Intraventricular heart pump with narrow head

Abstract

A heart pump intended to be placed in the ventricle of the heart and to generate an induced fluid flow in the direction of a sigmoid valve, comprising: a fixed casing with an upper part and a lower part forming a propulsion chamber for propelling a fluid towards its upper end, at least one side opening between the upper and lower parts forming a chamber for a fluid inflow from the outside towards the propulsion chamber, and a power part arranged in the casing for delivering the fluid from the side opening to the outlet of the propulsion chamber. The propulsion chamber comprises an upper body and a discharge head part; the discharge head part has an outer cross section narrower than the outer cross section of the upper body.

Description

Detailed Description of the Invention

[0001] The present invention relates to pumps, and in particular to axial flow pumps intended to be immersed in a fluid.

[0002] The present invention relates more particularly, but not exclusively, to pumps for ventricular assist, for example, battery-powered pumps intended to be inserted into the human body to assist blood circulation.

[0003] Heart failure (HF), a progressive decline in the heart's ability to provide the blood flow necessary for an individual's metabolic needs in daily life, is the second leading cause of death in the Western world. Treatment of HF, which involves increasing blood flow appropriately according to the patient's needs, has progressed but remains inadequate.

[0004] Intraventricular heart pumps are intended to be inserted into the systemic ventricle of a patient's heart. Hearts do not all have the same dimensions. It may be necessary to design several pumps of different sizes.

[0005] The aim of the present invention is to avoid such a proposition by proposing a new pump suitable for accommodating hearts of various sizes. Another object of the present invention is a pump that is efficient regardless of the state of the heart, whether diastolic or not.

[0006] At least one of the objects is achieved by means of a heart pump intended to be placed partially or wholly within the ventricle of the heart and to generate a guided fluid flow in the direction of the aortic sigmoid valve; this pump comprises: - a fixed casing having an upper part, when the heart pump is arranged vertically, forming a propulsion chamber for propelling fluid towards its upper end, and a lower part fixedly attached to the upper part; - at least one lateral opening between the upper and lower parts, forming a chamber for the fluid inflow from the outside towards the propulsion chamber; a power section disposed within the casing for delivering fluid from the side opening to an outlet of the propulsion chamber; It is equipped with:

[0007] According to the present invention, the propulsion chamber comprises an upper body and a discharge head portion; the discharge head portion has an outer cross section that is narrower than the outer cross section of the upper body; and the discharge head portion has an outer cross section whose diameter or maximum distance is comprised between 14 and 16 mm.

[0008] "Cross-section" means the area of ​​a surface seen in a cross section perpendicular to the axis of impelling a fluid. "External cross-section" means a cross-section whose contours closely match the outer contour of the impelling chamber, as opposed to an inner cross-section, which refers to the interior space through which the fluid circulates.

[0009] The pump of the present invention has the advantage of having a narrow head suitable for efficiently propelling fluid toward the sigmoid valve at the aortic inlet. The 14-16 mm range allows for an appropriate ejection head regardless of the state of the heart. Indeed, regardless of whether the heart is in diastolic or diastolic phase, whether it is a child's or an adult's heart, i.e., whether it is small or large, the range specified by the present invention allows for the pump to be efficiently positioned close to the aorta without contacting it. "Close" means a sufficient distance for the propelling fluid flow to be strong enough to open the sigmoid valve and for the fluid to enter the aorta. This distance varies depending on the pump's power output.

[0010] The exact same heart can have a variety of dimensions. For example, a heart in diastole has a volume significantly larger than the volume of the same heart in a non-diastolic state. Notably, the dimensions of the aortic ostium remain the same regardless of the level of dilation of the heart.

[0011] The size of the head also allows for the passage of physiological or spontaneous flow. In the setting of heart failure, the heart may still have the ability to contract, albeit inadequately, to eject fluid toward the aorta. The resulting flow is physiological, while the flow generated by the pump is induced flow, providing a flow equivalent to or replacing the majority of the physiological flow.

