small fluid bearings, potentially resulting in less blood trauma in these areas.

[0042] An electromagnetic motor, consisting of a linear motor unit 50 and at least one rotary motor unit, actuates the piston 20 in a manner that is more efficient than other pulsatile blood pumps. For translational motion, two coils wound around the center of the pump 100 housing are energized with opposite current directions for optimal force generation. Rotational motion is achieved by one or two radial flux motors.

[0043] 2A-2B show the actuation system in more detail. In addition to the centrally located linear motor unit 50, two rotary motor units 60, 61 are located to the left and right of it. Each rotary motor unit 60, 61 is interpreted as a multi-phase rotary induction motor including radially polarized permanent magnet arrays 62, 63 located within the piston 20 and segmented windings 64, 65 including multiple phases of wire coils wound around the axial side and circumference of the soft magnetic back yoke and cylindrical piston chamber 12. Here, the rotary motor units 60, 61 are realized as two-phase unipolar permanent magnet stepper motors. The magnetic flux path of the rotary motor unit 60 is indicated by a dashed line in FIG. 2B and provides a torque moment that causes rotation of the piston 20.

[0044] 3A and 3B are cross-sectional views of the piston chamber 12 and piston 20 according to an exemplary embodiment. The two inlets 32, 42 may have diameters of 5 to 25 mm and are connected to the left and right atria, respectively, via, for example, conical fibrous material. The outlets 34, 44 may have similar diameters of 5 to 25 mm and may be connected to graft material and anastomosed to the pulmonary artery and aorta. As already mentioned above, the piston 20 is electromagnetically driven during translational reciprocation and uniform rotational motion within the cylindrical piston chamber 12. As shown in FIG. 3A, translational motion from the left chamber 30 to the right chamber 40 pumps blood, filling the aorta through the outlet 34. Simultaneously, the right chamber 40 is filled through the inlet 42. The left inlet 32 ​​and right outlet 44 are closed by the piston 20. As shown in FIG. 3B, rotation of the piston 20 opens the inlet 32 ​​of the left chamber 30 and closes the inlet 42 of the right chamber 40. Translation from right to left empties the right chamber 40 and fills the left chamber 30. By way of example only, for an adult pump, the overall length L1 may be 100 mm, the length L2 of the piston 20 may be 83 mm, and the diameter D of the piston chamber 12 may be 50 mm.

[0045] Furthermore, the piston 20 has a left base surface 22 facing the left chamber 30 and a right base surface 23 facing the right chamber 40. A curved portion (or notch) 24 in the left base surface 22 is curved inward such that (i) when the outlet 34 of the left chamber 30 is closed, the inlet 32 ​​of the left chamber 30 is open, at the end position of the piston 20 shown in Figure 3A, and (ii) when the outlet 34 of the left chamber 30 is closed, the inlet 32 ​​of the left chamber 30 is open, at the end position of the piston 20 shown in Figure 3B. Furthermore, a curved portion (or notch) 25 in the right base surface 23 is curved inward such that (i) when the outlet 44 of the right chamber 40 is closed, the inlet 42 of the right chamber 40 is open, at the first end position of the piston 20, and (ii) when the inlet 42 of the right chamber 40 is closed, the outlet 44 of the right chamber 40 is open. In other words, the base surfaces 22, 23 on the left and right sides of the piston 20 do not extend perpendicular to the longitudinal axis of the piston 20. The base surfaces 22, 23 are not flat, but have a surface contour that includes an area that is curved inward (i.e., towards the piston 20), which makes it possible to avoid pressure peaks during pumping and improves hemocompatibility.

[0046] According to an exemplary embodiment, the movement frequency of the piston 20 may be between 2 and 10 Hz. The resulting flow and pressure profiles in the left chamber 30 are shown in Figure 4. The simple geometry of the blood piston 20 and the piston chamber 12 allows for very high precision and provides smooth surfaces in contact with the blood, reducing the risk of clot formation. Each stroke pumps and fills the chambers 30, 40, which have a volume of between 5 and 50 ml.

