Heart pump assembly with pump housing configured to reduce hemolysis

Abstract

A percutaneously insertable blood pump assembly includes a pump section, a catheter attached to a proximal end of the pump section, a first opening section distal to and in fluid communication with the pump section, an insertion cannula attached to and in fluid communication with the first opening section, and a second opening section distal to and in fluid communication with the insertion cannula. One of the first and second opening sections is a blood outlet from the insertion cannula. The blood outlet has a body portion, an opening portion, and an annular portion. A plurality of struts in the opening portion extend from the body portion and connect the body portion to the annular portion. At least a portion of the struts along their length from the body portion of the outlet to the annular portion of the outlet is asymmetrical.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 589,719, filed October 12, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This article describes a heart pump assembly, and more specifically a heart pump assembly having a pump housing configured to reduce hemolysis during use. Background Technology

[0004] A cardiac pump (such as a percutaneous intracardiac cardiac pump assembly) can be inserted into the heart to deliver blood from the heart into the arteries. When deployed in the heart, the cardiac pump assembly draws blood from the left ventricle and drains it into the aorta, or draws blood from the right ventricle and drains it into the pulmonary artery. Specifically, for left ventricular support, blood enters the cardiac pump assembly via a blood inlet located at the distal end of the cardiac pump assembly, travels through the cannula of the cardiac pump assembly, and exits via multiple outlets defined on the pump housing located at the proximal end of the cardiac pump assembly. Summary of the Invention

[0005] This document describes a percutaneously insertable blood pump assembly having a pump section, a catheter attached to a proximal end of the pump section, a first opening section distal to and in fluid communication with the pump section, an insertion cannula attached to and in fluid communication with the first opening section, and a second opening section distal to and in fluid communication with the insertion cannula. One of the first and second opening sections can be a blood outlet from the insertion cannula. The blood outlet may have a body portion, an opening portion, and a ring portion. A plurality of struts in the opening portion may extend from the body portion and connect the body portion to the ring portion. The struts may be asymmetrical along at least a portion of their length from the body portion of the outlet to the ring portion of the outlet.

[0006] In one alternative aspect, the blood outlet may be a first opening section. In another alternative aspect, the blood outlet may be a second opening section.

[0007] In any of the above aspects, the asymmetric strut has a cross-section including a leading edge and a trailing edge, the leading edge forming a first angle and the trailing edge forming a second angle. In any of the above aspects, the main body portion of the blood outlet may have an outer periphery and an inner periphery, and the leading edge of the strut may be removed from the outer periphery of the main body portion, and the trailing edge portion may be removed from the inner periphery of the main body portion. In any of the above aspects, the first angle and the second angle form an acute angle. In one aspect, the first angle may be from about 10 degrees to about 70 degrees. In another aspect, the first angle may be from about 20 degrees to about 45 degrees. In another aspect, the first angle may be from about 30 degrees to about 40 degrees.

[0008] In another aspect, the second angle may be from about 5 degrees to about 45 degrees. In another aspect, the second angle may be about 20 degrees. In another aspect, at least one of the leading edge and the trailing edge is rounded or rounded, or a combination of rounded and rounded. In one aspect, the fillet has a radius of about 1.25 mm.

[0009] In any of the foregoing aspects, both the leading and trailing edges are rounded or circular, or a combination of rounded and circular. In another aspect, the support has a hydrofoil-like cross-section along at least a portion of its length from the body portion of the outlet to the annular portion of the outlet. In an alternative aspect of any of the foregoing aspects, the support has a hydrofoil-like cross-section along its entire length from the body portion of the outlet to the annular portion of the outlet.

[0010] In any of the above aspects, the multiple holes may have a certain size and each hole may be approximately the same size.

[0011] In any of the above aspects, the percutaneously insertable blood pump assembly may have a non-invasive tip distal to the second opening segment. Attached Figure Description

[0012] Figure 1 This is a perspective view of the heart pump assembly, based on one aspect of the components described in this article.

[0013] Figure 2 yes Figure 1 A partial perspective view of the perforated end portion of the pump housing of a heart pump assembly.

