INTRAVENTRIC HEART PUMP WITH CONGESTED HEAD

Description

[0001] The present invention relates to a pump, in particular an axial pump, intended to be immersed in a fluid.

[0002] The present invention relates to a ventricular assist pump. For example, it is a battery-powered pump intended to be inserted into a human body to assist blood circulation.

[0003] Heart failure (HF), the progressive inability of the heart to provide the blood flow necessary to meet an individual's metabolic needs in everyday life, is the second leading cause of death in Western countries. Treatment for heart failure, which involves increasing blood flow in a manner appropriate to the patient's needs, is progressing but remains insufficient.

[0004] An intraventricular heart pump is intended to be inserted into a systemic ventricle of a patient's heart. Not all hearts are the same size. It may be necessary to design several pumps of different sizes.

[0005] Document CA2472088A1 is known, describing a heart pump of both radial and axial type. This document describes a box with a lateral opening for blood inlet. An internal turbine propels the blood towards an upper outlet head.

[0006] The present invention aims to avoid such designs by providing a new pump adapted to be compatible with many core sizes.

[0007] The invention also aims to provide an effective pump regardless of the state of the heart, whether dilated or not.

[0008] At least one of the objectives is achieved with a heart pump according to claim 1.

[0009] By section, we mean the surface area seen along a cut perpendicular to the propulsion axis of the fluid. By external section, we mean a section whose contour follows the external contour of the propulsion chamber, as opposed to an internal section which would concern the internal volume in which the fluid circulates.

[0010] The pump according to the present invention has the advantage of having a narrowed head whose dimension is adapted to efficiently propel the fluid towards the sigmoid valves at the entrance to the aorta. The range of 14 to 16 mm allows for a suitable outlet head regardless of the state of the heart. Indeed, whether the heart is dilated or not, whether it is a child's heart or an adult's heart, that is to say a small heart or a large heart, the range defined by the present invention allows the pump to be effectively positioned close to the aorta without coming into contact. By close is meant a sufficient distance so that the flow of propelled fluid is powerful enough to separate the sigmoid valves and for the fluid to enter the aorta. This distance depends on the power of the pump.

[0011] The same heart can have different dimensions. For example, a dilated heart has a volume that is much larger than the volume of the same heart in a non-dilated state. Remarkably, the dimension of the aortic inlet remains the same regardless of the level of dilation of the heart.

[0012] The size of the head also allows for the passage of natural or spontaneous flow. In the case of heart failure, the heart may still be able to contract to push the fluid back, but insufficiently, towards the aorta. The flow created is thus a natural flow, while the flow generated by the pump is an induced flow that mainly complements or replaces the natural flow.

[0013] Therefore, proposing a fixed dimension for the outlet head between 14mm and 16mm according to the invention, allows good circulation of the induced and natural flows. This dimension allows sufficient passage of the natural flow around the head.

[0014] According to an advantageous characteristic of the invention, the external section of the upper body may have a diameter, or a greater distance, of between 17 and 20 mm.

[0015] According to one embodiment of the invention, the external section of the upper body has a diameter, or greater distance, equal to 18mm.

[0016] With such an arrangement, the upper body is suitably sized to accommodate means for propelling the fluid toward the outlet head. The upper body is wider than the outlet head.

[0017] Advantageously, the outlet head may have a distance along a propulsion axis of between 5 and 10 mm. Such a head may, for example, be in the form of a straight cylinder guiding the flow of fluid outwards towards the aorta.

[0018] The outlet head may, for example, include blades, the set of blades constituting a rectifier capable of increasing the speed and giving the fluid a predetermined profile at the outlet.

[0019] According to an additional characteristic, the pump according to the invention may comprise a shoulder at the connection between the upper body and the outlet head, this shoulder having a concave shape. By concave shape is meant a shape rounded towards the inside so that the natural flow flows along the shoulder without stagnation.

[0020] According to an advantageous characteristic of the invention, the propulsion chamber can be in the form of a right circular cylinder.

[0021] According to an advantageous embodiment, the upper body may have a flared external shape from the intake chamber to the outlet head. Preferably, the progression of the diameter of the propulsion chamber is progressive and without shoulders.

[0022] The head diameter may be less than, greater than, or equal to the smallest diameter of the propulsion chamber.

[0023] According to an advantageous characteristic of the invention, the connecting elements may have a general shape curved towards the outside. The curved shape may mean that the connecting elements are inscribed along a rounded, generally spherical shape, the diameter of which is greater than the diameter of the lower end of the propulsion chamber and the diameter of the upper end of the lower part of the casing.