[0047] By way of example only, the height H of the curved portions 24, 25 may be 20 mm, and the depth D of the curved portions 24, 25 may be 28 mm. As can be further seen from Figures 3A and 3B, the surface contours of the left base surface 22 and the right base surface 23 are point-symmetrical to each other. In this way, the manufacturing process can be simplified, and the pumping volumes of the two chambers 30, 40 are essentially equal. In this way, optimal operation with minimal risk of blood trauma can also be ensured.

[0048] The outer surface (or piston shell region) of the piston 20 and the inner surface (or inner shell region) of the piston housing's piston chamber 12 can be manufactured with ultra-high precision due to their simple rotational symmetry. A hydrodynamic bearing with a gap clearance of 0-500 μm is thus realized. This bearing can withstand forces greater than 20 N and ensure smooth piston motion at less than 95% of the maximum eccentricity without risk of dry friction or material wear. Figure 5 shows an example of the load capacity of such a bearing with a gap of 75 μm, illustrating the theoretical load capacity of a blood pump versus eccentricity at a rotational frequency of 3 Hz.

[0049] The reciprocating motion combined with the pressure difference between the left and right chambers 30 and 40 can lead to additional bearing stabilization due to the Lomakin effect. A certain gap clearance is required to allow sufficient gap flow necessary to cool the bearing area (heat due to the motor coils) and meet the requirement of a maximum local temperature rise of 2°K. Furthermore, because the gap is small, only small amounts of blood components enter the gap of such hydrodynamic bearings, potentially resulting in less blood trauma in these areas.

[0050] 6A-6D illustrate another exemplary embodiment of a blood pump 100. An electromagnetic motor system simultaneously drives translational and rotary piston motion. In the embodiment shown in the drawings, translational motion is achieved by a linear motor unit 50. The linear motor unit 50 includes an axially polarized, ring-shaped permanent magnet array 52 that generates a magnetic field and is composed of a permanent magnet 54 and a soft magnetic material ring 55. The permanent magnet array 52 is disposed within the piston 20. Additionally, a segmented winding 56 is routed around the cylindrical piston chamber 12 and includes a back yoke 57 and a segmented copper coil 58. During operation, the soft magnetic material ring 55 directs magnetic flux through the segmented copper coil 58, which is routed around the center of the piston chamber 12. Position-dependent energization of the coil segments 58 generates a Lorentz force in the axial direction.

[0051] For rotational motion, permanent magnets 67 adjacent to the curved portions 24, 25 of the piston 20 are radially polarized and connected via a soft magnetic hollow shaft 66 to form lightweight permanent magnet arrays 62, 63. A soft magnetic back yoke 68 closes the magnetic flux path of the permanent magnets 67 and guides them through wiring coils 70, 71, 72. The three-phase wiring coils 70, 71, 72 are wound around the axial side and circumference of the entire piston chamber 12. In this way, a three-phase slotless permanent motor is realized. [Explanation of symbols]

[0052] 10 Pump housing 12 piston chamber 20 pistons 22 Left base surface 23 Right base surface 24 Curved portion of left base surface 22 25 Curved portion of right base surface 23 30 Left Chamber 32 inlet of left chamber 30 34 Outlet of left chamber 30 40 Right Chamber 42 inlet of right chamber 40 44 Outlet of right chamber 40 50 Linear motor unit 52 Permanent Magnet Array 54 Segmented Winding 60, 61 Rotation motor unit 62, 63 Permanent magnet array 64, 65 Segmented winding 66 Soft magnetic hollow shaft 67 Permanent Magnets 68 Soft magnetic back yoke 70, 71, 72 Wiring coil 100 Blood Pump

Claims

1. A blood pump (100), comprising: The blood pump (100) comprises a pump housing (10), a free-floating piston (20) slidable in an axial and rotational direction, a linear motor unit (50) and at least one rotary motor unit (60, 61); The pump housing (10) comprises a pump housing (10) having a cylindrical piston chamber (12); the axially and rotationally slidable free-floating piston (20) is centrally disposed within a cylindrical piston chamber (12), thereby dividing the cylindrical piston chamber (12) into a left chamber (30) and a right chamber (40); The left chamber (30) and the right chamber (40) each include an inlet (32, 42) and an outlet (42, 44) disposed transversely to the right chamber (40) and the left chamber (30), and communicating with the right chamber (40) and the left chamber (30); the linear motor unit (50) is configured to generate an electromagnetically driven translational movement of the piston (20) alternately between a first end position and a second end position along a longitudinal axis of the piston chamber (12); the at least one rotary motor unit (60, 61) is configured to generate an electromagnetically driven continuous rotational movement of the piston (20) about the longitudinal axis during translational movement of the piston (20) between the first end position and the second end position.