[0014] Figure 3 yes Figure 2 A partial sectional view of the pump housing end portion with the opening along line AA at the intersection of the support and the main body of the pump housing end portion.

[0015] Figure 4 This is a partial perspective view of an exemplary prior art opening end portion of the pump housing of a heart pump assembly.

[0016] Figure 5 It shows in Figure 4 Blood recirculation at the outlet of the opening in the pump housing.

[0017] Figure 6 It shows in Figure 2 Blood recirculation at the outlet of the opening in the pump housing.

[0018] Figure 7 It shows when blood flows through Figure 4 The wall shear stress at the outlet of the pump casing opening.

[0019] Figure 8 It shows when blood flows through Figure 2 The wall shear stress at the outlet of the pump casing opening. Detailed Implementation

[0020] Various aspects of this disclosure have been described in detail with reference to the accompanying drawings, wherein like reference numerals identify similar or identical elements. It should be understood that the disclosed aspects are merely examples of this disclosure and may be embodied in various forms. Well-known functions or constructions have not been described in detail to avoid obscuring this disclosure with unnecessary detail. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as the basis for the claims and as a representative basis for teaching those skilled in the art to apply this disclosure differently with virtually any suitable detailed structure.

[0021] A cardiac pump assembly can be inserted percutaneously into the heart via the aorta. A blood inlet is positioned to pass through the aortic valve in the left ventricle to draw blood from the left ventricle and drain it into the aorta. Blood enters the cardiac pump assembly via the blood inlet located at the distal end of the assembly, travels through the cannula of the assembly, and exits via multiple outlets defined on the pump housing located at the proximal end of the assembly. The inventors have recognized and understand that the currently available design of the pump housing of the cardiac pump assembly generates high wall shear stress on the blood as it exits through the outlets of the pump housing, resulting in significant blood recirculation and potentially causing hemolysis in the bloodstream.

[0022] The cardiac pump assembly described herein provides a cardiac pump assembly with an improved pump housing. The pump housing can be constructed and designed to prevent or reduce wall shear stress on blood as it passes through the outlet of the pump housing and to prevent excessive blood recirculation. The reduction in wall shear stress and excessive blood recirculation thereby reduces hemolysis in the bloodstream, as will be described in detail below.

[0023] Figure 1 An example is shown of a heart pump assembly 10 according to the present technology, including an improved perforated portion of a pump housing 12. Reference Figure 1In the illustrated embodiment, the perforated portion of the pump housing can be a blood outlet 17. The blood outlet 17 is illustrated as being located at the distal end of the pump housing 12. The blood outlet 17 may be integral with or attached to the pump housing 12. The heart pump assembly 10 includes a pump housing 12 having a hole or outlet opening 30 in the blood outlet 17, a cannula 14, a blood inlet 16, and a non-invasive tip 18 for stabilizing the heart pump assembly 10 in the ventricle of the heart. The heart pump assembly 10 can be varied in any number of ways. For example, this document... Figure 1 An embodiment may include a motor (not shown) within the pump housing 12, or a motor that may be located outside the patient’s body and operatively coupled to a rotor (not shown) via a drive shaft or cable (not shown).

[0024] See you again Figure 1 The cannula 14 extends between its proximal end 20 and distal end 22. At the distal end 22 of the cannula 14, the cannula 14 and the blood inlet 16 are connected to each other and in fluid communication. The proximal end 20 of the cannula 14 may also be connected to the blood outlet 17 of the pump housing 12. The blood inlet 16 may also be connected to the atraumatic tip 18. Thus, the blood inlet 16, the cannula 14, the pump housing 12, and the atraumatic tip 18 are all connected to form the heart pump assembly 10. The pump housing 12, the blood inlet 16, the cannula 14, and the blood outlet 17 are all in fluid communication with each other. In other respects, for example, for a blood pump located on the right side of the heart, the blood inlet may be proximal and the blood outlet may be distal relative to the insertion site of the blood pump.

[0025] In the illustrated aspect, the blood inlet 16 extends between its distal end 24 and proximal end 26. The blood inlet 16 includes a plurality of openings 28 defined and positioned between the distal end 24 and proximal end 26 to allow blood to enter and travel through the cannula 14. An atraumatic tip 18 may be attached at the distal end 24 of the blood inlet 16, such as... Figure 1 As shown in the image.