[0012] For this purpose, the invention proposes fixed dimensions for the ejection head comprised between 14 mm and 16 mm, which allow a good circulation of the induced and physiological flows, and which allow a sufficient passage of the physiological flows around the head.

[0013] According to an advantageous feature of the invention, the outer cross section of the upper body may have a diameter or maximum distance comprised between 17 and 20 mm.

[0014] According to an embodiment of the invention, the outer cross section of the upper body has a diameter or maximum distance equal to 18 mm. With such an arrangement, the upper body is suitably dimensioned to accommodate the means for propelling fluid towards the dispensing head, the upper body being larger than the dispensing head.

[0015] Advantageously, the discharge head may have a distance of 5 to 10 mm along the propeller shaft, and may for example be in the shape of a right cylinder directing the fluid flow outwards towards the aorta.

[0016] The discharge head may comprise, for example, vanes, a set of vanes constituting a flow straightener capable of increasing the velocity and giving the fluid a predetermined profile at the discharge outlet.

[0017] According to a further feature, the pump of the present invention can have a concave shoulder where the upper body and the discharge head join, where "concave" means a curved, recessed shape that allows physiological flow to flow around the shoulder without stagnation. According to an advantageous feature of the invention, the propulsion chamber may be in the shape of a right circular cylinder.

[0018] According to an advantageous embodiment, the upper body may have a flared outer shape from the inlet chamber to the discharge head. Preferably, the diameter of the impulse chamber increases gradually without a shoulder. The diameter of the head portion may be smaller than, larger than, or equal to the smallest diameter of the propulsion chamber.

[0019] In addition to the above, in particular, the propulsion chamber can be fixedly attached to the lower part of the casing by a connecting element, the upper part of which is directly connected to the lower end of the propulsion chamber, so that at the connection location the outer surface of the propulsion chamber is flush with the connecting element.

[0020] According to the invention, the connecting element may have an outwardly curved overall shape, which may mean that the connecting element is inscribed along the overall shape of a rounded sphere of diameter greater than the diameter of the lower end of the propulsion chamber and greater than the diameter of the upper end of the lower part of the casing.

[0021] By way of example, the linking element may comprise four posts.

[0022] According to an advantageous feature of the invention, the pillars may be provided with extensions leading to the interior of the propulsion chamber; these extensions act as guide vanes that straighten the fluid flow towards the upper part of the casing. For example, the posts may be connected to one another by transverse bands spaced apart from the ends of the posts.

[0023] According to an embodiment of the present invention, the propulsion chamber may include a rotor for propelling fluid towards the dispensing head.

[0024] Advantageously, the pump may comprise a processing unit configured to control the rotor in a pulsed manner.

[0025] Other advantages and features of the present invention will become apparent from a consideration of the detailed description of non-limiting embodiments and from the accompanying drawings. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a general view of an intraventricular heart pump according to the present invention; [Figure 2] 1 is a perspective view of the casing of an intraventricular heart pump according to the present invention; [Figure 3] 1 is a simplified diagram illustrating the dimensions of a narrow head according to the present invention. [Figure 4] 1 is a schematic diagram showing an impeller with spiral blades on the outside of the rotor according to the present invention. [Figure 5] 1 is a simplified diagram illustrating an impeller having post extensions and inner spiral blades forming guide vanes in accordance with the present invention; [Figure 6] 1 is a schematic diagram illustrating an impeller with internal spiral blades according to the present invention.

[0027] The embodiments described hereinafter are in no way limiting; variations of the present invention can be implemented by including only features selected from among the features described hereinafter, especially if the selected features are selected separately from the other features described and this selection of features provides a technical advantage or is sufficient to differentiate the present invention over the prior art. This selection includes at least one, preferably functional, feature, without structural details, or with only a portion of structural details, if this portion alone provides a technical advantage or is sufficient to differentiate the present invention over the prior art.