2. 2. The blood pump of claim 1, The linear motor unit (50) is a polyphase linear induction motor including an axially polarized ring-shaped permanent magnet array (52) disposed within the piston (20) and a segmented winding (56) routed around the cylindrical piston chamber (12).

3. 3. The blood pump according to claim 1 or 2, The rotary motor unit (60, 61) is a polyphase rotary induction motor including a radially polarized permanent magnet array (62, 63) disposed within the piston (20) and segmented windings (64, 65) wound along the axial side and circumference of the cylindrical piston chamber (12).

4. 4. The blood pump according to claim 3, The radially polarized permanent magnet arrays (62, 63) are positioned adjacent to curved portions (24, 25) of each base surface (22, 23) of the piston (20) facing the left chamber (30) and the right chamber (40), respectively.

5. A blood pump according to any one of claims 1 to 4, the inlet (32) and the outlet (34) of the left chamber (30) are arranged opposite each other across the longitudinal axis of the cylindrical piston chamber (12); The blood pump, wherein the inlet (42) and the outlet (44) of the right chamber (40) are arranged opposite each other across the longitudinal axis of the cylindrical piston chamber (12).

6. A blood pump according to any one of claims 1 to 5, The piston has a length of 60 to 100 mm. A blood pump having a piston radius of 40 to 60 mm.

7. A blood pump according to any one of claims 1 to 6, A blood pump, wherein the volume of the left chamber (30) or the right chamber (40) is 5 to 50 ml.

8. A blood pump according to any one of claims 1 to 7, A blood pump, wherein the translational motion of the piston (20) has a motion frequency of 2 to 10 Hz.

9. A blood pump according to any one of claims 1 to 8, In the first end position, the piston (20) has a side surface that closes the inlet (32) of the left chamber (30) and the outlet (44) of the right chamber (40), Meanwhile, the outlet (34) of the left chamber (30) and the inlet (42) of the right chamber (40) are open; Thereby, the closure conditions of the inlets (32, 42) and the outlets (34, 44) are exactly reversed in the second end position.

10. 10. The blood pump of claim 9, The piston (20) has a left base surface (22) facing the left chamber (30) and a right base surface (23) facing the right chamber (40); the curved portion (24) of the left base surface (22) is curved inward such that (i) when the inlet (32) of the left chamber (30) is closed at the first end position of the piston (20), the outlet (34) of the left chamber (30) is open, and (ii) when the outlet (34) of the left chamber (30) is closed at the second end position of the piston (20), the inlet (32) of the left chamber (30) is open; a curved portion (25) of the right base surface (23) that is curved inward such that (i) when the outlet (44) of the right chamber (40) is closed at the first end position of the piston (20), the inlet (42) of the right chamber (40) is open, and (ii) when the inlet (42) of the right chamber (40) is closed at the second end position of the piston (20), the outlet (44) of the right chamber (40) is open.

11. 11. The blood pump of claim 10, A blood pump, wherein the surface contours of the left base surface (22) and the right base surface (23) are point-symmetrical with respect to each other with respect to a center point on the longitudinal axis of the piston (20).

12. A blood pump according to any one of claims 1 to 11, a shunt connected between the inlets (32, 42) of the left chamber (30) and the right chamber (40); The shunt is configured to allow pressure equilibrium between both chambers (30, 40).

13. A blood pump according to any one of claims 1 to 12, During the translational movement of the piston (20) between the first end position and the second end position, the rotational movement of the piston (20) about the longitudinal axis is asynchronous or non-uniform with respect to the translational movement.

14. A blood pump according to any one of claims 1 to 13, A blood pump, comprising: a fluid bearing provided between an outer surface of the piston (20) and an inner surface of the piston chamber (12) of the pump housing (10).

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