[0026] The non-invasive tip 18 can be shaped to have, for example, Figure 1 The flexible extension of the curved end portion is shown. Alternatively, the atraumatic tip 18 may be configured as a straight extension or a ball. Furthermore, the atraumatic tip 18 may include a lumen for allowing a guidewire to pass through it. The atraumatic tip 18 acts as a mechanical spacer, providing a gap between the plurality of openings 28 of the blood inlet 16 and the tissue forming the inner surface of the heart. This gap prevents the plurality of openings 28 from aspirating into the walls of the heart, heart valves (e.g., the mitral valve), or any other anatomical structures in the heart. This reduces the risk of blockage of one or more of the plurality of openings 28 of the blood inlet 16 and reduces or prevents damage to cardiac tissue.

[0027] The pump housing 12 is configured to house an impeller (not shown) and a motor (not shown). The motor is used to rotate the impeller to draw blood from the heart into the heart pump assembly 10. Specifically, the rotation of the impeller blades creates suction through the cannula 14, causing blood to flow into the heart pump assembly 10. Blood enters the cannula 14 and travels through it, exiting the heart pump assembly 10 through a plurality of outlet openings 30 defined in an outlet portion 17 of the pump housing 12 located at the proximal end of the cannula 14.

[0028] refer to Figure 1 and Figure 2 The pump housing 12 extends between its distal end 32 and proximal end 34 and includes a plurality of outlet openings 30 defining and positioning an outlet portion 17 between the distal end 32 and proximal end 34. The plurality of outlet openings 30 are oriented radially about the circumference of the outlet portion 17 of the pump housing 12, wherein each of the plurality of outlet openings 30 is spaced substantially uniformly apart. Each of the plurality of outlet openings 30 has an associated length measured parallel to axis X, a width measured radially relative to the X-axis, and an area. For example, each outlet opening 30 has a length, width, and area through which blood from the cannula 14 can exit the heart pump assembly 10. In one aspect, the dimensions (e.g., length, width, and area) of each of the plurality of outlet openings 30 are similar, such that the shape and size of the outlet openings 30 are substantially the same. The plurality of outlet openings 30 may have any suitable shape to allow blood to exit the heart pump assembly 10. For example, the plurality of outlet openings 30 may be oblong, elliptical, square, teardrop-shaped, circular, or any other suitable shape.

[0029] For details, please refer to the following: Figure 2 Each of the plurality of outlet openings 30 is defined by edges 36 and 38 and separated from each other by a strut 46. Edges 36 together define an end ring 40 of the outlet portion 17 of the pump housing 12. Edges 38 together define an end 42 of the outlet portion 17 of the pump housing 12 from which the outlet openings 30 and the strut 46 extend. The strut 46 has an outer edge 44. In one aspect, the outer edge 44 is rounded or rounded or a combination of rounded and rounded.

[0030] refer to Figure 2 and Figure 3 Each of the plurality of struts 46 extends between edges 36 and 38 in an asymmetrical or non-linear shape relative to edges 36 and 38. In one aspect, the strut 46 has a hydrofoil-like cross-section that can extend along the entire length of the strut from edge 38 to edge 36. The hydrofoil-like cross-section extends to the end ring 40. Reference Figure 2The cross-section AA of the support 46 allows the cross-sectional profile of the support 46 to be understood relative to its extending edge 38. In this respect, the horizontal cross-section of each support 46 has, as shown in the figure... Figure 3 The hydrofoil-like profile is shown. While the applicant does not wish to be bound by a particular theory, the hydrofoil-like cross-section of the strut 46 of the pump housing 12 reduces the higher wall shear stress on the blood flowing through the multiple outlet openings 30 of the pump housing 12 of the heart pump assembly 10 as the blood exits, and also prevents significant blood recirculation. This, in turn, reduces hemolysis, which can be caused by the strut being placed in the blood flow exiting from the multiple outlet openings 30 of the outlet portion 17 of the pump housing 12 of the heart pump assembly 10. In other words, the outlet portion 17 of the pump housing 12 with the strut configuration described herein exerts less turbulence on the blood flowing through the strut compared to a conventional strut design lacking a hydrofoil-like profile with rounded leading and trailing edges. Those skilled in the art will recognize that reduced flow turbulence results in laminar flow of the blood flowing through the strut 146, which will exert less stress on the red blood cells in the blood and reduce hemolysis.