[0028] In particular, all of the described variations and all of the embodiments are intended to be combined with one another in any combination, unless there is a reason to the contrary from a technical point of view. In the figures, elements common to several figures have the same reference numerals. FIG. 1 shows an intraventricular heart pump.

[0029] The heart is generally designated by the reference numeral 1. Shown is the right ventricle 2, which functions to eject blood through a sigmoid valve 4 towards the pulmonary artery 3. The left ventricle 5 functions to carry out systemic circulation by ejecting oxygenated blood through a sigmoid valve 7 towards the aorta 6.

[0030] The right atrium 8 supplies blood to the right ventricle 2 via atrioventricular valves 9. The left atrium 10 supplies blood to the left ventricle 5 via atrioventricular valves 11.

[0031] The pump according to the present invention is generally designated by the reference numeral 12. The pump is fixed to the apex of the left ventricle 5. The pump may be connected by wire or wirelessly to a management unit (not shown) outside the heart. The pump may be connected to one or more probes or sensors (not shown) for detecting heart rate, etc.

[0032] The lower part of the pump, which houses the motor, may be partially external to the heart, partially within the thickness of the apex, or completely inside the heart. In the example of Figure 1, the lower part of the pump is partially external to the heart, which may be advantageous, especially for motor maintenance.

[0033] The pump comprises a casing consisting of an upper part 13 rigidly attached to a lower part 14 by connecting elements 15. These connecting elements may comprise one or more posts 15 that connect the two parts 13 and 14 while leaving a wide passageway for the blood.

[0034] In the example of Figure 1, the lower part 14 constitutes the stator of the motor. The casings 13, 14 and 15 are intended to remain fixed. Between the upper and lower parts 13 and 14 there is an inlet chamber 16, which is a cavity interrupted only by the connecting element 15. In operation, the pump is intended to draw blood contained in the ventricle 5 through the inlet chamber 16, convey it through the upper part 13 of the casing and expel it towards the valve 7 by means of the upper outlet.

[0035] To pump blood, the pump comprises an impeller 17 designed around an elongated body 18 with one or more spiral blades 19 wound around it. When rotating, the impeller picks up the blood and propels it towards the discharge, which is the pump's main function. The main flow is therefore the flow pumped by the impeller 17.

[0036] The impeller is carried by a transmission shaft 20 which has a bell 21 at its end opposite the impeller. The assembly of impeller 17, transmission shaft 20 and bell 21 is rigid and suitable for rotation. For this purpose, bell 21 constitutes the rotor of a motor formed with a fixed stator 14. This motor 14 and 21 is a brushless motor with an external rotor. It is a synchronous machine equipped with an electronic control system (not shown) which may or may not be available from outside the heart.

[0037] The impeller is suitable for rotational movement about its axis and relative to the casings 13, 14 which remain fixed. The inlet pivot 25 and the outlet pivot 23 are on the axis of rotation of the impeller and hold it on its axis when it is magnetically levitated during rotational movement. In a variant (not shown), one or both of the two pivot areas can be provided with a connection to a bearing which allows the rotation of the impeller.

[0038] The invention is particularly notable for the fact that the upper part 13 of the casing is provided with a discharge head 22 for propelling blood leaving the pump in the direction of the aorta 6.

[0039] 2 illustrates a perspective view of a pump according to the present invention. The lower portion 14, post 15, and upper portion 13 are visible. The upper portion 13 comprises an upper body 26 and a discharge head 22. The upper body 26 has a flared shape that increases in size from the post 15 to the discharge head 22. The upper body 26 terminates in a shoulder of decreasing diameter (when the pump is vertically oriented, the lower portion faces downward) to connect to a discharge head having a diameter smaller than that of the upper portion of the upper body.

[0040] Transverse bands 27 are also provided which connect the columns together to support the columns of the inlet chamber while leaving openings for the inflow of blood and the evacuation of returning blood between the bell 21 and the fixed lower part 14. FIG. 3 is a diagram illustrating some dimensions of the dispensing head and upper body.