[0024] For example, the connecting elements may include four rods.

[0025] According to an advantageous characteristic of the invention, the rods may include extensions extending into the interior of the propulsion chamber; these extensions serving as inducer blades to make the flow of fluid linear towards the upper part of the casing.

[0026] For example, the rods can be connected to each other by a lateral band arranged at a distance from the ends of these rods.

[0027] According to one embodiment of the invention, the propulsion chamber may comprise a rotor for propelling the fluid towards the outlet head.

[0028] Advantageously, the pump may comprise a processing unit configured to control the rotor in a pulsed mode.

[0029] Other advantages and characteristics of the invention will appear on examining the detailed description of a non-limiting embodiment, and the appended drawings, in which: [ Fig. 1 ] There figure 1 is a general view of an intraventricular heart pump according to the invention, [ Fig. 2 ] There figure 2 is a perspective view of a casing of an intraventricular heart pump according to the invention, [ Fig. 3 ] There figure 3 is a simplified schematic view illustrating the dimensions of a narrowed head according to the invention, [ Fig. 4 ] There figure 4 is a schematic view of a turbine with helical blades outside the rotor according to the invention, [ Fig. 5 ] There figure 5 is a simplified schematic view illustrating the extensions of rods forming inducer blades and a turbine with internal helical blades according to the invention, [ Fig. 6 ] There figure 6 is a schematic view of a turbine with internal helical blades according to the invention.

[0030] The embodiments which will be described below are in no way limiting; it will be possible in particular to implement variants of the invention comprising only a selection of characteristics described below isolated from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. This selection comprises at least one preferably functional characteristic without structural details, or with only a part of the structural details if this part only is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art.

[0031] In particular, all the variants and embodiments described are intended to be combined with each other in all combinations where there is no technical obstacle to this.

[0032] In the figures, elements common to several figures retain the same reference.

[0033] On the figure 1 An intraventricular heart pump is illustrated.

[0034] The heart is generally designated by the reference 1. We distinguish the right ventricle 2 which has the function of ejecting blood towards the pulmonary artery 3 through sigmoid valves 4. The left ventricle 5 has the function of carrying out systemic circulation by ejecting blood filled with oxygen towards the aorta 6 via sigmoid valves 7.

[0035] The right atrium 8 supplies blood to the right ventricle 2 via atriopulmonary valves 9. The left atrium 10 supplies blood to the left ventricle 5 via atriopulmonary valves 11.

[0036] The pump according to the invention is generally referenced 12. It is fixed to the apex of the left ventricle 5. It can be connected wired or wirelessly to a management unit (not shown) external to the heart. It can be connected to one or more probes or sensors (not shown) for detecting the heart rate or other.

[0037] The lower part of the pump housing the motor can be partially outside the core, partially within the thickness of the apex or entirely within the core. In the example of the figure 1 , the lower part of the pump is partially outside the core, which can be an advantage for engine maintenance in particular.

[0038] The pump comprises a casing composed of an upper part 13 rigidly connected to a lower part 14 by means of connecting elements 15. These connecting elements may comprise one or more rods 15 connecting the two parts 13 and 14 while leaving wide passages for the blood.

[0039] In the example of the figure 1 , the lower part 14 constitutes the stator of a motor. The casing, 13, 14 and 15, is intended to remain fixed. Between the upper part 13 and the lower part 14, there is an inlet chamber 16 which is an open space, only hindered by the connecting elements 15. In operation, the pump is intended to suck the blood contained in the ventricle 5 via the inlet chamber 16, conduct it through the upper part 13 of the casing and eject it through the upper outlet towards the valve 7.

[0040] To suck the blood, the pump comprises an impeller 17 designed from an oblong body 18 around which one or more helical blades 19 are wound. In rotation, the impeller sucks the blood and propels it towards the outlet. This is the main function of the pump. The main flow is therefore that which is pumped by the impeller 17.

[0041] The turbine is carried by a transmission shaft 20 which comprises at the opposite end of the turbine a bell 21. The turbine 17, transmission shaft 20 and bell 21 assembly is rigid and capable of rotating. To do this, the bell 21 constitutes the rotor of the motor formed with the fixed stator 14. This motor 14 and 21 is a “brushless” type motor with an external rotor. It is a synchronous machine equipped with an electronic control system (not shown) accessible from outside the core or not.