[0031] Figure 3 A portion of a cross-sectional view of a strut 46 extending from the edge of the body 42 of the outlet portion 17 of the pump housing 12 is shown. The strut 46 spans a leading edge 48 and a trailing edge 50. In one aspect, both edges 48, 50 are rounded. As blood flows over the strut, the rounded edges reduce blood flow loss that could impede blood flow and cause hemolysis. The rounded edges also reduce hemolysis of red blood cells in contact with the strut as blood flows over it. For reference, the upper periphery 41 of the edge of the body 42 is referred to as the top side of the cross-section of the strut 46. The lower periphery 43 of the edge of the body 42 is referred to as the bottom side of the cross-section of the strut 46. Figure 3 As can be seen, the top side of the leading edge 48 of the strut 46 can be shaped such that the upper periphery 41 extends away from the edge of the body 42. Similarly, the trailing edge 50 can be shaped such that the lower periphery 43 extends away from the edge of the body 42, thereby allowing each strut 46 to have a hydrofoil profile.

[0032] As from Figure 3As can be seen from the cross-sectional view, the cross-sectional shape of the strut 46 resembles a hydrofoil profile, at least in the leading edge portion 52 and the trailing edge portion 54 of the strut 46. As shown, the strut 46 may be rounded at the leading edge 48, then its width increases rearward to span from the outer perimeter 41 of the edge of the body 42 to the inner perimeter 43, and then its width decreases toward the trailing edge 50, which may also be rounded. Both the leading edge 48 and the trailing edge 50 are shaped such that they define or form acute angles. Specifically, the angle of the leading edge 48 of the strut 46 may be represented by tangents T1 and T2 extending from opposite sides of the leading edge 48. Lines T1 and T2 extend to form a vertex, and the leading edge angle is angle B. In one aspect, the strut 46 may be configured such that the leading edge angle B is from about 30 degrees to about 70 degrees. As used herein, "about" means about ten percent of the value to which the term is applied. In one aspect, the leading edge angle B may be from about 20 degrees to about 45 degrees. In another aspect, the leading edge angle may be from about 30 degrees to about 40 degrees. Tangents T3 and T4 extending from opposite sides of the trailing edge 50 extend to form apexes, illustrating the trailing edge angle C, which in one aspect can be from about 5 degrees to about 45 degrees. The trailing edge angle C may be smaller than the leading edge angle B. This angle of the strut balances the strength of the strut 46 with its benefit of reducing wall shear stress on the blood flowing through the strut. In one aspect, each rounded corner of the leading edge 48 and the trailing edge 50 has a radius of about 0.05 inches (about 1.25 mm). Although in the illustrated aspect, the outlet 17 of the pump housing 12 includes three struts 46, it is contemplated that the outlet 17 of the pump housing 12 may include any suitable number of struts 46.

[0033] The heart pump assembly 10 is made of one or more materials having suitable properties for the desired application, including strength, weight, rigidity, etc. In one aspect, thermoplastics (e.g., polypropylene, polyethylene, etc.) are used to form the blood inlet 16, the non-invasive tip 18, and the pump housing 12.

[0034] Figure 4 This is a perspective view of an exemplary prior art pump housing 56 of a heart pump assembly. The prior art outlet portion 56 of the pump housing has a plurality of struts 58 that are symmetrical in length and relative to the body 57 of the outlet 59 from which the struts 58 extend, rather than being hydrofoil-shaped in length as in the struts 46 of the outlet 17 of the pump housing 12 described herein. (The last sentence appears to be incomplete and possibly refers to a different concept.) Figure 6 Compared to the blood recirculation at position 64 shown in the diagram when blood flows through the outlet opening 30 of the improved outlet 17 of the pump housing 12 used for the components described herein, the prior art design of the pump outlet 56 causes greater blood recirculation when blood flows through the outlet 60 of the pump housing outlet 56, such as... Figure 5 As shown at position 62. Furthermore, the blood flow at the outlet 56 of the prior art pump housing... Figure 5There is some turbulence at position 62. Furthermore, as... Figure 8 Compared to the wall shear stress generated by the improved outlet 17 of the pump housing 12 described herein, as shown at position 68, ... Figure 7 As shown at position 66, the design of the outlet 56 of the prior art pump housing generates high wall shear stress when blood passes through the outlet 60 of the outlet 56 of the pump housing.