[0041] The present invention requires that the diameter of the discharge head be fixed at 14-16 mm. This range allows for the coexistence of both induced flow 28 from the pump and spontaneous or natural flow 29 resulting from the natural contraction of the heart. In fact, this dimensioning is compatible with hearts of any size and regardless of their state, i.e., diastolic or not. The narrowing of the head allows for efficient placement of the pump close to the aorta without obstructing the passage of spontaneous flow. The head diameter is large enough to generate flow that can reach the aorta.

[0042] Preferably, the height of the discharge head is comprised between 5 and 10 mm. The bend 30 allows for the creation of a connection between the small-diameter discharge head 22 and the upper body 26, which has a diameter greater than that of the discharge head. The upper body has a diameter of 17 to 20 mm in its upper part. In particular, it is intended that the diameter of the discharge head can reach 17 mm if the diameter of the upper body is greater than 17 mm.

[0043] Figure 4 shows in more detail the impeller 17 attached to the transmission shaft 20 and bell 21. The outlet pivot 23, which is hemispherical, is located at the top of the impeller and on its axis of rotation. The helical blades 19 surround the body 18 from its bottom end to approximately three-quarters of the way around. There are no blades at the top of the impeller.

[0044] The transmission shaft 20 is rigidly connected to the lateral vanes 31, two of which are visible and the third is hidden. There are three lateral vanes, but there may be only one, two, or four or more. In any case, the lateral vanes 31 must leave an opening 32 to allow fluid to enter the interior of the bell 21. In the example shown, the inlet pivot 25 is located above the bell 21, but other embodiments can be envisaged in which the inlet pivot is arranged inside the bell 21.

[0045] FIG. 5 shows a cross-sectional view of an impeller with internal helical blades. The pump motor includes a fixed stator, the upper body 23, and a rotor or impeller 33. In the example of FIG. 5, the impeller 33 is a hollow right circular cylinder. The hollow portion also has the shape of a right circular cylinder, but it may have any other shape, such as a flared, elongated, or structured shape. The hollow central portion of the impeller 33 has helical blades 34 on its inner surface for propelling the fluid toward the discharge head 22. The helical blades may be a single blade 34 or several blades with fixed or variable pitches that run the entire length of the impeller's inner surface or only a portion of it. The impeller 33 is designed to rotate relative to the upper body 23. Ideally, the upper body 23 is a stator that includes a magnetic element, such as a magnetic winding 35. This magnetic element may magnetically cooperate with a magnetic element, such as a permanent magnet 36 disposed on the interior or exterior surface of the impeller 33. Electronic means (not shown) are provided to control the winding 35 to start the impeller 33. The assembly constitutes a brushless motor. The gap between the impeller 33 and the upper body 23 is straight and inscribed in a right circular cylinder, but can have other non-linear shapes, whether flared or not.

[0046] Optionally, a fixed strut 37 is arranged inside the impeller 33, which allows improving the blood flow during pump operation, i.e. when the impeller 33 is rotating relative to the upper body 23. This strut 37 can be fixed at both ends, for example to the fixed lower part 38 of the casing and to the discharge head 22 via the outlet vanes 39. It is also possible to envisage a strut 37 that is fixed at only one end.

[0047] Other arrangements of the struts 37 are conceivable, such as struts that rotate but are translationally fixed; in this case the struts 37 can be fixed to the impeller 33 by arms that allow the struts to remain within the rotational axis of the turbine.

[0048] A bearing arrangement may be provided between the impeller and the upper body 23 to hold the impeller. Other means may be provided to hold the rotating impeller in the casing without contact. In particular, floating arrangements, fluidic, magnetic, etc., with or without end retention, are envisaged.

[0049] Also shown in Figure 5 are extensions 40 of the posts 15. These extensions form guide vanes inside the propulsion chambers. These extensions are located at the inlets of the propulsion chambers 23, 22 to straighten the fluid flow towards the impeller.