[0042] The turbine is capable of performing rotational movements along its axis and relative to the casing 13, 14 which remains fixed. In the axis of rotation of the turbine there is an input pivot 25 and an output pivot 23 which maintain the turbine in its axis when it is in magnetic levitation during rotational movements. In a variant not shown, one or both pivot zones may comprise bearing connections allowing the turbine to rotate.

[0043] The invention is particularly remarkable in that the upper part 13 of the casing comprises an outlet head 22 for propelling the blood outside the pump, towards the aorta 6.

[0044] On the figure 2 A pump according to the invention is illustrated in perspective. The lower part 14, the rods 15 and the upper part 13 are distinguished. The latter comprises an upper body 26 and the outlet head 22. The upper body 26 has a flared shape, the dimensions increasing from the rods 15 to the outlet head 22. The upper body 26 ends with a shoulder reducing its diameter to connect the outlet head which has a diameter smaller than the diameter of the upper part of the upper body (when the pump is arranged vertically, the lower part being downwards).

[0045] A lateral band 27 is also provided connecting the rods together so as to solidify the rods of the intake chamber, while leaving openings for the intake of blood and the evacuation of backscattered blood between the bell 21 and the fixed lower part 14.

[0046] There figure 3 is a schematic view illustrating some dimensions of the outlet head and upper body.

[0047] The present invention requires the diameter of the outlet head to be set between 14 and 16 mm. This range of values ​​makes it possible to accommodate both an induced flow 28 from the pump and a spontaneous or natural flow 29 from the natural contraction of the heart. Indeed, this sizing is compatible with any heart size and whatever the state of the heart, i.e. dilated or not. The narrowing of the head allows for efficient positioning of the pump, close to the aorta without blocking the passage of the spontaneous flow. The diameter of the head is large enough to be able to generate a flow capable of reaching the aorta.

[0048] Preferably, the height of the outlet head is between 5 and 10 mm. An elbow 30 makes it possible to make the connection between the outlet head 22 of reduced diameter and the upper body 26 of diameter greater than the diameter of the outlet head. The upper body has on its upper part a diameter of between 17 and 20 mm. In particular, when the diameter of the upper body is greater than 17 mm, the diameter of the outlet head can reach 17 mm.

[0049] On the figure 4 The turbine 17 is shown in a little more detail, connected to the transmission shaft 20 and to the bell 21. The output pivot 23, in the form of a half-sphere, is located at the top of the turbine and in the axis of rotation. The helical blades 19 surround the body 18 from the foot until they cover approximately three-quarters of the body 18. The top of the turbine is bladeless.

[0050] The transmission shaft 20 is firmly connected to side blades 31, two of which are visible and a third hidden. There are three side blades, but there may be only one, two or more than three. In all cases, the side blades 31 must leave openings 32 so that the fluid can penetrate inside the bell 21. In the example illustrated, the inlet pivot 25 is located above the bell 21, but other embodiments can be envisaged where the inlet pivot is arranged inside the bell 21.

[0051] On the figure 5 is shown, in sectional view, a turbine with internal helical blades. The pump motor comprises a fixed stator, which is the upper body 23, and a rotor or turbine 33. In the example of the figure 5 , the turbine 33 is a hollow straight cylinder. The hollow part also has a straight cylindrical shape, but it can have a completely different shape such as a flared, oblong or structured shape. The hollow central part of the turbine 33 carries on its internal surface a helical blade 34 to propel the fluid towards the outlet head 22. It can be a single blade 34 or several blades, with fixed or variable pitch, over the entire length of the internal surface of the turbine or over only a part. The turbine 33 is designed to rotate relative to the upper body 23. Ideally, the upper body 23 is a stator comprising magnetic elements such as magnetic windings 35. The latter can cooperate magnetically with magnetic elements such as, for example, permanent magnets 36 arranged inside or on the external surface of the turbine 33.Electronic means (not shown) are provided to control the windings 35 so as to activate the turbine 33. The assembly constitutes a “brushless” type motor. The air gap between the turbine 33 and the upper body 23 is straight, it fits into a straight cylinder, but it can be of another non-straight shape, flared or not.

[0052] Optionally, a fixed column 37 is arranged inside the turbine 33 and makes it possible to improve the flow of blood when the pump is in operation, that is to say the turbine 33 is rotating relative to the upper body 23. This column 37 can be fixed by both ends, for example to a fixed lower part 38 of the casing and to the outlet head 22 via outlet blades 39. It is also possible to envisage a column 37 fixed at only one end.