[0035] As stated above, the design and construction of the plurality of struts 46 at the outlet 17 of the pump housing 12 of the cardiac pump assembly 10, as described herein, effectively reduces wall shear stress and blood recirculation as blood exits through the plurality of outlet openings 30 of the outlet 17 of the pump housing 12 of the cardiac pump assembly 10. As stated above, the outlet housing with the aforementioned struts reduces hemolysis in the bloodstream. Specifically, the improved design of the pump housing 12 with the plurality of struts 46 reduces blood flow turbulence at the outlet openings 30 of the pump housing 12, wherein each strut has a hydrofoil-like profile. This reduces hemolysis in the patient's bloodstream. Figure 6 and Figure 8 The image illustrates this laminar flow within the pump housing 12 of the heart pump assembly 10.

[0036] This document describes a percutaneously insertable blood pump assembly, which may include: a pump section; a catheter attached to a proximal end of the pump section; a first opening section distal to and in fluid communication with the pump section; an insertion cannula attached to and in fluid communication with the first opening section; and a second opening section distal to and in fluid communication with the insertion cannula. In one aspect, one of the first and second opening sections is a blood outlet from the insertion cannula. In another aspect, the blood outlet may have a body portion, an opening portion, and a ring portion, wherein a plurality of orifices in the opening portion may be separated and defined by a plurality of struts extending from the body portion and engaging the body portion to the ring portion. In yet another aspect, the struts are asymmetrical along their length from the body portion of the outlet to the ring portion of the outlet.

[0037] In any of the above aspects, the blood outlet can be a first opening section outlet or a second opening section. In any of the above aspects, the asymmetric strut can have a cross-section that includes a leading edge and a trailing edge, the leading edge forming a first angle and the trailing edge forming a second angle. In any of the above aspects, the main body portion of the blood outlet can have an outer periphery and an inner periphery, and the leading edge of the strut is removed from the outer periphery of the main body portion, and the trailing edge portion is removed from the inner periphery of the main body portion. In another aspect, the first angle of the leading edge and the second angle of the trailing edge can form an acute angle. In another aspect, the first angle of the leading edge is about 10 degrees to about 70 degrees, or about 20 degrees to about 45 degrees, or about 30 degrees to about 40 degrees.

[0038] On the other hand, the second angle of the trailing edge is about 5 degrees to about 45 degrees or about 20 degrees.

[0039] On the other hand, the percutaneously insertable blood pump assembly may have at least one of a leading edge and a trailing edge that is rounded or rounded, or a combination of rounded and rounded.

[0040] On the other hand, the percutaneously insertable blood pump assembly may have rounded edges with a radius of approximately 1.25 mm. Alternatively, the leading and trailing edges of the percutaneously insertable blood pump assembly may be rounded, chamfered, or a combination of rounded and chamfered edges.

[0041] On the other hand, the strut of the percutaneously insertable blood pump may have a hydrofoil-like cross-section along at least a portion of its length from the body portion of the outlet to the annular portion of the outlet, or it may have a hydrofoil-like cross-section along its entire length from the body portion of the outlet to the annular portion of the outlet. On the other hand, the plurality of orifices of the percutaneously insertable blood pump may have a dimensional arrangement, and each orifice may be substantially the same size. On the other hand, the percutaneously insertable blood pump assembly may have a non-invasive tip distal to the second opening section.

[0042] As previously stated herein, if the pump is configured to operate on the right side of the heart rather than the left side, the outlet as described herein may be located at the distal end of the assembly and not attached to the pump housing as described herein.