[0050] Figure 6 shows an example of the impeller 33 of Figure 5. In this example, given as a non-limiting example, it is an elongated hollow cylindrical body 41 provided with several blades 34a, 34b, 34c, 34d on its inner wall. Such a turbine can be advantageously used in a pump immersed in a fluid.

[0051] The function of the blades 34a, 34b, 34c, 34d is to force the fluid through the impeller, and the orientation and dimensioning of the blades are intended to draw in and then propel the fluid after it passes through the rotating impeller.

[0052] In the example of FIG. 6, four spiral blades 34a, 34b, 34c, and 34d start from one end of the impeller, inscribe themselves in a spiral line without intersecting each other, and reach the other end.

[0053] Of course, the invention is not limited to the examples described so far, and many adjustments can be made to these examples without going beyond the scope of the invention as described.

Claims

1. A heart pump (12) intended to be placed partially or entirely within the ventricle of the heart (1) and to generate a guided fluid flow in the direction of the aortic sigmoid valve; said pump comprising: a fixed casing (13, 14, 15) comprising an upper part (13) when the heart pump is placed vertically, forming a propulsion chamber for propelling the fluid towards its upper end, and a lower part (14) fixedly attached to the upper part; - at least one lateral opening between the upper and lower parts forming a chamber (16) for the fluid inflow from the outside towards the propulsion chamber; a power section (14, 21) arranged in the casing for conveying fluid from the side opening to the outlet of the propulsion chamber; Equipped with 1. A heart pump comprising: a thrust chamber comprising an upper body (26) and a discharge head (22) at the end of the upper body (26); the discharge head is arranged in the ventricle and is intended to propel the flow of fluid, and the heart pump does not pass through the sigmoid valve of the aorta; the discharge head has an arbitrary outer cross section narrower than the outer cross section of the upper body; the discharge head (22) has an outer cross section whose diameter or maximum distance is comprised between 14 and 16 mm; and the thrust chamber (13) is fixedly attached to the lower part of the casing by a connecting element (15) with an upper part of the connecting element directly connected to the lower end of the thrust chamber (13) so that at the connecting point the outer surface of the thrust chamber is flush with the connecting element.

2. 2. Heart pump according to claim 1, characterized in that the outer cross section of the upper body (26) has a diameter or maximum distance comprised between 17 and 20 mm.

3. 3. Heart pump according to claim 1 or 2, characterized in that the outer cross section of the upper body (26) has a diameter or maximum distance equal to 18 mm.

4. 3. Heart pump according to claim 1 or 2, wherein the ejection head (22) has a distance along the propeller axis comprised between 5 and 10 mm.

5. 3. Heart pump according to claim 1 or 2, characterized in that the connection between the upper body and the discharge head is provided with a concave shoulder (30).

6. 3. Heart pump according to claim 1 or 2, characterized in that the impulse chamber (13) is in the shape of a right circular cylinder.

7. 3. A heart pump according to claim 1 or 2, characterized in that the upper body (26) has a flared outer shape from the inlet chamber to the discharge head.

8. 3. Heart pump according to claim 1 or 2, characterized in that the connecting element (15) has an outwardly curved overall shape.

9. 3. Heart pump according to claim 1 or 2, characterized in that the connecting element (15) comprises four posts.

10. 3. Heart pump according to claim 1 or 2, characterized in that the pillars have extensions (40) that lead to the interior of the impulse chamber (13); these extensions act as guide vanes that straighten the fluid flow towards the upper part of the casing.

11. 3. Heart pump according to claim 1 or 2, characterized in that the pillars are connected to one another by transverse bands (27) arranged at a distance from the ends.

12. 3. Heart pump according to claim 1 or 2, characterized in that the impulse chamber comprises a rotor (33) for impelling the fluid towards the discharge head.

13. 13. The heart pump of claim 12, further comprising a processing unit configured to control the rotor in a pulsed manner.

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