[0053] Other modes of arrangement of the column 37 can be envisaged, such as for example a column in rotation but fixed in translation, in this case the column 37 can be fixed to the turbine 33 by means of an arm allowing the column to remain in the axis of rotation of the turbine.

[0054] Rolling mechanisms may be provided between the turbine and the upper body 23 to hold the turbine. Other means may be provided to keep the turbine rotating in the casing without contact. In particular, a mechanism by lift, by fluid, by magnetization, etc., with or without holding edges, may be envisaged.

[0055] On the figure 5 , we also distinguish extensions 40 of the rods 15. These extensions constitute inducer blades inside the propulsion chamber. These extensions are arranged at the inlet of the propulsion chamber 23, 22 to make the flow of the fluid linear in the direction of the turbine.

[0056] On the figure 6 an example of turbine 33 of the figure 5 . In the example described in a non-limiting manner, it is a body 41 in the form of an elongated hollow cylinder whose internal wall comprises several blades 34a, 34b, 34C, 34d. Such a turbine can advantageously be used in a pump immersed in a fluid.

[0057] The blades 34a, 34b, 34c, 34d serve to convey the fluid through the turbine. The orientation and dimensioning of the blades are designed so that the fluid is sucked in and then propelled after passing through the rotating turbine.

[0058] In the example of the figure 6 , the four helical blades 34a, 34b, 34C, 34d, start from one end of the turbine, follow helical lines without ever crossing, and arrive at the other end.

[0059] Of course, the invention is not limited to the examples which have just been described. Numerous modifications can be made to these examples without departing from the scope of the present invention which is defined by the following claims.

Claims

1. Heart pump (12) intended to be positioned partially or entirely in a ventricle of a heart (1) and to generate an induced flow of fluid in the direction of the sigmoid valves of the aorta; this pump comprising: - a fixed casing (13, 14, 15) provided with a top part (13), when the heart pump is positioned vertically, forming a propulsion chamber for propelling the fluid towards the top end, and a bottom part (14) attached in a fixed manner to the top part, - at least one side opening between the top part and the bottom part and forming a chamber (16) for fluid inlet from the outside towards the propulsion chamber, - a power unit ( 14, 21) arranged inside the casing to drive the fluid from the side opening right up to the outlet of the propulsion chamber, - the propulsion chamber comprises an upper body (26) and an outlet head (22); the outlet head having a narrowed external cross section with respect to an external cross section of the upper body; the outlet head (22) having an external cross section the diameter, or the largest distance, of which is comprised between 14 and 16 mm; and in that the propulsion chamber (13) is attached in a fixed manner to the bottom part of the casing by means of linking elements (15) the top part of which is directly connected to the bottom end of the propulsion chamber (13), the heart pump being characterized in that the outer surface of the propulsion chamber is flush with the linking elements at the place of connection.

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

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

4. Heart pump according to any one of the preceding claims, characterized in that the outlet head (22) has a distance along a propulsion axis comprised between 5 and 10 mm.

5. Heart pump according to any one of the preceding claims, characterized in that it comprises a shoulder (30) at the connection between the upper body and the outlet head, this shoulder having a concave shape.

6. Heart pump according to any one of the preceding claims, characterized in that the propulsion chamber (13) is in the shape of a straight circular cylinder.

7. Heart pump according to any one of the preceding claims, characterized in that the upper body (26) has an outer shape that is flared from the inlet chamber right up to the outlet head.

8. Heart pump according to any one of the preceding claims, characterized in that the linking elements (15) have a general shape that is curved toward the outside.

9. Heart pump according to any one of the preceding claims, characterized in that the linking elements (15) comprise four pillars.

10. Heart pump according to claim 9, characterized in that the pillars include prolongations (40) right up to the inside of the propulsion chamber (13); these prolongations serving as inducer vanes to make the flow of the fluid linear in the direction of the top part of the casing.

11. Heart pump according to any one of claims 9 or 10, characterized in that the pillars are attached to one another by a lateral (27) band arranged at a distance from the ends.

12. Heart pump according to any one of the preceding claims, characterized in that the propulsion chamber comprises a rotor (33) to propel the fluid towards the outlet head.

13. Heart pump according to claim 12, characterized in that it comprises a processing unit configured to control the rotor according to a pulsed mode.