[0043] Based on the foregoing and with reference to the accompanying drawings, those skilled in the art will understand that certain modifications may be made to this disclosure without departing from its scope. While several embodiments of this disclosure have been shown in the drawings, they are not intended to limit the disclosure thereto, as the disclosure is intended to be as broad as will be permitted in the art, and the specification should be understood accordingly. Therefore, the above description should not be construed as restrictive, but merely as examples of particular aspects. Those skilled in the art will contemplate other modifications within the scope and spirit of the appended claims.

Claims

1. A percutaneously insertable blood pump assembly, comprising: Pump section; A conduit attached to the proximal end of the pump section; The first opening section is located on the far side of the pump section and is in fluid communication with it; A cannula is attached to and in fluid communication with the first opening section; as well as The second opening section is located distal to and in fluid communication with the cannula; One of the first opening section and the second opening section is the blood outlet from the cannula; The blood outlet includes a main body portion, an opening portion, and an annular portion, wherein a plurality of holes in the opening portion are separated and defined by a plurality of struts extending from the main body portion and connecting the main body portion to the annular portion, wherein each of the plurality of struts is asymmetrical along its length from the main body portion of the outlet to the annular portion of the outlet.

2. The percutaneously insertable blood pump assembly according to claim 1, wherein, The blood outlet is the first opening section.

3. The percutaneously insertable blood pump assembly according to claim 1, wherein, The blood outlet is the second opening section.

4. The percutaneously insertable blood pump assembly according to any one of claims 1 to 3, wherein, The asymmetric strut has a cross-section including a leading edge and a trailing edge, the leading edge forming a first angle and the trailing edge forming a second angle.

5. The percutaneously insertable blood pump assembly according to claim 4, wherein, The main body portion of the blood outlet includes an outer periphery and an inner periphery, wherein the leading edge of the strut is removed from the outer periphery of the main body portion, and at least a portion of the trailing edge is removed from the inner periphery of the main body portion.

6. The percutaneously insertable blood pump assembly according to any one of claims 4 to 5, wherein, The first angle and the second angle form an acute angle.

7. The percutaneously insertable blood pump assembly according to any one of claims 4 to 6, wherein, The first angle is approximately 10 degrees to approximately 70 degrees.

8. The percutaneously insertable blood pump assembly according to any one of claims 4 to 7, wherein, The first angle is approximately 20 degrees to approximately 45 degrees.

9. The percutaneously insertable blood pump assembly according to any one of claims 4 to 8, wherein, The first angle is approximately 30 degrees to approximately 40 degrees.

10. The percutaneously insertable blood pump assembly according to any one of claims 4 to 9, wherein, The second angle is approximately 5 degrees to approximately 45 degrees.

11. The percutaneously insertable blood pump assembly according to any one of claims 4 to 10, wherein, The second angle is approximately 20 degrees.

12. The percutaneously insertable blood pump assembly according to any one of claims 5 to 11, wherein, At least one of the leading edge and the trailing edge is rounded or rounded, or a combination of rounded and rounded.

13. The percutaneously insertable blood pump assembly according to claim 12, wherein, The rounded corners have a radius of approximately 1.25 mm.

14. The percutaneously insertable blood pump assembly according to any one of claims 5 to 13, wherein, Both the leading edge and the trailing edge are rounded, or a combination of rounded and rounded.

15. The percutaneously insertable blood pump assembly according to any one of claims 1 to 14, wherein, Each of the plurality of pillars has a hydrofoil-shaped cross-section along at least a portion of its length from the main body portion of the outlet to the ring portion of the outlet.

16. The percutaneously insertable blood pump assembly according to any one of claims 1 to 14, wherein, Each of the plurality of pillars has a hydrofoil-shaped cross-section along the entire length from the main body portion of the outlet to the ring portion of the outlet.

17. The percutaneously insertable blood pump assembly according to any one of claims 1 to 16, wherein, The plurality of holes have a certain size and the size of each hole is approximately the same.

18. The percutaneously insertable blood pump assembly according to any one of claims 1 to 17, further comprising a non-invasive tip distal to the second opening segment.

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